JP2013095055A - Indicator and authenticity judging method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indicator which has a higher forgery prevention effect by imparting a plurality of forgery preventive functions and to provide an authenticity judging method thereof.SOLUTION: The indicator is comprised of a base material layer with a light transmission part. An adhesive layer having a light transmissive property, a metal layer having a layer thickness of 10 nm or more and 50 nm or less, a light transmissive material layer having a rugged structure with an aspect ratio of 0.1-1.5, and a printing layer are stacked on the light transmission part. The metal layer is formed on a part of the light transmissive material layer surface like a pattern.

Description

  The present invention relates to a display body for determining whether an article is a genuine product or a non-authentic product and a method for determining the authenticity thereof.

  It is desired that counterfeiting is difficult for articles such as securities, certificates, branded products, electronic devices, and personal authentication media. For this reason, such an article may support a display body having an excellent anti-counterfeit effect.

  2. Description of the Related Art Conventionally, various configurations are known as display bodies that have been subjected to forgery prevention technology. For example, in order to increase the security level of a fluorescent image formed product using fluorescent light emitting ink, a fluorescent image formed product containing two types of phosphors having different wavelength regions of fluorescence emitted from the respective phosphors is used ( Patent Document 1).

  Further, an intaglio latent image that can be confirmed only from a specific angle is disclosed (Patent Document 2).

  Moreover, a medium for authenticity determination by a combination of a hologram layer, a light reflective layer, and an alignment film is disclosed (Patent Document 3).

  In addition, although application to anti-counterfeiting technology is not intended, in recent years, research on optical effects using structural birefringence has been made (Non-Patent Documents 1 and 2).

  However, since all of the above proposals are based on one forgery prevention function, there is a problem in providing a higher level of security.

  In addition, each of the above proposals observes the reflected image of the reflected light of the display body visually, and does not pay attention to the transmitted image of the transmitted light when the display body is transmitted through the light.

Japanese Patent Laid-Open No. 10-250214 JP 11-291609 A JP 2005-091786 A

Makoto Okada, Optics (published by the Japan Society of Applied Physics), Vol. 35, No. 5, P280-281 (2006) Makiko Imatsuki et al., Konica Minolta Technology Report, No. 3, P62-67 (2006)

  An object of the present invention is to provide a display body having a more advanced anti-counterfeit effect by providing confirmation by direct observation and a plurality of anti-counterfeit confirmation functions by observation through a medium, and a method for determining authenticity thereof. It is to provide.

As means for solving the above problems, the invention according to claim 1 is a display body including a base material layer having a light transmission portion,
In the light transmission part, a light-transmitting adhesive layer, a metal layer having a thickness of 10 nm to 50 nm, a light-transmitting material layer formed with a concavo-convex structure having an aspect ratio of 0.1 to 1.5, and printing The layers are stacked,
In the display body, the metal layer is formed in a pattern on a part of the surface of the light transmissive material layer.

  The invention according to claim 2 is characterized in that the printed layer is formed in a pattern and covers a part of the display body without covering the entire surface of the light transmission part of the display body. The display body according to Item 1.

  The invention according to claim 3 is characterized in that a printing layer is provided on the other surface of the base material layer not provided with the printing layer so as to cover a part of the light transmission portion. The display body according to claim 1 or 2.

  According to a fourth aspect of the present invention, the light transmissive material layer includes a plurality of convex linear structures having an average height of 50 to 500 nm or a plurality of concave linear structures having an average depth of 50 to 500 nm. And one of a first region in which the average period is 200 to 500 nm, a plurality of convex shapes having an average height of 50 to 500 nm, and a plurality of concave shapes having an average depth of 50 to 500 nm. The display body according to any one of claims 1 to 3, wherein the display body has a shape body selected from two or more and has a second region that is two-dimensionally arranged with an average period of 200 to 500 nm. It is.

Moreover, the invention according to claim 5 is the display body according to any one of claims 1 to 4,
Visually observe through a linear polarizer, and confirm that the latent image can be confirmed at the portion corresponding to the first region, and that the latent image will change in brightness by rotating the linear polarizer. This is a method for determining the authenticity of a display body characterized by the following.

  Further, the invention according to claim 6 is such that the display body according to claim 4 is tilted, and at least one area of the first area or the second area is visually observed to confirm a latent image. An authenticity determination method for a display body, characterized in that authenticity is determined by causing a change in color of a latent image by changing an inclination angle.

  The invention according to claim 7 allows light to pass through the display body according to claim 4, visually observes transmitted light in at least one of the first region and the second region, and transmits the light. A method for determining authenticity of a display body, wherein authenticity determination is performed based on whether light is colored, a transmitted image can be confirmed, and colors of a first area and a second area are different.

