JP2013222060A - Image display body and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display body and an article which are capable of displaying images different between observation with transmitted light and observation with reflected light.SOLUTION: In the image display body, a light-transmissive layer comprising a light-transmissive substrate and a relief structure formation layer and a print layer are formed on a metal thin film layer having light reflectivity and light permeability. The image display body has a plurality of relief structure parts which are formed in the relief structure formation layer and comprise a plurality of convex portions projecting from the metal thin film layer toward the relief structure formation layer with a height of 300 nm or more and 500 nm or less or a plurality of concave portions dented from the relief structure formation layer toward the metal thin film layer with a depth of 300 nm or more and 500 nm or less and have the convex or concave portions arrayed therein like a lattice with an average inter-center distance of 200 nm or more and 500 nm or less. The print layer is periodically formed on a plane in a direction horizontal to the light-transmissive layer, on the light-transmissive layer side opposite to the side where the relief structure formation layer is provided, between the relief structure formation layer and the metal thin film layer, or between the light-transmissive substrate and the relief structure formation layer.

Description

  The present invention relates to an image display body whose appearance changes depending on observation conditions used for anti-counterfeiting and the like, and in particular, an image display body whose picture changes by observation of transmitted light and reflected light, and the image display body. It relates to the provided article.

  In recent years, it has a different visual effect from ordinary printed materials for the purpose of preventing counterfeiting of securities such as gift certificates and checks, cards such as credit cards, cash cards, ID cards, and certificates such as passports and licenses. An image display body is formed in the form of a transfer foil, a sticker, or the like, and is attached to a surface of a certificate such as the securities or a card, and is provided by pressure bonding. In addition, for goods other than securities and certificates, the distribution of counterfeit goods has become a social problem, and there are increasing opportunities to apply the same anti-counterfeit technology to such articles.

  Examples of anti-counterfeiting technologies include micro characters, special light-emitting ink, watermarks, diffraction gratings, and holograms. This forgery prevention technology can be roughly divided into two. One is forgery countermeasures that determine authenticity using a simple device or measuring device. The other is anti-counterfeiting that can be easily determined by the naked eye.

  In recent years, security devices have been developed in which various fine structures are produced by an electron beam drawing apparatus (EB apparatus) and can be visually differentiated from similar technologies. As a most general security device, there is a surface relief type rainbow hologram (for example, see Patent Document 1).

  Rainbow holograms have a more complex structure than ordinary printed materials, and are difficult to manufacture unless they are a specific vendor with high microfabrication technology. A large-scale replication device is required for replication. This makes it difficult to replicate easily. For this reason, it is difficult to produce a counterfeit product.

  In addition, since it is reproduced with light close to a single wavelength when illuminated, it can be observed in bright and vivid colors corresponding to the seven colors of the rainbow, and the color and image pattern change when the observation conditions change The way you look. For this reason, the difference from other members can be easily discriminated visually.

  For these reasons, the rainbow hologram is excellent for visual security applications and has been widely used as an image display for preventing counterfeiting.

  However, in the rainbow hologram, the color of the reproduced image changes greatly even if the observation condition changes slightly, so it is difficult to identify the difference in the color of the image.

  For this reason, even in a rainbow hologram in which different images are recorded, there is a problem that it is easy to give an impression similar to an observer, and it is difficult to discriminate the difference in the recorded images between holograms.

JP-A-2-72320

“Principles of Holography”, Optronics, p. By Hari Haran

  The problem to be solved by the present invention is to provide an image display body and an article capable of displaying different images when observed with transmitted light and reflected light.

  An image display body according to claim 1 of the present invention forms a light transmissive layer and a print layer comprising a light transmissive base material and a concavo-convex structure forming layer on a metal thin film layer having light reflectivity and light transmissive property. A plurality of protrusions formed on the concavo-convex structure forming layer and projecting from the metal thin film layer to the concavo-convex structure forming layer at a height of 300 nm or more and 500 nm or less, or It consists of a plurality of recesses that are recessed at a depth of 300 nm or more and 500 nm or less from the concavo-convex structure forming layer toward the metal thin film layer, and the projections or the recesses are arranged in a grid pattern with an average center distance of 200 nm or more and 500 nm or less A plurality of concavo-convex structure portions, and the printed layer is formed on the light transmission layer side opposite to the surface on which the concavo-convex structure formation layer is provided, or between the concavo-convex structure formation layer and the metal thin film layer. Between or Characterized in that it is periodically formed on the light transmitting layer and the horizontal plane anywhere between the serial light transmitting substrate and the uneven structure formation layer.

