JP2013218595A - Display body and authenticity determination method of the same - Google Patents

Abstract

An object of the present invention is to provide a display body having a more advanced anti-counterfeit effect by providing a plurality of anti-counterfeit functions.
An assembly of unit cells in which a first interface region made of a dielectric layer and a second interface region having a metal layer are sequentially stacked or adjacent to each other on one surface of a light-transmitting substrate. a display structure that comprises a body, either of said first interface region and the second interface region is a display body which is characterized in that at 100 nm ² or more 160000Nm ² or less.
[Selection] Figure 1

Description

  The present invention relates to a display body having an anti-counterfeit effect by surface plasmon resonance and a method for determining its authenticity.

  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 Patent Document 1, in order to increase the security level of a fluorescent image formation using a fluorescent light emitting ink, a fluorescent image formation containing two types of phosphors having different wavelength regions of fluorescence emitted from the respective phosphors Is used. Patent Document 3 discloses an intaglio latent image that can be confirmed only from a specific angle. Patent Document 4 discloses a medium for authenticity determination using a combination of a hologram layer, a light reflective layer, and an alignment film.

  However, since all of the above proposals are based on one anti-counterfeit function, there is a problem in providing a higher level of anti-counterfeit effect.

  In addition, any 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 2004-181791 A JP 11-291609 A JP 2005-091786 A Japanese translation of PCT publication No. 2002-530687 JP 2009-535670 A JP-A-5-273500 JP 2008-139508 A

  An object of the present invention is to provide a display body having a more advanced anti-counterfeit effect by providing a plurality of anti-counterfeit functions.

According to the first aspect of the present invention, a first interface region made of a dielectric layer and a second interface region having a metal layer are sequentially stacked or adjacent to each other on one surface of a light-transmitting substrate. A display unit composed of a set of unit cells,
Either of said first interface region and the second interface region is a display body which is characterized in that at 100 nm ² or more 160000Nm ² or less.

  The invention according to claim 2 of the present invention is the display body according to claim 1, wherein the pattern shapes of the first interface region and the second interface region are different.

  Further, the invention according to claim 3 of the present invention is the display body according to claim 1 or 2, characterized in that the unit cell is composed of aggregates having different periods of the unit cells.

  The invention according to claim 4 of the present invention is the display body according to claim 3, wherein the period is 50 nm to 500 nm.

  Further, in the invention according to claim 5 of the present invention, the real part of the complex dielectric constant in the visible light wavelength region of the metal layer is a negative value. It is a display.

  The invention according to claim 6 of the present invention is the display body according to any one of claims 1 to 5, wherein the metal layer is made of metal fine particles.

  Further, in the invention according to claim 7 of the present invention, the layer thickness of each of the dielectric layer and the metal layer satisfies the following formula (1). Is the body.

δ: layer thickness c: speed of light ω: angular frequency ε1: dielectric constant of dielectric layer ε2: dielectric constant of metal layer

  The invention according to claim 8 of the present invention is the display body according to any one of claims 1 to 7, wherein the metal layer has a thickness of 10 nm to 200 nm.

  The invention according to claim 9 of the present invention is the display body according to any one of claims 6 to 8, wherein a layer thickness of the metal fine particles is 2 nm or more and 20 nm or less.

  The invention according to claim 10 of the present invention is the display object authenticity determination method according to any one of claims 1 to 9, wherein light is incident on the display body and the transmitted light is visually observed. This is a method for determining the authenticity of a display body characterized by confirming.

According to the present invention, a unit cell in which a first interface region made of a dielectric layer and a second interface region having a metal layer are sequentially stacked or adjacent to each other on one surface of a light-transmitting substrate. a display member made of an aggregate of, by the first interface region and one of the unit cell area of the second interface region 100 nm ² or more 160000Nm ² or less, it is possible to obtain a surface plasmon resonance effect, In addition to conventional pattern formation by reflected light, pattern formation by transmitted light is possible.