  According to an eighth aspect of the present invention, the display body according to the fourth aspect transmits light through a linear polarizer, and transmits at least one of the first region and the second region. The light is visually observed, and the transmitted light in the first region changes from colorless to colored and from colored to colorless according to the direction of linearly polarized light, and the transmitted light in the second region changes in color regardless of the direction of linearly polarized light. This is a method for determining the authenticity of a display body, characterized in that authenticity is determined by not causing it.

  According to the present invention, it is possible to provide a plurality of anti-counterfeit functions for confirmation of chromatic color by diffracted light and confirmation by observation through the above-described linear polarizer, and the provided prevention function is provided. Since different latent images and changes in latent images can be obtained for each region by reflected light and transmitted light, it is possible to provide a display body having a higher level of forgery prevention effect and a true / false determination method.

FIG. 10 is a cross-sectional view illustrating an example of a display body according to one embodiment of the present invention. It is sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. FIG. 10 is a plan view illustrating an example of a display body according to one embodiment of the present invention. It is a perspective view showing an example of a plurality of convex line structures in the present invention. It is a perspective view which shows an example of the some convex part structure in this invention. It is a perspective view which shows the other example of the some convex part structure in this invention shown in FIG. It is a top view which shows the other example of the display body which concerns on 1 aspect of this invention. It is a top view which shows an example of the back surface of the display body which concerns on 1 aspect of this invention. It is a top view which shows an example in the case of observing the reflected light of the display body shown in FIG. 3 through a linear polarizer. It is a top view which shows the other example in the case of observing the reflected light of the display body shown in FIG. 3 through a linear polarizer. It is a perspective view which shows an example in the case of observing the front of the display body shown in FIG. 3 with the reflected light from a display body. It is a perspective view which shows an example in the case of observing the front of the display body shown in FIG. 3 with the transmitted light which permeate | transmitted the display body. It is a perspective view which shows the other example in the case of observing the front of the display body shown in FIG. 3 with the transmitted light from a display body.

  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 cross-sectional view illustrating an example of a display body according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating another example of the display body according to one embodiment of the present invention. 1 and 2, directions parallel to the main surface of the display body 100 and orthogonal to each other are defined as an X direction and a Y direction, and a direction perpendicular to the main surface of the display body 100 is defined as a Z direction.

  The display body 100 shown in FIGS. 1 and 2 includes a base material 10a, a light transmission portion 10b provided on the base material 10a, an adhesive layer 11, a metal layer 12, a light transmissive material layer 13, and printing. Layer 14. 1 and 2 illustrate a case where the light transmissive material layer 13 is located on the front side with respect to the metal layer 12 as an example.

  FIG. 2 illustrates a case where the printing layer 14 is provided on the surface of the base material 10a to which the laminated body 200 is not attached in the form shown in FIG.

  A plurality of convex portions or concave portions are provided on one main surface of the light transmissive material layer 13. As a material of the light transmissive material layer 13, for example, a resin having visible light permeability can be used. In particular, when a thermoplastic resin, a thermosetting resin, or a photocurable resin is used, the plurality of convex portions or concave portions can be easily formed by transfer using the original plate. Therefore, in this case, if a plurality of convex portions or concave portions are formed on the original plate with high accuracy, a precise mass-produced replica can be manufactured relatively easily.

  The light transmissive material layer 13 may have a single layer structure or a multilayer structure. The light transmissive material layer 13 may be colored by adding a dye to the resin.

The metal layer 12 covers at least part of the main surface of the light transmissive material layer 13 provided with a plurality of convex portions or concave portions. By providing this layer, the optical effect due to the plurality of convex portions or concave portions can be made more remarkable.

  Examples of the material of the metal layer 12 include metal materials such as aluminum, silver, and gold. The metal layer 12 may have a single layer structure or a multilayer structure.

  The metal layer 12 can be formed by a thin film forming technique such as vapor deposition and sputtering, for example. In addition, by spatially distributing the region where the metal layer 12 exists, an image can be expressed using the distribution of the metal layer 12.

  The layer thickness of the metal layer 12 is preferably in the range of 10 nm to 50 nm, and more preferably in the range of 10 nm to 30 nm. By doing so, the optical effect described later appears more remarkably.

  FIG. 3 is a plan view illustrating an example of a display body according to one embodiment of the present invention. FIG. 3 includes a display part DP1 and a display part DP2, and the interface part IP1 and the interface part IP2 constituting the display part DP1 and the display part DP2 are formed in the light transmissive material layer 13, The convex part or concave part is provided. An optical effect is obtained by the plurality of convex portions or concave portions.

  As described above, the interface part IP1 and the interface part IP2 may include a flat part in addition to the structure of a plurality of convex parts or concave parts. Hereinafter, these configurations and optical effects will be described.

  In the example shown in FIG. 3, the display unit DP1 is provided apart from the display unit DP2.

