JPH115373A - Image display medium and transfer sheet used for manufacturing the same - Google Patents

Abstract

(57) [Summary] To provide an image display medium having OVD images different from one another. A release layer (22) is provided on one surface of a support (21).
Using a transfer sheet formed by stacking a back coat layer 25 on the other surface of the support 21 while laminating the D layer 23 and the adhesive layer 24, the transfer target has a small area by a thermal head. An image display medium manufactured by transferring a dot shape to form a halftone image, wherein an OVD dot has any one of three primary colors of RGB (red, green, and blue) at a specific observation point. It consists of a combination of three types of OVD patterns having such spatial frequencies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display medium which is transferred and adhered to various articles such as credit cards, securities, certificates, etc., and a thermal transfer method in which an image is heated and transferred by a thermal head. The present invention relates to a transfer sheet used for manufacturing an image display medium by forming the same, and in particular, to a light diffraction structure such as a hologram or a diffraction grating (hereinafter referred to as OVD: Optical Variable Depth).
and a transfer sheet used for manufacturing the image display medium.

[0002]

2. Description of the Related Art In recent years, development of OVD images, such as hologram images and diffraction grating images, capable of expressing a stereoscopic image or a special decoration image using light interference has been advanced. OVD technology of these holograms and diffraction gratings requires advanced manufacturing technology and is difficult to duplicate. Therefore, as an effective means of preventing forgery, it is used by sticking to cards such as credit cards, ID cards, and prepaid cards. Have been.

[0003] Furthermore, due to its high decorativeness, it is often used for articles such as packaging materials, books, pamphlets, and POPs. OVDs such as holograms and diffraction gratings
Has a diffraction structure such as a fine concavo-convex pattern or a striped pattern having a different refractive index. Here, a technique for optically expressing an image such as the hologram image or the diffraction grating image is collectively referred to as OVD. Will be used.

By the way, as a means for attaching such an OVD to an article, a method of transferring and forming the OVD using a transfer sheet has conventionally been used. Hereinafter, a conventional OVD image forming method will be briefly described.

FIG. 9 is a sectional view showing a configuration example of a conventional hologram transfer sheet. That is, in the hologram transfer sheet, as shown in FIG. 9, a release layer 92 is formed on one surface of a base material 91 as a support.
An OVD layer 93 including a relief layer 931 provided with an OVD pattern such as a hologram or a diffraction grating and a reflective thin film layer 932 provided so as to cover the relief forming surface of the relief layer 931 is formed thereon.

The OVD layer 93 has a reflective thin film layer 9
An adhesive layer 94 is formed on 32. Further, on the other surface of the base material 71, a back coat layer 75 is formed.

In the above description and the following description, the upper and lower relations are reversed in the cross-sectional view and the description, but the upper and lower relations are in the direction of observing the transfer sheet (or transferred to an article). It is not essential because it changes according to the usage state in the case).

The relief forming surface of the relief layer 931 is on the opposite side of the base material 91. When the relief layer 931 is transferred and formed on the surface of the article, the release layer 92 is peeled off at the interface with the base material 91, and Since it migrates and functions as a protective layer, it may be referred to as a “peelable protective layer”.

Further, the layers transferred to the article side, excluding the base material 91, are collectively referred to as "transfer layers". Furthermore, each drawing schematically represents the configuration of the transfer sheet, and the dimensions such as the thickness of each layer are not based on actual products.

[0010] On the other hand, a hologram is generally produced by an optical photographing method to produce a relief-type master hologram having a fine concavo-convex pattern. Mass replication is performed by a well-known method of copying a plate and heating and pressing the press plate on the hologram forming layer 931. This type of hologram is called a relief hologram.

Also, unlike a relief type hologram,
There is a so-called volume hologram that records interference fringes in a volume direction using a recording material such as a photosensitive resin. In this type of hologram, a so-called Lippmann hologram is generally used, which is a reflection hologram in which the refractive index of a photosensitive resin is changed in the volume direction.

