JP6973550B2 - Hologram structure - Google Patents

Description

The present invention relates to a hologram structure having excellent information confidentiality.

A hologram is one in which the wave surface of an object light is recorded on a photosensitive material as interference fringes by interfering two lights of the same wavelength (object light and reference light), and has the same wavelength as the reference light at the time of recording the interference fringes. When the light of the above is applied, a diffraction phenomenon occurs due to the interference fringes, and it is possible to reproduce the same wave plane as the original object light. Holograms are often used for anti-counterfeiting applications because they have advantages such as a beautiful appearance and relatively difficult duplication.
As a method of using a hologram, a method of reproducing as an optical image by transmitting or reflecting reference light to the hologram is known.
For example, Patent Document 1 describes that an optical image is reproduced by projecting diffracted light reflected by a laser-reflecting hologram onto a screen, and authenticity is determined based on the information obtained from the reproduced optical image. ..

Japanese Patent No. 4872964

However, in the case of reproducing and using an optical image on a screen as described in Patent Document 1, there is a problem that the confidentiality of the information is low, such that the information obtained by the optical image can be seen by people around.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hologram structure having excellent information confidentiality.

In order to achieve the above object, the present invention has a hologram layer having a hologram forming region, and in the hologram forming region, a phased Fourier transform hologram that converts light incident from a point light source into a desired optical image. Is recorded, and the above-mentioned optical image provides a hologram structure characterized in that information that can be analyzed by an electronic device is in an encrypted shape.

According to the present invention, a phased Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded in the hologram forming region, so that the hologram structure can be viewed in a plan view by the point light source. An optical image can be reproduced in the upper hologram forming region.
Further, since the optical image has a shape in which information that can be analyzed by an electronic device is encrypted, the information can be obtained by analyzing the optical image reproduced in the hologram forming region by the electronic device. can.
Therefore, in the hologram structure, only the user who knows that the encrypted information is recorded in the optical image reproduced by the point light source in the hologram forming region can acquire the information. It will be excellent in confidentiality.

In the present invention, it is preferable that the shape is a bar code, a two-dimensional bar code, or a digital watermark. This is because these encrypted shapes are highly versatile.

In the present invention, the hologram forming region is a reflective hologram forming region, and the hologram structure preferably has a vapor-deposited layer formed so as to be in contact with the uneven surface of the hologram forming region of the hologram layer. .. This is because the hologram forming region is a reflective hologram forming region, so that the hologram structure can easily take out information using a portable electronic device such as a smartphone as an electronic device.

In the present invention, in the hologram forming region of the hologram layer, a hologram cell capable of converting light incident from a point light source into an optical image and a hologram cell formed on the same plane as the hologram cell are formed in a pattern in a plan view. It is preferable that a diffraction grating cell that draws a diffraction grating pattern is arranged by being arranged in. The hologram structure can reproduce the diffraction grating pattern in the hologram forming region before the light from the point light source is incident, and can reproduce the optical image when the light from the point light source is incident. Therefore, the hologram structure can be pretended to have a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is excellent in confidentiality of information. ..

In the present invention, it is preferable that the diffraction grating design is a plane diffraction grating design that can reproduce the design in a plane. This is because the planar diffraction grating design can be easily made to have high brightness, and the diffraction grating design having excellent visibility can be reproduced. Therefore, the hologram structure can be more effectively disguised as having a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is superior in confidentiality of information. Because it becomes.

In the present invention, it is preferable that the diffraction grating design is a three-dimensional diffraction grating design that can reproduce the design three-dimensionally. The three-dimensional grating pattern makes it possible to draw the observer's attention to the diffraction grating pattern. Therefore, the hologram structure can be more effectively disguised as having a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is superior in confidentiality of information. Because it becomes.

In the present invention, it is preferable that the hologram structure has an adhesive layer formed on the surface of the hologram layer on the uneven surface side of the hologram layer forming region and is used as a hologram seal. This is because the hologram structure can be easily concealed information to the adherend by using the hologram structure as a hologram sticker.

In the present invention, the hologram structure is formed on the surface of the hologram layer on the surface on the uneven surface side of the hologram layer forming region and on the surface of the hologram layer opposite to the uneven surface. It is preferable to have an easily peelable layer and a peeling base material formed on the surface of the easy-to-peel layer opposite to the hologram layer, and to be used as a hologram transfer foil. This is because the hologram structure can give concealed information to the adherend by using the hologram structure as the hologram transfer foil.

In the present invention, it is preferable that the hologram structure is used as an information recording medium. This is because the hologram structure is excellent in the confidentiality of information and can be used as an information recording medium having excellent confidentiality of information.

The present invention has an effect of being able to provide a hologram structure having excellent information confidentiality.

It is a schematic plan view which shows an example of the hologram structure of this invention. FIG. 3 is a cross-sectional view taken along the line AA of FIG. It is explanatory drawing explaining the use method of the hologram structure of this invention. It is explanatory drawing explaining the use method of the hologram structure of this invention. It is explanatory drawing explaining the reproduction method of the light image using the hologram structure. It is explanatory drawing explaining the reproduction method of the light image using the hologram structure. It is explanatory drawing explaining the reproduction method of the light image using the hologram structure. It is explanatory drawing explaining the hologram formation region in this invention. It is explanatory drawing explaining the surface unevenness of the hologram cell in this invention. It is explanatory drawing explaining the hologram cell in this invention. It is a schematic plan view which shows the other example of the hologram structure of this invention. 11 is a cross-sectional view taken along the line BB of FIG. It is explanatory drawing explaining the diffraction grating symbol in this invention. It is explanatory drawing explaining the diffraction grating cell in this invention. It is explanatory drawing explaining the image display layer in this invention. It is a schematic sectional drawing which shows the other example of the hologram structure of this invention. It is a schematic sectional drawing which shows the other example of the hologram structure of this invention. It is a schematic sectional drawing which shows the other example of the hologram structure of this invention. It is a schematic sectional drawing which shows the other example of the hologram structure of this invention. It is a schematic sectional drawing which shows the other example of the hologram structure of this invention. It is explanatory drawing explaining the use method of the hologram structure of this invention.

Hereinafter, the hologram structure of the present invention will be described in detail.
The hologram structure of the present invention has a hologram layer having a hologram forming region, and a phase type Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded in the hologram forming region. The optical image is characterized in that the information that can be analyzed by an electronic device is in an encrypted shape.
In such a hologram structure of the present invention, the hologram forming region is a reflective hologram forming region, and the hologram structure is formed so as to be in contact with the uneven surface of the hologram forming region of the hologram layer. It can be divided into two modes: a mode having a layer (first aspect) and a mode in which the hologram forming region is a transmission type hologram forming region (second aspect).
Hereinafter, the hologram structure of the present invention will be described separately for each aspect.

A. Aspect I The aspect I of the hologram structure of the present invention is the hologram structure described above, wherein the hologram forming region is a reflective hologram forming region, and the hologram structure is the hologram of the hologram layer. It is an embodiment having a vapor-deposited layer formed so as to be in contact with the uneven surface of the formed region.

Such a hologram structure of this embodiment will be described with reference to the drawings.
FIG. 1 is a schematic plan view showing an example of the hologram structure of this embodiment, and FIG. 2 is a sectional view taken along line AA of FIG. As shown in FIGS. 1 and 2, the hologram structure 10 of this embodiment has a hologram layer 1 having a hologram forming region 11, and the light incident from a point light source is desired in the hologram forming region 11. A phase-type Fourier-transformed hologram that is converted into an image is recorded, and the optical image is in a shape in which information that can be analyzed by an electronic device is encrypted.
Further, the hologram forming region 11 is a reflective hologram forming region, and the hologram structure 10 has a vapor deposition layer 2 formed so as to be in contact with the uneven surface 1a of the hologram forming region 11 of the hologram layer 1. be.
The hologram structure 10 shows an example in which the transparent base material 3 is laminated on the surface of the hologram layer 1 opposite to the vapor deposition layer 2.
In FIG. 1, the description of the transparent base material is omitted for the sake of simplicity. Further, in FIG. 1, the region surrounded by the broken line is the hologram forming region 11.

According to this aspect, a phased Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded in the hologram forming region, so that the hologram structure can be viewed in a plan view by the point light source. An optical image can be reproduced in the upper hologram forming region.
Therefore, since the hologram structure can reproduce an optical image in the hologram forming region, information can be obtained without separately preparing a screen or the like for projecting the optical image.
Further, since the optical image has a shape in which information that can be analyzed by an electronic device is encrypted, information can be obtained by analyzing the optical image reproduced in the hologram forming region by the electronic device. ..
For this reason, the hologram structure can acquire information only by a user who knows that encrypted information reproduced by a point light source is recorded in the hologram forming region. It will be excellent in confidentiality.

In addition, the light image can be reproduced only when it is irradiated with light from a point light source.
For these reasons, the hologram structure is excellent in the confidentiality of information.