  The structure of the interface part IP1 formed in the light transmission part 10b constituting the display part DP1 shown in FIG. 3 has a plurality of convex line structures or concave line structures arranged one-dimensionally as shown in FIG. ing. A plurality of convex line structures or concave line structure lattice vectors constituting the interface part IP1 are provided so as to be parallel to the X direction.

  For example, since the interface portion IP1 forms a diffraction grating pattern, the interface portion IP1 displays a chromatic color derived from the diffracted light when the observation angle is an angle at which the diffracted light is emitted. Here, the “diffraction grating” means a structure that generates a diffracted wave when irradiated with illumination light. The “diffraction grating” includes not only a plurality of grooves exemplified below but also interference fringes recorded on a hologram.

  The interface part IP1 includes, for example, a plurality of grooves arranged one-dimensionally. Each of these grooves may be linear or curved. In the example shown in FIGS. 3 and 4, the display portion DP1 and the interface portion IP1 include a plurality of grooves arranged in parallel to each other along the Y axis.

  FIG. 4 shows a perspective view of the interface part IP1 constituting the display part DP1 shown in FIG. The example shown in FIG. 4 includes a plurality of grooves having an average height H1 and an average period D1 that are linearly arranged one-dimensionally in the Y direction.

  A plurality of convex line structures or concave line structures provided in the interface portion IP1 exhibit birefringence based on, for example, a polarization separation effect. Hereinafter, the polarization separation effect will be described by taking the structure shown in FIGS. 3 and 4 as an example.

In the example shown in FIGS. 3 and 4, the interface portion IP1 includes a plurality of grooves parallel to each other. Hereinafter, polarized light that vibrates perpendicularly to the groove is referred to as TE polarized light, and polarized light that vibrates parallel to the groove is referred to as TM polarized light.

  The period of the plurality of grooves is d, the wavelength of incident light is λ, and the incident angle is θ0. At this time, if the condition of the following formula (1) is satisfied, the interface portion IP1 can be regarded as a thin film having an effective refractive index of neff. This effective refractive index neff varies depending on the polarization direction of incident light, and is expressed by the following equations (2) and (3) in the first approximation.

dcosθ 0 <λ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ （1）
TE polarized light: nTE = {(1-f) n1 ² + f × n2 ² } ^1/2 (2)
TM polarized light: nTM = [n1 ² × n2 ² / {f × n1 ² + (1-f) n2 ² }] ^1/2
・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ (3)
n1 represents the refractive index of the outside world in contact with the layer provided with the plurality of grooves.
n2 represents the refractive index of the layer provided with a plurality of grooves.
f represents the ratio of the width of each groove to the period d.

  As can be seen from the equations (2) and (3), when f is not 0 or 1, the effective refractive index nTE of TE-polarized light and the effective refractive index nTM of TM-polarized light are different from each other. This is called “structural birefringence”. Due to this structural birefringence, light incident on the plurality of grooves generates a phase difference δ represented by the following formula (4).

  δ = (nTE−nTM) h (4) where h is the height of a plurality of convex line structures Alternatively, it represents the depth of the concave line structure. As is apparent from the equation (4), it is possible to generate a desired phase difference δ by adjusting h.

  When the interface portion IP1 has a plurality of convex line structures or concave line structures arranged one-dimensionally, the average period D1 is preferably in the range of 200 nm to 500 nm, and preferably in the range of 250 nm to 400 nm. More preferably. When such a configuration is employed, even when visible light is used as incident light, the condition of the above formula (1) can be satisfied in a wide angle range.

  When the interface portion IP1 includes a plurality of convex line structures or concave line structures arranged one-dimensionally, the average height or depth H1 is preferably in the range of 50 nm to 500 nm, and preferably 70 nm to More preferably, it is within the range of 140 nm. When such a configuration is adopted, the brightness change according to the direction of the transmission axis of the linear polarizer becomes larger when observed through a linear polarizer described later.

  When the interface portion IP1 includes a plurality of convex line structures or concave line structures arranged one-dimensionally, the aspect ratio is preferably in the range of 0.1 to 1.5, 0.5 to More preferably, it is within the range of 1.5. When such a configuration is employed, even when visible light is used as incident light, the condition of the above formula (1) can be satisfied in a wide angle range, and observation is performed through a linear polarizer described later. In some cases, the change in brightness according to the direction of the transmission axis of the linear polarizer becomes larger.

  The interface portion IP2 formed in the light transmissive material layer 13 constituting the display portion DP2 shown in FIG. 3 has a shape selected from one or more of the plurality of convex shapes and concave shapes shown in FIG. The body is arranged two-dimensionally. A shape selected from one or more of a plurality of convex shapes and concave shapes constituting the interface part IP2 shown in FIGS. 3 and 5 is two-dimensionally arranged in the X direction and the Y direction. , Provided. In the example shown in FIGS. 3 and 5, the interface portion IP3 is composed of a plurality of convex shaped bodies.