  When the image display body which concerns on Claim 2 of this invention observes from the orthogonal | vertical direction with respect to the surface of the light transmission layer on the opposite side to the said metal thin film layer, the said printing layer and the said uneven | corrugated structure part adjoin. And the printed layer is 40% or more and 60% or less of the area of the concavo-convex structure portion.

  The image display body according to claim 3 of the present invention is characterized in that the period of the print layer is 3 μm or more and 145 μm or less.

  The image display body according to a fourth aspect of the present invention is characterized in that the transmittance of the print layer at a visible light wavelength is 10% or less.

  The image display body according to claim 5 of the present invention is characterized in that an average center-to-center distance of the convex portions or the concave portions is different in each of the plurality of concave and convex structure portions.

  In the image display body according to claim 6 of the present invention, an image of a pattern, a character, a symbol, or the like is displayed by the plurality of concavo-convex structure portions having different average center-to-center distances of the convex portions or the concave portions, and the printed layer displays the images. An image such as a pattern, a character, or a symbol different from the uneven structure portion is displayed.

  The image display body according to claim 7 of the present invention is characterized in that a layer thickness on a flat surface of the metal thin film layer is not less than 30 nm and not more than 100 nm.

  An article according to an eighth aspect of the present invention is characterized in that the image display body according to any one of the first to seventh aspects is supported through an adhesive layer having light permeability.

  The image display body according to claim 1 of the present invention has a region having a light transmitting function and a printing region (printing layer) due to the concavo-convex structure. The region having the light transmitting function is a low reflection region, and is displayed in black, dark gray or the like when observed by illuminating light from the observation direction (reflection observation). Further, when light is illuminated and observed from a direction opposite to the observation direction (transmission observation), the transmitted light can be observed. On the other hand, when the print area is reflected and observed, the printed color can be perceived. However, since general ink has low transmittance, it is difficult to observe transmitted light even if it is observed through transmission. Further, by forming a print region having a fine periodicity, different images can be displayed for transmission observation and reflection observation.

  According to the image display body of claim 2 of the present invention, the ratio of the concavo-convex structure portion to the area of the light transmission layer when observed from the surface of the light transmission layer opposite to the metal thin film layer is 40. % To 60%. By setting the ratio in this way, it is possible to maintain the resolution of both the transmission observation and reflection observation display images.

  According to the image display body according to claim 3 of the present invention, it is difficult to observe the shape of each part during transmission observation and reflection observation when the period of the printed layer is set to 3 μm or more and 145 μm or less with the naked eye. is there.

  According to the image display body of the fourth aspect of the present invention, since the transmittance of the print layer is low, it is easy to observe the transmitted light in the region having the light transmitting function at the time of transmission observation.

  According to the image display body of claim 5 of the present invention, since the average center distance between the convex portions or the concave portions is different in each concavo-convex structure portion, different colors can be observed when the transmission observation is performed.

  According to the image display body according to claim 6 of the present invention, it is possible to change the display image in the transmission observation and the reflection observation by displaying different patterns, characters, and symbols in both the uneven structure portion and the printed layer. . Therefore, the eye catching effect (eye-catching effect) can be enhanced, and the design of the image display body can be enhanced.

  According to the image display body of claim 7 of the present invention, the film thickness on the flat surface of the metal thin film layer is 30 nm or more and 100 nm or less. By molding the metal thin film layer under these conditions, it is possible to achieve both a light-transmitting function and low reflectivity due to the concavo-convex structure.