Further, unlike a hologram image capable of reproducing a three-dimensional image, a plurality of types of simple diffraction gratings are arranged in a small area to form pixels, and a diffraction grating image such as a grating image or a pixel gram expressing an image is also provided. In addition, mass copying is performed by the same method as that of the relief hologram, and the hologram is used as a means for preventing forgery by sticking it to articles such as credit cards, securities, certificates, and the like.

On the other hand, as a method of transferring and attaching a transfer sheet having OVDs copied in large quantities, a transfer sheet is arranged between a heated stamp of metal and an object to be transferred, and the transfer sheet is stamped. In general, a hot stamping method of pressing a transfer target is used, and a roll transfer method using a heated roll instead of a heated marking is also used.

In addition, the use of these transfer sheets having OVD as overcoats for cards has also been expanding, and in this connection, a thermal head transfer system for transferring a transfer sheet using a thermal head has also been used. .

[0015]

However, OVDs such as the holograms and diffraction gratings described above are suitable for mass-copying and pasting the same image from the original. There is a problem that it is not possible to attach different images such as images one by one.

[0016] Therefore, it is not particularly preferable when the OVD is used as an anti-counterfeiting means, for example, by sticking it to articles such as credit cards, securities, certificates and the like.
An object of the present invention is to provide different OVs one by one for a plurality of objects to be transferred.
An object of the present invention is to provide a transfer sheet to which a D image can be attached.

Another object of the present invention is to provide a transfer sheet capable of adhering an OVD image to a transfer object so that a true full-color image without chromatic aberration can be visually recognized when observed at a specific observation point. To provide.

On the other hand, the purpose of the present invention is to
An object of the present invention is to provide an image display medium having a VD image.
It is another object of the present invention to provide an image display medium having different OVD images one by one and having a unique decorative effect.

It is a further object of the present invention to provide an image display medium having an OVD image so that a true full-color image without chromatic aberration can be visually recognized when observed at a specific observation point.

[0020]

In order to achieve the above object, in the transfer sheet according to the first aspect of the present invention, a release layer, an optical diffraction structure (OVD) layer, and an adhesive layer are provided on one surface of a support. And a back coat layer on the other surface of the support, wherein the OV
The OVD patterns formed on the D layer are three types of OVDs having spatial frequencies such that the observation color at a specific observation point is one of the three primary colors of RGB (red, green, and blue), and each OVD is formed. Area is alternately arranged.

Therefore, in the transfer sheet according to the first aspect of the present invention, the OVD pattern formed on the OVD layer is such that the observation color at a specific observation point is one of the three primary colors of RGB (red, green, and blue). Using three types of OVDs having different spatial frequencies, and using a transfer sheet in which areas in which the respective OVDs are formed are alternately arranged.
By transferring a combination of (red, green, and blue) OVD patterns, different OVD images can be attached to a plurality of objects to be transferred one by one.

Further, in the transfer sheet according to the second aspect of the present invention,
In the transfer sheet according to the first aspect of the present invention, the chromatic aberration at the observation point is corrected by changing the spatial frequency of the OVD in accordance with the angle from the observation point with reference to the center of the area where the OVD is formed.

Therefore, in the transfer sheet according to the second aspect of the invention, the chromatic aberration at the observation point is reduced by changing the spatial frequency of the OVD based on the center of the area where the OVD is formed, in accordance with the angle from the observation point. Using the corrected transfer sheet, the center of the image is arranged at the center of the area where the OVD is formed, and the OVD pattern is transferred, so that when observed at a specific observation point, a true full-color image without chromatic aberration can be obtained. An OVD image that can be visually recognized can be attached.

On the other hand, in the image display medium according to the third aspect of the present invention, a release layer and an optical diffraction structure (OV) are formed on one surface of the support.
D) A layer and an adhesive layer are laminated, and a back sheet layer is laminated on the other surface of the support. An image display medium manufactured by transferring to form a halftone image, wherein OVD dots are
It is formed by combining three types of OVD patterns having a spatial frequency such that an observation color at a specific observation point is any of the three primary colors of RGB (red, green, and blue).