  FIG. 5 shows a perspective view of the interface part IP2 constituting the display part DP2 shown in FIG. FIG. 6 is a perspective view showing another example of the interface part IP2. The example shown in FIG. 5 includes a plurality of convex shaped bodies having a height H2 and an average period D2 arranged in parallel to the X direction and the Y direction.

  In the example shown in FIG. 6, a plurality of convex shaped bodies are arranged at a height H2 and an average period D2 in parallel with a straight line that intersects the X direction and the Y direction at an angle of 45 degrees. In this case, as described later, the authenticity determination method of the display body 100 is different, and the forgery prevention effect is enhanced.

  The plurality of convex shaped bodies shown in FIG. 5 constituting the interface part IP2 are formed with an average period D2 and an average height H2. The plurality of convex shaped bodies may have a structure including a plurality of convex shaped bodies extending in a direction other than the direction shown in FIG.

  The plurality of convex shaped bodies in the interface portion IP2 typically have a tapered shape. Examples of the tapered shape include a semi-spindle shape, a cone shape such as a cone and a pyramid, and a truncated cone shape such as a truncated cone and a truncated pyramid. The side surfaces of the plurality of convex shaped bodies may be composed only of inclined surfaces or may be stepped. The tapered shape of the plurality of convex shaped bodies is useful for reducing the reflectance of light incident on the interface portion IP2, as will be described later.

  As described above, since the plurality of convex shaped bodies are regularly arranged, the interface portion IP2 functions as a diffraction grating. Specifically, the plurality of convex shapes shown in FIGS. 5 and 6 function in substantially the same manner as a diffraction grating in which grooves are arranged as indicated by dotted lines.

  Further, as described above, the convex shaped body has a tapered shape. When such a structure is employed, if the average period D2 is sufficiently short, the interface portion IP2 can be regarded as having a refractive index that continuously changes in the Z direction. For this reason, the reflectance with respect to the regular reflection light at the interface portion IP2 is small no matter what angle is observed. The interface portion IP2 does not substantially emit diffracted light in the normal direction of the display body 100.

  Therefore, the portion of the display body 100 corresponding to the interface portion IP2 displays, for example, black or dark gray when reflected from the normal direction. Here, “black” means that the wavelength within a range of 400 nm to 700 nm is obtained when the portion of the display body 100 corresponding to the interface IP2 is irradiated with light from the normal direction and the intensity of specular reflection light is measured. Means that the reflectance of all the light components is 10% or less, and “dark gray” means that the portion corresponding to the interface portion IP2 of the display body 100 is irradiated with light from the normal direction and is regularly reflected. When the light intensity is measured, it means that the reflectance is about 25% or less for all light components whose wavelengths are in the range of 400 nm to 700 nm which is the wavelength of visible light.

  As described above, the interface portion IP2 displays black or dark gray when observed from the front. Therefore, the part corresponding to the display part DP2 in the display body 100 looks like, for example, a black or dark gray print layer when observed from the front. Since the interface portion IP2 functions in substantially the same manner as the diffraction grating, the interface portion IP2 displays a chromatic color derived from the diffracted light when the observation angle is an angle at which the diffracted light is emitted.

The average period D2 of the shape body selected from one or more of the plurality of convex shape bodies and concave shape bodies in the interface portion IP2 is 500 nm or less, and preferably the shortest wavelength of visible light or less (for example, 400 nm or less). . More preferably, a structure having a function of emitting the first-order diffracted light and appearing black or dark gray is obtained by setting the wavelength to ½ or more of the shortest wavelength of visible light, that is, 200 nm or more and 400 nm or less. When the average period D2 is set to less than 200 nm, a structure that looks black or dark gray is obtained, but the function of emitting diffracted light cannot be obtained. In general, as the average period D2 of a shape selected from one or more of a plurality of convex shapes and concave shapes decreases, the brightness and saturation decrease, enabling a black display, As the average period D2 increases, the luminance slightly increases, resulting in a structure that is perceived as dark gray.

  In addition, the larger the average height or the average depth H2, the more black display is possible, and the luminance increases as the average height or depth decreases, so that it is perceived as dark gray. Typically, it is desirable that the average height or depth H2 be ½ or more of the average period D2. Specifically, when the average period D2 is 500 nm, dark gray can be displayed by setting the average height or depth H2 to 250 nm or more, and the average height of 500 nm or more which is larger than the average period D2. By making the height or depth H2, a blacker display is possible.

  With the above-described configuration, the portion corresponding to the display unit DP2 of the display body 100 looks like, for example, a black or dark gray print layer when observed from the front. Since the interface portion IP2 functions in substantially the same manner as the diffraction grating, the interface portion IP2 displays a chromatic color derived from the diffracted light when the observation angle is an angle at which the diffracted light is emitted.

