KR102502702B1 - Security sheet comprising watermark - Google Patents

Abstract

a first sheet containing first silver coins, a second sheet, and an intermediate sheet disposed between the first sheet and the second sheet, wherein the first sheet and the second sheet are transparent or translucent sheets; The intermediate sheet includes a pattern layer having an inclined surface inclined at a predetermined angle and repeatedly formed with an inclined pattern, and a security sheet having a light blocking layer formed on the inclined surface. According to the present invention, by providing various visual effects according to the viewing direction under transmitted light, there is an effect of improving the security of silver coins.

Description

Security sheet containing silver coins {SECURITY SHEET COMPRISING WATERMARK}

The present invention relates to a security sheet containing silver coins, and more particularly, to a security sheet in which silver coins are observed differently depending on directions.

Security sheets such as banknotes, securities, gift certificates, passports, identification cards, security labels, official documents, admission tickets, and various tickets often include security elements to prevent forgery and alteration.

Security element technologies used in security sheets include hologram, watermark, security thread, security fiber, security ink such as color conversion ink, and security printing without special equipment. There are a lot of technologies that can be checked. In particular, silver coins are widely used as security elements that can satisfy both identification and forgery prevention functions because they are not duplicated by copying or scanning and have decorative effects.

A silver coin can be created by making a difference in opacity for each area of the sheet. In the case of paper sheets, silver coins can be formed in the wet stage. For example, when paper pulp is deposited on a fabric including an embossed portion formed with grooves and protrusions in a paper machine, the amount of pulp deposited on the grooves is relatively large and the amount of pulp deposited on the protrusions is relatively small. That is, a portion having a relatively higher or lower paper density than the rest of the embossed portion is formed. Therefore, when the paper sheet is observed under transmitted light after passing through drying, silver coins are observed due to the difference in transmitted light according to the paper density.

In addition, the silver coin can be formed by mechanically embossing the sheet using a watermarking roll or the like, thereby generating a difference in density for each region.

As such, since silver coins can be relatively easily implemented by generating a difference in density for each area of the sheet, there is a limit in terms of security. Moreover, since silver coins depend on visual identification, there is a problem in that it is not easy for an observer to distinguish them even if they are not perfectly identically reproduced. Therefore, it is required to improve the usability of silver coins by further adding security to silver coins.

EP 1122360 B1

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a security sheet containing silver coins with improved security. Specifically, it is an object of the present invention to provide a security sheet in which silver coins are observed with different sharpness depending on the direction.

In addition, another object of the present invention is to provide a security sheet capable of providing a visual effect in which a silver coin image changes according to a direction.

The object of the present invention is not limited to the above, and other objects and advantages of the present invention not mentioned can be understood by the following description.

A security sheet according to an embodiment of the present invention includes a first sheet including a first silver coin, a second sheet, and an intermediate sheet disposed between the first sheet and the second sheet, and comprising the first sheet and the second sheet. The second sheet is a transparent or translucent sheet, and the intermediate sheet includes a pattern layer having an inclined surface inclined at a predetermined angle and repeatedly formed with an inclined pattern, and a light blocking layer is formed on the inclined surface.

The intermediate sheet may overlap an entire area where the first silver coin is formed in a vertical direction of the security sheet.

When the security sheet is viewed from the direction of the second sheet under transmitted light, the first silver coin may be observed with different sharpness depending on the viewing direction. In particular, when viewed from a direction parallel to the inclined surface, the first silver coin can be most clearly observed.

According to one embodiment of the present invention, the intermediate sheet may overlap a part of the area where the first silver coin is formed in a vertical direction of the security sheet and may not overlap the other part.

At this time, a portion of the area where the first silver coin is formed overlapping the intermediate sheet can be most clearly observed when viewed from a direction parallel to the inclined surface.

Also, according to one embodiment of the present invention, the second sheet may include a second silver coin. The second silver coin may include an area that does not overlap with the intermediate sheet in a vertical direction of the security sheet, and when viewed from the second sheet direction under transmitted light, at least a portion of the first silver coin and the second silver coin may merged and observed.

According to one embodiment of the present invention, the pattern layer of the intermediate sheet includes a first area in which inclined patterns having inclined surfaces inclined at a first angle are repeatedly formed, and an inclined pattern having inclined surfaces inclined at a second angle are repeatedly formed. A second area may be included, and the first angle and the second angle may be different from each other. In addition, the inclination pattern of the first area and the inclination pattern of the second area may be left-right symmetrical to each other.

In this case, a part of the area where the first silver coin is formed may overlap the first area in a vertical direction, and another part of the area where the first silver coin is formed may overlap the second area in a vertical direction. Accordingly, when viewed from the direction of the second sheet under transmitted light, the observed image of the first silver coin may change according to the viewing direction.

In embodiments of the present invention, the light blocking rate of the light blocking layer may range from 70% to 95%, and the light blocking layer may be a metal thin film or an insulating thin film made of one or more layers.

Also, in embodiments of the present invention, the intermediate layer may be a polymer film.

The present invention discloses an article comprising a security sheet according to any one of the above.

According to the present invention, there is an effect of providing a security sheet containing silver coins with improved security. Specifically, there is an effect of providing a security sheet in which silver coins are observed with different sharpness depending on the direction.