Further, since the hologram forming region is a reflective hologram forming region, the hologram structure can easily take out information by using a portable electronic device such as a smartphone as an electronic device.
As an example of using the hologram structure when the electronic device is a smartphone having a flash light as a point light source and a camera capable of capturing an optical image, as shown in FIG. 3A, the smartphone flashes as a point light source 21. When the hologram forming region 11 is photographed 22a by the camera as the recognition portion 22 of the above shape in the state where the light is not turned on, as shown in FIG. 3B, an optical image is contained in the hologram forming region 11. Since is not reproduced, it is not possible to capture the shape of the optical image.
On the other hand, as shown in FIG. 4A, in a state where the smartphone turns on the flashlight as the point light source 21 and the light 21a is incident on the hologram forming region 11, the hologram forming region 11 is measured by the camera as the recognition portion 22. As shown in FIG. 4B, it is possible to photograph the reproduced light image 12 in the hologram forming region 11.
Then, information can be retrieved by analyzing the shape of the optical image taken by using software installed on the smartphone.

The hologram structure of this embodiment has a hologram layer and a vapor deposition layer.
Hereinafter, each configuration in the hologram structure of this embodiment will be described.

1. 1. Hologram layer The hologram layer in this embodiment has a hologram forming region.
The above-mentioned optical image has a shape in which information that can be analyzed by an electronic device is encrypted.

(1) Optical image In this embodiment, the optical image reproduced by incident light from a point light source into the hologram forming region has a shape in which information that can be analyzed by an electronic device is encrypted.
Here, the shape in which the information is encrypted means that the digital information has an encrypted shape and has a pattern shape visually different from the original digital information.
The fact that analysis is possible with an electronic device means that the original digital information can be extracted from the above-mentioned shape represented by a pattern by using the electronic device.
Examples of such a shape include a barcode, a two-dimensional bar code such as a QR code (registered trademark), a digital watermark, and the like. This is because the hologram structure facilitates the acquisition of information.
The information may be any information that is protected by being encrypted, for example, an authentication number, a keyword, an Internet address (URL), an e-mail address, product information, and a character string indicating that the product is genuine. Alternatively, a string, a person's name, a place name, an address, a date, etc. can be mentioned. A plurality of the above information may be included in the shape represented by one optical image.

The electronic device may be any device that can recognize the shape and can perform analysis processing to extract the original information from the shape.
As the electronic device, an electronic device dedicated to the analysis process, an electronic device in which software capable of the analysis process is installed, and the like can be used.
Examples of electronic devices include a point light source capable of irradiating a hologram forming region of a mobile phone with a camera function, a smartphone, and the like, and a camera capable of capturing the shape of an optical image reproduced in the hologram forming region. A portable electronic device having the above can be mentioned.

(2) Hologram forming region The hologram forming region is a region in which a phase-type Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded.
The hologram forming region is a reflective hologram forming region.

Here, recording a phase-type Fourier transform hologram means that the phase information of the Fourier transform image obtained through the Fourier transform of the original image is multivalued and recorded as the depth. Therefore, an uneven surface is formed in the hologram forming region of the hologram layer in which the phase Fourier transform hologram is recorded.
The hologram layer converts the light incident from the point light source into a desired light image by the height difference of the uneven shape constituting the uneven surface of the hologram forming region, that is, functions as a Fourier transform lens. By such a function, the light incident from an arbitrary point light source is diffracted in a plurality of predetermined directions to form a predetermined image as an optical image. The above-mentioned function may be referred to as a "Fourier transform lens function".

The reflection type hologram forming region means that when a point light source is arranged on the observation surface side and the hologram layer is viewed in a plan view from the observation surface side, an optical image can be reproduced in the hologram forming region.

The hologram forming region refers to a region capable of converting light incident from a point light source into a desired light image, and specifically, is the minimum that can include all of the hologram cells that can be converted into the light image. It is an area surrounded by a rectangle of area.

The size of the hologram forming region in a plan view is preferably a size in which the entire image of the optical image can be recognized by an electronic device in the hologram forming region.
As illustrated in FIG. 5, when the hologram forming region 11 has a small plan view size (FIG. 5A), the electronic device 20 has an overall image of the optical image 12 (in FIG. 5, a QR code (registered trademark). )), Only a part of them may be recognized (Fig. 5 (b)). Further, as illustrated in FIG. 6, the electronic device 20 may be brought close to the hologram structure 10 in order to make the entire image of the optical image 12 reproducible in the hologram forming region 11 having a small plan view size. It is conceivable (FIG. 6 (a)), but in this case, the size of the reproduced optical image 12 (QR code (registered trademark) in FIG. 6) is small, and the electronic device 20 is represented by the optical image 12. It becomes difficult to recognize the code (registered trademark) (Fig. 6 (b)).
On the other hand, as illustrated in FIG. 7, when the plan view size of the hologram forming region 11 is a predetermined size or more, the hologram structure 10 brings the electronic device 20 close to the hologram structure 10. All of the entire image of the optical image 12 (QR code (registered trademark) in FIG. 7) can be reproduced in the hologram forming region 11 (FIG. 7 (b)) without causing it to be reproduced (FIG. 7 (b)). The QR code (registered trademark) displayed by the optical image 12 can be easily recognized.

The plan view size differs depending on the type of the electronic device and the type of the shape of the optical image, that is, the type of encryption, etc., but the electronic device is a smartphone and the type of the shape is a QR code (registered trademark). ), It is preferably at least 15 mm square or more, and preferably within the range of 15 mm square or more and 50 mm square or less. Since the lower limit of the plan view size is within the above range, it is reproduced in the hologram forming region as an optical image using a smartphone, more specifically, with the flashlight, which is a point light source, turned on. This is because it is easy to take a picture of the QR code (registered trademark) with a camera, analyze the shape of the taken QR code (registered trademark) with software, and retrieve the original information.
Further, when the upper limit of the plan view size is within the above range, the cost of the hologram structure can be easily reduced.
The fact that the hologram forming region has a planar view size of 5 mm square or more means that the hologram forming region has a planar view shape including at least a square range of 5 mm square. Therefore, when the hologram forming region is rectangular, the length of the short side thereof is 5 mm or more, and when the hologram forming region is square, the length of one side thereof is long. Is 5 mm or more.

Further, the size of the optical image reproduction region in which the optical image in the hologram forming region is reproduced is such that the electronic device can recognize the shape of the optical image and analyze it to extract the encrypted information. It often depends on the type of the electronic device, the type of the shape of the optical image, etc., but when the electronic device is a smartphone and the type of the shape is a QR code (registered trademark), it is usually 10 mm square. It can be within the range of ~ 30 mm square.
The optical image reproduction area is a rectangular area having the smallest area that can surround the optical image.

The area ratio occupied by the optical image reproduction region of the hologram forming region may be the entire surface of the hologram forming region or a part of the hologram forming region.
This is because the area ratio is a part of the hologram forming region, so that only the user who knows that the optical image is reproduced in the part of the region can acquire the information.
Further, since the area ratio is the entire surface of the hologram forming region, it becomes easy to read the shape of the optical image by an electronic device.
When the optical image reproduction region is a part of the hologram forming region, the area ratio occupied by the optical image reproduction region of the hologram forming region can be 50% or less, preferably 40% or less, and 10%. It is preferably% or more and 20% or less. This is because the hologram structure is more excellent in the confidentiality of information due to the above area.

As shown in FIG. 8A, the hologram forming region is one hologram cell 12a (hereinafter, simply referred to as simply) in which a phase type Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded. , May be referred to as a hologram cell), but may be a hologram forming region 11 (hereinafter, may be simply referred to as a single hologram region), but is usually as shown in FIG. 8 (b). This is a hologram forming region 11 (hereinafter, may be referred to as a large-format hologram region) in which a plurality of hologram cells 12a are arranged and enlarged.
The QR code (registered trademark) in FIG. 8 shows an example of a shape represented by an optical image 12 reproduced in a single or large format hologram region, respectively.

When the hologram forming region is a large-format hologram region, the size of each hologram cell constituting the hologram forming region in a plan view may be such that the hologram forming region can be formed with high accuracy.
The plan view size is preferably in the range of 0.25 mm square or more and 5 mm square or less. This is because when the plan view size is within the above range, the hologram structure facilitates reproduction of an optical image into the hologram forming region.
The plan view size refers to the size of the smallest square that can include the hologram cell. Therefore, when the hologram cell is a square with a side of 1 mm, the plan view size is 1 mm square. Further, when the planar view shape of the hologram cell is a circular shape having a diameter of 1 mm, the plan view size is 1 mm square.

The ratio of the area in the plan view to the hologram forming region of the hologram cell is not particularly limited as long as it can reproduce a desired optical image, but is preferably 25% or more. Above all, it is desirable that it is 50% or more. This is because the hologram structure can clearly reproduce an optical image because the area ratio is within the above range.

The shape of the hologram cell in a plan view may be any shape as long as it can form a hologram forming region having a desired shape in a plan view. Specifically, the plan view shape shall be a square shape, a rectangular shape, a trapezoidal shape, a triangular shape, a pentagonal shape, a polygonal shape such as a hexagonal shape, a circular shape, an elliptical shape, a star shape, a heart shape, or the like. However, from the viewpoint of easy formation of the hologram forming region, a square shape or a rectangular shape is usually used.

