JP2021177248A - Hologram structure - Google Patents

Abstract

To provide a hologram structure that has a high forgery prevention function and security function, and has an excellent design property.SOLUTION: The present invention relates to a hologram structure that has a reflection-type Fourier transform hologram region and a transmission-type Fourier transform hologram region, where the reflection-type Fourier transform hologram region is a region to transform reflected light into a first optical image, the reflected light being light made incident from a point source and reflected on a concavo-convex surface of a first hologram layer having the concavo-convex surface on its surface, and the transmission-type Fourier transform hologram region is a region to transform transmitted light into a second optical image, the transmitted light being light made incident from the point source and transmitted through a second hologram layer arranged in a pattern.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hologram structure having excellent anti-counterfeiting properties and design properties.

In recent years, hologram structures are often used for anti-counterfeiting applications because of their advantages such as relatively difficult duplication and beautiful appearance. There are various types of such hologram structures depending on a method of recording an original image as interference fringes, a principle of displaying an optical image by a hologram, and the like. For example, an embossed hologram, a volumetric hologram, an electronic hologram, a Fourier transform hologram which is a computer composite hologram, and the like can be mentioned.

By using such a hologram structure, it is possible to identify the authenticity and improve the anti-counterfeiting function and the security function. Attempts have also been made to impart designability by using the light image displayed by the hologram structure. For example, Patent Document 1 discloses an optical structure for authenticity proof having a plurality of micro-optical unit areas.

Japanese Patent No. 4872964

Conventionally, various hologram structures have been proposed, but further improvement of anti-counterfeiting function and security function and addition of superior designability are required. An object of the present invention is to provide a hologram structure having a high anti-counterfeiting function and a security function, and also having an excellent design property.

The present invention is a hologram structure having a reflection type Fourier conversion hologram region and a transmission type Fourier conversion hologram region. In the reflection type Fourier conversion hologram region, light incident from a point light source has an uneven surface on the surface. This is a region for converting the reflected light reflected by the uneven surface of the hologram layer into a first light image, and the transmission type Fourier transform hologram region is a second region in which light incident from a point light source is arranged in a pattern. Provided is a hologram structure characterized by being a region for converting transmitted light transmitted through a hologram layer into a second light image.

According to the present invention, since the hologram structure has the reflection type Fourier conversion hologram region, the light from the point light source can be reflected to display the first light image, and the transmission type Fourier conversion hologram region can be displayed. By having the light, the light from the point light source can be transmitted and the second light image can be displayed. Therefore, it is possible to obtain a hologram structure having excellent anti-counterfeiting property and design property, which can display a predetermined light image according to the irradiation direction of the point light source.

In the present invention, the second hologram layer is preferably arranged on the uneven surface side of the first hologram layer. The uneven surface of the first hologram layer has a function of reflecting light from a point light source to display a first light image. At this time, the second hologram layer is arranged on the uneven surface side of the first hologram layer. As a result, the light from the point light source is easily reflected due to the difference in refractive index between the first hologram layer and the second hologram layer. Therefore, it is possible to display a clearer first light image.

In the present invention, the reflective Fourier transform hologram region and the transmissive Fourier transform hologram region preferably have overlapping regions in a plan view. By having the reflective Fourier transform hologram region and the transmissive Fourier transform hologram region overlap in a plan view, the anti-counterfeiting property can be further improved.

In the present invention, it is preferable that the diffraction grating region further includes a diffraction grating region for displaying the diffraction pattern, and the diffraction grating region is located in a region that does not overlap with the reflection type Fourier transform hologram region in a plan view. By further having a diffraction grating region for displaying the diffraction pattern, it is possible to further improve the anti-counterfeiting property. In addition, a diffracted pattern can be displayed, and excellent design can be exhibited.

In the present invention, it is preferable that the first hologram layer has an adhesive layer on the uneven surface side and is used as a hologram seal. It is possible to impart a high anti-counterfeiting function, a security function, and an excellent design to the adherend to which the hologram sticker is attached.

In the present invention, the heat-sealing layer is provided on the concavo-convex surface side of the first hologram layer, and the easily peelable layer is provided on the surface opposite to the concavo-convex surface of the first hologram layer. It is preferable to have a peeling base material on the surface opposite to the first hologram layer and use it as a hologram transfer foil. It is possible to impart a high anti-counterfeiting function, a security function, and an excellent design property to the adherend to which the hologram transfer foil is attached.

In the present invention, it is preferably used as an information recording medium. The hologram structure of the present invention can be used as an information recording medium having a high anti-counterfeiting function and a security function and also having excellent design.

The present invention has the effect of being able to provide a hologram structure having excellent anti-counterfeiting properties and design properties.

It is a schematic cross-sectional view which shows an example of the hologram structure of this invention. It is explanatory drawing for demonstrating the hologram structure of this invention. It is explanatory drawing for demonstrating the hologram structure of this invention. It is explanatory drawing for demonstrating the hologram structure of this invention. It is a schematic plan view and a schematic sectional view which shows an example of the hologram structure of this invention. It is a schematic cross-sectional view which shows an example of the 1st hologram layer in this invention. It is explanatory drawing for demonstrating the hologram structure of this invention. It is a schematic cross-sectional view which shows another example of the hologram structure of this invention. It is a schematic cross-sectional view which shows an example of the 2nd hologram layer in this invention. It is explanatory drawing for demonstrating the hologram structure of this invention. It is explanatory drawing for demonstrating the 1st use embodiment of the hologram structure of this invention. It is explanatory drawing for demonstrating the 2nd use mode of the hologram structure of this invention. It is explanatory drawing for demonstrating the 3rd use mode of the hologram structure of this invention.

Hereinafter, the hologram structure of the present invention will be described.

The hologram structure of the present invention is a member having a reflective Fourier transform hologram region and a transmissive Fourier transform hologram region. In the reflective Fourier transform hologram region, light incident from a point light source has an uneven surface on the surface. It is a region for converting the reflected light reflected by the uneven surface of the first hologram layer having the first light image into a first light image, and in the transmission type Fourier conversion hologram region, the light incident from the point light source is arranged in a pattern. It is a member characterized in that it is a region for converting the transmitted light transmitted through the second hologram layer into a second light image.

Hereinafter, the hologram structure of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the description, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

FIG. 1 is a schematic cross-sectional view showing an example of the hologram structure of the present invention. As illustrated in FIG. 1, the hologram structure 100 of the present invention has a second hologram layer 1a having an uneven surface on the surface and a second hologram layer 1a arranged in a pattern on one surface side of the first hologram layer 1a. It has a hologram layer 1b. Further, the hologram structure 100 shown in FIG. 1 has an adhesive layer 2 arranged on a surface of the second hologram layer 1b opposite to the uneven surface of the first hologram layer 1a, and a second hologram layer 1b of the adhesive layer 2. This is an example of having a separator 3 arranged on the surface opposite to the above, and a transparent base material 4 arranged on the surface opposite to the uneven surface of the first hologram layer 1a.

The second hologram layer 1b is arranged in a pattern on the uneven surface side of the first hologram layer 1a. Therefore, in the region where the second hologram layer 1b is not provided between the first hologram layer 1a and the adhesive layer 2, the adhesive layer 2 is usually arranged so as to fill the uneven surface of the first hologram layer 1a.

2 (a) and 2 (b) and 3 (a) and 3 (b) are explanatory views for explaining the hologram structure of the present invention. As shown in FIG. 2A, by Fourier transforming the original image on which a predetermined pattern is drawn, a first hologram layer 1a having a reflective Fourier transform hologram region in which the Fourier transform image 10'is recorded is obtained. be able to. As shown in FIG. 2 (b), the reflective Fourier transform hologram region reflects the light L ₁₀ incident from the point light source on the uneven surface formed on the surface of the first hologram layer 1a, and is reflected in FIG. 2 (a). ) Can be converted into the first optical image 10. Further, as shown in FIG. 3A, a second hologram layer 1b having a transmission type Fourier transform hologram region in which a Fourier transform image 20'is recorded by Fourier transforming an original image on which a predetermined pattern is drawn is performed. Can be obtained. As shown in FIG. 3B, the transmissive Fourier transform hologram layer 1b _{shields the light L 20} incident from the point light source in a pattern by the second hologram layer 1b, and is as shown in FIG. 3A. It can be converted into a second light image 20. Note that the reference numerals not described in FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b) can be the same as those in FIGS. 1 (a) and 1 (b) described above. The description here is omitted.

According to the present invention, since the hologram structure has the reflection type Fourier conversion hologram region, the light from the point light source can be reflected to display the first light image, and the transmission type Fourier conversion hologram region can be displayed. By having the light, the light from the point light source can be transmitted and the second light image can be displayed. Therefore, when the point light source is irradiated from the side visually recognized by the observer, the light from the point light source is reflected by the reflective Fourier transform hologram region and enters the observer's eyes. Therefore, the observer can visually recognize the first optical image. On the other hand, when the point light source is irradiated from the side opposite to the side viewed by the observer, the light from the point light source passes through the transmission type Fourier transform hologram region and enters the observer's eyes. Therefore, the observer can visually recognize the second light image. As described above, the hologram structure of the present invention can display a predetermined light image according to the irradiation direction of the observer. Therefore, for example, it is difficult to visually recognize the first light image or the second light image without knowing that the first light image or the second light image is displayed, and for this reason, it is expensive. It can exhibit anti-counterfeiting properties and is suitable for authenticity determination. In addition, the hologram structure of the present invention can display a first light image and a second light image. Therefore, for example, by making the patterns displayed by the first light image and the second light image correspond to each other, for example, the patterns displayed by the first light image and the second light image have one meaning. , It is possible to exhibit higher anti-counterfeiting property, and it is possible to obtain a hologram structure suitable for authenticity determination.

Further, according to the present invention, since there are two types of hologram regions, a reflection type Fourier transform hologram region by the first hologram layer and a transmission type Fourier transform hologram region by the second hologram layer, one of the hologram regions is tentatively destroyed. Even if this is the case, authenticity can be determined by using the other hologram region.