Therefore, in the image display medium according to the third aspect of the present invention, the OVD dots are spatial frequencies such that the observation color at a specific observation point is one of the three primary colors of RGB (red, green, and blue). By combining three types of OVD patterns having
An image display medium having a D image can be obtained.

In the image display medium according to the fourth aspect of the present invention, a release layer and an optical diffraction structure (OV) are formed on one surface of the support.
D) A layer and an adhesive layer are laminated, and a back sheet is laminated on the other surface of the support. An image display medium manufactured by forming a halftone dot image by transferring so as to be displaced and overlapping a print image in a dot shape having an area, and
When the VD dot is RGB, the observation color at a specific observation point is RGB
It consists of a combination of three types of OVD patterns having a spatial frequency such that it becomes one of the three primary colors (red, green, and blue).

Therefore, in the image display medium according to the fourth aspect of the present invention, the OVD dots formed so as to be displaced and superimposed on the print image have an observation color of RGB (red, red, (Green, blue) by combining three types of OVD patterns having a spatial frequency to be one of the three primary colors, one by one.
An image display medium having a VD image and further having a unique decorative effect can be obtained by superimposing the print image and the OVD image with the same data.

Further, in the image display medium according to the fifth aspect of the present invention, in the image display medium according to the third or fourth aspect, the OVD dot at the center of the image is used as a reference.
The chromatic aberration at the observation point is corrected by changing the spatial frequency of the OVD according to the angle from the observation point.

Therefore, in the image display medium according to the fifth aspect of the present invention, the OVD dot at the center of the image is used as a reference.
By changing the spatial frequency of the OVD according to the angle from the observation point and correcting the chromatic aberration at the observation point, an OVD that allows a genuine full-color image without chromatic aberration to be visually recognized when observed at a specific observation point An image display medium having an image can be obtained.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view showing a configuration example of a transfer sheet according to the present embodiment.

In FIG. 1, a release layer 22 is formed on one surface of a substrate 21 as a support.
2, an OVD layer 23 is formed. In this example, the OVD layer 23 includes a relief layer 231 having a relief type OVD (relief hologram or diffraction grating pattern) on a surface opposite to the release layer 22, and a relief type OVD.
The reflective thin film layer 232 provided on the surface of D is formed by vapor deposition or sputtering.

This relief type OVD is a relief type OVD.
It is possible to form a nickel press plate on which a fine concavo-convex pattern constituting D is formed on the relief layer 231 by a known method such as heating and pressing.

Further, the adhesive layer 24 is formed on the reflective thin film layer 232. Further, a back coat layer 25 is formed on the other surface of the substrate 21 (the surface opposite to the surface on which the release layer 22 is formed).

Next, the role of each layer constituting the transfer sheet and the constituent materials thereof will be described in detail. Base material 21
Is a transparent polyethylene terephthalate film having a thickness of 12 μm.

Examples of the substrate 21 include synthetic resins such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, and polystyrene, natural resins, paper,
It is possible to use one selected alone from synthetic paper or the like, or a composite selected from the above and combined.

The release layer 22 is provided to more effectively transfer the relief layer 231 to a transfer target (not shown). A composition having the following compounding ratio is prepared by a gravure printing method. , Drying temperature 110 ° C, thickness 0.8μm
It is formed with.

Acrylic resin: 30 parts Polyester resin: 5 parts Toluene: 40 parts Methyl ethyl ketone: 40 parts Methyl isobutyl ketone: 20 parts As the release layer 22, a thermoplastic acrylic resin,
Chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin,
Cellulose-based resins, chlorinated polypropylene resins, or those obtained by adding oil silicone, fatty acid amide, and zinc stearate to these resins can be used. Alternatively, an inorganic substance may be used.

