阅读说明：本技术 信息记录体及个人证件 (Information recording medium and personal identification card ) 是由 箕轮和代 南川直树 于 2018-05-22 设计创作，主要内容包括：在个人证件中,浮雕层及金属层构成光学安全补丁,该光学安全补丁包括：第一部分,其包含改质区域、以及从记录层的厚度方向观察时与改质区域重叠的浮雕层的一部分；第二部分,其包含非改质区域、以及从厚度方向观察时与非改质区域重叠的浮雕层的一部分。从厚度方向观察时,第一部分使入射到第一部分的光透过,并且第二部分吸收入射到第二部分的光,由此来隐藏记录区域,另外从与厚度方向正交的方向观察时,第一部分和第二部分将入射到光学安全补丁的光作为衍射光射出。(In a personalized document, the relief layer and the metallic layer constitute an optical security patch comprising: a first portion including a modified region and a part of the relief layer overlapping the modified region when viewed in a thickness direction of the recording layer; and a second portion including the non-modified region and a part of the relief layer overlapping the non-modified region when viewed in the thickness direction. The first portion transmits light incident on the first portion when viewed in the thickness direction, and the second portion absorbs light incident on the second portion to conceal the recording region, and the first portion and the second portion emit light incident on the optical security patch as diffracted light when viewed in a direction orthogonal to the thickness direction.)

1. An information recording medium includes:

a recording layer including a non-recording region having a carbonizing property by irradiation of a laser beam and a recording region surrounded by the non-recording region and displaying predetermined information by carbonization by irradiation of the laser beam;

a relief layer that is a plurality of convex surfaces that overlap the entire recording region when viewed in the thickness direction of the recording layer and that are two-dimensionally arranged in a region larger than the recording region, that includes the plurality of convex surfaces having an arrangement pitch of the convex surfaces of 190nm to 580nm, and that has light-transmitting properties;

a metal layer that overlaps the entire recording region when viewed in the thickness direction and covers the plurality of convex surfaces in the region, the metal layer being mainly made of a metal and including a modified region that overlaps the entire recording region when viewed in the thickness direction and has a light-transmitting property and an unmodified region that is a portion other than the modified region,

the relief layer and the metal layer constitute an optical security patch comprising: a first portion including the modified region and a part of the relief layer aligned with the modified region when viewed from the thickness direction; a second portion including the non-modified region and a part of the relief layer aligned with the non-modified region when viewed from the thickness direction,

in the optical security patch, the first portion transmits light incident to the first portion and the second portion absorbs light incident to the second portion when viewed in the thickness direction, thereby concealing the recording area, and the first portion and the second portion emit light incident to the optical security patch as diffracted light when viewed in a direction orthogonal to the thickness direction.

2. The information recording medium according to claim 1,

the modified region surrounds the entire edge of a region overlapping with the recording region when viewed from the thickness direction.

3. The information recording medium according to claim 1 or 2,

the information recording medium further includes a colored layer which overlaps the optical security patch when viewed in the thickness direction, has a size extending further outside the optical security patch, and has a predetermined color,

the colored layer includes a through hole that overlaps the optical security patch when viewed in the thickness direction and partitions a space extending further outside the optical security patch.

4. The information recording medium according to any one of claims 1 to 3,

the plurality of convexities being laid two-dimensionally on the entirety of the relief layer as viewed in the thickness direction,

the metal layer covers the entire convex surface when viewed from the thickness direction,

the recording region is an inner recording region including a portion located at an edge of the relief layer and inside the edge when viewed from the thickness direction,

the information recording medium further includes an outer recording region including a portion located further outside than the edge of the relief layer when viewed in the thickness direction and connected to the inner recording region.

5. The information recording medium according to any one of claims 1 to 4,

the metal layer is mainly composed of any one selected from the group consisting of aluminum, nickel and iron,

the recording area has a black color.

6. A personalized document comprising the information recording medium according to any one of claims 1 to 5,

the information recording body displays personal information to which a specific person belongs.

7. The personalized document of claim 6, wherein,

the personalized document further comprises:

a carrier film which supports the information recording medium and has flexibility; and

and an adhesive layer on a side of the information recording medium opposite to the carrier film side.

8. A personal identification card comprising the information recording medium according to claim 1,

the information record body displays personal information to which a specific person belongs,

the recording area is an inner recording area displaying the personal information as the information,

the information recording medium further includes an outer recording region which is located further outside an edge of the relief layer when viewed in the thickness direction and displays the same personal information as the personal information included in the inner recording region.

Background

As a personal identification card such as a card or a passport, a personal identification card having a laser-carbonized layer and a hologram layer is known. The laser carbonized layer has a characteristic of being discolored to black by absorbing laser light of a specific wavelength. In the laser carbide layer, a face image of an individual or the like is written as information to which the specific individual belongs. The hologram layer is configured to display an image formed by diffracted light in accordance with a change in refractive index or an uneven structure of the hologram layer (see, for example, patent document 1).

Disclosure of Invention

Technical problem to be solved by the invention

However, in such personalized documents, there is a demand for improving the designability of the personalized document.

The above-described situation is not limited to the information recording medium used as a personal identification card, and may be applied to an information recording medium used for an application other than a personal identification for entertainment, the information recording medium including a portion carbonized by irradiation with a laser beam and a portion configured to emit diffracted light.

The invention aims to provide an information recording medium and a personal identification card capable of improving design.