Hereinafter, the hologram structure of the present invention will be described in detail.

1. 1. Configuration The hologram structure of the present invention has a reflective Fourier transform hologram region and a transmissive Fourier transform hologram region.

Hereinafter, the reflective Fourier transform hologram region and the transmissive Fourier transform hologram region in the hologram structure of the present invention will be described.

(1) Reflective Fourier Converted Hologram Region In the reflective Fourier transformed hologram region of the present invention, the light incident from a point light source reflects the reflected light reflected by the uneven surface of the first hologram layer having an uneven surface on the surface. This is the area to be converted into an optical image.

The reflective Fourier transform hologram region in the present invention diffracts the light incident from the point light source in a plurality of directions due to the uneven structure on the surface of the first hologram layer, and converts it into a desired first optical image based on the original image. be able to. That is, the reflective Fourier transform hologram region in the present invention functions as a Fourier transform lens. The above function may be described as a Fourier transform lens function.

The plan-view size of the reflective Fourier transform hologram region can be appropriately adjusted according to the use of the hologram structure of the present invention, and is not particularly limited. The specific plan-view size of the reflective Fourier transform hologram region is, for example, preferably in the range of 5 mm square or more and 50 mm square or less, particularly preferably in the range of 5 mm square or more and 30 mm square or less, and particularly 5 mm. It is preferably within the range of the angle or more and 15 mm square or less. When the plan view size of the reflective Fourier transform hologram region is the above lower limit, the first optical image converted by the reflective Fourier transform hologram region becomes easy to see. In addition, the anti-counterfeiting property can be improved by the reflective Fourier transform hologram region, and excellent designability can be obtained. On the other hand, when the plan view size of the reflective Fourier transform hologram region is the above upper limit, the hologram structure of the present invention can be manufactured at low cost. In addition, a print layer for displaying a predetermined image in combination with the first optical image converted by the reflective Fourier transform hologram region can be easily formed.

Here, the fact that the plane view size of the reflection type Fourier transform hologram region is 5 mm square or more means that the reflection type Fourier transform hologram region has a plan view shape including at least a square range of 5 mm square. Therefore, for example, when the reflective Fourier transform hologram region is rectangular, it means that the length of its short side is 5 mm or more, while when the reflective Fourier transform hologram region is square, it means that the length is 5 mm or more. It means that the length of one side is 5 mm or more.

Reflection Fourier transform hologram area in the present invention include, for example, as shown in FIG. 4 (a), may be an area where the first light image 20 by a single Fourier transform hologram area R ₁ is displayed, FIG. as shown in 4 (b), it may be an area where the first light image 20 is displayed by the Fourier transform hologram area R ₂ large format an enlarged Fourier transform hologram area R ₁ arrayed to. Incidentally, FIG. 4 (a), the first light image 20 shown in (b), for a single Fourier transform hologram area R ₁ or Fourier transform hologram area R ₂ of the large-sized, and reflects light from the point light source It shows the pattern that is expressed at the time. In the present invention, the reflective Fourier transform hologram region is preferably a large-format Fourier transform region. The first optical image converted by the reflective Fourier transform hologram region can be magnified, and the visibility can be further improved.

Reflection Fourier transform hologram area in the present invention, for example as described in FIG. 4 (a), when a single Fourier transform hologram area R ₁ is an area for displaying the first light image 20, of the single plan view size of the Fourier transform hologram area R ₁ is preferably a size that can be formed with high accuracy. Specifically, for example, it is preferably in the range of 0.25 mm square or more and 5 mm square or less. The plan view size of the single Fourier transform hologram region here refers to the size of the smallest square including the single Fourier transform hologram region. Therefore, for example, when the single Fourier transform hologram region is a square with a side of 1 mm, the plan view size is 1 mm square, and the plan view shape of the single Fourier transform hologram region is a circular shape with a diameter of 1 mm. In some cases, the plan view size is 1 mm square.

In the present invention, any shape of the single Fourier transform hologram region constituting the reflective Fourier transform hologram region can be appropriately selected depending on the use of the hologram structure of the present invention and the like. Specific plan-view shapes of a single Fourier transform hologram region include, for example, a rectangular shape such as a square or a rectangle, a polygonal shape such as a trapezoidal shape, a triangular shape, a pentagonal shape, or a hexagonal shape, a circular shape, an elliptical shape, or a star. Examples thereof include a mold shape and a heart shape, but from the viewpoint of easy formation, a rectangular shape is preferable.

In the present invention, as shown in FIG. 4 (a), when the reflection-type Fourier transform hologram area is a single Fourier transform hologram area R _1, the plan view shape of the reflection-type Fourier transform hologram area, It corresponds to the plan view shape of the single Fourier transform hologram region described above. On the other hand, as shown in FIG. 4 (b), when the reflection-type Fourier transform hologram area is a Fourier transform hologram area R ₂ large format that arranges a plurality single Fourier transform hologram area R _1, reflection Fourier transform hologram As the plan view shape of the region, any shape can be appropriately selected depending on the use of the hologram structure of the present invention and the like. Since the specific plan view shape of the reflective Fourier transform hologram region can be the same as the plan view shape of the single Fourier transform hologram region described above, the description here is omitted.

The reflection type Fourier transform hologram region in the present invention may be a region that overlaps with the transmission type Fourier transform hologram region described later in a plan view. In the present invention, the entire surface of the reflective Fourier transform hologram region may overlap with the transmission type Fourier transform hologram region described later in plan view, or a part of the reflection type Fourier transform hologram region may be a transmission type described later. It may overlap with the Fourier transform hologram region in plan view. In FIG. 5A, a part of the reflective Fourier transform hologram region in which the Fourier transform image 10'for displaying the first optical image is recorded is the Fourier transform image 20'for displaying the second optical image. It is a schematic plan view which shows the hologram structure 100 which overlapped in the plan view with the transmission type Fourier transform hologram region in which. 5 (b) is a cross-sectional view taken along the line AA of FIG. 5 (a), FIG. 5 (c) is a cross-sectional view taken along the line BB of FIG. 5 (a), and FIG. ) Is a cross-sectional view taken along the line CC of FIG. 5 (a). Here, FIG. 5B shows an example in which the adhesive layer 2 is arranged on the uneven surface side of the first hologram layer 1a, but for example, it covers the entire surface of the first hologram layer 1a on the uneven surface side. The second hologram layer 1b may be arranged on the surface. In this case, the second hologram layer 1b can function as a reflective layer for suitably reflecting light on the uneven surface of the first hologram layer 1a in the reflective Fourier transform hologram region. The reference numerals shown in FIGS. 5 (b) to 5 (d) can be the same as those in FIG. 1 described above, and thus the description thereof will be omitted here.

In the present invention, for example, as shown in FIG. 5A, the ratio of the reflective Fourier transform hologram region A in the hologram structure 100 in the plan view can display a desired first optical image. It suffices to have a certain ratio, and can be appropriately adjusted according to the use of the hologram structure and the like. For example, it is preferably 25% or more, and more preferably 50% or more. Further, as shown in FIG. 5A, when a part of the reflection type Fourier transform hologram region A has a region C that overlaps with the transmission type Fourier transform hologram region B described later in a plan view, the total reflection type Fourier transform is performed. When the hologram region A is 100%, the ratio of the region C in which the reflective Fourier transform hologram region A and the transmissive Fourier transform hologram region B overlap in a plan view is preferably 5% or more, among others. It is preferably 25% or more, and particularly preferably 50% or more. In the present invention, in the total reflection type Fourier transform hologram region, the ratio of the region where the reflection type Fourier transform hologram region and the transmission type Fourier transform hologram region overlap in a plan view is within the above-mentioned predetermined range. It is possible to further improve the anti-counterfeiting property of the structure. In the hologram structure, for example, the Fourier transform image 10'shown in FIG. 2A for displaying the first optical image and the Fourier transform image 20 shown in FIG. 3A for displaying the second optical image, for example. By overlapping with'in the plan view, the following effects are obtained. That is, for example, by making the patterns displayed by the first light image and the second light image correspond to each other, for example, the patterns displayed by the first light image and the second light image have one meaning. , It is possible to exhibit higher anti-counterfeiting property, and it is possible to obtain a hologram structure suitable for authenticity determination.

(A) First Hologram Layer In the reflective Fourier transformed hologram region of the present invention, the light incident from a point light source reflects the light reflected by the uneven surface of the first hologram layer having an uneven surface on the surface into a first optical image. Can be converted. That is, the reflective Fourier transform hologram region has a first hologram layer.

The first hologram layer in the present invention may be formed at least in the reflective Fourier transform hologram region, but is usually FIG. 5 (b) and FIG. 5 which are cross-sectional views taken along the line AA of FIG. 5 (a). As shown in FIG. 5 (c) which is a cross-sectional view taken along the line BB of (a) and FIG. 5 (d) which is a cross-sectional view taken along the line CC of FIG. 5 (a), only the reflection type Fourier transform hologram region is used. Instead, the first hologram layer 1a is continuously formed in the transmission type Fourier transform hologram region described later. Here, "continuously formed" means that it is sufficient that the first hologram layer is formed without interruption, and a single first hologram layer may be arranged integrally, and a plurality of first hologram layers may be arranged integrally. May be arranged in parallel. In the present invention, the former is preferable from the viewpoint of manufacturing.

As described above, the first hologram layer in the present invention is not a member formed only in the reflective Fourier transform hologram region, but whether or not it is the reflective Fourier transform hologram region in the region having the first hologram layer is determined. , It can be confirmed by whether or not the surface of the first hologram layer is an uneven surface. That is, in the present invention, the region having the uneven surface in the first hologram layer corresponds to the reflective Fourier transform hologram region.

In the reflective Fourier transform hologram region, the concave-convex structure forming the concave-convex surface formed on the surface of the first hologram layer is a Fourier transform image that is multi-valued based on the data of the original image displayed as the first optical image. Is. Such a concavo-convex structure is usually composed of a large number of curved or linear convex or concave portions extending in parallel in a specific direction, as shown in FIG. 2 (a).