The relief layer 231 has good embossing formability, hardly causes press unevenness, and provides a bright reproduced image.
A resin having good adhesion to the release layer 22 and the reflective thin film layer 232, a composition having the following compounding ratio is obtained by a gravure printing method at a drying temperature of 110 ° C. and a thickness of 0.5 μm. Is formed.

Vinyl chloride-vinyl acetate copolymer: 25 parts Urethane resin: 10 parts Methyl ethyl ketone: 70 parts Toluene: 30 parts Further, the OVD forming surface has a relief layer 2 having such a composition.
31 is formed by performing press molding at a plate surface temperature of 165 ° C.

The relief layer 231 may be made of thermoplastic resin such as polycarbonate resin, polystyrene resin, polyvinyl chloride resin, etc., unsaturated polyester resin, melamine resin, epoxy resin, urethane (meth) acrylate, polyester (meth) Thermosetting resins such as acrylate, epoxy (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and triazine (meth) acrylate or mixtures thereof, and thermoformable materials having radically polymerizable unsaturated groups It is possible to use a material other than the above as long as it has a stability capable of forming OVD.

The reflective thin film layer 232 is a layer that reflects light rays, and is formed by vacuum evaporation of Al having a thickness of 60 nm. As a method for forming the reflective thin film layer 232, a film forming means such as a sputtering method or an ion plating method can be applied in addition to the vacuum evaporation method, and the film thickness is 10 nm to 150 nm. Is preferably within the range.

The reflective thin film layer 232 may be made of a material having metal reflectivity.
For example, metals such as Au, Ag, and Cu can be considered. Also,
As the reflective thin film layer 232, a high-refractive-index transparent material having both light reflectivity and light transmittance can be used.

That is, the relief layer 231 (refractive index n =
It is possible to use a material having a higher refractive index than 1.3 to 1.5) and having transparency, for example, an inorganic material as shown in Table 1 below.

[0044]

[Table 1]

The adhesive layer 24 is prepared by coating a composition having the following compounding ratio with a drying temperature of 110 by a gravure printing method.
And a thickness of 1.0 μm. Vinyl chloride-vinyl acetate copolymer: 30 parts Polyester resin: 20 parts Methyl ethyl ketone: 50 parts Toluene: 50 parts As the adhesive layer 24, besides, the reflective thin film layer 23
As long as it does not alter or affect the quality of 2, it may be a commonly used one, for example, an acrylic adhesive, a polyester-based polyamide, etc., but is not limited thereto.

The back coat layer 25 is a layer for preventing sticking when transferring with a thermal head and for preventing a transfer sheet from sticking to the thermal head.
A composition having the following compounding ratio is formed by gravure printing at a drying temperature of 110 ° C. and a thickness of 1.0 μm.

Vinyl-based resin: 50 parts Isocyanate curing agent: 5 parts Silicone WAX: 1 part Methyl ethyl ketone: 50 parts Toluene: 50 parts The back coat layer 25 is configured to prevent the transfer sheet from sticking to the thermal head. Any binder may be used as long as it is used. Examples of the binder include a thermoplastic acrylic resin, a cellulose-based resin, a polyester-based resin, or a thermosetting resin of acrylic polyol or polyester polyol, and a silicone-based EB-curable resin. It is possible to use

In addition, it is possible to use those obtained by adding various surfactants as slip agents, lubricants such as polyethylene wax and silicone wax, and fillers such as talc as necessary.

FIG. 2 is a plan view showing a configuration example of the transfer sheet according to the present embodiment. That is, as shown in FIG. 2, the transfer sheet according to the present embodiment has an OVD pattern formed on the OVD layer 23 having different spatial frequencies from each other in order to obtain a color diffraction grating image. The observation color at the observation point is RGB
Three types of OVDs having a spatial frequency such that one of the three primary colors (red, green, blue)
Area (red OVD area 11, green OV
D areas 12 and blue OVD areas 13) are alternately arranged.