The uneven shape of the uneven surface of the hologram cell is when a plurality of multi-valued Fourier transform images formed based on the image data of the original image to be displayed as an optical image are arranged in the vertical and horizontal directions up to a desired range. Corresponds to the pattern of the Fourier transform image.
As a method for forming such an uneven surface of the hologram cell in the hologram forming region, any method can be used as long as it is possible to form an uneven surface capable of converting the light incident from the point light source into a desired optical image, and general Fourier is used. A method for forming a conversion hologram can be used.
Specifically, the above-mentioned forming method forms a master original plate having an unevenness pattern corresponding to a Fourier transform image, and the unevenness of the original plate is formed on a coating film of a resin material such as an ultraviolet curable resin formed on a substrate such as PET. A method of forming an uneven surface of a hologram cell by transferring a pattern can be mentioned.
Further, by transferring the uneven pattern of the master original plate a plurality of times, it is possible to form a hologram layer having a hologram forming region in which a plurality of hologram cells are arranged.

As a method of forming the master original plate, a Fourier transform image is formed by calculation based on the image data of the original image to be displayed. Next, the data of the Fourier transform image is multivalued to two or more values and converted into electron beam drawing data, and the electron beam drawing data is arranged to a desired range. For example, 10 electron beam drawing data are arranged vertically and 10 horizontally. Next, a method of creating a master original plate with an electron beam drawing apparatus based on the arranged electron beam drawing data can be used.
When the binarized data of the Fourier transform image is used as the electron beam drawing data, the uneven shape of the uneven surface becomes a two-step uneven shape as shown in FIG. 9A. When a valued product is used, it has a four-stage uneven shape as shown in FIG. 9 (b).
In this embodiment, it is preferable that the multi-valued data of the Fourier transform image is multi-valued to four or more values, that is, the uneven shape is four or more steps. In the hologram structure, when the Fourier transform image is obtained by binarization, the optical image reproduced in the hologram forming region displays two images having a mirror image relationship, whereas the hologram structure is quaternized. In the one obtained by the above multi-value increase, it is possible to display one image as the optical image reproduced in the hologram forming region. Therefore, the hologram structure can set the shape of the optical image with a high degree of freedom.

The lattice pitch of the uneven surface may be any as long as it can convert the light incident from the point light source into a desired light image.
Specifically, the lattice pitch is preferably in the range of 1.0 μm to 80.0 μm. This is because when the lattice pitch is within the above range, the hologram structure facilitates reproduction of an optical image into the hologram forming region.
The grid pitch refers to, for example, the width indicated by P in FIG.

Here, as illustrated in FIG. 10, a point light source 21 is arranged at a predetermined distance L1 with respect to the hologram forming region 11 of the hologram structure 10, and is observed at a predetermined distance L2 from the hologram forming region 11. When the observer 30 observes the hologram forming region 11, the following equation (1) holds for the lattice pitch so that the observer 30 can observe the entire image of the optical image in the entire hologram forming region 11. be able to.
Λ is the wavelength of the diffracted light, P is the lattice pitch of the uneven surface, θ1 is the incident angle for reaching the end of the hologram forming region from the light source, and θ2 is the observer of the diffracted light from the end of the hologram forming region. The diffraction angle for reaching, n is the order of diffraction.
P = nλ / (sinθ1 + sinθ2) (1)

As a specific calculation example of the lattice pitch, when the hologram forming region is a square shape with a side of 15 mm, L1 is 50 mm, L2 is 300 mm, and the light has a wavelength of 550 nm, sin θ2 = 0.025. There is, sin θ1 = 0.148, and the lattice pitch P required for the observer to observe the entire image of the optical image in the entire hologram forming region is calculated to be 3179 nm at the shortest.
Further, when the hologram forming region is a square shape with a side of 15 mm, L1 is 1990 mm, L2 is 2000 mm, and the light has a wavelength of 550 nm, it is calculated as sin θ2 = 0.00374 and sin θ1 = 0.00377. The lattice pitch P is calculated to be 73236 nm at the shortest.
Further, when the hologram forming region is a square shape with a side of 10 mm, L1 is 60 mm, L2 is 60 mm, and the light has a wavelength of 550 nm, sin θ2 = 0.083 and sin θ1 = 0.083 is calculated. The lattice pitch P is calculated to be 3313 nm at the shortest.

The depth of the uneven shape may be such that an optical image representing a desired shape can be reproduced. The depth can be, for example, in the range of 0.05 μm to 0.5 μm, and more preferably in the range of 0.1 μm to 0.2 μm. This is because when the depth is within the above range, the hologram structure can stably reproduce an optical image.
The depth is shown by, for example, D in FIG.

Regarding the depth of the uneven shape, when the uneven shape of the uneven surface of the reflective hologram forming region is a quaternary type (4 steps) obtained by digitizing the data of the Fourier transform image, the reflective hologram is formed. In the region, the following equation (2) can be established.
Note that λ is the wavelength of the diffracted light as in Eq. (1).
D = λ / 6 + λ / 12 (2)

As a specific calculation example of the depth of the uneven shape, when light having a wavelength of 550 nm is diffracted in the reflective hologram forming region, the uneven depth D is calculated to be 550 nm / 6 + 550 nm / 12≈140 nm. ..

In the hologram forming region, the wavelength of the point light source capable of exhibiting the above-mentioned Fourier transform lens function is not particularly limited, and a desired wavelength can be targeted. The wavelength of the point light source is not limited to monochromatic light having one wavelength, and may be light including multiple wavelengths, or may be white light.

(3) Diffraction grating cell In the hologram forming region, only the hologram cell capable of converting the light incident from the point light source into the optical image may be arranged, but the light incident from the point light source may be the light. A hologram cell that can be converted into an image and a diffraction grating cell that is formed on the same plane as the hologram cell and is arranged in a pattern in a plan view to draw a diffraction grating pattern are arranged. You may.
By having the diffraction grating cell, the hologram structure can reproduce the diffraction grating pattern in the hologram forming region before the light from the point light source is incident, and when the light from the point light source is incident, the optical image is displayed. It becomes reproducible. Therefore, the hologram structure can be pretended to have a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is excellent in confidentiality of information. ..
11 is a schematic plan view showing an example of a hologram structure in the case where both the hologram cell 12a and the diffraction grating cell 13a are provided in the hologram forming region 11, and FIG. 12 is a sectional view taken along line BB of FIG. be.
11 and 12 show an example in which the diffraction grating symbol 13 is the letter “F”.

Here, the term "formed on the same plane" means that the hologram cell and the diffraction grating cell are formed on the same surface of the hologram layer. That is, both the uneven surface of the hologram cell and the uneven surface of the diffraction grating cell are formed on the same surface of the hologram layer.

The above-mentioned diffraction grating symbol reproduces a pattern-shaped symbol in which a diffraction grating cell is arranged by irradiating visible light as reference light.
Here, the diffraction grating pattern is a pattern drawn by diffraction grating cells arranged in a pattern in a plan view. The original design is divided into, for example, grid-shaped fine cells, and the divided fine cells are divided into diffraction gratings. It was drawn by replacing it with a cell.
FIG. 11 described above shows an example in which the diffraction grating pattern 13 is drawn by arranging the diffraction grating cells 13a in the pattern of the letter “F”, and the reference light with respect to the diffraction grating pattern 13. By irradiating with, the letter "F" is reproduced as the diffraction grating pattern 13 in the hologram forming region 11.

Specifically, the design can be appropriately set according to the use of the hologram structure of this embodiment, and examples thereof include patterns, line drawings, characters, figures, and symbols.

When the hologram forming region is a region in which the optical image is reproduced, the symbol may specify a region in the hologram forming region in which the optical image is reproduced.
When a portable electronic device such as a smartphone is used as an electronic device for reading an optical image, the above information is obtained by taking an optical image using a camera mounted on the smartphone and analyzing the captured image with software. Take out. By the way, in smartphones and the like, the flashlight is usually turned on only when the camera is shooting. Therefore, when the flashlight before shooting is not turned on, it may not be possible to confirm whether or not the reproduction area of the optical image is within the shooting range even by looking at the display screen of the smartphone. On the other hand, since there is a pattern for specifying the reproduction area of the optical image, it is possible to specify the shooting range without turning on the flashlight before shooting. Therefore, the hologram structure makes it easy to acquire information.
For example, as a symbol for specifying the reproduction region of the optical image, specifically, as shown in FIG. 13A, the reproduction region of the optical image 12 is a region surrounded by a dashed line, and the upper left of the hologram forming region 11. In the case of a part of the region, the frame-shaped symbol 13 surrounding the reproduction region of the optical image as illustrated in FIG. 13 (b), and the four corners of the reproduction region of the optical image as illustrated in FIG. 13 (c). The symbol 13 and the like having the shape shown can be mentioned. In FIGS. 13 (b) and 13 (c), the hologram structure has four corners so as to be in a state where a frame-shaped pattern is arranged along the outer circumference of the shooting range displayed on the screen of the smartphone or to touch the four corners of the shooting range. By confirming the state in which the indicated pattern is arranged and taking a picture, the shape represented by the optical image can be stably taken.