Means for solving the problems

An information recording medium for solving the above problems includes: a recording layer including a non-recording region having a property of being carbonized by irradiation of a laser beam and a light-transmitting property, and a recording region surrounded by the non-recording region and displaying predetermined information by the carbonization caused by the irradiation of the laser beam; a relief layer which is a plurality of convexities that are two-dimensionally arranged in a region that overlaps with the entire recording region when viewed in the thickness direction of the recording layer and that is larger than the recording region, and which includes the plurality of convexities having an arrangement pitch of 190nm to 580nm inclusive and has a light-transmitting property; and a metal layer that overlaps the entire recording region when viewed in the thickness direction and covers the plurality of convex surfaces in the region, wherein the metal layer is mainly made of a metal and includes a modified region that overlaps the entire recording region when viewed in the thickness direction and has a light-transmitting property and an unmodified region that is a portion other than the modified region. The relief layer and the metal layer constitute an optical security patch comprising: a first portion including the modified region and a part of the relief layer aligned with the modified region when viewed from the thickness direction; a second portion including the non-modified region and a part of the relief layer aligned with the non-modified region when viewed from the thickness direction. The first portion transmits light incident to the first portion and the second portion absorbs light incident to the second portion when viewed in the thickness direction to conceal the recording region, and the first portion and the second portion emit light incident to the optical security patch as diffracted light when viewed in a direction orthogonal to the thickness direction.

The personal identification card for solving the above problems includes the information recording medium having an information recording medium for displaying personal information to which a specific individual belongs.

According to the above configuration, when the information recording medium is viewed from the thickness direction of the recording layer, the recording area included in the recording layer is hidden by the optical security patch, and therefore the recording area is not easily recognized by the viewer. On the other hand, when viewed from a direction perpendicular to the thickness direction of the recording layer, the optical security patch emits diffracted light, and therefore the recording area becomes visible to the observer due to the contrast between the color of the diffracted light and the color of the recording area. Thus, according to the information recording medium, when the direction in which the information recording medium is viewed is changed, the image displayed on the information recording medium can be changed, and as a result, the design of the information recording medium is improved.

The personalized document for solving the above problem includes the information recording body which displays the personal information to which a specific person belongs, the recording region being an inner recording region which displays the personal information as the information, and further including an outer recording region which is located further outside than an edge of the relief layer as viewed in the thickness direction and displays the same personal information as the personal information included in the inner recording region.

According to the above structure, it is difficult for an observer of the personalized document to notice the inner recording area. Therefore, in the personalized document, even if the outer recording region is tampered with, there is a high possibility that the inner recording region is not tampered with. Therefore, it is possible to determine whether or not the personalized document is falsified based on a mismatch between the information of the outer recording area and the information of the inner recording area.

Drawings

FIG. 1 is a plan view showing the structure of a personalized document in a plan view facing the surface of the personalized document in the first embodiment of an information recording medium and the personalized document;

FIG. 2 is a cross-sectional view showing a structure of a first example of a personalized document, i.e., a structure along the line I-I in FIG. 1;

FIG. 3 is a cross-sectional view showing the structure of a second example of a personalized document, i.e., the structure along the line I-I in FIG. 1;

FIG. 4 is a cross-sectional view showing a constitution of a personalized document of a third example, i.e., a constitution along the line I-I of FIG. 1;

fig. 5 is a perspective view showing the structure of an optical security patch together with a part of a recording layer;

FIG. 6 is a schematic diagram for explaining the function of a relief layer provided in an optical security patch;

FIG. 7 is an action diagram for explaining the action of the personalized document;

FIG. 8 is an action diagram for explaining the action of the personalized document;

FIG. 9 is a cross-sectional view showing the structure of a transfer foil used for manufacturing a personalized document;

FIG. 10 is a process diagram showing a transfer step in a method for producing a personalized document;

FIG. 11 is a process diagram showing a printing step in a method for manufacturing a personalized document;

FIG. 12 is a process diagram showing a laminating step in a method for producing a personalized document;

FIG. 13 is a process diagram showing an irradiation step in a method for producing a personalized document;

FIG. 14 is a partial plan view showing a part of the structure of a recording layer in a modification of a personalized document;

FIG. 15 is an operation diagram for explaining the operation of a modification example of the personalized document;

FIG. 16 is an operation diagram for explaining the operation of a modification example of the personalized document;

FIG. 17 is a partial cross-sectional view showing a part of the constitution of a personalized document in a second embodiment of an information recording medium and a personalized document;

FIG. 18 is a partial plan view showing a part of the structure of the personalized document when the personalized document is viewed from the thickness direction of the recording layer;

FIG. 19 is a cross-sectional view showing the structure of a personalized document in a third embodiment of the personalized document;

FIG. 20 is a cross-sectional view showing the structure of a personalized document according to a fourth embodiment of the personalized document.

Detailed Description

[ first embodiment ]

A first embodiment of the present invention, in which an information recording medium and a personalized document are embodied, will be described with reference to fig. 1 to 13. Hereinafter, the structure of the personalized document, the function of the personalized document, the method of producing the personalized document, the material for forming each part of the personalized document, and examples will be described in order.

[ Structure of Individual document ]

The structure of the personalized document will be described with reference to fig. 1 to 6.

As shown in FIG. 1, the personalized document 10 is in the form of a plate. The personalized document 10 includes one face or surface 10F that constitutes the personalized document 10. In a top view opposite surface 10F of personalized document 10, personalized document 10 displays first image PIC1, second image PIC2, and third image PIC 3. The first image PIC1 and the second image PIC2 are images that contain information for determining the holder of the personalized document 10.

The first image PIC1 is the portrait of the holder. The second image PIC2 includes any one or combination of the holder's nationality, name, birthday, or personal number. The first image PIC1 may be an image other than the portrait of the holder, or may be only a face image. The second image PIC2 may contain other information than those described above, and may contain different features.

Third image PIC3 is the name of personalized document 10. The third image PIC3 may be an image containing information different from the name of the personalized document 10. The second image PIC2 and the third image PIC3 contain either or both letters or numbers. The second image PIC2 and the third image PIC3 may contain other characters different from the symbols and letters.

The personalized document 10 is provided with an optical security patch 11. In a plan view facing the surface 10F, the optical security patch 11 is viewed through the surface 10F. The optical security patch 11 is circular in outline. The outline of the optical security patch 11 may also be elliptical. Furthermore, the outline of optical security patch 11 may be a shape other than a circle, such as a polygon. In addition, optical security patch 11 does not overlap any of first image PIC1, second image PIC2, and third image PIC3 in a plan view opposing surface 10F. Optical security patch 11 may also overlap at least one of these images in a top view opposite surface 10F.