  When the above-described configuration is adopted for the interface portion IP2, and at least a part of the print layer 14 shown in FIG. 3 is a black or dark gray print layer, the interface portion IP2 and the print layer 14 are difficult to distinguish. Therefore, forgery of the display body 100 becomes more difficult.

  As described above, the display body 100 includes one or more of the interface portion IP1 in which a plurality of convex line structures or concave line structures are arranged in a one-dimensional manner, and a plurality of convex shape bodies and concave shape bodies. Are provided with an interface portion IP2 provided in a two-dimensional array.

  In FIG. 7, the light-impermeable printing layer 14a is provided in the region where the laminated body 200 is attached on the light transmitting portion 10b, and the light transmitting portion 10b is exposed to the region where the laminated body 200 is not attached. The top view of the display body 100 at the time of providing the transparent printing layer 14b is shown. By doing so, the visual observation image at the time of authenticity determination described later changes.

  FIG. 8 is a plan view in which the surface of the display body 100 to which the stacked body 200 is not attached is the upper surface. By providing the light-impermeable printing layer 14c on the surface to which the laminated body 200 is not attached, the visual observation images of the display part DP1a and the display part DP1b at the time of authenticity determination to be described later change.

  In the display body 100 shown in FIGS. 3, 7, and 8, the thickness of the metal layer 12 is 10 nm to 50 nm. Therefore, when light is irradiated from the back surface of the display body 100, the display portion DP <b> 1, the display portion DP <b> 2, Transmitted light can be observed in the light transmitting portion 10b.

  The display part DP1 corresponding to the interface part IP1 exhibits birefringence. Therefore, when the display unit DP1 is observed through a linear polarizer, the brightness changes according to the direction of the transmission axis of the linear polarizer.

On the other hand, since the display part DP2 corresponding to the interface part IP2 does not exhibit birefringence, the brightness does not change even if the direction of the transmission axis of the linear polarizer is changed. In addition, since the reflectance of the display part DP2 indicates 10% or less, the display part DP2 corresponding to the interface part IP2 of the display part 100 looks black or dark gray when observing the normal direction.
Therefore, the display body 100 can perform authenticity determination by observation through a linear polarizer.

  In addition, both the interface portion IP1 and the interface portion IP2 have a function of a diffraction grating. Therefore, by observing from the observation direction in which the diffracted light is emitted, the interface portion IP1 and the interface portion IP2 can confirm the chromatic color derived from the diffracted light.

  When the interface part IP1 and the interface part IP2 have the structure shown in FIGS. 4 and 5, the chromatic color derived from the diffracted light can be confirmed in both the interface part IP1 and the interface part IP2 in the X direction. On the other hand, when the interface portion IP1 and the interface portion IP2 have the structure shown in FIG. 4 and FIG. 6, diffracted light from the interface portion IP1 can be confirmed in the X direction, and at an angle inclined by 45 degrees from the X direction to the Y direction. The diffracted light by the interface part IP2 can be confirmed. As described above, it is possible to change the chromatic color derived from the diffracted light according to the installation angle of the interface portion IP1 and the interface portion IP2.

  The double authenticity determination can be performed by combining the confirmation of the chromatic color by the diffracted light and the confirmation by observation through the linear polarizer described above. Therefore, the display body 100 has a high anti-counterfeit effect.

  Furthermore, since the layer thickness of the metal layer 12 of the multilayer body 200 is 10 nm to 50 nm as described above, when light is irradiated from the back surface of the display body 100, a specific wavelength is obtained in the display portion DP1 and the display portion DP2. Corresponding transmitted light can be confirmed. In addition, the specific wavelength which permeate | transmits display part DP1 and display part DP2 is the average period D1 of several convex line structure or concave line structure of interface part IP1, and several convex shape body or concave shape body of interface part IP2. Depending on the average period D2 and the observation angle of the transmitted light.

  By combining the confirmation of the transmitted light corresponding to the specific wavelength, the confirmation of the chromatic color by the diffracted light and the confirmation by observation through the linear polarizer, the forgery prevention effect is further enhanced.

Further, in the confirmation of the transmitted light corresponding to the specific wavelength described above, when the light irradiated from the back surface of the display body 100 is irradiated through the linear polarizer, according to the direction of the transmission axis of the linear polarizer, The wavelength of the transmitted light of the display unit DP1 changes.
As described above, since the display body 100 can perform a plurality of authenticity determinations, the forgery prevention effect is high.

  The authenticity determination of the display body 100 is performed by observation through a linear polarizer as described above. More specifically, the authenticity determination method of the display body 100 includes observing at least one of the display unit DP1 and the display unit DP2 through a linear polarizer.

  FIG. 9 is a plan view showing an example when the display body 100 shown in FIG. 3 is observed through the linear polarizer 300. FIG. 10 is a plan view showing another example when the display shown in FIG. 3 is observed through a linear polarizer.