Examples of the method of forming a concavo-convex structure on the surface of the first hologram layer in the present invention to obtain a reflective Fourier transform hologram region include the following methods. That is, a master original plate having a concavo-convex structure corresponding to the Fourier transform image is formed. Next, a method of applying a resin material such as an ultraviolet curable resin on a base material such as polyethylene terephthalate to form a coating film, and then transferring the unevenness pattern of the master original plate to the coating film. Can be mentioned. When the uneven pattern of the master original plate is transferred only once, a single Fourier transform hologram region can be obtained. On the other hand, when the uneven pattern of the master original plate is transferred a plurality of times, a large-sized Fourier transform hologram region having a desired size in which a single Fourier transform hologram region is arranged can be obtained.

Further, as a method for forming the master original plate described above, for example, the following method can be mentioned. That is, a Fourier transform image is formed by calculation based on the image data of the original image. Next, the data obtained by multiplying the data of the Fourier transform image into two or more values is converted into electron beam drawing data, and the electron beam drawing data is arranged within a desired range. Specifically, a predetermined number of electron beam drawing data are arranged in the vertical and horizontal directions, respectively. Next, a method of creating a master original plate using an electron beam drawing apparatus based on the arranged electron beam drawing data can be mentioned.

In the present invention, for example, when a master original plate is created by converting the binarized data of the Fourier transform image data into electron beam drawing data, the uneven structure obtained by using the master original plate is shown in FIG. As shown in a), it has a two-stage uneven shape. On the other hand, when the master original plate is created by converting the quaternized data of the Fourier transform image into the electron beam drawing data, the uneven structure obtained by using the master original plate is as shown in FIG. 6 (b). It has a four-step uneven shape. Even when it is quaternized, it may partially have a one-step or two-step uneven shape. In the present invention, when the data of the Fourier transform image is multivalued, it is preferably quaternized or more. In other words, it is preferable that the uneven structure on the surface of the first hologram layer has four or more steps. This is because it is possible to display a first light image having a more complicated pattern. The reference numerals not described in FIGS. 6A and 6B can be the same as those in FIG. 1 described above, and thus the description thereof will be omitted here.

In the present invention, when the uneven structure on the surface of the first hologram layer is four or more steps, the first optical image observed by the light reflected by the uneven surface of the first hologram layer is one image. On the other hand, when the uneven structure on the surface of the first hologram layer has two stages, the first optical image observed by the light reflected by the uneven surface of the first hologram layer has a mirror image relationship centered on the 0th order light2. It becomes one image.

The lattice pitch of the concavo-convex structure formed on the surface of the first hologram layer is preferably such that the light incident from the point light source can be converted into a desired first light image. The lattice pitch of the specific uneven structure is preferably in the range of 1.0 μm or more and 80.0 μm or less, for example. The grid pitch of the uneven structure means, for example, the distance indicated by the reference numeral P in FIGS. 6 (a) and 6 (b).

Here, as shown in FIG. 7, the reflection type Fourier transform region in which the Fourier transform image 10'is recorded in the hologram structure 100 is irradiated with light from a point light source arranged at the _{height T 1, and the height is increased.} when the observer observes the reflection type Fourier transform hologram area from the T _2, for the viewer to observe the entire image of the first optical image in the entire area of the Fourier transform hologram regions, the grating pitch, the following equation It is preferable to design based on (1).
P = nλ / (sinθ1 + sinθ2) (1)
In the above equation (1), λ is the wavelength of the diffracted light, P is the lattice pitch of the concavo-convex structure, θ1 is the incident angle when the light reaches the end of the reflective Fourier transformed hologram region from the point light source, and θ2 is The diffraction angle for the diffracted light to reach the observer from the end of the reflective Fourier transformed hologram region, n is the order of diffraction.

A specific calculation example of the above-mentioned lattice pitch will be described. When the reflective Fourier transform hologram region has a square shape with a side of 15 mm, T ₁ is 50 mm, T ₂ is 300 mm, and the wavelength of the diffracted light is 550 nm, sin θ2 is 0.025 and sin θ1 is 0. It is calculated as 148. Then, the lattice pitch P required for the observer to observe the entire image of the first optical image in the entire region of the reflective Fourier transform hologram region can be calculated to be 3179 nm at the shortest. Further, when the reflective Fourier transform hologram region has a square shape with a side of 15 mm, T ₁ is 1990 _{mm, T 2} is 2000 mm, and the wavelength of the diffracted light is 550 nm, sin θ2 is 0.00374 and sin θ1 is 0.00374. It is calculated as 0.00377.
Then, the lattice pitch P required for the observer to observe the entire image of the first optical image in the entire region of the reflective Fourier transform hologram region can be calculated to be 73236 nm at the shortest.
Further, when the reflective Fourier transform hologram region has a square shape with a side of 10 mm, T1 is 60 mm, T2 is 60 mm, and the wavelength of the diffracted light is 550 nm, sinθ2 is 0.083 and sinθ1 is 0. It is calculated as 083. Then, the lattice pitch P required for the observer to observe the entire image of the first optical image in the entire region of the reflective Fourier transform hologram region can be calculated to be 3313 nm at the shortest.

The height difference of the uneven structure on the surface of the first hologram layer is not particularly limited as long as it can convert the incident light into a desired first light image. The height difference of the specific uneven structure can be, for example, in the range of 0.01 μm or more and 1.5 μm or less, and more preferably in the range of 0.05 μm or more and 1.0 μm or less. When the height difference of the uneven structure is within the above range, it is possible to stably convert the incident light into a desired first light image. The height difference of the concave-convex structure here refers to the distance from the surface of the highest convex portion to the surface of the deepest concave portion in the concave-convex structure, and is indicated by reference numeral D in FIGS. 6 (a) and 6 (b), for example. Let it be a distance.

The first hologram layer in the present invention is preferably made of a material capable of forming a concavo-convex structure on the surface as a reflective Fourier transform hologram region and exhibiting a desired Fourier transform lens function. Further, the first hologram layer in the present invention is preferably made of a material exhibiting a predetermined refractive index. The refractive index of the first hologram layer is not particularly limited because it can be appropriately selected depending on the use of the hologram structure of the present invention and the like. Further, the wavelength that serves as a reference for the refractive index of the first hologram layer can be appropriately selected from the range of, for example, 400 nm or more and 750 nm or less, and is not particularly limited. In the present invention, the refractive index at a wavelength of 555 nm is preferably in the range of 1.3 or more and 2.0 or less, and particularly preferably in the range of 1.33 or more and 1.8 or less. The refractive index of the first hologram layer can be measured using, for example, a spectroscopic ellipsometer.

Examples of the material of the first hologram layer in the present invention include a resin material used for forming a general relief type hologram. Specific examples of the resin material include thermosetting resins, thermoplastic resins, ultraviolet curable resins, ionizing and radiation curable resins, and the like.

The first hologram layer in the present invention may contain other materials in addition to the above-mentioned materials, if necessary. Other materials include, for example, photopolymerization initiators, polymerization inhibitors, deterioration inhibitors, plasticizers, lubricants, colorants such as dyes and pigments, extender pigments for increasing the amount and preventing blocking, fillers such as resins, and surfactants. Examples thereof include additives such as activators, antifoaming agents, leveling agents, and thixotropic property-imparting agents.

The thickness of the first hologram layer in the present invention is preferably such that the first hologram layer has self-supporting property. The specific thickness is, for example, preferably in the range of 0.05 mm or more and 5 mm or less, and particularly preferably in the range of 0.1 mm or more and 3 mm or less. On the other hand, when the first hologram layer does not have self-supporting property and is formed on a transparent substrate described later, the thickness of the first hologram layer may be, for example, in the range of 0.1 μm or more and 50 μm or less. It is preferable, and above all, it is preferably in the range of 0.5 μm or more and 20 μm or less. Here, the thickness of the first hologram layer means, for example, the distance _{indicated by the reference numerals D 1a shown in FIGS. 5 (b) to 5 (d).}

(B) First light image The reflective Fourier transform hologram region in the present invention reflects the light incident from a point light source on the uneven surface formed on the surface of the first hologram layer and converts it into a first light image. The area.

The pattern of the first light image displayed by the reflective Fourier transform hologram region in the present invention can be, for example, a pattern, a line drawing, a character, a figure, a symbol, or the like, and is appropriately selected according to the application of the hologram structure. be able to. In the present invention, the first light image displayed by the reflection type Fourier transform hologram region may have the same pattern as the second light image displayed by the transmission type Fourier transform hologram area described later, and may have different patterns. It may be.

In the present invention, for example, as shown in FIG. 2B, when a point light source is irradiated from the transparent base material 4 side of the hologram structure 100, the light L ₁₀ is reflected on the uneven surface of the first hologram layer 1a.
As a result, the observer on the transparent substrate 4 side can visually recognize the first optical image which is the star-shaped pattern shown by reference numeral 10 in FIG. 2 (a). Although not shown, for example, even when the point light source is irradiated from the separator 3 side in FIG. 2B, the light from the point light source is the second hologram layer on the uneven surface of the first hologram layer 1a. It reflects in the area not covered by 1b. Therefore, the observer can visually recognize the first optical image to some extent from the separator 3 side, although it depends on the difference in refractive index between the first hologram layer 1a and the member in contact with the surface of the first hologram layer 1a. It will be possible. In the present invention, from the viewpoint of displaying the first light image more clearly, as shown in FIG. 2B, a point light source is irradiated from the transparent base material 4 side, and the observer is observed from the transparent base material 4 side. It is preferable that the first light image 10 is visually recognized. The light emitted from the point light source can be sufficiently reflected by the uneven surface formed on the surface of the first hologram layer in the reflective Fourier transform hologram region. Therefore, the light emitted from the point light source can be sufficiently contributed to the display of the first light image.