FIGS. 2-4 show a cross-sectional configuration of the personalized document 10 along line I-I of FIG. 1. In fig. 2 to 4, the thickness and size of each part are exaggerated for convenience of illustration of each part constituting the personalized document 10. In fig. 2 to 4, in particular, the thickness and size of the optical security patch is further exaggerated compared to other parts of the personalized document 10 for the sake of convenience in illustrating the structure of the optical security patch. In the following, three examples in which the sectional structures of the personalized document 10 are different from each other will be described in order.

[ first example ]

As shown in fig. 2, the personalized document 10 is provided with an optical security patch 11 and a recording layer 12. The recording layer 12 is composed of a recording region 12a and a portion other than the recording region 12 a. The recording region 12a is a portion surrounded by a non-recording region (i.e., a portion other than the recording region 12 a) having a carbonizing property caused by irradiation of a laser beam, and displaying predetermined information by carbonization caused by irradiation of a laser beam.

Optical security patch 11 includes relief layer 21 and metal layer 22. The relief layer 21 overlaps the entire recording region 12a when viewed in the thickness direction of the recording layer 12, and includes a plurality of two-dimensionally arrayed convex surfaces 21a in a region extending outward of the recording region 12 a. In other words, the relief layer 21 overlaps the entirety of the recording region 12a when viewed from the thickness direction of the recording layer 12, and contains a plurality of convexities 21a arranged two-dimensionally in a region larger than the recording region 12 a. In the plurality of convex surfaces 21a, the arrangement pitch of the convex surfaces 21a is 250nm or more and 500nm or less. The relief layer 21 has light transmittance.

The metal layer 22 overlaps the entirety of the recording region 12a when viewed from the thickness direction of the recording layer 12, and covers the plurality of convexities 21a in a region extending toward the outside of the recording region 12 a. In other words, the metal layer 22 overlaps the entirety of the recording region 12a when viewed from the thickness direction of the recording layer 12, and covers the plurality of convexities 21a in a region larger than the recording region 12 a. The metal layer 22 is primarily a metal. The metal layer 22 includes modified regions 22a and non-modified regions 22 b. The modified region 22a overlaps the entire recording region 12a when viewed in the thickness direction of the recording layer 12, and is light-transmissive. The non-modified region 22b is a portion of the metal layer 22 other than the modified region 22 a. The modified region 22a is a region in which the metal layer 22 mainly composed of metal is modified by irradiation with a laser beam. The modified region 22a is a region without a metal oxide or a metal layer. The light transmittance of the modified region 22a is higher than that of the non-modified region 22 b.

The main component of the metal layer 22 may be any one selected from the group consisting of aluminum, nickel, or iron, or an alloy thereof. In this case, the recording region 12a may have black. In the metal layer 22, 80 mass% or more of the components are metals, and the metal layer 22 may contain oxygen, carbon, or the like as components other than metals.

The metal layer 22 covers a part or the whole of the relief layer 21. The metal layer 22 may be formed by depositing an inorganic substance such as a metal on the relief layer 21. After the metal layer 22 is deposited, the metal layer 22 may be formed by etching the metal layer 22 to cover a portion of the relief layer 21. The deposition of the metal layer 22 may employ vacuum evaporation, sputtering, chemical deposition. The personalized document 10 may further include a transparent reflective layer on the embossed layer 21. The transparent reflective layer may be located between the metallic layer 22 and the relief layer 21 or on the side of the metallic layer 22 opposite the relief layer 21. The transparent reflective layer may be inorganic. The inorganic material of the transparent reflective layer may be a metal compound or a silicon compound. The metal compound may be metal oxide, metal sulfide, metal fluoride, metal nitride. The metal of the metal compound may be aluminum, titanium, zinc, tin. The silicon compound may be silicon oxide. The transparent reflective layer covers the whole or a part of the embossed layer 21. The transparent reflective layer may be modified by laser light to be a modified transparent reflective layer. The transparent reflective layer may not be modified by the laser beam.

In this configuration, the color of the metal layer 22 and the color of the recording region 12a are easily recognized as substantially the same color by the viewer OB. Therefore, when the personalized document 10 is viewed from the thickness direction of the recording layer 12, it is more difficult for the observer OB to recognize the recording region 12 a.

The optical security patch 11 comprises: a first portion 11a including a modified region 22a and a part of the relief layer 21 aligned with the modified region 22a when viewed from the thickness direction of the recording layer 12; and a second portion 11b including the non-modified region 22b and a part of the relief layer 21 aligned with the non-modified region 22b when viewed in the thickness direction of the recording layer 12.

The optical security patch 11 is configured as follows when viewed from the thickness direction of the recording layer 12: of the light incident to the entire optical security patch 11, the first portion 11a transmits the light incident to the first portion 11a, and the second portion 11b absorbs the light incident to the second portion 11b, thereby hiding the recording area 12 a. The optical security patch 11 is configured such that the first portion 11a and the second portion 11b emit diffracted light when viewed from a direction orthogonal to the thickness direction.

The recording layer 12 includes a portion carbonized by irradiation of laser light, in addition to the recording region 12a described above. This portion displays the second image PIC2 described above in a top view opposite surface 10F of personalized document 10. In this way, it is preferable that the recording layer 12 includes, in a portion carbonized by irradiation of the laser beam: the recording area 12a, which is a portion overlapping the optical security patch 11, and the portion other than the recording area 12a, which is a portion not overlapping the optical security patch 11, are viewed from the thickness direction of the recording layer 12. Further, it is preferable that the area occupied by the recording region 12a is 30% or more and 70% or less of the total area of the portion carbonized by the irradiation of the laser beam when viewed from the thickness direction of the recording layer 12.

The personalized document 10 further comprises a back laminating layer 13, a coloured layer 14 and a surface laminating layer 15. The back laminate layer 13 and the surface laminate layer 15 are light-transmissive. The backside laminate layer 13 and the surface laminate layer 15 may be transparent. The colored layer 14 is colored. The color of the colored layer 14 may be white or light, etc. The back laminate 13 may also be colored.