That is, the red OVD area 11 has a diffraction grating having a basic spatial frequency of 1140 line / mm, and the green OVD area 12 has a basic spatial frequency of 1310 lin.
An e / mm diffraction grating and a blue OVD area 13 are each formed with a diffraction grating having a fundamental spatial frequency of 1540 line / mm, and the three types of OVD patterns are alternately arranged to form a transfer sheet.

Here, the basic spatial frequency is the above-mentioned OVD
Refers to the spatial frequency of the OVD arranged at the center of the area where is formed. In order to control the transfer sheet feeding mechanism, the register mark 14 is similarly formed of a diffraction grating.

On the other hand, in this embodiment, a diffraction grating manufactured by the two-beam interference method is used as the OVD pattern. That is, in the present embodiment, in order to produce a transfer sheet capable of adhering an OVD image to a transfer target such that an authentic full-color image without chromatic aberration can be visually recognized when observed at a specific observation point. Then, based on the center of the area where the OVD is formed, the spatial frequency of the OVD is changed in accordance with the angle from the observation point to correct the chromatic aberration at the observation point.

Hereinafter, when observed at a specific observation point,
A method for producing an OVD transfer sheet in which a genuine full-color image without chromatic aberration can be visually recognized will be described by taking a diffraction grating as an example.

Here, before describing the method of manufacturing a diffraction grating by the two-beam interference method of the present embodiment, first, a method of manufacturing a diffraction grating by the conventional two-beam interference method will be described.

FIG. 7 is a schematic view showing a method of manufacturing a diffraction grating by the conventional two-beam interference method, and FIG. 8 is a schematic view showing observation results of an image display medium using a diffraction grating by the conventional two-beam interference method. .

FIG. 7 shows a conventional two-beam interference imaging method.
As shown in the figure, the laser beam 62 from the laser 61 is
The laser beam 62 divided into two by the beam splitter 63 is spread into a parallel light beam having a required area through a mirror 67, an objective lens 64, a pinhole filter 65, and a collimator lens 66. A diffraction grating is produced by intersecting the resist 68 at an angle determined according to the required spatial frequency, creating interference fringes by two light beams, and recording the interference fringe on the resist 68.

Since the diffraction grating manufactured by this method is manufactured by interference between parallel lights, the spatial frequency of the diffraction grating is the same at any position. As shown in FIG. 8, when the image display medium 71 is observed at the observation point 73 in an environment under white parallel light 72 (under sunlight), as shown in FIG. And the end looks different colors.

This is because, since the spatial frequency of the diffraction grating is the same, when the wavelength of the light beam entering the eye from the center of the image is observed at an angle at which the required color is obtained, the observation comes from the end of the image. The light beam 74 having the wavelength of the color required for the viewpoint does not enter the eyes, and the light beam 7 having the wavelength deviated from the wavelength of the required color.
This is because 5 enters the eye from the end of the image.

Therefore, in order to solve the above-mentioned problem, it is necessary to produce a diffraction grating that converges a light beam having a color wavelength necessary for an observation point. FIG. 4 is a schematic diagram illustrating a method of manufacturing a diffraction grating according to the present embodiment, and FIG. 5 is a schematic diagram illustrating an example of a method of observing an image display medium according to the present embodiment.

That is, as shown in FIG.
The laser light 42 from No. 1 is divided into two by the beam splitter 43, and one of the laser light 42 divided by the beam splitter 43 is divided into a mirror 47 and an objective lens 4.
4. Pinhole filter 45, collimator lens 66
Through the objective lens 44 and the pinhole filter 45 to spread the other part of the laser light 42 into a diffused light beam, and then register these at an angle determined according to the required spatial frequency. 68
A diffraction grating is produced by crossing the light beams upward and forming interference fringes by two light beams and recording the interference fringes on the resist 48.

That is, one light beam is used as a point light source, interference fringes are produced by a diffuse light beam and a parallel light beam, recorded on the resist 48, and a diffraction grating is produced. In the present embodiment,
As shown in FIG. 5, the surface of the image display medium 51 is irradiated with white parallel light 52 from the zenith direction 45 degrees, and is observed at an observation point 53 which is a 0-degree position in front of the image display medium 51. The distance between the surface and the observation point 53 is defined as 30 cm.