Further, for example, as shown in FIG. 8B, when the second hologram layer 1b, which will be described later, is arranged on the surface opposite to the uneven surface of the first hologram layer 1a, it is usually the first. The high refractive index layer 14 is formed at the interface between the hologram layer 1a and the adhesive layer 2. In the case of such a hologram structure, it is preferable that the first optical image is irradiated with a point light source from the separator 3 side and visually recognized by the observer from the separator 3 side. This is because the light from the point light source can be reflected by the difference in refractive index between the first hologram layer 1a and the high refractive index layer 14. In the case of the configuration shown in FIG. 8B, even when the point light source is irradiated from the transparent substrate 4 side, the light from the point light source forms the second hologram layer 1b. It is incident on the uneven surface of the first hologram layer 1a from the open region and is reflected. Therefore, although it depends on the size of the opening region in which the second hologram layer 1b is not formed, the observer can visually recognize the first optical image to some extent from the transparent substrate 4 side. In the present invention, from the viewpoint of displaying the first light image more clearly, it is preferable that the point light source is irradiated from the separator 3 side as described above and the observer visually recognizes the first light image from the separator 3 side. When a point light source is irradiated from the transparent substrate 4 side, light is incident on the first hologram layer 1a from the opening region where the second hologram layer 1b is not formed, so that it depends on the size of the opening region. Therefore, the amount of light incident on the first hologram layer 1a may be limited. A detailed description of FIG. 8B will be described in the section “(2) Transmissive Fourier transform hologram region” described later, and thus the description thereof will be omitted here.

(C) Others In the present invention, examples of the point light source that irradiates the reflective Fourier transform hologram region with light include a laser light source. The wavelength of the point light source is not particularly limited, and it is preferable that the reflective Fourier transform hologram region can satisfactorily exhibit the Fourier transform lens function. In the present invention, the wavelength of the point light source may be monochromatic light having one wavelength, light including multiple wavelengths, or white light.

(2) Transmission-type Fourier transform hologram region The transmission-type Fourier transform hologram region in the present invention blocks light incident from a point light source in a pattern by a second hologram layer arranged on one surface side of the first hologram layer. It is a region to be converted into a second optical image.

The transmitted Fourier transform hologram region in the present invention is a region in which light incident from a point light source converts transmitted light transmitted through a second hologram layer arranged in a pattern into a second light image. That is, the transmission type Fourier transform hologram region in the present invention functions as a Fourier transform lens. The above function may be described as a Fourier transform lens function.

The transmission type Fourier transform hologram region in the present invention is, for example, as shown in FIG. 3A, a region in which the Fourier transform image 20'in which the second hologram layer is formed in a pattern is recorded. The transmission type Fourier transform hologram region in the present invention may be a region in which the second optical image is displayed by a single Fourier transform hologram region, similarly to the above-mentioned reflection type Fourier transform hologram region, and a single Fourier. It may be a region in which a second optical image is displayed by a large-format Fourier transform hologram region in which a plurality of transform hologram regions are arranged and enlarged.

The specific description of the plane view size, plan view shape, etc. of the transmission type Fourier transform hologram region may be the same as that described in the above-mentioned "(1) Reflection type Fourier transform hologram region". Since it can be done, the description here is omitted.

The transmission type Fourier transform hologram region in the present invention may be a region that overlaps with the above-mentioned reflection type Fourier transform hologram region in a plan view. In the present invention, the entire surface of the transmissive Fourier transform hologram region may overlap with the above-mentioned reflective Fourier transform hologram region in a plan view, or a part of the transmissive Fourier transform hologram region may overlap with the above-mentioned reflective type Fourier transform hologram region. It may overlap with the Fourier transform hologram region in plan view. In FIG. 5A, a part of the transmission type Fourier transform hologram region in which the Fourier transform image 20'for displaying the second optical image is recorded is the Fourier transform image 10'for displaying the first optical image. It is a schematic plan view which shows the hologram structure 100 which overlapped in the plan view with the reflection type Fourier transform hologram region in which.

In the present invention, for example, as shown in FIG. 5A, the ratio of the transmission type Fourier transform hologram region B in the hologram structure 100 in the plan view can display a desired second optical image. It suffices to have a certain ratio, and can be appropriately adjusted according to the use of the hologram structure and the like. For example, it is preferably 25% or more, and more preferably 50% or more. Further, as shown in FIG. 5A, when a part of the transmission type Fourier transform hologram region B has a region C that overlaps the above-mentioned reflection type Fourier transform hologram region A in a plan view, the total transmission type Fourier transform is performed. When the hologram region B is 100%, the ratio of the region C in which the transmission type Fourier transform hologram region B and the reflection type Fourier transform hologram region A overlap in a plan view is preferably within a predetermined range. The ratio can be the same as the ratio when the total reflection type Fourier transform hologram region A is set to 100% described in the section of "(1) Reflective Fourier transform hologram region". Therefore, the description here is omitted. In the present invention, the proportion of the region in which the transmission type Fourier transform hologram region and the reflection type Fourier transform hologram region overlap in the plan view in the total transmission type Fourier transform hologram region is within the above-mentioned predetermined range, so that the hologram It is possible to further improve the anti-counterfeiting property of the structure. This is the Fourier transform image 20'shown in FIG. 3A for displaying the second optical image and the Fourier transform image 20'shown in FIG. 2A for displaying the first optical image in the hologram structure. This is because the transformed image 10'overlaps in the plan view, so that the configuration can be made more complicated and it is difficult to imitate.

(B) Second Hologram Layer The second hologram layer in the present invention is a member arranged in a pattern on one surface side of the first hologram layer.

8 (a) and 8 (b) are schematic cross-sectional views showing an example of the hologram structure of the present invention. In the present invention, the second hologram layer 1b may be arranged on the uneven surface side of the first hologram layer 1a as shown in FIG. 8A, or as shown in FIG. 8B. The second hologram layer 1b may be arranged on a surface opposite to the uneven surface of the first hologram layer 1a. In the present invention, as shown in FIG. 8A, it is preferable that the second hologram layer 1b is arranged on the uneven surface side of the first hologram layer 1a. When the hologram structure 100 of the present invention is observed from the transparent substrate 4 side, the uneven structure formed on the surface of the first hologram layer is blocked by the second hologram layer in the reflective Fourier transform hologram region. It can be fully observed without. Further, in the transmission type Fourier transform hologram region, the second hologram layer arranged in a pattern can be sufficiently observed. Therefore, by observing the hologram structure of the present invention from one surface, when the light from the point light source is reflected, the first optical image converted by the reflective Fourier transform hologram region can be observed, and the point can be observed. When the light from the light source is transmitted, the second light image converted by the transmission type Fourier transform hologram region can be observed.

On the other hand, as shown in FIG. 8B, when the second hologram layer 1b is arranged on the surface opposite to the uneven surface of the first hologram layer 1a, the first hologram layer 1a and the first hologram layer 1a are usually arranged. The high refractive index layer 14 is formed between the hologram layer 1a and the member in contact with the uneven surface side. By doing so, in the uneven structure formed on the surface of the first hologram layer 1a due to the difference in refractive index between the first hologram layer 1a and the high refractive index layer 14, the transparent base material 4 side or the separator 3 side It is possible to sufficiently reflect the light emitted from the light source. This makes it possible to satisfactorily observe the first optical image in the reflective Fourier transform hologram region. Further, when observing the second optical image in the transmission type Fourier conversion hologram region in the hologram structure 100 shown in FIG. 8B, light is irradiated from the light source on the transparent substrate 4 side and observed from the separator 3 side. Alternatively, the light may be irradiated from the light source on the separator 3 side and observed from the transparent substrate 4 side. From the viewpoint of observing the second light image, the irradiation direction and the observation direction of the light from the light source are not particularly limited. A preferred embodiment when observing the first optical image using the hologram structure 100 shown in FIG. 8 (b) is described in the above section "(1) Reflective Fourier transform hologram region". The description of is omitted. Further, since the reference numerals not described in FIGS. 8A and 8B can be the same as those in FIG. 1 described above, the description thereof is omitted here.

In the transmission type Fourier transform hologram region, the second hologram layer arranged on one surface side of the first hologram layer is a multi-valued Fourier transform based on the data of the original image displayed as the second optical image. It is a statue. The second hologram layer is a member capable of blocking light incident from a point light source in a pattern. In other words, the second hologram layer is a member having a light-shielding property and arranged in a pattern. Such a second hologram layer is usually composed of a large number of curved or linear patterns extending in parallel in a specific direction, as shown in FIG. 3A.

As a method of arranging the second hologram layer in a pattern in the present invention to obtain a transmission type Fourier transform hologram region, the second hologram layer is made to transmit light from a point light source on one surface side of the first hologram layer. Any method may be used as long as it is arranged in a pattern so that a desired second light image can be displayed at the time, and it can be appropriately selected depending on the material used for the second hologram layer and the like. Specifically, for example, a method of forming the second hologram layer in a pattern by using a laser drawing method, a demeta printing method, a resist printing method, a mask vapor deposition method, a sputtering method, an ion plating method, or the like can be mentioned. In the present invention, it is particularly preferable to form the second hologram layer by using a laser drawing method. Since variable pattern formation can be performed, it is suitable for forming a hologram structure having high anti-counterfeiting property and excellent design.

In the present invention, the pitch of the second hologram layer formed in a pattern is preferably such that the light incident from the point light source can be converted into a desired second light image. Since the specific pitch of the second hologram layer can be the same as the lattice pitch described in the section of "(1) Reflective Fourier transform hologram region (a) First hologram layer" above, the pitch here is described here. The description is omitted. The pitch of the second hologram layer formed in a pattern means, for example, the distance indicated by the reference numeral P in FIG.

The second hologram layer has a function of blocking light incident from a point light source in a pattern. Therefore, the thickness of the second hologram layer is preferably such that it can sufficiently block the light incident from the point light source, and is appropriately suitable depending on the type of material used for the second hologram layer and the manufacturing method. You can choose. In the present invention, for example, the thickness of the second hologram layer is preferably in the range of 0.01 μm or more and 50 μm or less, and more preferably 0.03 μm or more and 20 μm or less. The thickness of the second hologram layer means, for example, the distance indicated by reference numeral D in FIG.