In the personalized document 10, the back laminate 13, the colored layer 14, the recording layer 12, and the surface laminate 15 are stacked in the order described. In the personalized document 10, the optical security patch 11 is located between the recording layer 12 and the surface laminate layer 15. In other words, the optical security patch 11 is enclosed by the recording layer 12 and the surface lamination layer 15. In the personalized document 10, the printed portion 16 is located between the colored layer 14 and the recording layer 12. The printing portion 16 is a portion formed by printing. The printing portion 16 may be formed by printing ink or toner.

The printing portion 16 is formed by printing ink. The printing may be offset, letterpress, or gravure printing. The ink used to form the printing portion 16 may be an offset ink, a relief ink, or a gravure ink, depending on the printing method. The ink used to form the printing portion 16 may be a resin ink, an oil ink, or a water-based ink, depending on the composition. The ink used to form the printing portion 16 may be an oxidative polymerization type ink, a penetration drying type ink, an evaporation drying type ink, or an ultraviolet curing type ink, depending on the drying method. The ink can be pigment ink and dye ink. The pigment ink may be an inorganic pigment ink or a polymeric pigment ink. The dye ink may be azo dye ink or the like. The printed portion 16 includes the region of the second image PIC2 and the region of the third image PIC 3.

The optical security patch 11 further comprises an adhesive layer 23. The adhesive layer 23 is located on the opposite side of the relief layer 21 with respect to the metal layer 22. The metal layer 22 bonds the laminate including the relief layer 21 and the metal layer 22 to the recording layer 12. The adhesive layer 23 is light-transmitting. The adhesive layer 23 transmits an image formed by a layer located on the side opposite to the metal layer 22 with respect to the adhesive layer 23.

[ second example ]

As shown in fig. 3, the personalized document 10 of the second example differs from the personalized document 10 of the first example in that the optical security patch 11 is not located between the recording layer 12 and the surface laminating layer 15, but between the colored layer 14 and the recording layer 12. In the personalized document 10 of the second example, among the optical security patches 11, the first portion 11a including the modified region 22a is aligned with the recording region 12a when viewed from the thickness direction of the recording layer 12, and the second portion 11b including the non-modified region 22b is aligned with a portion other than the recording region 12a in the recording layer 12 when viewed from the thickness direction of the recording layer 12.

[ third example ]

As shown in fig. 4, a personalized document 10 of a third example includes: a first optical security patch 11A located between the recording layer 12 and the surface lamination layer 15, and a second optical security patch 11B located between the colored layer 14 and the recording layer 12. The first optical security patch 11A has a configuration equivalent to the optical security patch 11 provided in the personalized document 10 of the first example, and the second optical security patch 11B has a configuration equivalent to the optical security patch 11 provided in the personalized document 10 of the second example.

The structure of optical security patch 11 will be described in more detail with reference to fig. 5 and 6. The optical security patches included in the personal documents 10 of the first to third examples differ from each other in position with respect to the recording layer 12, but have a common function. Therefore, the optical security patch 11 provided in the personalized document 10 of the first example will be described below, and the description of the optical security patch included in the personalized document 10 of the second and third examples will be omitted.

Further, in fig. 5, the plurality of convex surfaces 21a included in the relief layer 21 are illustrated for convenience, each convex surface 21a is shown as a convex portion protruding from the recording layer 12 toward the surface laminate layer 15, and the size of each convex portion is exaggerated. In fig. 5, the metal layer 22 and the adhesive layer 23 of the optical security patch 11 are not shown.

As shown in fig. 5, the relief layer 21 includes a plurality of convex surfaces 21a, and the plurality of convex surfaces 21a are arranged in the two-dimensional direction as described above. The plurality of convex surfaces 21a are periodically arranged along a one-dimensional direction or a two-dimensional direction. In the plurality of convex surfaces 21a, a pitch P arranged along one direction is 190nm or more and 580nm or less, and a pitch P arranged along a direction orthogonal to the one direction is also 190nm or more and 580nm or less. In the plurality of convex surfaces 21a, the distance between the apexes of the convex surfaces 21a is the pitch P at which the convex surfaces 21a are arranged. The plurality of convexities 21a are two-dimensionally located on the whole or a part of the relief layer 21 as viewed from the thickness direction of the recording layer 12. Further, the metal layer 22 covers all or a part of the convex surface 21 a.

Each convex surface 21a has a substantially conical surface shape. Preferably, the size of the convexes 21a (i.e., the size of the regions defined on the recording layer 12 when the convexes 21a are projected onto the recording layer 12) and the height of the convexes 21a are equal for all the convexes 21 a.

Here, the refractive index in a cross section orthogonal to the direction in which each convex surface 21a protrudes is determined by the ratio of the relief layer 21 in the cross section and the member located around the relief layer 21. In addition, if the pitch P of the convex surfaces 21a is substantially equal to or smaller than the wavelength of visible light, the refractive indices in the cross section are all considered to be the same. The pitch P of the convex surfaces 21a is equal to or less than the center wavelength of visible light. Specifically, the pitch P of the convex surfaces 21a may be 580nm or less. In a cross section orthogonal to the direction in which the convex surface 21a protrudes, the proportion occupied by the relief layer 21 gradually decreases in the direction from the relief layer 21 toward the adhesive layer 23, while the proportion occupied by members located around the convex surface 21a gradually increases. Therefore, since there is no portion where the refractive index changes greatly in the direction in which the convex surface 21a protrudes, reflection and refraction on the convex surface 21a are suppressed in the light incident on the convex surface 21a, and the light incident on the convex surface 21a passes through the convex surface 21 a.

Since the convex surface 21a is covered with the metal layer 22 containing metal as a main component, light transmitted through the convex surface 21a is absorbed by the metal layer 22 by contact with the metal layer 22. Further, at the boundary between the convex surface 21a and the metal layer 22, the light incident on the convex surface 21a is multiply reflected, so every time the light is reflected at the boundary, a part of the light incident on the convex surface 21a is absorbed by the metal layer 22.