  According to the article according to claim 8 of the present invention, a conventional article is obtained by pasting or combining the image display body according to any one of claims 1 to 7 with a printed matter, a card, or other articles. It is possible to provide a high anti-counterfeiting effect.

The schematic diagram which shows typically the composition of the image display object concerning the embodiment of the present invention, and the enlarged view of portion A. FIG. 2 is a longitudinal side view taken along line II in FIG. 1. The longitudinal side view along the II line of Drawing 1 concerning a modification. The longitudinal side view along the II line of Drawing 1 concerning a modification. The schematic diagram which shows the printing pattern of a printing layer. The perspective view which shows an example of the form employable as the convex part of the uneven structure part in FIG. The top view which shows the convex part in FIG. The figure explaining the behavior of the light which permeate | transmits an uneven | corrugated structure part. The schematic diagram which shows an example of the image obtained when light injects into an image display body from the observer side, and observes the reflected light. The schematic diagram which shows an example of the image obtained when light injects into an image display body from the observer side, and observes the diffracted light. The schematic diagram which shows an example of the image obtained when light injects into the image display body from the opposite side to an observer side, and the transmitted light is observed.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view showing a configuration of an image display body according to an embodiment of the present invention and an enlarged view of a portion A, and FIG. 2 is a longitudinal side view taken along line II in FIG. The image display body 10 is composed of a laminate of a light transmissive layer 11 including a light transmissive substrate 100 and a concavo-convex structure forming layer 101, a printed layer 103, and a metal thin film layer 102. In the example shown in FIG. 2, the printed layer 103 side is the front side (observer side), and the metal thin film layer 102 side is the back side.

  In the example shown in FIG. 2, the print layer 103 is formed on the light transmission layer 11. However, as shown in FIG. 3, the print layer 103 is formed between the light transmission layer 11 and the metal thin film layer 102. Moreover, as shown in FIG. 4, you may form between the transparent base material 100 and the uneven structure formation layer 101. FIG.

  The light transmissive substrate 100 is formed of a film or sheet that can be handled by itself. As a material of the light transmissive substrate 100, for example, polyethylene terephthalate (PET), polycarbonate (PC), or the like can be used.

  The concavo-convex structure forming layer 101 is a layer formed on the light-transmitting substrate 100, and the concavo-convex structure portion is formed on the surface of the concavo-convex structure forming layer 101. This uneven structure portion will be described later in detail. As a method for forming the concavo-convex structure portion in the concavo-convex structure forming layer 101, for example, a resin is applied on the light transmissive substrate 100 to form the concavo-convex structure forming layer 101, and a stamper is applied to the concavo-convex structure forming layer 101. A method of curing the resin while pressing can be used. As the resin applied on the light transmissive substrate 100, a thermoplastic resin, a thermosetting resin, a light curable resin, or the like having a light transmitting property can be used.

  The material of the metal thin film layer 102 is not particularly limited, but it is preferable to use a metal material such as aluminum that exhibits a high reflectance with respect to visible light. The metal thin film layer 102 is preferably about 30 to 100 nm in view of optical characteristics. As a method of laminating the reflective layer, a thin film can be formed with high accuracy by following the relief structure by a vapor deposition method such as a vacuum deposition method and a sputtering method.

  The printed layer 103 displays images such as characters, pictures, symbols, and the like, and has a characteristic that the visible light transmittance is 10% or less and the visible light is hardly transmitted. If the transmittance exceeds 10%, the transmitted light of the printing layer 103 and the transmitted light of the concavo-convex structure are mixed during transmission observation, and thus the transmittance needs to be lowered. As a method for determining the transmittance, a monochromatic laser beam is incident on the printing layer 103, the transmitted light is measured with a light intensity measuring device, and the ratio is calculated from the ratio of the incident light and the transmitted light.

  Further, as shown in FIG. 5, the print layer 103 is, for example, a stripe shape (FIG. 5A) or a halftone dot shape (FIG. 5B), that is, periodically printed on the XY plane. The color to be printed is preferably high in luminance. The pitch of the period is 3 μm to 145 μm. When the observer observes the state of the image display body 10 at a position 500 mm away from his / her own eye, the resolution of a human eye with a visual acuity of 1.0 is generally 1 minute, and thus the limit of eye resolution is limited. Therefore, a structure of 145 μm or less cannot be decomposed.