  A linear polarizer 300 shown in FIG. 9 has a transmission axis T parallel to the X axis. A linear polarizer 300 shown in FIG. 10 has a transmission axis T parallel to the Y axis.

  When the arrangement of the display body 100 and the linear polarizer 300 is as shown in FIG. 9, the display unit DP1 looks black or dark gray equivalent to the display unit DP2 when observed through the linear polarizer 300. When the arrangement of the display body 100 and the linear polarizer 300 is as shown in FIG. 10, the display unit DP2 looks relatively brighter than the display unit DP2 when observed through the linear polarizer 300. Thus, when the display unit DP1 of the display body 100 is observed through the linear polarizer 300, the brightness changes according to the direction of the transmission axis of the linear polarizer. Therefore, the authenticity of the display body 100 can be determined by examining the presence or absence of this brightness change.

  As the linear polarizer 300, for example, a linear polarizing film is used. The linear polarizer 200 preferably further includes a diffusion plate. In this case, the diffusion plate is used by being bonded to the front surface, the back surface, or both surfaces of the linear polarizer 200, for example. When the diffusing plate is used, when the display unit DP1 is observed through the linear polarizer 200, it is possible to visually recognize the change in brightness according to the change in the observation direction more clearly.

  As described above, the second authenticity determination of the display body 100 is performed by observation from the observation direction in which the diffracted light is emitted. More specifically, the second authenticity determination method of the display body 100 includes observing at least one of the display unit DP1 and the display unit DP2 via diffracted light.

  FIG. 11 is a plan view showing an example when the light source LS is incident at an angle at which the diffracted light of the display unit DP2 can be observed in the display body 100 shown in FIG. 3, and the diffracted light is observed by the observer OB.

  In FIG. 11, since the plurality of convex line structures or concave line structures forming the display portion DP1 are arranged one-dimensionally in parallel with the Y direction, the diffracted light cannot be emitted in the observer OB direction. Low brightness. On the other hand, the shape body selected from one or more of the plurality of convex shape bodies and concave shape bodies forming the display portion DP2 is two-dimensionally arranged in the X direction and the Y direction. The light can be emitted in the direction of the observer OB, and the observer OB can confirm the chromatic color due to the diffracted light corresponding to the display unit DP2.

  On the other hand, when the display body 100 shown in FIG. 11 is rotated by 90 degrees, the plurality of convex line structures or concave line structures forming the display portion DP1 are arranged one-dimensionally in parallel with the Y direction. The diffracted light is emitted in the direction of the observer OB, and the observer OB can confirm the chromatic color due to the diffracted light corresponding to the display unit DP1. Further, in the display unit DP2, a shape body selected from one or more of a plurality of convex shape bodies and concave shape bodies forming the display portion DP2 is two-dimensionally arranged in the X direction and the Y direction. Therefore, the diffracted light can be emitted in the direction of the observer OB, and the observer OB can confirm the chromatic color by the diffracted light corresponding to the display unit DP2. That is, the observer OB can confirm the chromatic color of the diffracted light corresponding to each of the display part DP1 and the display part DP2.

  Thus, the display part DP1 and the display part DP2 of the display body 100 can confirm the chromatic color of the diffracted light according to the observation direction of the display body 100. More specifically, it is examined whether the chromatic color of the diffracted light corresponding to the display portion DP1 changes by rotating the display body by 90 degrees. Therefore, the authenticity of the display body 100 can be determined by examining the presence or absence of a change in the chromatic color of the diffracted light.

  When examining the presence or absence of a change in the chromatic color of the diffracted light, the display body 100 is rotated 90 degrees in FIG. This is because the lattice vector directions of the plurality of convex line structures or concave line structures of the interface portion IP1 corresponding to the display portion DP1, and the plurality of convex shapes and concave shapes of the interface portion IP2 corresponding to the display portion DP2. This is because the arrangement direction of the shape bodies selected from one or more of them is substantially parallel.

  Here, when the arrangement direction of the interface portion IP2 is not parallel to the arrangement direction of the interface portion IP1, the rotation angle of the display body 100 when examining the change in the chromatic color of the diffracted light of the display body 100 Is not 90 degrees. More specifically, when the arrangement direction of the interface portion IP1 and the arrangement direction of the interface portion IP2 form an angle of 45 degrees, the display body 100 is rotated 45 degrees to change the chromatic color of the diffracted light. It is possible to check for the presence or absence.

In the display body 100 described above, both of the interface portions IP1 and IP2 include a plurality of convex portions or concave portions. Therefore, by preparing an original plate having a structure corresponding to these and performing duplication using this, precise production can be performed while maintaining the configuration, positional relationship and function of both. Therefore, the reliability of the display body 100 which is a genuine product is increased, and the certainty of the authenticity determination is increased.