In the metal layer 22, the light absorption as described above occurs in the non-modified region 22b having metallic luster, and the light absorption hardly occurs in the modified region 22a having transparency. Therefore, the light incident on the modified region 22a passes through the modified region 22 a.

The recording area 12a displays personal information, which is information for specifying the holder of the personalized document 10. The recording area 12a is an example of an inner recording area. The recording area 12a displays the personal number included in the second image PIC2 as personal information. That is, the personalized document 10 includes, as an example of the outer recording region, the printing portion 16 on which the first image PIC1 is printed when viewed in the thickness direction of the recording layer 12, and is located further outside than the edge of the embossed layer 21, wherein the first image PIC1 includes the same personal information as the personal information included in the recording region 12 a.

Note that the personal information in the recording area 12a may be the same as any one of the plurality of personal information in the first image PIC1, and may be any one of the nationality, name, and date of birth, or a combination thereof. Note that the personal information of the recording area 12a may be the same as the personal information of the second image PIC2, and in this case, the recording area 12a may display the portrait of the holder.

Referring to fig. 6, the diffracted light emitted from the relief layer 21 will be described.

Fig. 6 schematically shows a diffraction grating having a period smaller than the center wavelength of visible light, i.e., 580 nm. For convenience of explanation and illustration, fig. 6 shows only red, green, and blue diffracted lights as the first-order diffracted lights emitted from the diffraction grating.

In the diffraction grating, the emission angle β of the m-th order diffracted light (m ═ 0, ± 1, ± 2, · · ·) can be calculated by using the following expression (1) when the light travels in a plane perpendicular to the longitudinal direction of the grooves of the diffraction grating.

d ═ m λ/(sin α -sin β) … formula (1)

In the formula (1), d is the period of the diffraction grating, m is the diffraction order, and λ is the wavelength of the incident light and the wavelength of the diffracted light. Further, α is an emission angle of 0 th-order diffracted light, that is, transmitted light or regular reflected light. That is, the absolute value of α is equal to the incident angle of incident light, and in the reflection-type diffraction grating, the incident direction of incident light and the emission direction of regular reflection light are symmetrical with respect to the front view direction, which is the direction in which the diffraction grating is viewed from the front. In the above-described personalized document 10, the front view direction is the thickness direction of the recording layer 12.

When the diffraction grating is a reflection type, the angle α is 0 ° or more and less than 90 °. When the diffraction grating is illuminated from an oblique direction, a range including an angle in the direction in which the normally reflected light is emitted is a positive range, and a range including an angle in the direction in which the illumination light is incident is a negative range. When the emission direction of the diffracted light is included in the same range as the emission direction of the normally reflected light, that is, in a positive range, the angle β has a positive value. On the other hand, if the emission direction of the diffracted light is included in the same range as the incident direction of the illumination light, that is, in a negative range, the angle β has a negative value.

When the observer looks at the diffraction grating, out of the diffracted lights emitted from the diffraction grating, the diffracted light contributing to the image display seen by the observer is only the diffracted light having the emission angle β of 0 °. However, when the period d is smaller than the wavelength λ, since there is no incident angle α satisfying the formula (1), the observer who looks at the diffraction grating cannot see the diffracted light. Thus, among the diffraction gratings, the diffraction grating having the small period d, that is, the period d smaller than the wavelength λ does not emit the diffracted light in the front view direction, and the diffraction grating having the period d around the wavelength λ emits the diffracted light only to the extent that the diffracted light is hardly visible in the front view direction.

The periodically arranged convex surfaces 21a are diffraction gratings.

As shown in fig. 6, the period d of the diffraction grating DG formed by the convex surface 21a is larger than 1/2, which is the shortest wavelength of visible light, and smaller than the center wavelength of visible light. That is, the period d of the diffraction grating DG is larger than 190nm and smaller than 580 nm. The incident light IL emitted from the light source LS is white light composed of a plurality of lights having different wavelengths, and when the incident light IL enters the diffraction grating DG from an oblique direction, the diffraction grating DG emits the emitted light RL which is normally reflected light or 0 th order diffracted light.

The diffraction grating DG emits red diffracted light DLr, green diffracted light DLg, and blue diffracted light DLb as first-order diffracted light. However, the emission angle β r of the red diffracted light DLr, the emission angle β g of the green diffracted light DLg, and the emission angle β b of the blue diffracted light DLb are negative values.

For this reason, the optical security patch 11 displays a black image or a gray image in the thickness direction of the recording layer 12. Note that black is in such a state: when white light is irradiated from the thickness direction of the recording layer 12 and the intensity of the regular reflection light is measured, the reflectance is 10% or less in light of all wavelengths included in the range of 400nm to 700 nm. In addition, gray is a state: when white light is irradiated from the thickness direction of the recording layer 12 and the intensity of the normally reflected light is measured, the reflectance is greater than 10% and about 25% or less in light of all wavelengths included in the range of 400nm to 700 nm.

When a black image is displayed in the optical security patch 11, it is preferable that the higher the height of the convex surface 21a is, the smaller the rate of change in the refractive index in the convex surface 21a along the direction in which the convex surface 21a protrudes is. On the other hand, the lower the height of the convex surface 21a, the higher the reflectance of the convex surface 21a, and the higher the brightness of the image displayed by the optical security patch 11. As a result, optical security patch 11 displays a gray image.

The pitch P of the convex surfaces 21a may be in the range of 190nm to 580 nm. The height of the convex surfaces 21a may be greater than 1/2 of the pitch P of the convex surfaces 21 a. If the height of the convex surface 21a is 1/2 or more of the pitch P, the convex surface 21a can suppress reflection of incident light with respect to the thickness direction of the recording layer 12. The height of the convex surface 21a may be equal to or less than the pitch P. If the height of the convex surface 21a is not more than the pitch P, the formation of the convex surface 21a is easy. Therefore, the height of the convex surface 21a is preferably 95nm or more and 580nm or less.

[ Effect of personalized document ]

The operation of the personalized document 10 will be described with reference to fig. 7 and 8. The operation of the personalized document 10 having the black structure in the recording region 12a will be described below.