  Therefore, when the pitch of the period is 145 μm or less, the adjacently arranged halftone dots cannot be decomposed. Therefore, by setting the pitch of the period to 145 μm or less, it is possible to provide the image display body 10 that displays a higher quality image. When the thickness is 3 μm or less, it is difficult to form the printing layer 103 with sufficiently high accuracy.

  Various inks such as offset ink, letterpress ink, and gravure ink are used depending on the printing method of the printing layer 103. Inks used for printing can be classified by composition such as resin-type ink, oil-based ink, water-based ink, and classification by drying method, such as oxidation polymerization ink, penetrating drying ink, evaporation drying ink, and ultraviolet curable ink. And can be appropriately selected according to the type of substrate and the printing method.

  In addition, toner made by attaching colored particles such as graphite and pigment to plastic particles with charging properties can be transferred to a substrate such as polyethylene terephthalate (PET) film or paper using static electricity, and then heated and fixed. A technique for forming a printed layer is also common.

  The image display body 10 can further include other layers such as an adhesive layer and an adhesive layer. In this case, it is desirable to form the adhesive layer and the adhesive layer so as to cover the metal thin film layer 102. Further, the adhesive layer and the pressure-sensitive adhesive layer are light transmissive. When the image display body 10 includes both the light transmissive layer 11 and the metal thin film layer 102, the shape of the surface of the metal thin film layer 102 is generally almost the same as the shape of the interface between the light transmissive layer 11 and the metal thin film layer 102. Therefore, when the adhesive layer or the adhesive layer is provided as described above, it is possible to prevent the surface of the metal thin film layer 102 from being exposed. Therefore, it is possible to make it difficult to copy the uneven structure for the purpose of counterfeiting.

  Next, the concavo-convex structure portions 20 and 22 formed in the concavo-convex structure forming layer 101 will be described.

  The concavo-convex structure portions 20 and 22 each have a plurality of convex portions protruding from the metal thin film layer 102 toward the concavo-convex structure forming layer 101 or a plurality of concave portions recessed from the concavo-convex structure forming layer 101 toward the metal thin film layer 102. They are arranged periodically with an average center-to-center distance of ˜500 nm. Moreover, the height of a convex part or the depth of a recessed part is 300 nm-500 nm. In the future, for the sake of simplicity of explanation, the explanation will be made with a focus on the convex portion, but the convex portion may be replaced with a concave portion.

  6 and 7 are a perspective view and a plan view in which the convex portions 200 are periodically arranged in parallel with the X axis and the Y axis at an average center distance D1 less than the wavelength of visible light. The above shows an example in which typical convex portions 200 are arranged, and they may be arranged in parallel with a straight line where the X axis and the Y axis intersect at an angle of 45 degrees.

  The convex portions 200 and 201 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 convex portions 200 and 201 may be composed of only inclined surfaces or may be stepped. The tapered shape of the convex portions 200 and 201 is useful for reducing the reflectance of light incident on the concavo-convex structure portions 20 and 22, as will be described later.

  In the case where the convex portions 200 and 201 are formed using a stamper, the tapered shape facilitates removal of the cured concavo-convex structure forming layer 101 from the stamper and contributes to improvement in productivity.

  As described above, the convex portions 200 and 201 have a tapered shape. When such a structure is employed, if the average center-to-center distance D1 is sufficiently short, the concavo-convex structure portions 20 and 22 can be regarded as having a refractive index that continuously changes in the Z direction.

  Therefore, the portions corresponding to the concavo-convex structure portions 20 and 22 in the image display body 10 display, for example, black or dark gray when reflected and observed from the normal direction. Here, the reflection observation generally refers to a case in which light is irradiated on the surface of the image display body 10 from a light source disposed above and the state of the surface of the image display body 10 is observed by reflected light from the surface of the image display body 10. I mean.