Reference numeral 54 denotes a light beam having a wavelength of a color necessary for the viewpoint to be observed. On the premise of the observation method as described above, in the present embodiment, the spatial frequency, wavelength, and wavelength are defined by defining the colors of RGB as 620 nm for R light, 540 nm for G light, and 460 nm for B light.
From the relational expression of the incident / reflection angle, the basic spatial frequency of the diffraction grating formed in each OVD area of RGB and the spatial frequency of the peripheral position are determined.

Further, the actual photographing is performed for the required R, G,
Using a laser beam having the same wavelength as the wavelength of the B light, an optical system equivalent to the observation method is used. That is, the image display medium 51
And a pinhole filter 45 at the same position as the observation point 53, and the crossing angle between the central light beam and the parallel light beam of the diffused light beam is set to 45 degrees, which is the same as the observation method.
A laser having a wavelength of 620 nm is used for capturing the red OVD area 11, a laser having a wavelength of 540 nm is used for capturing the green OVD area 12, and a laser having a wavelength of 540 nm is used for capturing the blue OVD area 13.
Each image is taken using a laser having a wavelength of 0 nm to produce a relief type diffraction grating.

Then, a nickel press plate in which the concavo-convex pattern is duplicated by the above-described known electroplating method is duplicated, and this press plate is heated and pressed onto the relief layer 231 by a known method. Such a transfer sheet is manufactured.

FIG. 3 is a plan view showing a configuration example of the image display medium according to the present embodiment manufactured using the above-described transfer sheet. That is, the image display medium 31 of the present embodiment converts the OVD pattern formed on the OVD layer 23 into three types of OVDs having a spatial frequency such that the observation color at a specific observation point is one of the three primary colors of RGB. age,
Using the above-described transfer sheet in which the areas 11, 12, and 13 in which the respective OVDs are formed are alternately arranged, a small area is applied to the transfer target (in this example, a white PVC card is used) by a thermal head. It is manufactured by transferring in a dot shape and forming (sticking) the OVD image 32 as a halftone image.

Thus, the image display medium 31 of the present embodiment has three types of OVD patterns in which OVD dots have a spatial frequency such that the observation color at a specific observation point is one of the three primary colors of RGB. Are obtained as a combination.

In the present embodiment, the spatial frequency of the OVD is changed in accordance with the angle from the observation point with respect to the center of the areas 11, 12, and 13 where the OVD is formed, so that the chromatic aberration at the observation point is obtained. Using the transfer sheet described above, the center of the image is moved to the area 11 where the OVD is formed,
The image display medium 31 is manufactured by arranging the OVD pattern at the center of 12, 13 and transferring (adhering) the OVD pattern.

In this case, the transfer of the transfer layer is performed by a known thermal transfer printer. The density of the RGB separation image is converted into data by expressing the size of the halftone dot area, and the number of heat generating dots of the thermal head is increased or decreased according to the halftone dot area to be transferred.
Transfers and prints the halftone dot decomposed image.

Next, in the image display medium 31 according to the present embodiment manufactured by the above method, the OV
The OVD patterns formed on the D layer 23 are three types of OVDs having a spatial frequency such that an observation color at a specific observation point is one of the three primary colors of RGB, and each OVD pattern is
When a transfer sheet is used, in which areas 11, 12, and 13 in which are formed are alternately arranged, and transfer is performed to an object to be transferred, RGB O
By transferring and attaching the VD patterns in combination, the OVD images 32 different from one another
Can be obtained.

That is, by changing the print data for each transfer object (card), it becomes possible to transfer and adhere different OVD images 32 one by one to a plurality of transfer objects. It is effective when 31 is used as a forgery prevention means by sticking it to an article such as a credit card, securities, certificates and the like.