The diffraction grating design may be a plane diffraction grating design that can reproduce the design in a plane, or may be a three-dimensional diffraction grating design that can reproduce the design in three dimensions.
This is because since the diffraction grating symbol is a planar diffraction grating symbol, it is easy to make the planar diffraction grating symbol highly bright, and the diffraction grating symbol having excellent visibility can be reproduced. Therefore, the hologram structure can be more effectively disguised as having a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is superior in confidentiality of information. Because it becomes.
Since the diffraction grating symbol is a three-dimensional diffraction grating symbol, the three-dimensional diffraction grating symbol makes it possible to attract the attention of the observer to the diffraction grating symbol. Therefore, the hologram structure can be more effectively disguised as having a diffraction grating pattern recorded in the hologram forming region and no optical image recorded, and is superior in confidentiality of information. Because it becomes.
The diffraction grating symbol may be a planar diffraction grating symbol or a three-dimensional diffraction grating symbol, or may be a combination of both.

As a method for forming the plane diffraction grating pattern, a method of drawing the diffraction grating pattern using a diffraction grating cell having the same amplitude of the diffracted light can be mentioned.
Further, as a method of making the amplitude of the diffracted light about the same, as described in Japanese Patent No. 49844938, a region in which the diffraction grating of the diffraction grating cell is formed (hereinafter, simply referred to as a diffraction grating forming region). There is a method of making the area of) about the same. That is, the planar diffraction grating pattern can be drawn by laying out diffraction grating cells having the same area of the diffraction grating forming region. Further, as for the area of the diffraction grating forming region of the same degree, it is sufficient as long as the plane diffraction grating pattern is reproducible as to how much the diffraction grating cell has the area of the diffraction grating forming region. It is appropriately set according to the size of the diffraction grating pattern, the presence / absence of color display, and the like.

Examples of the method for forming the three-dimensional diffraction grating pattern include a method of arranging a diffraction grating cell having a large amplitude of diffracted light on the central portion side from the end side of the diffraction grating symbol.
More specifically, in FIG. 11, the letter "F" is drawn by a drawing line in which three diffraction grating cells are arranged in the width direction (for example, 13a1, 13a2, and 13a3). In this case, the diffraction grating cells 13a2 arranged on the central side of the diffraction grating cells 13a1 and 13a3 arranged on the end side in the width direction of the drawing line are used as the diffraction grating cells having a large amplitude of the diffracted light. When the reference light is irradiated, the letter "F" can be reproduced so as to appear three-dimensionally.
Further, as a method of increasing the amplitude of the diffracted light from the end side to the center side, as described in Japanese Patent No. 49844938, diffraction having a large area of the diffraction grating forming region from the end side to the center side. A method of arranging a grating cell can be mentioned. That is, the three-dimensional diffraction grating symbol can be one in which a diffraction grating cell having a large area of the diffraction grating forming region is arranged on the central portion side from the end portion side of the diffraction grating symbol.
For example, as illustrated in FIG. 14, which is an enlarged view of the diffraction grating cells 13a1 to 13a3 in FIG. 11, the diffraction grating cells 13a1 and 13a3 arranged on the end side in the width direction of the drawing line are located closer to the center. The arranged diffraction grating cell 13a2 can be a diffraction grating cell having a large area of the diffraction grating forming region 13b.

The ratio of the area of the diffraction grating cell in the plan view to the hologram forming region is not particularly limited as long as the desired diffraction grating pattern can be drawn.
The ratio of the total area of the diffraction grating cells to the total area of the hologram cells in the hologram forming region (total area of the diffraction grating cells / total area of the hologram cells) clearly reproduces both the optical image and the diffraction grating pattern. It is not particularly limited as long as it can be used, but when the diffraction grating symbol is a plane diffraction grating symbol, it is preferably in the range of 1/4 to 3/4, and above all, 1 /. It is preferably in the range of 2 to 1, and particularly preferably in the range of 5/8 to 7/8. This is because when the ratio of the area is within the above range, the hologram structure has excellent visibility of both the optical image and the planar diffraction grating pattern.
Further, the total area ratio is preferably in the range of 1/3 to 3 when the diffraction grating symbol is a three-dimensional diffraction grating symbol, and in particular, in the range of 2/3 to 2. It is preferable, and in particular, it is preferably in the range of 1 to 5/3. This is because when the ratio of the area is within the above range, the hologram structure has excellent visibility of both the optical image and the three-dimensional diffraction grating pattern.

The lattice pitch, lattice angle, and lattice density (the area ratio of the diffraction grating cell to the symbol in a plan view) of the diffraction grating cell are appropriately set according to the symbol to be reproduced when the reference light is irradiated. It is a thing.
For example, by setting the grid pitch to about 1.2 μm, about 1.0 μm, and about 0.8 μm, respectively, light with wavelengths of 600 nm (for red), 500 nm (for green), and 400 nm (for blue) is diffracted. It is possible to make a color image reproducible.
Further, various patterns can be expressed by the lattice angle and the lattice density.

The size of the diffraction grating cell in a plan view can be appropriately set according to the diffraction grating pattern to be reproduced, and can be, for example, 5 μm square or more and 100 μm square or less. This is because a high-definition diffraction grating pattern can be drawn by having the above-mentioned plan view size. In addition, the existence of individual diffraction grating cells that draw the diffraction grating pattern can be concealed.

The shape of the diffraction grating cell in a plan view can be appropriately set according to the diffraction grating pattern to be reproduced, and can be, for example, the same as that of a hologram cell.

The method of forming the uneven surface of the diffraction grating cell in the hologram forming region can be the same as the method of forming a general diffraction grating pattern.

The reference light used for reproducing the diffraction grating pattern is not particularly limited, and one used for a general hologram can be used.
Specifically, as the reference light, light including visible light can be used.
For example, the reference light can be the same as the point light source used for reproducing the light image recorded in the hologram cell of the hologram layer.
The light source of the reference light is not limited to a point light source, but may be parallel light such as sunlight.
The hologram structure can reproduce the diffraction grating pattern by arranging it in a bright place where reference light from a light source other than the point light source is irradiated, and further, in the bright place, the point light source is placed on the hologram forming region. By arranging it in, the optical image can also be reproduced.

(4) Others The material constituting the hologram layer is not particularly limited as long as it can form an uneven shape for exhibiting the above-mentioned Fourier transform lens function in the hologram forming region and exhibits a predetermined refractive index. .. The refractive index indicated by the material constituting the hologram layer is not particularly limited, and can be appropriately set according to the use of the hologram structure of this embodiment.
Further, the wavelength that serves as a reference for the refractive index is not particularly limited, and may be appropriately selected from the range of 400 nm to 750 nm. Above all, in this embodiment, the refractive index at a wavelength of 555 nm is preferably in the range of 1.3 to 2.0, and particularly preferably in the range of 1.33 to 1.8. Here, the refractive index can be measured by a spectroscopic ellipsometer.

The material of the hologram layer is a resin material conventionally used for forming a relief type hologram or the like, for example, a cured product of a curable resin such as a thermosetting resin, an ultraviolet curable resin, or an ionizing radiation curable resin. Thermoplastic resin or the like can be used.

Examples of the thermosetting resin include unsaturated polyester resin, acrylic modified urethane resin, epoxy modified acrylic resin, epoxy modified unsaturated polyester resin, alkyd resin, and phenol resin. Examples of the thermoplastic resin include acrylic acid ester resin, acrylamide resin, nitrocellulose resin, and polystyrene resin. These resins may be homopolymers or copolymers composed of two or more kinds of constituents. Further, these resins may be used alone or in combination of two or more.

The above-mentioned thermosetting resin or thermoplastic resin includes various isocyanate compounds, metal soaps such as cobalt naphthenate and zinc naphthenate, organic peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide, benzophenone, acetophenone, anthraquinone and naphthoquinone. It may contain a thermosetting agent such as azobisisobutyronitrile or diphenylsulfide.

Examples of the ionized radiation curable resin include epoxy-modified acrylate resin, urethane-modified acrylate resin, and acrylic-modified polyester resin. Among them, urethane-modified acrylate resin is preferable, and is particularly shown in JP-A-2007-017643. A urethane-modified acrylic resin represented by the above chemical formula is preferable.

When the ionizing radiation curable resin is cured, a monofunctional or polyfunctional monomer, an oligomer, or the like can be used in combination for the purpose of adjusting the crosslinked structure and viscosity. Examples of the monofunctional monomer include mono (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, vinylpyrrolidone, (meth) acryloyloxyethyl succinate, and (meth) acryloyloxyethyl phthalate. And so on. The bifunctional or higher functional monomers are classified by skeletal structure and are classified into polyol (meth) acrylate (for example, epoxy-modified polyol (meth) acrylate, lactone-modified polyol (meth) acrylate, etc.), polyester (meth) acrylate, and epoxy (meth). ) Acrylate, urethane (meth) acrylate, other polybutadiene-based, isocyanuric acid-based, hydantin-based, melamine-based, phosphoric acid-based, imide-based, phosphazene-based poly (meth) acrylate and the like. In addition, various monomers, oligomers and polymers that are UV and electron beam curable are available.