In the present invention, the light incident from the point light source is shielded in a pattern by the second hologram layer and converted into a second light image. Here, "shielding" includes not only the case where the light incident from the point light source is completely blocked, but also the case where the light is shielded to the extent that it can be converted into a second light image. Specifically, the visible light transmittance of the second hologram layer is preferably 90% or less, particularly preferably 70% or less, and particularly preferably 50% or less. The visible light transmittance of the second hologram layer can be measured by, for example, a test method for the total light transmittance of a plastic-transparent substrate according to JIS K7361-1.

Further, in the present invention, it is preferable that the second hologram layer has a reflectivity for reflecting the light incident from the point light source. For example, as shown in FIG. 1, the second hologram layer 1b is arranged on the uneven surface side of the first hologram layer 1a, and as shown in FIG. 2B, a point light source is irradiated from the transparent substrate 4 side. Therefore, when the observer observes the first optical image from the transparent substrate 4 side, the first optical image can be visually recognized more clearly. It is considered that this is because the light incident from the point light source is effectively reflected by the second hologram layer 1b that follows so as to cover the uneven surface of the first hologram layer 1a. As the specific reflectivity of the second hologram layer, for example, the reflectance is preferably 5% or more, particularly preferably 10% or more, and particularly preferably 15% or more. The reflectance of the second hologram layer can be measured according to, for example, JIS K 7375.

The material of the second hologram layer in the present invention may be any material that can block the light incident from the point light source in a pattern and convert it into a desired second light image. Among them, a material having a predetermined light-shielding property as described above is preferable, and a material having both a predetermined light-shielding property and a reflective property as described above is particularly preferable. Specific examples thereof include aluminum, silver, gold, nickel, copper, chromium, titanium, titanium nitride, titanium carbide, nickel chromium, stainless steel, brass and the like. In the present invention, it is particularly preferable to use aluminum from the viewpoint of reflectivity and light-shielding property.

(C) Second Light Image The transmissive Fourier transform hologram region in the present invention is a region in which light incident from a point light source is shielded in a pattern by a second hologram layer and converted into a second light image.

The pattern of the second light image displayed by the transmission type Fourier transform hologram region in the present invention can be, for example, a pattern, a line drawing, a character, a figure, a symbol, or the like, and is appropriately selected according to the use of the hologram structure. be able to. In the present invention, the second light image displayed by the transmission type Fourier transform hologram region may have the same pattern as the first light image displayed by the above-mentioned reflection type Fourier transform hologram area, and may have different patterns. It may be.

In the present invention, for example, as shown in FIG. 3 (b), by irradiating a point light source from the separator 3 side of the hologram structure 100, the observer on the transparent substrate 4 side can see in FIG. 3 (a). It is possible to visually recognize the second light image which is the pattern of the face indicated by the reference numeral 20. Although not shown, for example, even when the point light source is irradiated from the transparent base material 4 side in FIG. 3B, the light from the point light source is shielded in a pattern by the second hologram layer 1b. .. Therefore, the observer can visually recognize the second optical image from the separator 3 side.

Further, for example, as shown in FIG. 8B, when the second hologram layer 1b is arranged on the surface opposite to the uneven surface of the first hologram layer 1a, the second optical image is displayed. The point light source may be irradiated from the separator 3 side and visually recognized by the observer from the transparent base material 4, or the point light source may be irradiated from the transparent base material 4 side and visually recognized by the observer from the separator 3 side. You may. In the present invention, from the viewpoint of displaying the first light image more clearly, it is preferable that the point light source is irradiated from the transparent base material 4 side and the observer visually recognizes it from the separator 3 side. The reason for this can be the same as that described in the section "(1) Reflective Fourier transform hologram region (b) First optical image", and thus the description thereof is omitted here.

(D) Others In the present invention, examples of the point light source that irradiates the transmitted Fourier transform hologram region with light include a laser light source. The wavelength of the point light source is not particularly limited, and it is preferable that the reflective Fourier transform hologram region can satisfactorily exhibit the Fourier transform lens function. In the present invention, the wavelength of the point light source may be monochromatic light having one wavelength, light including multiple wavelengths, or white light.

(3) Diffraction Grating Area Region The diffraction grating region in the present invention is a region for displaying a diffraction pattern. Further, the diffraction grating region is located in a region that does not overlap with the reflection type Fourier transform hologram region in a plan view. The diffraction grating region here includes the relief type hologram region.

The diffraction grating region refers to a region in which a plurality of pixels having a diffraction grating pattern are gathered. FIG. 10A is a schematic plan view showing an example of a diffraction grating pattern. As shown in FIG. 10A, the hologram structure 100 of the present invention has a first optical image or a first optical image or a region C in which at least a reflective Fourier transformed hologram region A, a transmissive Fourier transformed hologram region B, or an overlapped region C thereof. Although it has a region in which the second light image is displayed, it may have a diffraction grating region in which the diffraction grating patterns 30 for displaying the diffraction grating pattern are gathered, if necessary. This is because the anti-counterfeiting property can be further enhanced and the hologram structure having excellent design can be obtained. As shown in FIG. 10B, in the diffraction grating pattern 30, grid lines 31 having a predetermined line width d are arranged in a closed region 32 having a size corresponding to one pixel. The grid lines 31 are arranged at a predetermined pitch p and a predetermined angle θ. Although not shown, the diffraction grating region is preferably formed on the same plane as the reflective Fourier transform hologram region. Specifically, it is preferable that the diffraction grating pattern is arranged on the same plane as the first hologram layer in the present invention. Further, at this time, in the first hologram layer, the uneven surface side for forming the reflective Fourier transform hologram region and the surface side on which the diffraction grating pattern is recorded in the diffraction grating pattern are designed to be the same surface. It is preferable to do so.

The line width d, pitch p, and angle θ of the lattice lines in the diffraction grating pattern can be appropriately set to dimensional values to the extent that the light irradiated to the diffraction grating region is diffracted. In the diffraction grating region, a predetermined diffraction pattern can be displayed by collecting a plurality of types of diffraction grating patterns in which the line width d, pitch p, angle θ, and the like of the lattice lines are set to various dimensional values. In addition, various dimensional values and arrangements of the diffraction grating pattern are appropriately determined according to the pixel values assigned to each of a large number of pixels constituting the original image in the original image to be displayed by the diffraction grating region. The various dimensional values of the diffraction grating pattern are determined based on the image data of the original image captured by the computer.

The diffraction grating pattern constituting the diffraction grating region can be the same as that of a general diffraction grating pattern. Specifically, the diffraction grating pattern in the present invention is the same as the general diffraction grating pattern disclosed in JP-A-2008-191540, JP-A-2000-304912, JP-A-2008-07742, and the like. can do. Therefore, detailed description here will be omitted.

The diffraction grating region in the present invention is located in a region that does not overlap with the reflective Fourier transform hologram region in a plan view, and this is due to the following. That is, usually, the diffraction grating pattern constituting the diffraction grating region has an uneven structure on the surface. Then, it becomes difficult to arrange the diffraction grating region having the uneven structure on the surface in the region overlapping the reflective Fourier transform hologram region having the uneven structure on the surface of the first hologram layer in a plan view. As described above, the diffraction grating region in the present invention is located in a region that does not overlap in the plan view with the reflective Fourier transform hologram region, but the diffraction grating region and the transmission type Fourier transform hologram region have a region that overlaps in the plan view. You may do it.

Examples of the diffraction grating pattern displayed by the diffraction grating region in the present invention include patterns, line drawings, characters, figures, symbols, and the like. In addition, these diffraction grating patterns are combined with the pattern of the first light image converted by the reflective Fourier transform hologram region and the pattern of the second light image converted by the transmission type Fourier transform hologram region to complete one pattern. It may be designed to do so. In this case, the anti-counterfeiting property can be further improved.

The diffraction grating pattern in the present invention may be a plane diffraction grating pattern that can reproduce the pattern in a plane, a three-dimensional diffraction grating pattern that can reproduce the pattern three-dimensionally, or a plane diffraction grating pattern. It may be a combination of both the three-dimensional diffraction grating pattern and the three-dimensional diffraction grating pattern. When the diffraction grating pattern is a plane diffraction grating pattern or a three-dimensional diffraction grating pattern, a hologram structure having more excellent design can be obtained.

Examples of the method for displaying the plane diffraction grating pattern include the following methods. That is, there is a method in which the amplitude of the diffracted light is displayed by a diffraction grating pattern having the same degree. Here, as a method for making the amplitude of the diffracted light about the same, for example, the same method as described in Japanese Patent No. 49844938 can be used, and thus the description here is omitted.

The plane diffraction grating pattern can be displayed by laying out diffraction grating patterns having the same area of lattice lines. As for the area of the grating line, the diffraction grating pattern having the lattice line has only a reproducible plane diffraction grating pattern, and the size and color display of the reproduced plane diffraction grating pattern. It can be set as appropriate depending on the presence or absence of.

Examples of the method for forming the three-dimensional diffraction grating pattern include a method of arranging a diffraction grating pattern having a large amplitude of diffracted light on the central portion side of the edge side of the diffraction grating pattern. By doing so, when the reference light is irradiated, the diffraction grating pattern can be reproduced so as to appear three-dimensionally. Here, the method of arranging the diffraction grating pattern so that the amplitude of the diffracted light is larger on the central portion side than on the end portion side can be, for example, the same as the method described in Japanese Patent No. 4984938. Therefore, the description here is omitted.