  As described above, the third authenticity determination of the display body 100 is performed by irradiating light from the back surface of the display body 100 and observing the transmitted light. More specifically, the third authenticity determination method of the display body 100 includes observing at least one of the display unit DP1 and the display unit DP2 through transmitted light.

  FIG. 12 is a plan view showing an example in the case where light is emitted from the back surface of the display body 100 by the light source LS and the transmitted light TL is observed by the observer OB in the display body 100 shown in FIG.

  In FIG. 12, in the display part DP1 and the display part DP2, since the thickness of the metal layer 12 is 10 nm to 50 nm, transmitted light can be confirmed. Note that, since both the display portion DP1 and the display portion DP2 have a plurality of uneven structures at the interface portion IP1 and the interface portion IP2, the observable transmitted light has a chromatic color due to surface plasmon resonance. The chromatic color of the transmitted light depends on the average period and the incident angle of the light source LS. Further, in the uneven structure not covered with the metal layer 12 as shown in FIG. 1 or FIG. 2, the incident light IL from the light source LS is transmitted as it is, and the transmitted light can be confirmed.

  In addition, as shown in FIG. 7, when the light-transmitting printed layer 14b is provided on the light transmitting portion 10b, if light is incident from the back surface of the display body using the light source LS as shown in FIG. The transmitted light derived from the conductive print layer 14b can be confirmed. As described above, it is possible not only to check the transmission images of the display unit DP1 and the display unit DP2, but also to combine the light transmission unit 10b and the light transmissive printing layer 14b to determine the authenticity based on the transmission image.

  Further, as shown in FIG. 8, when the light-impermeable printing layer 14c is provided on the surface of the display body 100 where the laminated body 200 is not attached so as to include the region of the light transmission portion 10b, as shown in FIG. When light is incident on the back surface of the display body using the light source LS, the transmitted image of the display portion DP1b cannot be confirmed by the light-impermeable print layer 14c. In this manner, not only the transmission images of the display part DP1 and the display part DP2 but also the authenticity determination based on the transmission image can be performed by combining the light transmission part 10b and the light impermeable print layer 14c.

  As described above, by providing the light-impermeable printing layer or the light-transmissive printing layer in the printing layer 14, the reflection image and the transmission image are changed, so that the forgery prevention effect is further improved.

  Thus, by combining the display unit DP1 and the display unit DP2 and the print layer 14 in the display body 100, a transmission image of the display body 100 during observation of transmitted light can be observed. More specifically, a light source is incident from the back surface of the display body 100, and it is checked whether the transmitted light is a chromatic color. Furthermore, by providing a light-transmitting printing layer or a light-impermeable printing layer as the printing layer 14, it is examined whether there is a transmission image to be observed. Therefore, the authenticity of the display body 100 can be determined by examining the presence or absence of a change in the chromatic color of the transmitted light.

  As described above, the fourth authenticity determination of the display body 100 is performed by irradiating light through the linear polarizer from the back surface of the display body 100 and observing the transmitted light. More specifically, the fourth authenticity determination method of the display body 100 includes observing at least the display unit DP1 or the display unit DP2 through transmitted light.

FIG. 13 shows an example in the case where the display body 100 shown in FIG. 3 emits light from the light source LS from the back surface of the display body 100 through the linear polarizer 300 and the observer OB observes the transmitted light TL. FIG. In FIG. 13, the transmission axis T of the linear polarizer 300 is parallel to the Y axis.

  In FIG. 13, in the display portion DP1 and the display portion DP2, the thickness of the metal layer 12 is 10 nm to 50 nm, so that transmitted light can be confirmed. In the display part DP1, the lattice vector of the convex line structure or the concave line structure of the interface part IP1 is parallel to the X direction. For this reason, when incident light IL having linear polarization in the Y direction is incident, surface plasmons cannot be excited, and the transmitted light of the display portion DP1 becomes achromatic.

  On the other hand, in the display part DP2, since the convex part or concave part of the interface part IP2 is two-dimensionally arranged with respect to the X direction and the Y direction, incident light IL having linear polarization in the Y direction is incident. Even when the surface plasmon is excited, the transmitted light of the display portion DP2 becomes chromatic. In this way, by providing the incident light IL with linear polarization, it is possible to confirm the color change of the transmitted images of the display unit DP1 and the display unit DP2.

  In FIG. 13, when incident light IL having linear polarization in the X direction is incident, the transmitted light is chromatic in both the display portion DP1 and the display portion DP2. As described above, it is possible to confirm the change in the chromatic color of the transmitted image in the display unit DP1 and the display unit DP2 based on the polarization characteristic of the incident light IL, and it is possible to determine whether the transmitted image is authentic.

  The display body 100 may be used for purposes other than forgery prevention. For example, the display body 100 can be used as a toy, a learning material, or a decoration.