More specifically, examples of the bifunctional monomer and oligomer include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexanediol di (meth). Examples include acrylate. Examples of the trifunctional monomer, oligomer, and polymer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and aliphatic tri (meth) acrylate. Examples of the tetrafunctional monomer and oligomer include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and aliphatic tetra (meth) acrylate. Examples of the pentafunctional or higher functional monomers and oligomers include dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. Examples of the monomer and oligomer include a polyester skeleton, a urethane skeleton, and a (meth) acrylate having a phosphazene skeleton. The number of functional groups is not particularly limited, but if the number of functional groups is smaller than 3, the heat resistance tends to decrease, and if it exceeds 20, the flexibility tends to decrease, so that the number of functional groups is particularly high. Those in the range of 3 to 20 are preferable.

The content of the monofunctional or polyfunctional monomers and oligomers as described above can be appropriately adjusted, but is usually preferably 50 parts by weight or less with respect to 100 parts by weight of the ionizing radiation curable resin. It is preferably in the range of 0.5 parts by weight to 20 parts by weight.

Further, the hologram layer has, if necessary, a photopolymerization initiator, a polymerization inhibitor, a deterioration inhibitor, a plasticizer, a lubricant, a colorant such as a dye or a pigment, a surfactant, an antifoaming agent, a leveling agent, and a thixotropic property. Additives such as a primer may be added as appropriate.

When the hologram layer has self-supporting property, the film thickness of the hologram layer is preferably in the range of 0.05 mm to 5 mm, and more preferably in the range of 0.1 mm to 3 mm. On the other hand, when the hologram layer does not have self-supporting property and is formed on a transparent substrate described later, the film thickness of the hologram layer is preferably in the range of 0.1 μm to 50 μm, and more preferably 2 μm to 20 μm. It is preferably within the range of.
The film thickness of the hologram layer is specifically the distance shown by a in FIG. 2 already described.
Further, the size of the hologram layer in a plan view and the like can be appropriately set according to the use of the hologram structure of this embodiment.

The hologram layer in this embodiment has at least a hologram forming region, but may have a region (non-hologram forming region) in which a concave-convex shape is not formed in addition to the hologram forming region.
The ratio occupied by each of the above regions in the hologram layer is not particularly limited and may be appropriately selected depending on the intended use.

2. 2. Thin-film deposition layer The hologram structure of this embodiment has a vapor-deposited layer formed so as to be in contact with the uneven surface of the hologram-forming region of the hologram layer.

The vapor-filmed layer may have transparency or may be reflective.
When the thin-film deposition layer is a transparent thin-film deposition layer having transparency, the hologram-forming region of the hologram structure does not have gloss when viewed in a plan view. Therefore, in the hologram structure, the hologram forming region is concealed, and the hologram structure is excellent in the confidentiality of information.
On the other hand, when the thin-film deposition layer is a reflective vapor-filming layer having reflectivity, the hologram structure can clearly reproduce an optical image in the hologram forming region. Therefore, the hologram structure makes it easy to acquire information.

The transparent vapor deposition layer preferably has a total light transmittance (hereinafter, may be simply referred to as light transmittance) of 80% or more, and more preferably 90% or more. This is because the light transmittance makes the hologram structure more concealed in the hologram forming region.
The light transmittance is a value measured by JIS K7361-1 (a test method for the total light transmittance of a plastic-transparent material).

The material constituting the thin-film vapor deposition layer is not particularly limited as long as it is a material that causes a difference in refractive index from the hologram layer. Examples of the material capable of forming the reflective vapor film layer include Mg, Al, Ti, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge, Se, Rb, Pd, Ag, Cd, In and Sn. , Sb, Te, Au, Pb, or Bi and the like.
Further, as a material capable of forming the transparent thin-film deposition layer, for example, an oxide of the above metal can be mentioned.
The above materials may be used alone or in combination of two or more materials.

The thickness of the thin-film vapor deposition layer can be appropriately set from the viewpoints of ease of reproduction of an optical image, color tone, design, application, etc., and is preferably in the range of 50 Å to 1 μm, particularly in the range of 100 Å to 1000 Å. Is preferable.
Further, the thickness is preferably 200 Å or less from the viewpoint of imparting transparency to the thin-film vapor deposition layer, and may be more than 200 Å from the viewpoint of imparting concealment to the thin-film deposition layer. preferable.
The thickness of the thin-film vapor deposition layer is specifically the distance shown by b in FIG. 2 already described.

The formed portion of the vapor-filmed layer may be at least overlapped with all the uneven surfaces in the hologram forming region in a plan view, and may cover the entire surface of the hologram layer on the uneven surface side.
When the hologram forming region includes the diffraction grating cell together with the hologram cell, all the uneven surfaces refer to all the uneven surfaces of both the hologram cell and the diffraction grating cell.

As the method for forming the thin-film deposition layer, a general method for forming the thin-film deposition layer can be used, and examples thereof include a vacuum vapor deposition method, a sputtering method, and an ion plating method.

3. 3. Other Structures The hologram structure of this embodiment has a hologram layer and a vapor-deposited layer, but may have other structures if necessary.

(1) Transparent base material The hologram structure of this embodiment may have a transparent base material formed on a surface opposite to the uneven surface of the hologram layer. This is because having a transparent substrate can increase the thermal or mechanical strength of the hologram structure of this embodiment.

The transparent substrate may be formed so as to be in direct contact with the hologram layer, or may be formed via another layer.
For example, the transparent substrate can be bonded to the surface of the hologram layer via an interlayer adhesive layer described later.

The light transmittance of the transparent substrate is preferably 80% or more, and more preferably 90% or more. This is because the hologram structure makes it easy to visually recognize the light image by setting the light transmittance of the transparent base material within the above range.

Further, the transparent substrate having a lower haze value is preferable, and specifically, a transparent substrate having a haze value in the range of 0.01% to 5% is preferable, and the transparent substrate is preferably in the range of 0.01% to 3%. Some are preferable, and those in the range of 0.01% to 1.5% are particularly preferable. By setting the haze value of the transparent substrate within the above range, it is possible to display the optical image expressed in the hologram forming region without impairing the visibility. The haze value of the transparent substrate shall be a value measured in accordance with JIS K7136.

The constituent material of the transparent base material is not particularly limited as long as it exhibits the above-mentioned light transmittance and haze value, and is, for example, polyethylene terephthalate, polycarbonate, acrylic resin, cycloolefin resin, polyester resin, and polystyrene resin. , Resin films such as acrylic styrene resin, quartz glass, Pilex (registered trademark), and glass such as synthetic quartz plates can be used. Among them, as the transparent base material, it is preferable to use a resin film because it is lightweight and there is little risk of breakage, and polycarbonate is most suitable from the viewpoint of birefringence.

The transparent substrate may contain additives, if necessary.
Examples of the additive include a dispersant, a filler, a plasticizer, an antistatic agent, and the like.

The film thickness of the transparent substrate may be any thickness as long as it can have rigidity and strength to support the hologram layer or the like, and is preferably about 0.005 mm to 5 mm, and above all, 0. It is preferably in the range of 02 mm to 1 mm. Further, the shape of the transparent base material is not particularly limited, and can be appropriately selected depending on the usage pattern of the hologram structure of this embodiment.

The surface of the transparent substrate may be, for example, corona-treated in order to improve the adhesion to other layers.

(2) Image Display Layer The hologram structure of this embodiment preferably has an image display layer that displays an image that specifies an area in which an optical image is reproduced in the hologram forming region.
This is because it becomes easy to specify the region in which the optical image is reproduced in the hologram forming region, and the hologram structure makes it easy to acquire information.

Here, the image may be, for example, a pattern, a line drawing, a character, a figure, a symbol, or the like.
Specific examples of the image include an arrow pointing to a reproduction area of an optical image, a frame shape surrounding two sides of the reproduction area of an optical image, and the like, as illustrated in FIGS. 15A and 15B. Can be done.
Further, the image display layer is usually formed so as not to overlap the hologram forming region in a plan view, but when the image display layer overlaps the hologram forming region in a plan view, the image is described in the above “1. It can be the same as the symbol for specifying the region where the optical image is reproduced as described in the section "Hologram layer".

The image display layer may be any one capable of displaying a desired image, for example, a printing layer having a coloring material and a resin material, and a diffraction grating pattern drawn by a diffraction grating cell arranged in a pattern in a plan view. A second hologram layer having a second hologram layer and the like can be mentioned.
The print layer can easily draw images of various colors and patterns. The second hologram layer can display an image only when it is irradiated with reference light. Therefore, the print layer or the like can easily add further information to the hologram structure.
The image display layer may be of only one type, or may be used in combination of two or more types. For example, the image display layer may be one including a plurality of print layers, one including a print layer, a second hologram layer, and the like.
Hereinafter, the print layer and the second hologram layer will be described.