The ratio of the diffraction grating region to the reflection-type Fourier transform hologram region and the transmission-type Fourier transform hologram region described above in plan view is preferably a ratio such that a desired diffraction grating pattern can be displayed by the diffraction grating region. .. Further, each of the first light image and the second light image displayed by the reflection type Fourier transform hologram region and the transmission type Fourier transform hologram region and the diffraction grating pattern displayed by the diffraction grating region can be sufficiently visually recognized. It is preferable that the ratio is such that it can be achieved. When the diffraction grating pattern is a plane diffraction grating pattern, the ratio of the diffraction grating area to the reflection type Fourier transform hologram region and the transmission type Fourier transform hologram region described above is, for example, within the range of 1/4 or more and 3/4 or less. It is preferably in the range of 1/2 or more and 1 or less, and particularly preferably in the range of 5/8 or more and 7/8 or less. On the other hand, when the diffraction grating pattern is a three-dimensional diffraction grating pattern, the ratio of the diffraction grating area to the above-mentioned reflective Fourier transform hologram region and transmission type Fourier transform hologram region is, for example, within the range of 1/3 or more and 3 or less. It is preferably in the range of 2/3 or more and 2 or less, and particularly preferably in the range of 1 or more and 5/3 or less. In the above ratio, "with respect to the above-mentioned reflective Fourier transform hologram region and transmission type Fourier transform hologram region" means to the total region of the above-mentioned reflection type Fourier transform hologram region and transmission type Fourier transform hologram region. be.

The plan view size of the diffraction grating pattern can be appropriately set according to the displayed diffraction grating pattern, and is not particularly limited. For example, it can be in the range of 5 μm square or more and 100 μm square or less. When the plane view size of the diffraction grating pattern is within the above range, it is possible to display a high-definition diffraction grating pattern. In addition, the existence of individual diffraction grating patterns that display the diffraction grating pattern can be concealed, and anti-counterfeiting can be enhanced.

The planar view shape of the diffraction grating pattern can be appropriately selected according to the diffraction grating pattern to be reproduced, and is not particularly limited. For example, since it can be the same as the plan view shape of the single Fourier transform hologram region described in the above section "(1) Reflective Fourier transform hologram region", the description here is omitted.

As a method for forming the diffraction grating pattern, a method similar to a generally known method can be adopted, and thus the description thereof is omitted here.

The reference light used for reproducing the diffraction grating pattern is not particularly limited, and can be used in the same light as the reference light used for a general hologram. Specifically, as the reference light, light including visible light can be used. For example, as the reference light, the same light as the point light source used for displaying the first light image and the second light image converted by the reflection type Fourier transform hologram region and the transmission type Fourier transform hologram region described above can be used. .. By doing so, the diffraction grating pattern can be displayed at the same time as the display of the first light image or the second light image. The reference light is not limited to a point light source, and may be parallel light or the like.

(4) Other Structures The hologram structure of the present invention is a member having the above-mentioned reflective Fourier transform hologram region and transmission type Fourier transform hologram region, but may have other configurations if necessary. ..
Hereinafter, other configurations used in the hologram structure of the present invention will be described.

(A) Transparent base material The hologram structure of the present invention may have a transparent base material on the surface of the first hologram layer opposite to the side on which the uneven structure is formed. By having a transparent base material, the thermal strength or mechanical strength of the hologram structure of the present invention can be increased.

Here, "having a transparent base material on the surface of the hologram layer opposite to the side on which the concave-convex structure is formed" means that the hologram layer is directly on the surface on the side opposite to the side on which the concave-convex structure is formed. This includes a mode in which the transparent base material is arranged and a mode in which the transparent base material is arranged via another member on the surface opposite to the side on which the concave-convex structure of the hologram layer is formed.

The transparent substrate in the present invention preferably has a visible light transmittance of 80% or more, and more preferably 90% or more. When the visible light transmittance of the transparent base material is within the above range, when light is irradiated from the side where the transparent base material of the hologram structure is arranged, the first hologram layer and the first hologram layer and the first hologram layer are radiated through the transparent base material. Light can be sufficiently transmitted up to two hologram layers. On the other hand, when light is irradiated from the side opposite to the side where the transparent base material of the hologram structure is arranged, the second light image converted by the transmission type Fourier transform hologram region is displayed through the transparent base material. Can be done. The visible light transmittance of the transparent substrate can be measured by, for example, a test method for the total light transmittance of a plastic-transparent substrate according to JIS K7361-1.

The transparent substrate in the present invention preferably has a relatively low haze value. The specific haze value of the transparent substrate is, for example, preferably in the range of 0.01% or more and 5% or less, and particularly preferably in the range of 0.01% or more and 3% or less. , 0.01% or more and 1.5% or less is preferable. When the haze value of the transparent base material is within the above range, the first light image and the second light image can be satisfactorily displayed through the transparent base material. The haze value of the transparent base material can be measured according to, for example, JIS K7136.

As the material of the transparent base material in the present invention, it is preferable to select a material having a predetermined visible light transmittance and haze value as described above. Specific examples thereof include resin films such as polyethylene terephthalate, polycarbonate, acrylic resin, cycloolefin resin, polyester resin, polystyrene resin and acrylic styrene resin, and glass such as quartz glass, Pyrex (registered trademark) and synthetic quartz plate. In the present invention, it is preferable to use a resin film from the viewpoint of light weight and low risk of breakage, and it is more preferable to select polycarbonate from the viewpoint of birefringence.

The transparent substrate in the present invention may contain an ultraviolet absorber, a heat ray absorber, and the like. Deterioration of the hologram layer can be suppressed by exposing the hologram structure to ultraviolet rays, heat rays, or the like.

The thickness of the transparent base material in the present invention is preferably such that it can have sufficient rigidity and strength to support the first hologram layer and the second hologram layer. The thickness of the transparent base material is preferably in the range of 0.005 mm or more and 5 mm or less, and more preferably 0.01 mm or more and 1 mm or less. Further, the shape of the transparent base material can be appropriately changed according to the usage pattern of the hologram structure of the present invention.

The transparent base material in the present invention may be surface-treated in order to improve the adhesion with other members. Examples of the surface treatment on the transparent substrate include corona treatment.

(B) Adhesive layer The hologram structure of the present invention may have an adhesive layer on at least one surface, for example. In the present invention, the hologram structure of the present invention can be attached to a predetermined position by having an adhesive layer on either one surface of the hologram structure. Further, by having adhesive layers on both sides of the hologram structure, the hologram structure can be embedded in, for example, a card made of a resin such as polycarbonate, a personal information page of a passport, or the like. Note that FIG. 1 is an example in which the separator 3 is arranged on the surface of the adhesive layer 2 on the outermost layer side.

Here, "the hologram structure of the present invention may have an adhesive layer on either surface" refers to the following aspect. Specifically, the hologram layer may have an adhesive layer on a surface opposite to the side on which the uneven structure of the first hologram layer is formed. Further, the adhesive layer may be provided on the surface on which the uneven structure of the first hologram layer is formed, that is, on the uneven surface side of the first hologram layer. In the latter case, the adhesive layer may be formed so as to fill the uneven structure of the hologram layer, but at this time, there is a predetermined difference in refractive index between the first hologram layer and the adhesive layer. Is preferable. This is because the uneven structure of the first hologram layer reflects the light from the point light source and can be satisfactorily converted into the first light image.

Further, although it is not shown, "the adhesive layer may be provided on the surface opposite to the side on which the uneven structure of the first hologram layer is formed" is formed. An adhesive layer may be formed on the surface opposite to the surface on which the hologram layer is formed, and an adhesive layer may be formed on the surface opposite to the surface on which the uneven structure of the first hologram layer is formed via a transparent base material. Refers to what may be formed.
Next, "the adhesive layer may be provided on the surface of the first hologram layer on the side where the uneven structure is formed" means, for example, as shown in FIG. 1, the uneven structure of the first hologram layer 1a. It means that the adhesive layer 2 may be formed on the surface on the side where is formed.

In the present invention, for example, as shown in FIG. 1, when the adhesive layer 2 is provided on the surface of the first hologram layer 1a on the side where the uneven structure is formed, a predetermined position is provided between the first hologram layer and the adhesive layer. The difference in refractive index of is required. Here, the "predetermined refractive index difference" is, for example, a refractive index difference such that light from a point light source is scattered by the uneven structure of the first hologram layer and a desired first optical image can be displayed. It is preferable to have.

The adhesive layer in the present invention preferably has high transparency. Specifically, the visible light transmittance is preferably 80% or more, and more preferably 90% or more. When the visible light transmittance of the adhesive layer is within the above range, it is possible to suppress the shielding of light by the adhesive layer. The visible light transmittance of the adhesive layer can be measured by, for example, a test method for the total light transmittance of a plastic-transparent material according to JIS K7361-1.

The adhesive layer in the present invention preferably has a relatively low haze value. The specific haze value of the adhesive layer is, for example, preferably in the range of 0.01% or more and 5% or less, particularly preferably in the range of 0.01% or more and 3% or less, and particularly 0. It is preferably in the range of 0.01% or more and 1.5% or less. When the haze value of the adhesive layer is within the above range, it is possible to suppress the shielding of light by the adhesive layer. The haze value of the adhesive layer can be measured according to, for example, JIS K7136.

The adhesive layer in the present invention may be an adhesive layer having adhesiveness, or may be a re-peelable adhesive layer having both adhesiveness and re-peelability characteristics. When the adhesive layer in the present invention is an adhesive layer, the members constituting the hologram structure of the present invention are firmly bonded to each other, or the hologram structure is firmly bonded to the adherend. be able to. On the other hand, when the adhesive layer in the present invention is a re-peelable adhesive layer, the hologram structure of the present invention can be attached to a desired member. Such a re-peelable adhesion layer can easily repeat adhesion and peeling without leaving a mark on the adherend due to an adhesive or the like, and can minimize the influence on the adherend.

The adhesive layer in the present invention may contain an ultraviolet absorber or an infrared absorber, if necessary. Since the adhesive layer contains an ultraviolet absorber or an infrared absorber, it is possible to prevent the hologram structure of the present invention from being deteriorated by irradiation with ultraviolet rays or infrared rays. Further, the adhesive layer in the present invention may contain a tackiness-imparting agent, a tackiness adjusting agent, and the like.

The thickness of the adhesive layer in the present invention can be appropriately adjusted according to the use of the hologram structure of the present invention, and is not particularly limited. The specific thickness of the adhesive layer is, for example, preferably in the range of 1 μm or more and 500 μm or less, and particularly preferably in the range of 2 μm or more and 50 μm or less. When the thickness of the adhesive layer is within the above range, it is possible to suppress the shielding of light by the adhesive layer.