  In addition, the surface plasmon resonance effect can be obtained in a more complicated manner by changing the shape and film thickness of the first interface region and the second interface region, and further by changing the period of the unit cell. A forgery prevention effect can be obtained, and a more advanced authentication can be made.

FIG. 6 is a cross-sectional view illustrating an example of a display body according to one embodiment of the present invention. Sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. Sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. Sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. Sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. The perspective view which shows an example of each interface area | region. The perspective view which shows the other example of each interface area | region. The perspective view which shows the other example of each interface area | region. Sectional drawing which shows the other example of the display body which concerns on 1 aspect of this invention. The top view which shows an example of the cell in the interface of the dielectric material layer of this invention, and a metal layer or a metal fine particle layer. FIG. 6 is a plan view illustrating an example of a display body according to one embodiment of the present invention. The top view which shows an example in the case of observing the front of the display body shown in FIG. 9 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 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.

  A display body 100 shown in FIG. 1 depicts a case in which a base material 10, a dielectric layer 11 laminated on the base material 10, and a metal layer 12 are included. FIG. 1 illustrates a case where the metal layer 12 is positioned on the front side with respect to the dielectric layer 11 as an example.

  An interface region IP1 and an interface region IP2 are formed on one main surface of the dielectric layer 11. The interface region IP1 and the interface region IP2 may be formed with different surface energy or surface area. Further, the interface region IP1 and the interface region IP2 may be formed with different wettability. As a material of the dielectric layer 11, for example, a resin having visible light permeability can be used.

  The dielectric layer 11 may have a single layer structure or a multilayer structure. The dielectric layer 11 may be colored by adding a dye to the resin. Further, fine particles made of metal, semiconductor, ceramic, magnetic material, or the like may be added.

Further, it can be used as the material of the dielectric layer 11, for example, SiO ₂ or _TiO 2, inorganic materials such as MgF ₂ or mixtures thereof.

  In addition, when making the inorganic material into the dielectric material layer 11, it can form by thin film formation techniques, such as vapor deposition and sputtering, for example.

  The metal layer 12 covers either one of the first interface region IP1 and the second interface region IP2 provided in the dielectric layer 11. By providing the metal layer 12, an optical effect and surface plasmon resonance described later are generated. In the display body 100 shown in FIG. 1, the metal layer 12 is formed in the first interface region IP1.

  As a material of the metal layer 12, a metal material having a negative real part of the complex dielectric constant in the visible light wavelength region is required. For example, metal materials, such as aluminum, silver, and gold | metal | money, are mentioned. By doing so, surface plasmon resonance described later occurs in the visible light wavelength region. 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. Furthermore, in order to spatially distribute the metal layer 12, techniques such as mask vapor deposition, chemical etching, and laser processing are used. By distributing the metal layer 12 spatially, an image can be expressed using the distribution of the metal layer 12.

  The display body 100 shown in FIG. 2 depicts the case where the metal layer 12 is formed in the second interface region IP2 in the form shown in FIG.

  The display body 100 shown in FIG. 3 depicts a case where the metal layer 12 shown in FIG. By using the metal layer 12 as the metal fine particle layer 13, the behavior of the manifest plasmon resonance described later changes.

  The display body 100 shown in FIG. 4 includes a laminate 200 in which the metal layer 12a is sandwiched between the dielectric layer 11a and the dielectric layer 11b and the metal layer 12b is formed on the dielectric layer 11b in the form shown in FIG. The case is drawn. In FIG. 4, the metal layer 12a and the metal layer 12b are drawn so that the average period D is different, but the same average period D may be used.

  In the form shown in FIG. 1, the display body 100 shown in FIG. 5 has the metal layer 12 sandwiched between the dielectric layer 11a and the dielectric layer 11b, the metal fine particle layer 13 is formed on the dielectric layer 11b, and the metal fine particle layer 13 further. The case where the laminated body 200 formed by inserting | pinching with the dielectric material layer 11c is included is drawn. In FIG. 5, the metal layer 12 and the metal fine particle layer 13 are drawn so that the average period D is different, but the same average period D may be used.