(A) Print layer The print layer has a coloring material and a resin material.
Examples of the resin material include polycarbonates, polyesters, cellulose derivatives, norbornene resins, polyvinyl chlorides, polyvinyl acetates, acrylic resins, urethane resins, polypropylenes, polyethylenes, styrenes and the like. Resin can be used.
As the coloring material, those generally used as a printing layer can be used, and pigments such as inorganic pigments and organic pigments, acid dyes, direct dyes, disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimation properties can be used. Examples include dyes such as dyes.
Further, as the coloring material, fluorescent light emitting materials such as ultraviolet light emitting materials and infrared light emitting materials that emit fluorescence by absorbing ultraviolet rays or infrared rays, polarized cholesteric polymer liquid crystal pigments, and particles that serve as reflectors such as glass beads are also used. Can be done.
As the method for forming the print layer, that is, the printing method, the same method as the general method for forming the print layer can be used. Specific examples of the printing method include various printing methods such as inkjet printing, screen printing, offset printing, gravure printing, and flexographic printing.
Further, as the ink used for the printing layer, an ink used for forming a general printing layer can be used, and an ink obtained by dispersing or dissolving the resin material and the coloring material in a solvent can be used.

The formation position of the print layer is not particularly limited as long as it does not interfere with the reproduction and visual recognition of the optical image in the hologram formation region, and the hologram is formed on the surface opposite to the uneven surface of the hologram layer. It can be on the same plane as the layer, on the surface of the hologram layer on the uneven surface side, and the like.
FIG. 16 shows an example in which the printed layer 4 is formed on the surface of the transparent substrate 3 on the opposite side of the hologram layer 1 so as not to overlap the hologram forming region 11 in a plan view.

(B) Second Hologram Layer The second hologram layer has a diffraction grating pattern drawn by diffraction grating cells arranged in a pattern in a plan view, and the diffraction grating cells are arranged by irradiating with reference light. The pattern of the pattern shape is reproduced.
Since such a diffraction grating pattern, a diffraction grating cell, and reference light can be the same as those described in the above "1. Hologram layer", the description thereof is omitted here.

The material constituting the second hologram layer is not particularly limited as long as it can form a concave-convex shape that functions as a diffraction grating included in the diffraction grating cell.
Such a material can be the same as the constituent material of the hologram layer described in the above section "1. Hologram layer".

The film thickness of the second hologram layer may be any as long as it can stably form the uneven shape of the diffraction grating, and may be the same as the hologram layer described in the above section "1. Hologram layer". ..

The formation position of the second hologram layer is not particularly limited as long as it does not interfere with the reproduction and visual recognition of the optical image in the hologram formation region, and is on the surface opposite to the uneven surface of the hologram layer. , It can be on the same plane as the hologram layer, on the uneven surface of the hologram layer, and so on.
In FIG. 17, the second thin-film deposition layer 7 formed so as to be in contact with the uneven surface of the second hologram layer 6 and the diffraction grating pattern of the second hologram layer 6 is formed on the uneven surface of the hologram layer 1 with the hologram forming region 11. It shows an example which is formed so that it does not overlap in a plan view, and is formed through a vapor deposition layer 2 and an interlayer adhesive layer 5.

The hologram structure of this embodiment may have a second thin-film deposition layer formed so as to be in contact with the uneven surface of the diffraction grating pattern of the second hologram layer.
The second thin-film deposition layer is not particularly limited as long as the second hologram layer can function as a reflective hologram, and is generally used for a reflective hologram. Can be done. Specifically, the second thin-film deposition layer can be the same as the content described in the above-mentioned "2. Thin-film deposition layer" section.
In addition, in FIG. 17 already described, the second vapor deposition layer 7 formed so that the hologram structure 10 is in contact with the uneven surface of the second hologram layer on the surface of the second hologram layer 6 opposite to the hologram layer 1. It shows an example having.

(3) Interlayer Adhesive Layer The hologram structure of this embodiment may have an interlayer adhesive layer for adhering between the configurations.
As the interlayer adhesive layer, one generally used for a hologram structure can be used, and the layer is appropriately selected depending on the material constituting the transparent substrate, the hologram layer and the like.
As the 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.
The thickness of the interlayer adhesive layer is appropriately set depending on the size of the structure to be adhered and the like.

(4) Adhesive layer The hologram structure of this embodiment may have an adhesive layer formed on the surface of the hologram layer on the uneven surface side. This is because the hologram structure can be easily attached to the adherend by having the adhesive layer.

The adhesive layer may be transparent or may have light-shielding properties.

The adhesive layer may be a pressure-sensitive adhesive layer having adhesiveness, or may be a re-peelable adhesive layer having both adhesiveness and re-peelability characteristics.
The adhesive layer is an adhesive layer such as a two-component curable adhesive layer, an ultraviolet curable adhesive layer, a heat-curable adhesive layer, and a heat-melt type adhesive layer, similarly to the interlayer adhesive layer. Is also good.
When the adhesive layer is an adhesive layer, the hologram structure of this embodiment can be firmly attached to a desired member, and the hologram structure can be made difficult to peel off from the adherend.
Further, when the adhesive layer is a re-peelable adhesive layer, the hologram structure of this embodiment is attached to a desired member by adhering the adhesive layer between the re-peelable adhesive layer and the adherend so that air does not enter. Can be done. Such a re-peelable adhesion layer can easily repeatedly adhere and peel without leaving a mark on the adherend due to an adhesive or the like, and damage to the adherend can be suppressed.

When the adhesive layer is an adhesive layer, examples of the resin used for the adhesive layer include acrylic resin, ester resin, urethane resin, ethylene vinyl acetate resin, latex resin, epoxy resin, and polyurethane. Examples thereof include an ester resin, a fluororesin such as vinylidene fluoride resin (PVDF) and vinyl fluoride resin (PVF), and a polyimide resin such as polyimide, polyamideimide, and polyetherimide. The resin is preferably an acrylic resin, a urethane resin, an ethylene vinyl acetate resin, or a latex resin.

When the adhesive layer is a re-peelable adhesive layer, the resin used for the re-peelable adhesive layer includes, for example, an acrylic resin, an acrylic acid ester resin, a copolymer thereof, a styrene-butadiene copolymer, or the like. Examples thereof include natural rubber, casein, gelatin, rosin ester, terpene resin, phenol-based resin, styrene-based resin, Kumaron inden resin, polyvinyl ether, silicone resin and the like. The resin is preferably an acrylic resin or a silicone resin. This is because the acrylic resin can be adhered even if the surface of the adherend has some irregularities. In addition, the silicone resin does not easily lose its adhesive strength even after repeated adhesion and peeling.

The thickness of the adhesive layer is appropriately selected depending on the type and application of the hologram structure of this embodiment, but is usually preferably in the range of 1 μm to 500 μm, and particularly preferably in the range of 2 μm to 50 μm. Is preferable. This is because the adhesive layer has excellent adhesiveness when the thickness is within the above range.

(5) Release sheet Further, in the hologram structure of this embodiment, the release sheet may be arranged on the above-mentioned adhesive layer. Immediately before the hologram structure of this embodiment is attached to a desired adherend via an adhesive layer, the release sheet and the adhesive layer can be separated and used. This makes it possible to prevent foreign matter from adhering between the adhesive layer and the adherend.

The release sheet is not particularly limited as long as it can protect the adhesive layer and can be easily peeled from the adhesive layer. As such a release sheet, for example, a layer made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS) or the like can be used.
The thickness of the release sheet is appropriately selected according to the type and use of the hologram structure of this embodiment.

Further, it is preferable that the surface of the peeling sheet on the side in contact with the adhesive layer is subjected to a peeling treatment in order to facilitate the peeling operation with the adhesive layer. Examples of such a treatment method include silicone treatment, alkyd treatment, and the like, but are not particularly limited.

(6) Arbitrary member Further, even if the hologram structure of this embodiment has an ultraviolet absorbing layer, an infrared absorbing layer, an antireflection layer, or the like on the transparent substrate or the non-hologram forming region of the hologram layer. good. By having such a layer, it is possible to impart an ultraviolet absorbing function, an infrared absorbing function, an antireflection function, etc. to the hologram structure, and the hologram structure of this embodiment can also be used as various filters and the like. Become.
Since these layers can be the same as those generally used, the description thereof is omitted here.

4. Hologram structure The hologram structure of this embodiment may be used by adhering the hologram structure to the adherend, or may be used without adhering to the adherend.

The aspect of being used by adhering to the adherend is not particularly limited as long as it has an adhesive layer used for adhering to the adherend, and the hologram structure is the hologram layer. Concavo-convexity of the hologram layer forming region An embodiment having an adhesive layer formed on the surface on the surface side and used as a hologram seal (first usage mode), the hologram structure is the unevenness of the hologram layer forming region of the hologram layer. On the surface of the hologram layer opposite to the hologram layer, the heat seal layer formed on the surface on the surface side, the easily peelable layer formed on the surface of the hologram layer opposite to the uneven surface, and the easily peelable layer. Examples thereof include a mode (second use mode) in which the formed peeling base material is provided and used as a hologram transfer foil.
Further, as an embodiment in which the hologram structure is used without adhering to the adherend, an embodiment in which the hologram structure is used as an information recording medium (third usage embodiment) and the like can be mentioned.