The areas 11, 1 where the OVD is formed
Using the transfer sheet in which the chromatic aberration at the observation point is corrected by changing the spatial frequency of the OVD in accordance with the angle from the observation point with reference to the centers of the observation points 2 and 13, the center of the image is set to the area 11 where the OVD is formed. Place OVD at the center of 12,13
The image display medium 3 having the OVD image 32 so that a true full-color image without chromatic aberration can be visually recognized when observed at a specific observation point by transferring the pattern.
1 can be obtained.

That is, the image display medium 31 having the OVD image 32 manufactured by the method of the present embodiment has the same decorative effect as a diffraction grating image such as a conventional grating image or pixel gram, and is specified by the above-described method. By observing at the observation point of, it is possible to observe a true full-color image without chromatic aberration according to the RGB image data.

(Second Embodiment) The transfer sheet according to the present embodiment is different from the first embodiment only in that ZnS having transparency is used as the reflective thin film layer 232 of the transfer sheet in the first embodiment. However, unlike the first embodiment, the configuration of the other portions, the manufacturing method, and the like are all the same as those in the first embodiment.

Here, the reflective thin film layer 232 is a reflective material for illuminating OVD such as a hologram and a diffraction grating, and is a transparent material for transmitting image information of a transferred body. 80 nm thick ZnS is formed by a vacuum evaporation method.

FIG. 6 is a plan view showing a configuration example of the image display medium according to the present embodiment manufactured using the transfer sheet. The image display medium of the present embodiment is the same as the method of manufacturing the image display medium of the first embodiment described above, and uses a thermal transfer printer and a sublimable color ribbon as a transfer object to form a color image. The only difference from the first embodiment is that a printed transfer body (card) is used.

That is, the image display medium 8 of the present embodiment
Reference numeral 1 denotes an OVD pattern formed on the OVD layer 23 as three types of OVDs having a spatial frequency such that an observation color at a specific observation point is one of the three primary colors of RGB, and an area where each OVD is formed. Using the above-described transfer sheet in which 11, 12, and 13 are arranged alternately, a color image is printed in advance using a thermal transfer printer and a sublimable color ribbon to form a print image 83 (this example). In this case, a white PVC card is used to transfer the OVD image 82 as a halftone image (transfer) in the form of a dot having a small area by a thermal head.

In this case, as shown in FIG. 6, the printed color image data is used for OVD RGB image data,
The OV on the transfer sheet is superimposed on the print image 83 printed with the sublimable color ribbon so as to be slightly shifted in position.
The image display medium 81 is manufactured by transferring (adhering) the D image 82.

As a result, in the image display medium 31 according to the present embodiment, the OVD dots formed so as to be displaced and overlapped on the print image 83 are three-color OVD dots at a specific observation point. It is obtained as a combination of three types of OVD patterns having a spatial frequency such as one of the primary colors.

Next, in the image display medium 81 according to the present embodiment manufactured by the above-described method, an image having the same operation and effect as in the case of the image display medium 31 in the first embodiment described above. In addition to providing a display medium, the printed image 83 and the OVD image 82 having reflectivity and transparency are overlapped with the same data, that is, the printed image 83 and the OVD image 82 are overlapped with the same data. The image display medium (print card) 81 having the decorative effect of (1) can be obtained.

[0080]

As described above, according to the first aspect of the present invention, it is possible to provide a transfer sheet capable of sticking different OVD images one by one to a plurality of objects to be transferred. Also,
According to the second aspect of the present invention, it is possible to provide a transfer sheet capable of adhering an OVD image to a transfer object so that a true full-color image without chromatic aberration can be visually recognized when observed at a specific observation point. .

On the other hand, according to the third aspect of the present invention, an image display medium having different OVD images one by one can be provided.
According to the fourth aspect of the present invention, different OVDs one by one
An image display medium having an image and having a unique decorative effect can be provided.

Furthermore, according to the fifth aspect of the present invention, it is possible to provide an image display medium having an OVD image that allows a genuine full-color image having no chromatic aberration to be visually recognized when observed at a specific observation point.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a transfer sheet according to the present invention.