  The display body 100 shown in FIGS. 1, 2, 3, 4, and 5 illustrates 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. It may be located on the rear side. 4 and 5, when one or more dielectric layers 11, metal layers 12, and metal fine particle layers 13 are laminated, they are positioned on both sides of the light transmissive material layer 13. May be.

  Hereinafter, the detailed configuration and optical effect of the display body 100 shown in FIGS. 1, 2, 3, 4, and 5 will be described.

  As described above, the dielectric layer 11 includes the first interface region IP1 and the second interface region IP2. More specifically, the first interface region IP1 and the second interface region IP2 are two-dimensionally and periodically formed on the XY plane as shown in FIGS.

  In FIG. 6, both the first interface region IP1 and the second interface region IP2 occupy the same area with respect to the unit region IP0, and both have a square shape. In FIG. 7, in the unit region IP0, the area of the first interface region IP1 is smaller than the area of the second interface region IP2, and the shape is also a rectangular shape whose major axis is the Y-axis direction. . Further, in FIG. 8, in the unit region IP0, the area of the first interface region IP1 is smaller than the area of the second interface region IP2, and the shape of the first interface region IP1 is circular.

  6, 7, and 8, the first interface region IP <b> 1 and the second interface region IP <b> 2 have a square shape, a rectangular shape, or a circular shape. The shape may be a complicated shape such as a distorted circular shape or a geometric pattern. Thus, by making the shapes of the first interface region IP1 and the second interface region IP2 various, the characteristics of surface plasmon resonance, which will be described later, are changed, and polarization characteristics are imparted in the observation method of the display body 100. It becomes possible.

Either area size of the first interface region IP1 and the second interface region IP2 provided in the dielectric layer 11 is preferably at 100 nm ² or more 160000Nm ² or less per unit area IP0, 250 nm ² or more 90000Nm ² The following is more preferable. By doing so, it becomes possible to change the area ratio of the first interface region IP1 and the second interface region IP2, and the size of one of the first interface region IP1 and the second interface region IP2 is the visible light wavelength. Therefore, the characteristic of the optical effect described later changes.

  The layer thickness of the metal layer 12 is preferably in the range of 10 nm to 200 nm, and more preferably in the range of 10 nm to 50 nm. By doing so, the optical effect described later appears more remarkably.

  The layer thickness of the metal fine particle layer 13 is preferably in the range of 2 nm to 20 nm, and more preferably in the range of 5 nm to 20 nm. By doing so, the optical effect described later appears more remarkably.

  The average period D of each of the first interface region IP1 and the second interface region IP2 is preferably in the range of 50 nm to 500 nm, and more preferably in the range of 50 nm to 300 nm. By making the average period D different, the optical effect described later appears more prominently.

  For each specific region of the dielectric layer 11, the area ratio of the first interface region IP1 and the second interface region IP2 is changed, or the average period D is changed, and the shapes of the first interface region IP1 and the second interface region IP2 are changed. In addition, a pattern can be expressed by making each region a cell structure.

  In the first interface region IP1 and the second interface region IP2 formed in the dielectric layer 11, when the configuration as described above is adopted, the average period of the first interface region IP1 and the second interface region IP2 is originally equal. Since it is below the visible light wavelength, light in the visible light wavelength region cannot be transmitted. However, by laminating the metal layer 12 and the dielectric layer 11 adjacent to each other as shown in FIG. 1, a surface wave called surface plasmon is generated at the interface between the metal layer and the dielectric layer, and the surface plasmon and the propagation light are generated. Resonance (surface plasmon resonance) and the light of a specific wavelength are transmitted by combining.

  In order to effectively generate the surface plasmon resonance, the average period D and the layer thickness of the metal layer 12, the layer thickness of the metal fine particle layer 13, the unit region IP0 in the first interface region IP1 and the second interface region IP2 It is preferable that the parameter such as the region size is an optimum value depending on the metal material or dielectric material used.

  Here, plasmon is a collective vibration of free electrons or ions in a substance. The surface plasmon is a component in which the plasmon exudes to the metal surface (interface between the metal layer and the dielectric layer). Since these plasmons and surface plasmons are collective oscillations of free electrons or ions, they exhibit electromagnetic wave behavior.