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

Such a hologram structure of this embodiment will be described with reference to the drawings. FIG. 18 is a schematic cross-sectional view showing an example of the hologram structure of this embodiment. As illustrated in FIG. 18, the hologram structure 10 of this embodiment has an adhesive layer 31 formed on the surface of the hologram layer 1 on the uneven surface side of the hologram layer forming region 11, and is used as a hologram seal. It is a thing.
Since the reference numerals in FIG. 18 indicate the same members as those in FIGS. 1 and 2, the description thereof will be omitted here.
Further, in this example, the hologram structure 10 has a release sheet 32 on the surface of the adhesive layer 31 opposite to the hologram layer 1.

According to this aspect, by having the adhesive layer, it is possible to easily impart concealed information to the adherend.
As a specific application of such a hologram structure of this embodiment, it is attached to a ticket, a brand product, a quality control number label of a product, or the like, and a point light source is arranged on the hologram forming region in the hologram forming region. It can be mentioned that the authenticity is determined by using the light image reproduced in the above.

The hologram structure of this embodiment has an adhesive layer.
The adhesive layer may be the same as that described in the above section "3. Other configurations".
Further, if necessary, it may have other configurations described in the above-mentioned "3. Other configurations".

(2) Second usage mode The second usage mode of the hologram structure of this embodiment is a heat seal layer formed on the surface of the hologram layer on the uneven surface side of the hologram layer forming region, and the unevenness of the hologram layer. It has an easily peelable layer formed on the surface opposite to the surface and a peeling base material formed on the surface opposite to the hologram layer of the easy peeling layer, and is used as a hologram transfer foil. It is an aspect.

Such a hologram structure of this embodiment will be described with reference to the drawings. FIG. 19 is a schematic cross-sectional view showing an example of the hologram structure of this embodiment. As illustrated in FIG. 19, in the hologram structure 10 of this embodiment, the heat seal layer 33 formed on the surface of the hologram layer 1 on the uneven surface side of the hologram layer forming region 11 and the hologram layer 1 are described above. It has an easily peelable layer 34 formed on the surface opposite to the uneven surface, and a peeling base material 35 formed on the surface opposite to the hologram layer 1 of the easy peeling layer 34, and has a hologram. It is used as a transfer foil.
Since the reference numerals in FIG. 19 indicate the same members as those in FIGS. 1 and 2, the description thereof will be omitted here.
Further, in this example, the hologram structure 10 has a release sheet 32 on the surface of the heat seal layer 33 opposite to the hologram layer 1.

According to this aspect, since the hologram layer is provided, concealed information can be easily given to the adherend.
Further, since the peeling base material is formed on the side opposite to the uneven surface of the hologram layer via the peeling layer easy layer, it is possible to prevent the hologram structure from being damaged before being attached to the adherend. can.
As a specific application of such a hologram structure of this embodiment, a point light source is placed on a hologram forming region by transferring it to a ticket, a brand product, a quality control number label of a product, or the like in a desired pattern shape. Examples of applications for performing authenticity determination using an optical image reproduced in the hologram forming region can be mentioned.

The hologram structure of this embodiment has a heat seal layer, an easy peeling layer, and a peeling substrate.
Hereinafter, each configuration of the hologram structure of this embodiment will be described in detail.

The heat seal layer has a function of adhering the hologram layer and the adherend.

The heat-sealing layer is particularly limited as long as the hologram layer and the adherend can be adhered to each other, depending on the type of the adherend to which the hologram layer and the vapor-deposited layer are transferred from the hologram structure of this embodiment. It's not a thing.
As the heat seal layer, for example, a heat seal layer containing a thermoplastic resin described in Japanese Patent Application Laid-Open No. 2014-16422 can be used.

The peeling base material supports a hologram layer or the like.
Further, the peeling base material is one in which the hologram structure of this embodiment is adhered to an adherend and then peeled from the hologram structure.
The peeling substrate may be a transparent material or a light-shielding material.
The material and film thickness constituting the peeling base material can be, for example, the same as the transparent base material described in the above section "3. Other configurations", and thus the description thereof is omitted here.

The easily peelable layer is provided to easily separate the peeling base material and the hologram layer after the hologram layer is adhered to the adherend via the adhesive layer.
As such an easily peelable layer, the re-peelable adhesion layer described in the above section "3. Other configurations" can be used.

The location of the easily peelable layer in a plan view is not particularly limited as long as the peelable base material can be easily peeled off from the hologram layer.

The hologram structure of this embodiment may have other configurations described in the above-mentioned "3. Other configurations", if necessary.

(3) Third usage mode The third usage mode of the hologram structure of this embodiment is a mode used as an information recording medium.

Such a hologram structure of this embodiment will be described with reference to the drawings. FIG. 20 is a schematic cross-sectional view showing an example of the hologram structure of this embodiment. As illustrated in FIG. 20, in the hologram structure 10 of this embodiment, the back surface side protective layer 36 formed on the surface of the hologram layer forming region 11 of the hologram layer 1 on the uneven surface side and the hologram layer 1 are provided. It has a surface-side protective layer 37 formed on the surface opposite to the uneven surface and an intermediate base material 38 formed between the hologram layer 1 and the surface-side protective layer 37, and is used as an information recording medium. Is something that can be done.
Since the reference numerals in FIG. 20 indicate the same members as those in FIGS. 1 and 2, the description thereof will be omitted here.

According to this aspect, by using it as an information recording medium, it is possible to make an information recording medium having excellent confidentiality of information.
Specific uses of the hologram structure of this embodiment include, for example, cards such as credit cards, cash cards, and point cards, employee ID cards, identification cards such as driver's licenses, passports, passports, and the like.

The hologram structure of this embodiment has a hologram layer, but may have other configurations depending on the type of information recording medium.

Such other configurations include, for example, a back surface side protective layer formed on the surface of the hologram layer on the uneven surface side, and a front surface side protective layer formed on the surface of the hologram layer opposite to the uneven surface. An intermediate substrate formed between the hologram layer and the surface protective layer can be mentioned.
The surface-side protective layer is formed on the surface opposite to the uneven surface of the hologram layer to protect the hologram layer, and at least the region that overlaps the hologram-forming region in a plan view has transparency. Used.
The back surface side protective layer is formed on the surface opposite to the hologram layer of the vapor deposition layer to protect the hologram layer. When the hologram forming region is a reflective hologram forming region, the back surface side protective layer may have transparency or may have light-shielding property.
The intermediate base material is formed between the hologram layer and the front surface side protective layer to support the hologram layer, the front surface side protective layer, and the back surface side protective layer, and at least a region that overlaps the hologram forming region in a plan view. Is used which has transparency. The intermediate base material may also be used as a transparent base material.
The constituent materials and film thicknesses of the front surface side protective layer, the back surface side protective layer, and the intermediate base material can be, for example, the same as those of the transparent base material described in the above “3. Other configurations”. .. More specifically, polycarbonate can be used as a constituent material of the front surface side protective layer and the back surface side protective layer, and polyethylene terephthalate can be used as a constituent material of the intermediate base material.
Further, the front surface side protective layer, the back surface side protective layer, and the intermediate base material may be formed as long as they can protect the hologram layer or the like, but may cover the entire surface of the hologram layer.

Examples of the other configuration include 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.
The other configuration may include a functional layer such as an antenna layer including an antenna.
The location where the information recording layer, the functional layer, and the like are formed is not particularly limited as long as the position does not interfere with the reproduction and visual recognition of the optical image in the hologram forming region. Can be on the surface on the opposite side, on the same plane as the hologram layer, on the surface on the uneven surface side of the hologram layer, and the like.

5. Manufacturing Method The manufacturing method of the hologram structure of this embodiment is not particularly limited as long as it can accurately manufacture the hologram structure including each of the above configurations, and is the same as the general method for forming the hologram structure. The method can be used.
Specific examples of the manufacturing method include a method of preparing a transparent base material and forming a hologram layer.

6. Uses The hologram structure of this embodiment can be used for anti-counterfeiting purposes, and examples thereof include information recording media including cards such as credit cards and cash cards.
Further, the hologram structure may have an adhesive layer that can be adhered to another adherend, and may be used as a hologram structure seal or the like that can be attached to the adherend.
Further, the hologram structure may have a heat seal layer and may be used as a hologram structure transfer foil or the like that can be transferred to an adherend.

B. II Embodiment The II aspect of the hologram structure of the present invention is the above-mentioned hologram structure, wherein the hologram forming region is a transmission type hologram forming region.

The hologram structure of this aspect can be the same as that of FIGS. 1 and 2 already described, for example.

According to this aspect, the hologram structure can reproduce an optical image in a hologram forming region in a plan view by a point light source.
Further, the optical image has a shape in which information that can be analyzed by an electronic device is encrypted.
Therefore, the hologram structure is excellent in the confidentiality of information.