  Specific examples of the present invention will be described below, but the present invention is not limited to this embodiment.

  An ultraviolet curable resin was applied to the PET film with a gravure roll coater to form a concavo-convex structure forming film.

  Next, as a matrix used for replication, a first region in which a plurality of convex line structures having an average period of 400 nm and an average height of 200 nm are arranged one-dimensionally, and a plurality of elements having an average period of 400 nm and an average height of 150 nm A plurality of second regions in which the convex shaped bodies are two-dimensionally arranged is formed to produce a metal plate that expresses a picture.

  Next, an ultraviolet curable resin was pressed against the metal plate, irradiated with ultraviolet rays from a metal halide lamp, and after curing the ultraviolet curable resin, the metal plate was peeled off to form an uneven structure. Thereafter, aluminum was deposited on the concavo-convex structure by vacuum deposition to provide a light reflective material layer.

  An adhesive was applied to the light reflective material layer with a gravure roll coater, then transferred to a thick PET substrate, and the PET film was peeled off to obtain a display.

  The display body obtained as described above visually confirms the appearance and disappearance of the latent image composed of the first region by arranging a linearly polarizing film in the immediate vicinity of the display body and rotating the linearly polarizing film. did it.

  Further, the obtained display was tilted to an angle at which the diffracted light could be visually observed, and the diffracted light could be visually confirmed from the second region. In addition, by rotating the display body with the tilt angle fixed, the appearance and disappearance of the chromatic color composed of the diffracted light in the first region could be visually confirmed.

  In addition, when a light source is installed on the back surface of the obtained display body, light is incident and the transmitted light is visually observed, the transmitted light from the first region and the second region is chromatic. It was confirmed visually. Furthermore, when the light transmitted through the linear polarizer was incident and the transmission image of the display body was visually observed while rotating the linear polarizer, the color change of the transmitted light in the second region of the previous period was visually confirmed.

10a ... base material layer 10b ... light transmission part 11 ... adhesive layer 12 ... metal layer 13 ... light transmissive material layer 14 ... print layer 14a ... light Impervious printed layer 14b ... Light transmissive printed layer 14c ... Light impervious printed layer 100 ... Display body 200 ... Laminated body 300 ... Linear polarizer T ... Transmitted Axis DP1 ... display part DP2 ... display part IP1 ... interface part IP2 ... interface part LS ... light source IL ... incident light RL ... reflected light TL ... Transmitted light OB ... observer

Claims (8)

A display body comprising a base material layer having a light transmission part,
In the light transmission part, a light-transmitting adhesive layer, a metal layer having a thickness of 10 nm to 50 nm, a light-transmitting material layer formed with a concavo-convex structure having an aspect ratio of 0.1 to 1.5, and printing The layers are stacked,
The display body, wherein the metal layer is formed in a pattern on a part of the surface of the light transmissive material layer.   The display body according to claim 1, wherein the printed layer is formed in a pattern and covers a part of the display body without covering the entire surface of the light transmission portion of the display body.   The printing layer is provided on the other surface of the base material layer to which the printing layer is not attached so as to cover a part of the light transmission portion. Display body.   The light transmissive material layer is composed of a plurality of convex linear structures having an average height of 50 to 500 nm or a plurality of concave linear structures having an average depth of 50 to 500 nm, and the average period is 200 to 500 nm. A first region arranged one-dimensionally, a plurality of convex shapes having an average height of 50 to 500 nm, a shape selected from one or more of a plurality of concave shapes having an average depth of 50 to 500 nm, and The display body according to any one of claims 1 to 3, wherein the display body has a two-dimensionally arranged second region having an average period of 200 to 500 nm. The display body according to any one of claims 1 to 4,
Visually observe through a linear polarizer, and confirm that the latent image can be confirmed at the portion corresponding to the first region, and that the latent image will change in brightness by rotating the linear polarizer. A method for determining the authenticity of a display body characterized by the above.   The display body according to claim 4 is tilted, and at least one of the first area and the second area is visually observed to confirm the latent image, and the color change of the latent image can be achieved by changing the tilt angle of the display body. A method for determining authenticity of a display body, wherein authenticity determination is performed by causing an error.   5. The display body according to claim 4, wherein light is transmitted, the transmitted light of at least one of the first region and the second region is visually observed, and the transmitted light is colored. A method for determining authenticity of a display body, wherein authenticity determination is performed based on whether the first region and the second region have different colors.   5. The display body according to claim 4, wherein light transmitted through a linear polarizer is transmitted, and transmitted light of at least one region of the first region or the second region is visually observed, and transmitted through the first region. The light is judged to be authentic by changing from colorless to colored and from colored to colorless according to the direction of linearly polarized light, and the transmitted light in the second region does not change color regardless of the direction of linearly polarized light. A method for determining the authenticity of a characteristic display object.