  In order for the surface plasmon and the propagating light to resonate, a material configuration in which the surface plasmon is excited is essential, and at least an interface between the metal layer and the dielectric layer is necessary. Furthermore, in order to obtain the optical effect described later in the visible light wavelength region, the real part of the complex dielectric constant of the metal layer needs to be a negative value at least in the visible light wavelength region.

  Several methods have been proposed to resonate surface plasmon and propagating light, such as resonating by laminating a metal layer and a dielectric layer on one side of the prism, and a fine periodic structure at the interface between the metal layer and the dielectric layer. There is a method of resonating by forming.

  Surface plasmon excitation and resonance conditions are as follows: metal layer thickness and material, dielectric layer thickness, dielectric layer material, number of stacked metal layers and dielectric layers, interface shape between metal layers and dielectric layers Depends on etc.

  If the angular frequency of the excited surface plasmon is ω, the velocity of the electromagnetic wave is c, the dielectric constant of the dielectric layer is ε1, and the dielectric constant of the metal layer is ε2, the bleed length of the surface plasmon to the metal layer and the dielectric layer The depth δ is obtained from the following formula 2.

  The bleed length δ is an important parameter in determining the layer thickness of the metal layer and the dielectric layer, and when the metal layer and the dielectric layer are laminated, the layer thickness is less than the bleed length. By doing so, the surface plasmons excited at each interface are combined, and the resonance condition changes.

  Since the exudation length δ is such a length that the intensity of the excited surface plasmon becomes 1 / e, the surface plasmon exudes although it is weak even when the exudation length δ or more. Therefore, it is possible to make the layer thickness greater than the bleeding length δ. Here, e represents a natural number.

  In the display body 100 shown in FIGS. 1 and 2, the metal layer 12 in FIG. 1 is formed in the first interface region IP <b> 1 in the dielectric layer 11 with an average period D. On the other hand, the metal layer 12 of FIG. 2 is formed with the average period D in the second interface region IP2. When the average period D is the same value and the region sizes of the first interface region IP1 and the second interface region IP2 are the same value with respect to the unit interface IP0, the surface plasmon resonance conditions are the same. However, the average period D is different, or the region sizes of the first interface region IP1 and the second interface region IP2 are different. The material of the dielectric layer 11 is different. The material of the metal layer 12 is different. Etc., the surface plasmon resonance condition changes. More specifically, the wavelength of transmitted light changes in the optical effect described later. Furthermore, the surface plasmon resonance condition is also changed by providing a dielectric layer on the metal layer 12 in FIGS.

  In the display body 100 shown in FIG. 3, the metal layer 12 of the display body 100 shown in FIG. Since the metal layer 12 is used as the metal fine particle layer 13 and a plurality of metal fine particles are contained inside the metal fine particle layer 13, the surface plasmons of the fine particles are resonated and combined. As a result, the surface plasmon resonance conditions vary greatly.

  Further, in the display unit 100 shown in FIG. 4, the metal layer 12a is sandwiched between the dielectric layer 11a and the dielectric layer 11b, and the metal layer 12b is sandwiched between the dielectric layer 11b and air. By doing so, the number of stacked layers of the metal layer and the dielectric layer is different, so that the surface plasmon resonance condition changes. More specifically, when the thickness of the dielectric layer 11b satisfies the condition of the formula (1), the surface plasmon generated at the interface of the metal layer 12a may be combined with the surface plasmon generated at the interface of the metal layer 12b. As a result, the resonance condition of the surface plasmon changes.

  In the display unit 100 shown in FIG. 4, by satisfying one or both of the conditions of making the materials of the dielectric layers 11a and 11b different and making the materials of the metal layers 12a and 12b different. Since the surrounding environments of 12a and 12b are different, the resonance condition of the surface plasmon changes. In addition, the surface plasmon resonance conditions also change by changing parameters such as the average period D, region size, and layer thickness of the metal layers 12a and 12b.