Further, since the hologram forming region is a transmissive hologram forming region, for example, as illustrated in FIG. 21, in the hologram structure 10, the point light source 21 and the portion 22 that recognizes the shape of the optical image are arranged to face each other. It can also be used in the electronic device 20 to be used.
Furthermore, if the electronic device does not have a point light source, or if the battery is low and the flashlight cannot be used, for example, other points such as the moon, stars, and lighting. By arranging the light source on the side opposite to the observation surface of the hologram structure, it is possible to reproduce an optical image in the hologram forming region and analyze it with an electronic device to extract information.
In addition, it is easy for the hologram structure to reproduce an optical image by a point light source located at a distant distance, which is mainly observed at night, such as the moon, stars, building lighting, and fireworks. Is.

The hologram structure of this embodiment has a hologram layer.
Hereinafter, each configuration in the hologram structure of this embodiment will be described.
The method, use, and the like for manufacturing the hologram structure can be the same as those described in the above section "A. I.", and thus the description thereof is omitted here.

1. 1. Hologram layer The hologram layer in this embodiment has a hologram forming region.
The above-mentioned optical image has a shape in which information that can be analyzed by an electronic device is encrypted.
Since the optical image can be the same as the content described in the above-mentioned "A. I aspect", the description thereof is omitted here.

(1) Hologram forming region The hologram forming region is a region in which a phase-type Fourier transform hologram that converts light incident from a point light source into a desired optical image is recorded.
The hologram forming region is a transmissive hologram forming region.

The transmission type hologram forming region means that when a point light source is arranged on the side opposite to the observation surface and the hologram layer is viewed in a plan view from the observation surface side, an optical image can be reproduced in the hologram forming region. be.

The hologram forming region can be the same as the content described in the above-mentioned "A. I aspect" except for the depth of the uneven shape, and thus the description thereof is omitted here.

The depth of the uneven shape may be such that a desired optical image can be reproduced. The depth can be, for example, in the range of 0.5 μm to 1.5 μm, and more preferably in the range of 0.6 μm to 1.2 μm. This is because when the depth is within the above range, the hologram structure can stably reproduce an optical image.

Regarding the depth of the concave-convex shape, when the concave-convex surface of the concave-convex surface of the transmission-type hologram formation region is a quaternary type (4 steps) obtained by quadrupling the data of the Fourier transform image, the transmission-type hologram is formed. In the region, the following equation (3) can be established.
Note that λ is the wavelength of the diffracted light as in Eq. (1).
D = λ + λ / 2 (3)

As a specific calculation example of the depth of the uneven shape, assuming that light having a wavelength of 550 nm is diffracted, the uneven depth D is calculated as 550 nm + 550 nm / 2≈825 nm in the transmission type hologram forming region.

(2) Diffraction grating cell In the hologram forming region, only the hologram cell capable of converting the light incident from the point light source into the optical image may be arranged, but the light incident from the point light source may be the light. A hologram cell that can be converted into an image and a diffraction grating cell that is formed on the same plane as the hologram cell and is arranged in a pattern in a plan view to draw a diffraction grating pattern are arranged. You may.
Since such a diffraction grating cell can be the same as the content described in the above-mentioned "A. I aspect" section, the description thereof is omitted here.

2. 2. Other Structures The hologram structure of this embodiment has a hologram layer, but may have other structures if necessary.

(1) Transparent Vapor Deposition Layer The hologram structure of this embodiment preferably has a transparent vapor deposition layer formed so as to be in contact with the uneven surface of the hologram forming region of the hologram layer. This is because the hologram structure facilitates the reproduction of the optical image.
The transparent vapor-deposited layer can be the same as the content described in the section "2. Thin-film deposition layer" of the above "A. I mode", and thus the description thereof is omitted here.

(2) Others The hologram structure of this embodiment may have other configurations described in the section of "3. Other configurations" of the above "A. I aspect".
As another configuration, when it is used at least in a place where it overlaps with the hologram forming region in a plan view, a transparent one is usually used.

3. 3. Hologram structure The hologram structure of this embodiment may be used by adhering the hologram structure to the adherend, or may be used without adhering to the adherend.
The usage mode of such a hologram structure can be the same as the usage mode described in the section "4. Hologram structure" of the above "A. I mode".
Since the hologram forming region of the hologram structure of this embodiment is a transmissive hologram forming region, a structure that overlaps the hologram forming region in a plan view is usually used. Specifically, as the heat seal layer, the back surface side protective layer, and the like, which are not required to be transparent in the first aspect, those having transparency are usually used.
Further, as the adherend to which the hologram structure is adhered, usually, a material in which a region overlapping the hologram forming region in a plan view has transparency is used.

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

Examples are shown below, and the present invention will be described in more detail.

[Example 1]
<Formation of original plate and hologram structure>
A resist for dry etching was rotationally coated on the chromium thin film of the photomask blank plate in which the surface low-reflection chromium thin film was laminated on the synthetic quartz substrate by 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. A QR code obtained by encrypting information, which is an address (URL) on the Internet, into a QR code (registered trademark) in advance using an electron beam drawing device (MEBES4500: manufactured by ETEC) for this resist layer. An original image of the shape of (registered trademark) was created, and the quaternized pattern was exposed by calculating the original image with a computer, and the exposed portion of the resist resin was easily melted. Then, the developer was sprayed (spray developed) to remove the easily soluble portion to form a resist pattern.
The grid pitch of the pattern was set to 3313 nm at the shortest.
The depth of the pattern was 140 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, an original plate having a recess formed by etching the quartz substrate and a convex portion remaining without etching the quartz substrate and the chromium thin film was obtained. Further, the size of the original plate, that is, the size of the hologram cell was set to 0.25 mm.
A composition for forming a hologram layer (UV curable acrylate resin: refractive index 1.52, measurement wavelength 633 nm) was added dropwise to a polycarbonate sheet (transparent substrate) having a thickness of 0.5 mm to form a coating film of the above composition. Next, an original plate having irregularities was placed on the coating film and pressed. Next, the coating film was cured by irradiating with active radiation and then peeled off to form a hologram cell having an uneven surface in which the uneven type of the original plate was inverted. After that, stacking, pressing, curing and peeling of the original plate were repeated to form a hologram layer having a thickness of 2 μm having a 10 mm square hologram forming region in which hologram cells were spread.

Next, an Al layer having a film thickness of 100 nm was formed on the entire surface of the uneven surface side of the hologram layer by a sputtering method to obtain a hologram structure.

<Evaluation>
From a position 60 mm from the surface of the hologram layer of the hologram structure, an image is taken with the flash light turned on using a smartphone camera, and the shape (QR code (registered trademark)) represented by the captured light image is obtained. The URL could be obtained by analyzing it with an application that is software built into the smartphone.

1 ... Hologram layer 1a ... Concavo-convex surface 2 ... Evaporation layer 3 ... Transparent substrate 4 ... Printing layer 5 ... Interlayer adhesive layer 6 ... Second hologram layer 7 ... Second vapor deposition layer 10 ... Hologram structure 11 ... Hologram forming region 12 ... Optical image 12a ... Hologram cell 13 ... Diffraction grating design 13a ... Diffraction grating cell 15 ... Image 31 ... Adhesive layer 32 ... Peeling sheet 33 ... Heat seal layer 34 ... Easy peeling layer 35 ... Peeling substrate 36 ... Back side protective layer 37 … Surface side protective layer 38… Intermediate substrate

Claims (9)

It has a hologram layer with a hologram forming region and
In the hologram forming region, a phase-type Fourier transform hologram that transforms the light incident from a point light source that travels straight while diffusing radially into a desired optical image is recorded.
The light image, Ri shape der the analyzable information is encrypted in the electronic device,
The hologram forming region is a reflective hologram forming region.
The size of the viewed hologram formation region, the hologram structure, characterized in der Rukoto within the following 15mm square or 50mm square. The hologram structure according to claim 1, wherein the shape in which the information that can be analyzed by the electronic device is encrypted is a two-dimensional bar code. The hologram structure according to claim 1 or 2, wherein the hologram structure has a vapor-deposited layer formed so as to be in contact with the uneven surface of the hologram forming region of the hologram layer. In the hologram forming region of the hologram layer, a hologram cell capable of converting light incident from a point light source into the optical image and a hologram cell formed on the same plane as the hologram cell and arranged in a pattern in a plan view. The hologram structure according to any one of claims 1 to 3, wherein a diffraction grating cell for drawing a diffraction grating pattern is arranged. The hologram structure according to claim 4, wherein the diffraction grating design is a plane diffraction grating design that can reproduce the design in a plane. The hologram structure according to claim 4, wherein the diffraction grating design is a three-dimensional diffraction grating design that can reproduce the design three-dimensionally. The hologram structure has an adhesive layer formed on the surface of the hologram layer on the uneven surface side of the hologram layer forming region.
The hologram structure according to any one of claims 1 to 6, wherein the hologram structure is used as a hologram sticker. The hologram structure includes a heat seal layer formed on the surface of the hologram layer on the uneven surface side of the hologram layer forming region.
An easily peelable layer formed on the surface of the hologram layer opposite to the uneven surface,
A peeling base material formed on the surface of the easily peelable layer opposite to the hologram layer,
Have,
The hologram structure according to any one of claims 1 to 6, wherein the hologram structure is used as a hologram transfer foil. The hologram structure according to any one of claims 1 to 6, wherein the hologram structure is used as an information recording medium.

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