FIG. 2 is a plan view showing a first embodiment of a transfer sheet according to the present invention.

FIG. 3 is a plan view showing a first embodiment of the image display medium according to the present invention.

FIG. 4 is a schematic view showing a method for producing a diffraction grating in a transfer sheet according to the present invention.

FIG. 5 is a schematic view showing an example of an image display medium observation method according to the present invention.

FIG. 6 is a plan view showing a second embodiment of the image display medium according to the present invention.

FIG. 7 is a schematic view showing a method for manufacturing a diffraction grating by a conventional two-beam interference method.

FIG. 8 is a schematic diagram showing an observation result of an image display medium using a diffraction grating based on a conventional two-beam interference method.

FIG. 9 is a cross-sectional view illustrating a configuration example of a conventional hologram transfer sheet.

[Explanation of symbols]

 11: red OVD area, 12: green OVD area, 13: blue OVD area, 14: register mark, 21: base material, 22: release layer, 23: OVD layer, 231: relief layer, 232: reflective thin film layer, 24: adhesive layer, 25: back coat layer, 31: image display medium, 32: OVD image, 41: laser, 42: laser beam, 43: beam splitter, 44: objective lens, 45: pinhole filter, 46: collimator Lens 47: mirror 48: resist 51: image display medium 52: white parallel light 53: observation point 54: light beam having a wavelength of a color necessary for the viewpoint to be observed 61: laser 62: laser light , 63: beam splitter, 64: objective lens, 65: pinhole filter, 66: collimator lens, 6 7: mirror, 68: resist, 71: image display medium, 72: white parallel light, 73: observation point, 74: light beam having a wavelength of a color required for the viewpoint to be observed, 75: deviation from the wavelength of the required color 81: image display medium, 82: OVD image, 83: printed image, 91: base material, 92: release layer, 93: OVD layer, 931: relief layer, 932: reflective thin film layer, 94 ... Adhesive layer.

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Claims (5)

[Claims] 1. A lamination layer, an optical diffraction structure (OVD) layer and an adhesive layer are laminated on one surface of a support, and a back coat layer is laminated on another surface of the support. A transfer sheet having a spatial frequency such that an OVD pattern formed on the OVD layer has a spatial frequency such that an observation color at a specific observation point is one of three primary colors of RGB (red, green, and blue). A transfer sheet comprising a plurality of types of OVDs, and areas in which the respective OVDs are formed are alternately arranged. 2. The transfer sheet according to claim 1, wherein a spatial frequency of the OVD is changed in accordance with an angle from an observation point with reference to a center of the area where the OVD is formed.
A transfer sheet wherein chromatic aberration at an observation point is corrected. 3. A laminating layer, an optical diffraction structure (OVD) layer and an adhesive layer are laminated on one surface of the support, and a back coat layer is laminated on the other surface of the support. An image display medium manufactured by forming a halftone image by using a transfer sheet configured to transfer a dot shape having a small area to a transfer target body by a thermal head, wherein the OVD dots are specified. An image display medium comprising a combination of three types of OVD patterns having a spatial frequency such that the observation color at the observation point is one of the three primary colors of RGB (red, green, and blue). 4. A method of laminating a release layer, an optical diffraction structure (OVD) layer and an adhesive layer on one surface of a support, and laminating a back coat layer on the other surface of the support. Using a transfer sheet configured, a halftone dot image is formed by transferring by a thermal head to a transfer target body on which an image has been printed in advance in a dot shape having a small area so as to be displaced and superimposed on the printed image. An image display medium manufactured by the above method, wherein the OVD dots have three spatial frequencies such that an observation color at a specific observation point is one of three primary colors of RGB (red, green, and blue). An image display medium comprising a combination of the following OVD patterns. 5. The image display medium according to claim 3, wherein a spatial frequency of the OVD is changed in accordance with an angle from an observation point with reference to the OVD dot at the center of the image.
An image display medium characterized by correcting chromatic aberration at an observation point.