  Here, “black” means that the wavelength corresponding to 400 nm is obtained when the portion of the image display body 10 corresponding to the concavo-convex structure portions 20 and 22 is irradiated with light from the normal direction and the intensity of specular reflection light is measured. It means that the reflectance is 10% or less for all light components in the range of ˜700 nm, and “dark gray” is normal to the portion corresponding to the concavo-convex structure portions 20 and 22 in the image display body 10. When irradiating light from the direction and measuring the intensity of specularly reflected light, the reflectivity is about 25% or less for all light components whose wavelength is in the range of 400 nm to 700 nm, which is the wavelength of visible light. means.

  As described above, the concavo-convex structure portions 20 and 22 display black or dark gray when reflected from the front. Therefore, portions of the image display body 10 corresponding to the concavo-convex structure portions 20 and 22 appear, for example, as a black or dark gray print layer when reflected from the front.

  The average center distance D1 of the convex portions 200 and 201 is 200 nm to 500 nm. In general, as the average center distance D1 between the convex portions 200 and 201 decreases, the lightness and saturation decrease, enabling a blacker display, and the luminance increases as the average center distance D1 increases. The structure rises and is perceived as dark gray.

  Further, the higher the height of the convex portions 200 and 201, the more black display is possible. As the height decreases, the luminance increases and the image is perceived as dark gray. Typically, it is desirable that the heights of the convex portions 200 and 201 be 1/2 or more of the average center distance D1. Specifically, when the average center-to-center distance D1 is 500 nm, dark gray can be displayed by setting the height of the protrusions 200 and 201 to 250 nm or more, and is larger than the average center-to-center distance D1. A black display is possible by setting the height to 500 nm or more.

  However, if the average center-to-center distance D1 is shortened or the height of the convex part is high, it becomes difficult to form the convex part, so the average center-to-center distance D1 is 200 nm or more and the height is 500 nm or less. . Further, when the average center-to-center distance D1 is increased or the height of the convex portion is reduced, it becomes difficult to display black or dark gray. Therefore, the average center-to-center distance D1 is 500 nm or less and the height of the convex portion is 300 nm. That's it.

As shown in FIG. 4, when the convex portions 200 and 201 are periodically arranged, it also functions as a diffraction grating. Typical diffracted light is first-order diffracted light, and the emission angle β of the first-order diffracted light can be calculated from the following equation 1.

  In the above formula 1, d represents the distance between the concave or convex portions (average center distance), λ represents the wavelengths of incident light and diffracted light, and α represents the incident angle.

  As is clear from the above equation 1, the emission angle β of the first-order diffracted light changes according to the wavelength λ. That is, the concavo-convex structure portion composed of the convex portions (or concave portions) has a function as a spectroscope. Therefore, when the observation angle when observing the concavo-convex structure portion including the convex portion is changed when the illumination light is white light, the color perceived by the observer changes.

  However, when the average center-to-center distance D1 is set to less than 200 nm from the above formula 1, the function of emitting the first-order diffracted light cannot be obtained. Therefore, when it is desired to add the diffracted light function, it is necessary to arrange the convex portions 200 and 201 periodically and to set the average center distance D1 to 200 nm or more.

Next, the behavior of light transmitted through the concavo-convex structure portions 20 and 22 in which the plurality of convex portions 200 and 201 are formed will be described.
The concavo-convex structure portions 20 and 22 have an action similar to that of an interference filter formed by the optical thin film 30 shown in FIG. 8, and can reinforce or weaken light of a specific wavelength by repeating reflection and interference. A part of the incident light 304 incident on the optical thin film 30 at an angle θ is reflected by the surface of each layer and becomes reflected light 305 and is reflected to the side where the white light source 302 is present. There is also light traveling on the opposite side of 302.

The wavefront of the light that passes through the optical thin film 30 is a superposition of the wavefront of the light that passes through the optical thin film 30 after being repeatedly reflected an even number of times. When there is no phase difference between the wavefronts, the maximum transmitted light is obtained, and the difference in optical distance at that time is an integral multiple of the wavelength, and the following equation 2 is established.
mλ = 2 × TO × cos θ (Formula 2)
Here, m is the order and TO is the optical distance. TO takes into account the refractive index of the medium through which light propagates in addition to the physical distance. If the thickness of the optical thin film 30 is D and the refractive index is n,
TO = nD
Holds.