As shown in fig. 7, when the observer OB observes the personalized document 10 from the thickness direction of the recording layer 12, in other words, from the normal direction of the surface 10F, the second portion 11b of the optical security patch 11 absorbs light incident on the optical security patch 11, and the first portion 11a transmits light incident on the optical security patch 11. Therefore, a portion of the optical security patch 11 where the second portion 11b is located in a plan view opposing the surface 10F is recognized by the observer OB as an area having black due to absorption of light. On the other hand, in the optical security patch 11, the recording region 12a of the recording layer 12 is recognized through the modified region 22a in a plan view facing the front surface 10F, and the portion where the first portion 11a is located is recognized as a region having black color by the viewer OB due to the color of the recording region 12 a.

Therefore, the optical security patch 11 hides the recording area 12a included in the recording layer 12, and a single image formed by the optical security patch 11 and the recording area 12a is recognized by the observer OB. When the personalized document 10 is viewed from the thickness direction of the recording layer 12 in this way, the information in the recording region 12a is latent-imaged.

On the other hand, as shown in fig. 8, when the observer OB observes the personalized document 10 from a direction orthogonal to the thickness direction of the recording layer 12, in other words, from a direction orthogonal to the normal direction of the surface 10F, the observer OB can see diffracted light emitted from the optical security patch 11. At this time, in the optical security patch 11, the second portion 11b emits diffracted light toward the observer OB, and the first portion 11a also emits diffracted light toward the observer OB. However, the second portions 11b emit diffracted light with high brightness by reflection at the unmodified regions 22b, while the first portions 11a emit only reflected light generated by the refractive index of the relief layer 21 being different from the refractive index of the modified regions 22a, so the first portions 11a emit only diffracted light with lower brightness than the second portions 11 b. Further, since the first portion 11a has permeability, the recording region 12a located below the first portion 11a is also seen by the observer OB via the first portion 11 a. Therefore, the recording region 12a is seen by the observer OB according to the contrast between the color of the diffracted light emitted from the second portion 11b and the color of the recording region 12a through which the first portion 11a passes.

Thus, according to the personalized document 10, when the direction of viewing the personalized document 10 is changed, the image shown on the personalized document 10 can be changed, and as a result, the design of the personalized document 10 can be improved.

Here, in general, when an observer observes an article, particularly an article having low light reflection energy and light scattering energy, that is, an article having high light absorption, the observer aligns the relative positions of the light source and the article with respect to the eyes of the observer with the positions where regular reflection light can be recognized. Therefore, an observer who cannot know that the optical security patch 11 emits diffracted light in the negative range may not be able to see the diffracted light. In this case, it is difficult for the observer to notice that the optical security patch 11 can emit diffracted light.

In contrast, in the optical security patch including a plurality of convexes arranged at a pitch larger than the pitch P of the convexes 21a of the optical security patch 11, since the optical security patch emits diffracted light in the positive range, even an observer who does not know that the optical security patch emits diffracted light in the positive range has a high probability of seeing the diffracted light. In such an optical security patch, the angle formed by the normal viewing direction and the emission direction of the diffracted light is small. Therefore, the diffracted light emitted from the optical security patch is also easily visible to the observer.

For this reason, it is difficult for the observer of the personalized document 10 to notice the recording area 12 a. Therefore, in the personalized document 10, even if the first image PIC1 is tampered with, the recording area 12a is highly likely not to be tampered with. Therefore, based on the mismatch between the information of the first image PIC1 and the information of the recording area 12a, it can be determined whether the personalized document 10 has been tampered with.

[ method for producing personalized document ]

A method of manufacturing the personalized document 10 is described with reference to fig. 9 to 13. Hereinafter, a method for manufacturing the personalized document 10 of the first example among the personalized documents 10 of the first to third examples will be described in detail. Before describing the method of manufacturing the personalized document 10, the structure of the transfer foil used for manufacturing the personalized document 10 will be described.

As shown in fig. 9, the transfer foil 30 includes the optical security patch 11 and a carrier film 31 for supporting the optical security patch 11. The optical security patch 11 is supported by the carrier film 31 in a state of being peelable from the carrier film 31. In forming the transfer foil 30, first, the carrier film 31 is prepared. The carrier film 31 may be a plastic film. The surface of the carrier film 31 on which the optical security patch 11 is formed may be subjected to a process for easily peeling the optical security patch 11 from the carrier film 31.

Next, the embossed layer 21 is formed on one surface of the carrier film 31. In forming the relief layer 21, first, a coating film for forming the relief layer 21 is formed on the carrier film 31. Then, the original plate for forming the plurality of convex surfaces 21a is pressed against the surface of the coating film opposite to the surface contacting the carrier film 31, and the coating film is cured in this state or after the pressing. Thereby, the relief layer 21 including the plurality of convex surfaces 21a is formed. The metal layer 22 is formed on the surface of the embossed layer 21 opposite to the surface contacting the carrier film 31. Then, the adhesive layer 23 is formed on the surface of the metal layer 22 opposite to the surface contacting the relief layer 21. The metal layer 22 may be formed by a deposition method. The deposition method may be a sputtering method or a vacuum evaporation method. Thereby, the transfer foil 30 can be obtained.

The transfer foil 30 may have an intermediate layer between the embossed layer 21, the metal layer 22, and the adhesive layer 23.

As shown in fig. 10, a recording layer 12 is prepared when the personalized document 10 is manufactured. The recording layer 12 may be a plastic sheet. The plastic may be a thermoplastic. Next, the optical security patch 11 is transferred onto the surface 12F of the recording layer 12 using the transfer foil 30. In addition, the optical security patch 11 may also be transferred from the transfer foil 30 to the surface laminate layer.

As shown in fig. 11, a colored layer 14 is prepared. The colored layer 14 may be a plastic sheet. The plastic may be a thermoplastic. Then, the printed portion 16 is formed on the surface 14F of the colored layer 14. The printed portion 16 may be formed on the back surface of the recording layer 12, or a part of the printed portion 16 may be formed on the front surface 14F of the colored layer 14 and the remaining part of the printed portion 16 may be formed on the back surface of the recording layer 12.