The method for forming the adhesive layer is not particularly limited as long as it can arrange the adhesive layer at a desired position. For example, a method of forming an adhesive layer by directly applying a coating liquid for forming an adhesive layer forming an adhesive layer at a desired position and drying it can be mentioned. As a coating method for forming an adhesive layer, for example, various coating methods such as Mayer bar, gravure coat, gravure reverse coat, kiss reverse coat, three roll reverse coat, slit reverse die coat, comma coat, and knife coat are used. Can be mentioned.

(C) Separator In the present invention, when the outermost layer of the hologram structure has an adhesive layer, it is preferable to arrange the separator on the surface of the outermost layer of the adhesive layer. In other words, when the outermost layer of the hologram structure is a member having no adhesiveness, it is not necessary to arrange a separator in particular. By having the separator, it is possible to prevent foreign matter and the like from adhering to the surface of the adhesive layer. Further, when the hologram structure is created in a long shape and wound in a roll shape, it is possible to prevent the overlapping hologram structures from adhering to each other.

The separator in the present invention is not particularly limited as long as it is a member that can protect the adhesive layer and can be easily peeled off from the adhesive layer. Examples of such a separator include a resin layer composed of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, and the like.

The thickness of the separator in the present invention can be appropriately adjusted according to the type and use of the hologram structure of the present invention, and is not particularly limited.

In the separator of the present invention, it is preferable that the surface on the side in contact with the adhesive layer is subjected to a peeling treatment for facilitating the peeling operation with the adhesive layer. Examples of the peeling treatment include silicone treatment and alkyd treatment.

(D) High Refractive Index Layer In the present invention, a high refractive index layer may be provided on the uneven surface side of the first hologram layer, if necessary.

The high refractive index layer in the present invention can be formed by, for example, a resin composition for forming a high refractive index layer containing high refractive index particles such as zirconium oxide, diantimony pentoxide, antimony-doped tin oxide and a binder resin. .. Further, the high refractive index layer may be formed by a single polymer having a high refractive index itself, and zirconium oxide and pentoxide formed by a vapor deposition method such as a chemical vapor deposition method (CVD) or a physical vapor deposition method (PVD). (Ii) A thin film such as antimony may be used. In the present invention, it is particularly preferable to form a high refractive index layer with a resin composition for forming a high refractive index layer containing high refractive index particles and a binder resin.

Examples of the high refractive index particles used in the high refractive index layer include zinc oxide (ZnO; 1.90), titanium oxide (TiO ₂ ; 2.3 to 2.7), and cerium oxide (CeO ₂ ; 1.95). ), Indium tin oxide (ITO; 1.95), antimony-doped tin oxide (ATO; 1.80), yttrium oxide (Y ₂ O ₃ ; 1.87), zirconium oxide (ZrO ₂ ; 2.0), five Antimon oxide (Sb ₂ O ₅ ; 1.79) is preferably mentioned and can be appropriately selected depending on the intended use. The numerical value in parentheses indicates the refractive index.

The average particle size of the high-refractive index particles is, for example, preferably in the range of 5 nm or more and 200 nm or less, particularly preferably in the range of 5 nm or more and 100 nm or less, and particularly in the range of 10 nm or more and 80 nm or less. Is preferable. This is because when the average particle size of the high-refractive index particles is within the above range, the dispersed state of the high-refractive index particles can be obtained without impairing the light transmittance of the high-refractive index layer. In the present invention, high refractive index particles may be linked in a chain as long as the average particle size is within the above range.

The high refractive index particles may be surface-treated, if necessary. Examples of the surface treatment include a treatment of modifying the surface of high-refractive index particles using a silane coupling agent.
By performing such a treatment, the affinity with the binder resin can be improved, the high refractive index particles can be uniformly dispersed, and the aggregation of the high refractive index particles can be suppressed. Therefore, it is possible to suppress a decrease in the light transmittance of the high refractive index layer due to the increase in the size of the particles derived from aggregation, and a decrease in the coatability and the coating strength of the resin composition for forming the high refractive index layer.

The binder resin for dispersing the high-refractive index particles, other additives, and other detailed explanations can be the same as those disclosed in JP-A-2017-021293, for example. Is omitted.

(E) Interlayer Adhesive Layer The hologram structure of the present invention may have an interlayer adhesive layer for adhering the layers of each member constituting the hologram structure.

As such an interlayer adhesive layer, for example, a known adhesive layer such as a two-component curable adhesive layer, an ultraviolet curable adhesive layer, a heat-curable adhesive layer, or a heat-melt type adhesive layer can be used. can.

Since the thickness of the interlayer adhesive layer in the present invention can be appropriately adjusted according to the size of each member constituting the hologram structure and the like, the description thereof is omitted here.

The interlayer bonding layer in the present invention preferably has a predetermined transparency when it overlaps with the reflective Fourier transform hologram region or the transmissive Fourier transform hologram region in a plan view. The specific transparency can be the same as the transparency of the adhesive layer described in the above section "(b) Adhesive layer", and thus the description thereof is omitted here.

(F) Print layer The hologram structure of the present invention may have a print layer. The "printing layer" here refers to a layer on which information is printed using ink or the like. By having the printed layer, the design of the hologram structure of the present invention can be further improved.

The material of the printing layer may be any material that can be printed by various printing methods, and is not particularly limited. Examples thereof include polycarbonates, polyesters, cellulose derivatives, norbornene-based resins, polyvinyl chlorides, polyvinyl acetates, acrylic resins, urethane-based resins, polypropylene-based resins, polyethylene-based resins, and styrene-based resins. In addition, examples of the ink used for the printing layer include inks used in various printing methods such as inkjet printing, screen printing, offset printing, gravure printing, and flexographic printing.

Examples of the printing layer forming method include flat plate printing, concave printing, letterpress printing, basic printing method for stencil printing, flexo printing, resin letterpress printing, gravure offset printing, octopus printing, inkjet printing, transfer printing, electrostatic printing, etc. Examples include UV curable printing, printing, and waterless offset printing.

The printing layer in the present invention is a member that imparts design to the hologram structure. For example, the print layer is preferably a member that displays information different from the above-mentioned first light image and second light image. The information displayed by the print layer can be appropriately selected depending on the use of the hologram structure of the present invention and is not particularly limited, but for example, characters, symbols, marks, illustrations, patterns such as characters, company names, etc. Various character information such as product name, selling point, catch phrase, handling explanation, etc. can be mentioned.

The arrangement position of the print layer in the present invention is preferably a position that does not interfere with the display of the first light image and the second light image. Specifically, the print layer may be arranged on the surface side on which the uneven structure of the first hologram layer is formed, or may be arranged on the side opposite to the surface on which the uneven structure of the first hologram layer is formed. good. When the hologram structure of the present invention has a configuration as shown in FIG. 1, for example, and the print layer is arranged on the surface side where the uneven structure of the first hologram layer is formed, the print layer is the first. It may be arranged between the first hologram layer and the second second hologram layer, or may be arranged on the surface of the second hologram layer opposite to the first hologram layer.

(G) Arbitrary Structure The hologram structure of the present invention may have, for example, an ultraviolet absorbing layer, an infrared absorbing layer, an antireflection layer, or the like on the above-mentioned transparent base material. By having such an arbitrary configuration, the hologram structure of the present invention can be used as various filters and the like. As the ultraviolet absorbing layer, the infrared absorbing layer, the antireflection layer, and the like, generally known ones can be used, and thus the description thereof is omitted here.

2. Usage of Hologram Structure The hologram structure of the present invention has the following usage. An example of the usage mode of the hologram structure will be described separately for the first usage mode, the second usage mode, and the third usage mode.

(1) First Usage Mode The hologram structure of this mode has an adhesive layer on the uneven surface side of the first hologram layer, and is used as a hologram seal.

The hologram structure of this embodiment can be used as a hologram seal by having an adhesive layer 2 on the uneven surface side of the first hologram layer 1a, for example, as shown in FIG. 1 described above. Specifically, the adhesive layer 2 is provided as the outermost layer of the so-called hologram structure, which is the uneven surface side of the first hologram layer 1a and is opposite to the first hologram layer 1a of the second hologram layer 1b. Is preferable.

When the hologram structure of this embodiment is used as a hologram sticker, the hologram sticker is attached to an adherend via an adhesive layer. The adherend at this time may or may not have transparency at least in a region that overlaps with the transmissive Fourier transform hologram region in a plan view. As shown in FIG. 11A, when the hologram seal 100a is attached to the adherend 200 having transparency at least in a region that overlaps the transmissive Fourier transform hologram region in a plan view, the transparent base material 4 side. The light L ₁₀ can be reflected by the point light source to display the first light image, and the light L ₂₀ can be transmitted by the point light source through the adherend 200 to display the second light image. can. On the other hand, as shown in FIG. 11B, when the hologram seal 100a is attached to the non-transparent adherend 200, the light L ₁₀ is reflected from the transparent base material 4 side by a point light source. Although the first light image can be displayed, it is difficult to transmit the _{light L 20 from the point light source through the adherend 200.} Therefore, in this case, as shown in FIG. 11C, it is preferable to peel off the hologram sticker 100a from the adherend 200 to display the second light image. Reference numerals not described in FIGS. 11 (a) to 11 (c) can be the same as those in FIG. 1 described above, and thus the description thereof will be omitted here.

In this embodiment, when the adherend does not have transparency, the authenticity can be determined using the hologram sticker, and the anti-counterfeiting property can be further improved. Specifically, since the second light image can be displayed only when the hologram sticker is peeled off from the adherend and transmitted through a point light source, the hologram sticker is transparent for displaying the second light image. It is possible to hide the fact that it has a type Fourier transform hologram region, and it is possible to further improve the anti-counterfeiting property.

The hologram structure of this embodiment may have the configuration described in the above section "1. Configuration (4) Other configurations", if necessary.

Since the adhesive layer used in this embodiment can be the same as the content described in the above section "1. Configuration (4) Other configurations (b) Adhesive layer", the description here is omitted.

Specific uses of the hologram structure of this embodiment as a hologram sticker include, for example, affixing it to a ticket, a branded product, a quality control number label of a product, or the like to determine authenticity.