In the display body 100 shown in FIG. 5, the metal layer 12 is sandwiched between the dielectric layer 11a and the dielectric layer 11b, and the metal fine particle layer 13 is sandwiched between the dielectric layer 11b and the dielectric layer 11c. By doing so, not only the metal layer 12 and the dielectric layer 11 but also the metal fine particle layer 13 are laminated, so that the surface plasmon resonance condition changes. More specifically, since the characteristics of the surface plasmon generated at the interface between the metal layer 12 and the surface plasmon generated at the interface between the metal fine particle layer 13 are different, the bonding of the surface plasmons generated at the metal layer 12 and the metal fine particle layer 13 is different. The conditions are also different, and as a result, the surface plasmon resonance conditions change.

  As described above, the display unit 100 changes the area ratio of the first interface region IP1 and the second interface region IP2 or changes the average period D for each specific cell region of the dielectric layer 11. It is possible to express a pattern by changing the shape of the second interface region IP2. Furthermore, it is also possible to express a pattern by changing the number or order of lamination of the dielectric layers 11 and the metal layers 12 and the lamination material for each specific cell region.

  In FIG. 9, a one-dimensional or two-dimensional periodic structure is formed in the second interface region IP2. By doing so, it becomes easy to leave the metal layer 12 and the metal fine particle layer 13 in the first interface region IP1. Specifically, since the surface area of the first interface region IP1 and the second interface region IP2 can be made different by providing a periodic structure in the second interface region IP2, the second interface region IP2 is deposited when the metal layer 12 is deposited. The thickness of the metal layer becomes thinner, and the metal can be easily removed by chemical etching or laser processing. Further, since the surface area of the second interface region IP2 is larger than that of the first interface region IP1, the water repellency of the second interface region IP2 is improved. Therefore, the metal fine particles dispersed in a solvent, a binder, or the like are repelled from the second interface region IP2 and gathered in the first interface region IP1.

  As another method, the metal layer 12 and the metal fine particle layer 13 can be patterned by modifying each interface region with a hydrophilic molecule or a hydrophobic molecule in addition to the periodic structure.

  FIG. 10 shows an example of the cell 300 at the interface between the dielectric layer 11 and the metal layer 12 or the metal fine particle layer 13.

  In FIG. 10, the display area DP1 and the display area DP2 may have the same layer configuration, material, and structure, or may be different. In order to further improve the security, it is preferable that the display area DP1 and the display area DP2 have different layer configurations and materials. Furthermore, the average period D or the periodic period of the periodic structure including the first interface area IP1 and the second interface area IP2 More preferably, the region sizes per unit region IP0 are different.

  Furthermore, in order to further improve security, it is preferable to express information such as a pattern, characters, and numbers using the display area DP1 and the display area DP2. In FIG. 10, the display area DP1 is used as a background, and the alphabet “O” is expressed in the display area DP2. In this way, when information such as a pattern, characters, numbers, and the like is expressed by the display area, different effects can be obtained by a display body observation method described later.

  In FIG. 10, the number of display areas is two, but more preferably two or more.

  FIG. 11 shows one example of the display body of the present invention, and FIG. 12 shows an example in which the display body is observed through light.

In FIG. 11, the display area DP1 and the display area DP2 may have the same layer configuration, material, and structure, or may be different. In order to further improve the security, it is preferable that the display area DP1 and the display area DP2 have different layer configurations and materials. Furthermore, the average period D of the periodic structure including the interface area IP1 and the interface area IP2 or the unit area IP0. More preferably, the area size is different.

  In the display body 100 shown in FIG. 11, it is possible to observe the transmission color corresponding to the resonance condition of the surface plasmon in the display area DP1 and the display area DP2 by observing with light transmitted as shown in FIG. Become. More specifically, the average period D of the first interface region IP1 and the second interface region IP2 formed in the dielectric layer 11, and the region of the first interface region IP1 and the second interface region IP2 per unit region IP0. Due to the difference in size, the material of the dielectric layer 11, the metal layer 12, and the metal fine particle layer 13, the number of layers, and the order of the layers, the spectrum of the light transmitted through the display body 100 also changes as the resonance wavelength of the surface plasmon changes. As a result, a colored transmission image can be observed.