  At this time, since interference canceling out at each wavefront occurs at other wavelengths, the light hardly transmits to the surface opposite to the white light source 302. This means that by controlling the optical distance of the thin film, it is possible to control the wavelength of light transmitted to the surface opposite to the light source.

  By changing the average center-to-center distance D1 of the protrusions 200 and 201 provided in the uneven structure portions 20 and 22, the optical distance to the incident light of the light transmission layer 11 and the metal thin film layer 102 can be changed. Like the optical thin film 30, the structural units 20 and 22 can emit light having a specific wavelength with respect to incident light from a specific angle as transmitted light on a surface opposite to the light source. That is, by changing the average center-to-center distance D1 of the convex portion 200 provided in the concavo-convex structure portion 20, with respect to the incident light 304 from the white light source 302, a specific wavelength such as red, green, blue, or the like with respect to a fixed point. Can be emitted as transmitted light.

  Next, the place where the concavo-convex structure portions 20 and 21 are formed will be described. Here, a case where the printing unit 21 is printed in stripes will be described. The concavo-convex structure portions 20 and 22 are formed in all portions where the printing portion 21 is not provided, and the concavo-convex structure portions 20 and 22 are formed so as to form one pattern. Also in the printing unit 21, the printing unit 21 forms a pattern different from the concavo-convex structure units 20 and 22.

Next, the visual effect by the image display body 10 shown in FIG. 1 will be described.
FIG. 9 shows an example in which the front surface of the image display body 10 is observed with reflected light from the image display body 10 (reflection observation), and FIG. 10 shows the diffraction of the front surface of the image display body 10 from the image display body 10. An example in the case of observation with light is shown, and FIG. 11 shows an example in the case of observing the front of the image display body 10 with transmitted light from the image display body 10 (transmission observation).

As shown in FIG. 9, for example, light from a white light source 302 such as the sun or a fluorescent lamp above the observer 303 enters the image display body 10, and the observer 303 reflects from the surface of the image display body 10. Under observation conditions in which the light 305 is observed, the concavo-convex structure portions 20 and 22 of the image display body 10 are reflected light 305 by an antireflection / suppression effect by the plurality of convex portions 200 and 201 formed therein. Is observed in black or dark gray.
Further, the light incident on the printing unit 21 is reflected and the printed color is observed.

  In general, the human eye has a property that attention is paid to the brighter side and attention is not given to the darker side (hard to see). That is, when observing the reflected light, the human eyes are careful of the high-luminance printing unit 21, so that the black color of the concavo-convex structure portions 20 and 22 having low luminance is difficult to observe. Therefore, the color of the printing unit 21 is mainly observed.

  As shown in FIG. 10, when the image display body 10 is viewed by reflection observation with the light emitted from the image display body 10, the incident light 304 is incident on the image display body 10 at an angle satisfying the condition of the expression (1). In this way, by observing the image display body 10 from the angle at which the diffracted light is emitted, the diffracted light 307 by the concavo-convex structure portions 20 and 22 can be observed.

  As shown in FIG. 11, for example, when the image display body 10 is observed in such a positional relationship that the white light source 302 such as the sun or a fluorescent lamp is on the back side of the image display body 10 with respect to the observer 303, the white light source 302 The emitted incident light 304 to the image display body 10 enters from the back surface of the image display body 10 and reaches the observer 303 as light 306 transmitted through the concavo-convex structure portions 20 and 22.

  At this time, the wavelength of the light 306 transmitted through the concavo-convex structure portions 20 and 22 is determined according to the average center distance D1 between the plurality of convex portions 200 and 201 formed inside the concavo-convex structure portions 20 and 22. Therefore, the image display body 10 can display unique hues such as blue, red, and green by the light 306 transmitted through the concavo-convex structure portions 20 and 22. In the transmission observation, since the concavo-convex structure portions 20 and 22 are bright and the printing portion 21 is dark, only the concavo-convex structure portions 20 and 22 are observed. Moreover, since the uneven | corrugated structure parts 20 and 22 differ in the average center distance D1, it is possible to display a different hue.