As shown in fig. 12, the back surface laminate 13 and the surface laminate 15 are prepared, and the back surface laminate 13, the colored layer 14, the recording layer 12, and the surface laminate 15 are stacked in this order, and these layers are integrated to form a laminate 40. These layers may be integrated by heat or pressure. At this time, the surface lamination layer 15 is stacked on the recording layer 12 in such a manner that the optical security patch 11 located on the recording layer 12 is sandwiched between the recording layer 12 and the surface lamination layer 15. This makes it possible to obtain a laminate 40 having the optical security patch 11 inside.

As shown in fig. 13, a laser beam LB is irradiated from the surface lamination layer 15 side of the recording layer 12 of the laminate to a part of the recording layer 12 via the surface lamination layer 15 and the optical security patch 11. The laser beam LB is emitted from the irradiation device IE. Thereby, the recording region 12a is formed in the recording layer 12 after the irradiation of the laser beam LB. At the same time, a part of the metal layer 22 of the optical security patch 11 irradiated with the laser beam LB becomes the modified region 22 a. A part of the metal layer 22 irradiated with the laser beam LB is modified by energy given from the laser beam LB.

When the recording layer 12 is irradiated with the laser beam LB through the surface laminate layer 15 and the optical security patch 11, the focal position and power of the laser beam LB are set so that the recording region 12a can be formed in the recording layer 12 and a part of the metal layer 22 can be modified.

Here, when the energy applied to the recording layer 12 and the metal layer 22 by irradiation of the laser beam LB exceeds a predetermined magnitude, the area of the portion of the metal layer 22 where the modification occurs is larger than the area of the portion of the recording layer 12 where the carbonization occurs when viewed from the thickness direction of the recording layer 12. Therefore, in order to make the area of the modified region 22a equal to the area of the recording region 12a when viewed in the thickness direction of the recording layer 12, the energy of the laser beam LB irradiated to the recording layer 12 to form the edge of the recording region 12a may be smaller than the energy of the laser beam LB irradiated to the recording layer 12 to form the inner side of the edge of the recording region 12 a. In the recording layer 12, the laser beam LB is irradiated to the recording layer 12 from the inner side of the recording region 12a toward a portion corresponding to the edge so that the energy of the laser beam LB becomes smaller from the inner side of the recording region 12a toward the edge. The power of the laser beam LB to be irradiated may be in a range of 0.1W to 1W. The pulse width of the laser beam LB to be irradiated may be in a range of 10n seconds to 1 μ second. The optical density (OD value) of the recording region 12a may be in the range of 1.0 or more and 2.0 or less. The optical density (OD value) of the recording region 12a can be controlled by the drawing speed using the laser light.

Since the laser beam LB is irradiated along the thickness direction of the recording layer 12, the recording regions 12a and the modified regions 22a are formed so that one recording region 12a is aligned with one modified region 22a when viewed from the thickness direction of the recording layer 12 in the optical security patch 11. Thus, with reference to FIG. 2, the personalized document 10 of the first example described above can be obtained.

In forming the personalized document 10 of the second example, the recording layer 12 may be stacked on the colored layer 14 so that the optical security patch 11 is sandwiched between the colored layer 14 and the recording layer 12 when the laminate 40 is formed. Then, the recording layer 12 may be irradiated with the laser beam LB through the surface lamination layer 15. In this case, the focal position and power of the laser beam LB may be set so that the recording region 12a can be formed in the recording layer 12 and a part of the metal layer 22 located below the recording layer 12 can be modified.

In forming the personalized document 10 of the third example, the first optical security patch 11A may be transferred to the surface 12F of the recording layer 12 using the transfer foil 30, and the second optical security patch 11B may be transferred to the back surface of the recording layer 12 using the transfer foil 30. Then, when the laminated body 40 is formed, the colored layer 14, the recording layer 12, and the surface laminate layer 15 may be stacked such that the first optical security patch 11A is sandwiched between the recording layer 12 and the surface laminate layer 15 and the second optical security patch 11B is sandwiched between the colored layer 14 and the recording layer 12.

When the recording layer 12 is irradiated with the laser beam LB, the recording layer 12 may be irradiated with the laser beam LB through the surface laminate layer 15 and the first optical security patch 11A. In this case, the focal position and power of the laser beam LB may be set so that the recording region 12a can be formed in the recording layer 12 and a part of the metal layer 22 in the first optical security patch 11A and a part of the metal layer 22 in the second optical security patch 11B can be modified.

[ Material for Forming Each portion ]

The materials used to form the various components that make up the personalized document 10 will be described.

[ laminated layer ]

The back laminate layer 13 and the surface laminate layer 15 may be plastic sheets. The plastic sheet may be a PET (polyethylene terephthalate) sheet, PEN (polyethylene naphthalate) sheet, PP (polypropylene) sheet, polyvinyl chloride (PVC) sheet, amorphous polyester (PET-G) sheet, Polycarbonate (PC) sheet. Among them, as a substrate of a card or passport for personal identification, a PCV sheet, a PET-G sheet, and a PC sheet are easily processed by heat or pressure integration.

The thickness of each laminate layer may be 50 μm or more and 400 μm or less. Since the thickness of each laminate layer is 50 μm or more, the physical strength of each laminate layer is improved to such an extent that handling of each laminate layer is easy, and thus generation of wrinkles in each laminate layer can be suppressed when forming the printing portion 16 or the like. Further, since the thickness of each laminate layer is 400 μm or less, it is possible to suppress an increase in the influence of thickness variation or warpage of each laminate layer when producing the personalized document 10. The thickness of each laminate layer may be 75 μm or more and 100 μm or less.

[ recording layer ]

The recording layer 12 may be a plastic sheet having a property of being carbonized by irradiation with a laser beam of a predetermined wavelength. The recording layer 12 is made of polycarbonate as a main material, and may contain an energy absorber that absorbs laser light as an additive. Such a sheet is, for example, LEXAN series SD8B94 (LEXAN is a registered trademark) by SABIC.