(2) Second Usage Mode The hologram structure of this embodiment has a heat seal layer on the uneven surface side of the first hologram layer, and is an easily peelable layer on the surface opposite to the uneven surface of the first hologram layer. The peeling base material is provided on the surface of the easily peelable layer opposite to the first hologram layer, and is used as a hologram transfer foil.

The hologram structure of this embodiment can be used as, for example, the hologram transfer foil 100b as shown in FIG. For example, the hologram transfer foil 100b has a heat seal layer 5 on the outermost layer of the first hologram layer 1a on the uneven surface side, that is, on the surface of the second hologram layer 1b opposite to the first hologram layer 1a. The peelable layer 6 is provided on the surface of the first hologram layer 1a opposite to the uneven surface, and the peelable base material 7 is provided on the surface of the easy peelable layer 6 opposite to the first hologram layer 1a.

The hologram structure of this embodiment may have the configuration described in the above section "1. Configuration (4) Other configurations", if necessary.

Hereinafter, the configuration used for the hologram structure of this embodiment will be described.

(A) Heat-seal layer The heat-seal layer in this embodiment has a function of attaching a hologram structure to an adherend.

The heat seal layer in this embodiment is not particularly limited as long as the hologram structure can be attached to the adherend. Specific examples of the heat-sealing layer material include a heat-sealing layer containing a thermoplastic resin disclosed in Japanese Patent Application Laid-Open No. 2014-16422.

(B) Peeling base material The peeling base material in this embodiment is a member that supports the hologram structure. Further, the peeling base material in this embodiment is a member that is peeled off from the hologram structure after the hologram structure is attached to the adherend using the heat seal layer described above.

The peeling base material may or may not have transparency. The material and thickness of the peeling base material are the same as those of the transparent base material described in the above section "1. Composition (4) Other configurations (a) Transparent base material". Therefore, the description here is omitted.

(C) Easy-to-peel layer The easy-to-peel layer in this embodiment easily peels off the above-mentioned peeling base material from the hologram structure after the hologram structure is attached to the adherend via the above-mentioned heat seal layer. It is a member for.

The easy-to-peel layer in this embodiment can be, for example, the same as the re-peelable adhesive layer described in the above section “1. Configuration (4) Other configurations (b) Adhesive layer”.

The position of the easy-to-peel layer in the plan view in this embodiment is not particularly limited as long as the easy-to-peel layer can exert a desired function. The easily peelable layer may be arranged on the entire surface of the peeling base material in a plan view, or may be arranged in a pattern.

(3) Third Use Mode The hologram structure of this mode is characterized in that it is used as an information recording medium.

The hologram structure of this embodiment can be used as the information recording medium 100c, for example, as shown in FIG. For example, the information recording medium 100c is provided on the uneven surface side of the first hologram layer 1a, that is, on the surface of the second hologram layer 1b opposite to the first hologram layer 1a, via the interlayer adhesive layer 8 on the back surface side protective layer. It has 9a, has an intermediate base material 11 on the surface of the first hologram layer 1a opposite to the uneven surface, and is further bonded to the surface of the intermediate base material 11 opposite to the first hologram layer 1a. It has a surface side protective layer 9b via the layer 8.

Specific uses when the hologram structure of this embodiment is used as an information recording medium include, for example, credit cards, cash cards, point cards and other cards, employee ID cards, driver's licenses and other identification cards, passbooks and passports. And so on. In this embodiment, the member that overlaps the hologram structure in a plan view has a predetermined transparency. This is to display a first light image or a second light image by irradiating the hologram structure with light from a light source.

The hologram structure of this embodiment may have the configuration described in the above section "1. Configuration (4) Other configurations", if necessary. Further, as shown in FIG. 13, it may have an intermediate base material, a back surface side protective layer, a front surface side protective layer, and the like.

Hereinafter, the configuration used for the hologram structure of this embodiment will be described.

(A) Front-side protective layer and back-side protective layer The front-side protective layer and the back-side protective layer in this embodiment are usually transparent at least in a region that overlaps the reflective Fourier transform hologram region and the transmissive Fourier transform hologram region in a plan view. It is a member having a property.

Examples of the material used for the front surface side protective layer and the back surface side protective layer in this embodiment include polycarbonate. The specific materials and thicknesses used for the front surface side protective layer and the back surface side protective layer are described in the above section "1. Configuration (4) Other configurations (a) Transparent substrate". Since it can be the same as the material and thickness of the above, the description here is omitted.

The front surface side protective layer and the back surface side protective layer in this embodiment have a function of protecting the hologram structure. Therefore, it is preferable that the front surface side protective layer and the back surface side protective layer are formed so as to cover the entire surface of the hologram structure in a plan view.

(B) Intermediate base material The intermediate base material in this embodiment is a member for supporting the hologram structure, the surface side protective layer, and the like. Such an intermediate base material may be a member that also serves as the transparent base material described in the above section "1. Structure (4) Other configurations (a) Transparent base material".

Examples of the material used for the intermediate base material in this embodiment include polyethylene terephthalate. The specific material and thickness used for the intermediate base material are the same as the material and thickness of the transparent base material described in the above section "1. Composition (4) Other configurations (a) Transparent base material". Therefore, the description here is omitted.

The intermediate base material in this embodiment is usually formed so as to cover the entire surface of the hologram structure in a plan view.

(C) Other configurations Other configurations in this embodiment include, for example, an information recording layer for recording information. Examples of the information recording layer include a printing layer in which information is recorded by printing, a magnetic layer in which information is recorded by magnetism, an IC chip layer including an integrated circuit (IC) chip, and the like. In addition, it may have a functional layer such as an antenna layer including an antenna.

The other configurations described above can be appropriately arranged at positions that do not interfere with the display of the first light image and the second light image by the hologram structure of this embodiment.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

[Example]
(Formation of master original plate)
A photomask blank plate (mask blanks manufactured by ULVAC COATING Co., Ltd.) in which a surface low-reflection chromium thin film was laminated on a synthetic quartz substrate was prepared. A resist for dry etching was rotationally coated on the chromium thin film of the photomask blank plate with a spinner. ZEP7000 manufactured by Nippon Zeon Corporation was used as the resist for dry etching, and the resist was formed so as to have a thickness of 400 nm. An electron beam drawing apparatus (MEBES4500: manufactured by ETEC) was used to expose the resist layer to a pattern prepared in advance by a computer to easily dissolve the exposed portion of the resist resin. Then, the developer was sprayed (spray developed) to remove the easily soluble portion to form a resist pattern. The lattice pitch of the pattern was 3179 nm.
Subsequently, using the formed resist pattern, the chromium thin film in the portion not covered with the resist was removed by etching by dry etching to expose the quartz substrate. The exposed quartz substrate was then etched to form recesses in the quartz substrate. Then, by dissolving and removing the resist thin film, a master original plate having a concave portion formed by etching the quartz substrate and a convex portion remaining without etching the quartz substrate and the chromium thin film was obtained. The size of the master original plate was set to 150 mm × 150 mm square.

(Formation of reflective Fourier transform hologram region)
A polyethylene terephthalate film (A4300 manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was prepared as a transparent base material. A composition for forming a hologram layer (UV curable acrylate resin: refractive index 1.52, measurement wavelength 633 nm) was added dropwise to this transparent substrate to form a coating film of the above composition. Next, a master original plate having irregularities was placed on the coating film and pressed.
Next, the coating film was cured by irradiating active radiation with the master original plate stacked. Then, the master original plate was peeled off to form a first hologram layer having an uneven surface obtained by inverting the concave-convex type of the master original plate. After that, the master original plate was repeatedly stacked, pressed, cured, and peeled to form a 15 mm square reflective Fourier transform hologram region having a plurality of single Fourier transform hologram regions. The thickness of the first hologram layer having the reflective Fourier transform hologram region is 2 μm.

(Formation of transparent Fourier transform hologram region)
Next, the water-soluble ink was printed on the surface of the Al layer using a gravure printing plate cylinder on which a Fourier transform pattern different from that of the reflective Fourier transform hologram region was formed. The water-soluble ink used here is SL No14 Clear (revised) manufactured by Oike Advanced Film Co., Ltd. Next, an Al layer having a film thickness of 100 nm was formed on the entire surface of the first hologram layer on the uneven surface side by a sputtering method. Next, when the surface side of the Al layer was washed with water, the water-soluble ink melted down and the Al layer adhering to the water-soluble ink film was also removed. In this way, the second hologram layer in which the Al layer was formed in a pattern was formed.

[evaluation]
When a point light source was placed on the transparent base material side of the obtained hologram structure of the present invention and visually reflected and observed from the transparent base material side, the Fourier transformed third within the 15 mm square reflective Fourier transform hologram region. It was possible to observe a predetermined image by one hologram layer, that is, a first optical image with good visibility. Further, when a point light source was arranged on the second hologram layer side and transmission observation was performed from the transparent substrate side, a predetermined image by the second hologram layer, that is, a second light image could be observed with good visibility.

1a ... 1st hologram layer 1b ... 2nd hologram layer 2 ... Adhesive layer 3 ... Separator 4 ... Transparent base material 5 ... Heat seal layer 6 ... Easy peeling layer 7 ... Peeling layer 8 ... Interlayer adhesive layer 9a ... Back side protective layer 9b ... Surface side protective layer 10 ... 1st light image 20 ... 2nd light image 10', 20' ... Fourier transform image 11 ... Intermediate base material 100 ... Hologram structure 100a ... Hologram seal 100b ... Hologram transfer foil 100c ... Information recording medium

Claims (1)

A hologram structure having a reflective Fourier transform hologram region and a transmissive Fourier transform hologram region.
The reflective Fourier transform hologram region is a region in which light incident from a point light source converts the reflected light reflected by the uneven surface of the first hologram layer having an uneven surface on the surface into a first optical image.
The transmission type Fourier transform hologram region is a hologram in which light incident from a point light source converts transmitted light transmitted through a second hologram layer arranged in a pattern into a second light image. Structure.

Images