  In FIG. 12, when observing the display body 100 with transmitted light, the transmitted light of the display body 100 can be made different by providing the incident light IL with polarization characteristics. Specifically, this effect is possible because the surface plasmon has polarization response.

  When the shape of the first interface region IP1 or the second interface region IP2 covered with the metal layer 12 or the metal fine particle layer 13 has a major axis and a minor axis such as a rectangular shape or an elliptical shape, The above-mentioned polarization responsiveness appears remarkably. By doing so, it becomes possible to form a latent image at the time of transmission observation, and it becomes possible to further improve anti-counterfeiting resistance.

  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.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to this embodiment.

  A PET film was used as a light-transmitting substrate, and an ultraviolet curable resin was applied as a dielectric layer on one surface thereof with a gravure roll coater to obtain an interface region forming film.

  Next, in order to make the surface area of the interface region different, metal plates were prepared in which periodic concavo-convex structures were arranged so as to form a two-dimensional square lattice with an average period of 300 nm.

  Next, a periodic concavo-convex structure was formed by pressing the ultraviolet curable resin surface of the interface region forming film against a metal plate, irradiating with ultraviolet rays from a metal halide lamp, and curing, and then peeling the metal plate. Thereafter, aluminum was deposited on the concavo-convex structure by a vacuum deposition method so as to have a film thickness of about 50 nm to provide a metal layer. As is well known, the real part of the complex dielectric constant of aluminum shows a negative value in the visible light wavelength region.

  In the interface region where the periodic concavo-convex structure is formed and the metal layer is deposited, the thickness of the metal layer is thinner than the interface region where the periodic concavo-convex structure is not formed. Therefore, it can be easily removed by chemical etching. After the chemical etching treatment, the UV curable resin was cured with a layer thickness of 50 μm in a specific partial interface region to obtain a display.

  The display body obtained as described above transmits light so that a color of a transmission image is obtained in a region including only the dielectric layer and the metal layer and a region where the metal layer is sandwiched between the dielectric layers. It was confirmed visually that the taste was different.

DESCRIPTION OF SYMBOLS 10 ... Base material, 11 ... Dielectric layer, 12 ... Metal layer, 13 ... Metal fine particle layer, 100 ... Display body, 200 ... Laminated body, 300 ... Cell, D ... Average period, IP0 ... Unit region, IP1 ... First Interface region, IP2 ... second interface region, DP1 ... display region, DP2 ... display region, LS ... light source, IL ... incident light, TL ... transmitted light, OB ... observer.

Claims (10)

On one surface of a light-transmitting substrate, a first interface region made of a dielectric layer and a second interface region having a metal layer are composed of an assembly of unit cells that are sequentially stacked or adjacent to each other. Display body,
Display body, wherein either one of said first interface region and the second interface region is 100 nm ² or more 160000Nm ² or less.   The display body according to claim 1, wherein pattern shapes of the first interface region and the second interface region are different.   The display body according to claim 1, wherein the unit cell is composed of an aggregate having different periods.   The display body according to claim 3, wherein the period is 50 nm to 500 nm.   The display body according to claim 1, wherein the real part of the complex dielectric constant in the visible light wavelength region of the metal layer is a negative value.   The display body according to claim 1, wherein the metal layer is made of metal fine particles. The display body according to any one of claims 1 to 6, wherein each of the dielectric layer and the metal layer satisfies the following formula (3).
δ: layer thickness c: speed of light ω: angular frequency ε1: dielectric constant of dielectric layer ε2: dielectric constant of metal layer   The display body according to claim 1, wherein a thickness of the metal layer is 10 nm or more and 200 nm or less.   The display body according to any one of claims 6 to 8, wherein a layer thickness of the metal fine particles is 2 nm or more and 20 nm or less.   10. A method for determining the authenticity of a display body according to claim 1, wherein light is incident on the display body and the transmitted light is visually confirmed. .