The thickness of the recording layer 12 may be 50 μm or more and 400 μm or less for the same reason as that of the back laminate layer 13 and the front laminate layer 15. Alternatively, the thickness of the recording layer 12 may be 75 μm or more and 100 μm or less.

[ colored layer ]

The colored layer 14 may be a plastic sheet. As the material of the plastic sheet, the same kind of material as that of the back laminate 13 and the front laminate 15 can be used. In addition, the plastic sheet of the colored layer 14 may also contain a coloring agent. The colorant is dye, pigment, etc.

The thickness of the colored layer 14 may be 50 μm or more and 400 μm or less for the same reason as that of the back laminate layer 13 and the front laminate layer 15. Alternatively, the thickness of the colored layer 14 may be 75 μm or more and 100 μm or less.

[ printing part ]

The printing portion 16 has a color and a shape of characters, patterns, or the like in order to provide predetermined information to the personalized document 10.

The printing portion 16 is formed by printing ink. The printing may be offset, letterpress, or gravure printing. The ink used to form the printing portion 16 may be an offset ink, a relief ink, or a gravure ink, depending on the printing method. The ink used to form the printing portion 16 may be a resin ink, an oil ink, or a water ink, depending on the composition. The ink used to form the printing portion 16 may be an oxidative polymerization type ink, a penetration drying type ink, an evaporation drying type ink, or an ultraviolet curing type ink, depending on the drying method.

The ink forming the printed portion 16 may be a functional ink that changes color depending on the angle of incidence of light with respect to the personalized document 10 or the angle at which the personalized document 10 is viewed. The functional Ink may be an optically Variable Ink (Optical Variable Ink), a color shifting Ink, a pearlescent Ink, or the like.

The printing portion 16 may be formed by an electrophotographic method using toner. When the printing portion 16 is formed by an electrophotographic method, a toner is prepared by adhering color particles such as graphite or pigment to plastic particles having a charging property, and the toner is transferred to a printing object by static electricity generated by the charging. Then, the toner is fixed to the printing object by heating the printing object to which the toner is transferred. Thereby, the printed portion 16 can be formed on each of the laminated layers or the recording layer 12 described above.

[ Carrier film ]

The carrier film 31 of the transfer foil 30 may be a plastic film. The plastic film can be PEN film or PP film. The material of the membrane may be such that: the carrier film 31 is not deformed or modified by heat applied to the carrier film 31 or a solvent in contact with the carrier film when the embossed layer 21 is formed on the carrier film 31. Further, the carrier film 31 may be paper, synthetic paper, plastic multi-layer paper, or resin-impregnated paper.

The thickness of the carrier film 31 may be 4 μm or more. The thickness of the carrier film 31 may be 12 μm or more and 50 μm or less. Since the thickness of the carrier film 31 is 4 μm or more, the physical strength of the carrier film 31 is improved to such an extent that handling of the carrier film 31 is easy.

[ relief layer ]

The material of the relief layer 21 may be a thermoplastic resin, a thermosetting resin, an ultraviolet-curable resin. The thermoplastic resin may be a monomer of acrylic resin, epoxy resin, cellulose resin, vinyl resin, a mixture thereof, a composite thereof, a copolymer resin thereof. The thermosetting resin may be a urethane resin, a melamine resin, an epoxy resin, or a phenol resin. The ultraviolet curable resin may be a monomer of acrylic resin, urethane resin, epoxy resin, a mixture thereof, a composite thereof, or a copolymer resin thereof. The thickness of the relief layer 21 is 1 μm or more and 5 μm or less.

The material of the relief layer 21 may also be a cured polymer. The cured polymer may be a cured product of a monomer, an oligomer or a polymer having an ethylenically unsaturated bond or an ethylenically unsaturated group. Wherein, the monomer can be 1, 6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and the like. The oligomer may be an epoxy acrylate, a urethane acrylate, a polyester acrylate, or the like. The polymer may be urethane-modified acrylic resin or epoxy-modified acrylic resin.

[ Metal layer ]

The metal layer 22 is mainly made of metal. The metal of the metal layer 22 may be a single body of aluminum, nickel, iron, gold, copper, or tin, or an alloy thereof. As the metal of the metal layer 22, a simple substance of aluminum, nickel, or iron, or an alloy thereof is easily processed. The metal layer 22 may be formed using a deposition method. The deposition method of the metal layer 22 may be a vacuum evaporation method or a sputtering method. The thickness of the metal layer 22 may be

Above and

the following. Alternatively, the metal layer 22 may have a thickness of

Above and

the following. If the thickness of the metal layer 22 is

Above and

hereinafter, processing by laser light becomes easy.

[ adhesive layer ]

The adhesive layer 23 mainly contains an adhesive. The adhesive may be polyester resin, urethane resin, acrylic resin, or vinyl chloride resin. The adhesive layer 23 may contain a modifier. The modifier may be a monomer of a tackifier, a filler, a softener, a heat stabilizer, an antioxidant, or a mixture thereof.

The tackifier can be rosin resin, terpene phenol resin, terpene resin, aromatic modified terpene resin, petroleum resin, coumarone-indene resin, styrene resin, phenolic resin, xylene resin, their mixture, and their copolymer resin. The filler can be zinc white, titanium oxide, silicon dioxide, calcium carbonate, barium sulfate. The softener can be processing oil, liquid rubber and plasticizer. The thermal light stabilizer may be benzophenone, benzotriazole, hindered amine. The antioxidant may be aniline, phenol, phosphite, thioester.

The thickness of the adhesive layer 23 may be 0.1 μm or more and 10 μm or less. The thickness of the adhesive layer 23 may be 1 μm or more and 5 μm or less.

In forming the adhesive layer 23, an adhesive is applied to one surface of the release material and dried. Next, the adhesive is bonded to the metal layer 22. After that, the adhesive layer 23 can be formed on the metal layer 22 by separating the release material from the adhesive.

The adhesive may be applied by a roll coater, a knife coater, a roll coater, an air knife coater, a die coater, a bar coater, a gravure coater, a curtain coater, or the like.