  The plurality of convex portions 200 and 201 constituting the concavo-convex structure portions 20 and 22 have an average center-to-center distance D1 of 200 nm to 500 nm and a height of 300 nm to 500 nm. When the concavo-convex structure portions 20 and 22 are configured by such convex portions 200 and 201, as shown in FIG. 9, when the image display body 10 is observed by reflection, it looks black or dark gray. And under specific conditions like FIG. 10, the uneven structure part 20 inject | emits a diffracted light. Furthermore, as shown in FIG. 11, when the image display body 10 is observed through transmission, it is possible to display a unique hue by transmitted light.

Such a structure that realizes a characteristic perceptual effect completely different between reflection observation and transmission observation cannot be realized with other structures, and exhibits a high anti-counterfeit effect.
In addition, it is possible to change the pattern in reflection observation and transmission observation using the characteristic that human eyes generally pay attention to the brighter side and not to the darker side (not visible), High anti-counterfeit effect.

  DESCRIPTION OF SYMBOLS 10 ... Image display body, 11 ... Light transmission layer, 20 ... Uneven structure part, 21 ... Printing part, 22 ... Uneven structure part, 30 ... Optical thin film, 100 ... Light-transmitting base material, 101 ... Uneven structure forming layer, 102 DESCRIPTION OF SYMBOLS ... Metal thin film layer, 103 ... Printing layer, 200, 201 ... Convex part, 302 ... White light source, 303 ... Observer, 304 ... Incident light, 305 ... Reflected light, 306 ... Transmitted light, 307 ... Diffracted light.

Claims (8)

An image display body comprising a light-transmitting layer and a light-transmitting metal thin film layer, and a light-transmitting layer and a printing layer formed in the order of a concavo-convex structure forming layer, a light-transmitting substrate,
A plurality of protrusions formed on the concavo-convex structure forming layer and projecting from the metal thin film layer toward the concavo-convex structure forming layer at a height of 300 nm to 500 nm, or from the concavo-convex structure forming layer to the metal thin film layer A plurality of concavo-convex structure portions, each of which has a plurality of concave portions recessed at a depth of 300 nm or more and 500 nm or less, and wherein the convex portions or the concave portions are arranged in a lattice pattern with an average center distance of 200 nm or more and 500 nm or less. ,
The printed layer is on the side of the light transmissive layer opposite to the surface on which the concavo-convex structure forming layer is provided, between the concavo-convex structure forming layer and the metal thin film layer, or with the light transmissive substrate. An image display body characterized in that it is periodically formed on a surface in a horizontal direction with respect to the light transmission layer between any of the concavo-convex structure forming layers.   When observed from a direction perpendicular to the surface of the light transmission layer opposite to the metal thin film layer, the printed layer and the concavo-convex structure portion are adjacent to each other, and the printed layer is the concavo-convex structure portion. The image display body according to claim 1, wherein the image display body is 40% or more and 60% or less of the area.   The image display body according to claim 1, wherein a period of the print layer is 3 μm or more and 145 μm or less.   The image display body according to any one of claims 1 to 3, wherein a transmittance of the print layer at a visible light wavelength is 10% or less.   The image display body according to any one of claims 1 to 4, wherein an average center-to-center distance of the convex portion or the concave portion is different in each of the plurality of concave-convex structure portions.   Images of patterns, characters, symbols, etc. are displayed by the plurality of concave-convex structure portions having different average center distances of the convex portions or the concave portions, and images, characters, symbols, etc. different from the concave-convex structure portions by the printed layer The image display body according to claim 1, wherein an image is displayed.   The image display body according to any one of claims 1 to 6, wherein a layer thickness on a flat surface of the metal thin film layer is 30 nm or more and 100 nm or less.   An article comprising a light-transmitting substrate in which the image display body according to any one of claims 1 to 7 is supported via a light-transmitting adhesive layer.

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