In addition, according to the present invention, there is an effect of providing a visual effect in which a silver coin image changes depending on the direction.

However, the effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

In order to more fully understand the drawings cited herein, a brief description of each drawing is provided.
1 is a cross-sectional view of a security sheet according to a first embodiment of the present invention.
2 is a partially enlarged cross-sectional view of an intermediate sheet according to a first embodiment of the present invention.
3 is an exemplary plan view of a first silver coin according to a first embodiment of the present invention.
4 is a view for explaining visual effects when observing the security sheet according to the first embodiment of the present invention from various directions.
5 is a cross-sectional view of a security sheet according to a second embodiment of the present invention.
6 is an exemplary plan view of a first silver coin according to a second embodiment of the present invention.
7 is a view for explaining visual effects when observing a security sheet according to a second embodiment of the present invention from various directions.
8 is a cross-sectional view of a security sheet according to a third embodiment of the present invention.
9 shows an exemplary plan view of a first silver coin and a second silver coin according to a third embodiment of the present invention.
10 is another exemplary plan view of a first silver coin and a second silver coin according to a third embodiment of the present invention.
FIG. 11 is a diagram for explaining a visual effect of a silver coin in a direction corresponding to FIG. 10 .
12 is a cross-sectional view of a security sheet according to a fourth embodiment of the present invention.
13 is a partially enlarged cross-sectional view of an intermediate sheet according to a fourth embodiment of the present invention.
14 is a view for explaining visual effects when the security sheet according to the fourth embodiment of the present invention is observed from various directions.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail through detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention includes all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, numbers (eg, 1st, 2nd, etc.) used in the description process of this specification are only identifiers for distinguishing one component from another component.

In the embodiments of the present invention, components that are the same or correspond to each other will be described by giving the same reference numerals.

A security sheet according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4 .

1 is a cross-sectional view of a security sheet according to a first embodiment of the present invention. Referring to FIG. 1 , a security sheet 1 according to a first embodiment of the present invention includes a first sheet 10 including a first silver coin 41, an intermediate sheet 30, and a second sheet 20. consists of including

The first sheet 10 and the second sheet 20 may be transparent or translucent sheets. The first sheet 10 and the second sheet 20 may be paper sheets, fiber sheets, polymer sheets, plastic sheets, etc., but are not limited thereto. When the first sheet 10 and the second sheet 20 are fibrous sheets, they may be cellulosic fibers, particularly cotton fibers, and/or synthetic fibers, such as polyamide and/or polyester fibers. When the first sheet 10 and the second sheet 20 are polymer sheets, polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), polyester carbonate (PEC), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS), and the like.

The intermediate sheet 30 is disposed between the first sheet 10 and the second sheet 20 . The intermediate sheet 30 may be disposed on the entire bonding surface of the first sheet 10 and the second sheet 20 . Alternatively, it may be disposed only in an area sufficient to completely cover the formation area of the first silver coin 41 in a direction perpendicular to the security sheet 1 .

2 is a partially enlarged cross-sectional view of an intermediate sheet according to a first embodiment of the present invention. Referring to FIG. 2 , the intermediate sheet 30 may include a base layer 31 and a pattern layer 32 . The base layer 31 may be a transparent or translucent polymer film, but is not limited thereto. When the substrate layer 31 is a polymer film, polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), polyester carbonate (PEC), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene It may be a film comprising one or more of styrene (ABS).

The pattern layer 32 is formed on one surface of the base layer 31 and may include a plurality of repeated inclination patterns having an inclined surface 33 inclined at a predetermined inclination angle θ with respect to the base layer 32. . The inclination angle θ may be 45 degrees, but is not limited thereto. The inclination angle θ may be appropriately selected between 30 degrees and 80 degrees. The pattern layer 32 may be integrally formed with the base layer 31 . For example, a plurality of inclination patterns may be formed on one surface of the substrate layer 31 by an injection process using a mold having an inclination pattern or an impression process using a roll having an inclination pattern.

A light blocking layer 34 may be formed on the inclined surface 33 . The light blocking layer 34 blocks transmission of light, and the light blocking rate may be 70% or more, preferably 80% or more, and particularly preferably 90% or more. For example, a preferable range of the light blocking rate of the light blocking layer 34 may be 70 to 95%. The light blocking layer 34 may be formed of a single layer or a multi-layer metal thin film, or a multi-layer insulating film having different refractive indices. When the light blocking layer 34 is formed of a metal thin film, the metal thin film 34 is made of aluminum (Al), chromium (Cr), nickel (Ni), silver (Ag), palladium (Pd), titanium (Ti), It may be a material made of any one or a combination of cobalt (Co), tungsten (W), molybdenum (Mo), iron oxide, or carbon. The thickness of the metal thin film may range from 5 to 10 nm. The multilayer insulating film may be a material including any one or a combination of silicon oxide, aluminum oxide, titanium oxide, magnesium fluoride, aluminum fluoride, barium fluoride, calcium fluoride, or lithium fluoride. The thickness of the multilayer insulating film may range from 10 to 200 nm. The light blocking layer 34 may be formed by a vapor deposition method such as sputtering or evaporation.

The intermediate sheet 30 having the structure shown in FIG. 2 may be disposed between the first sheet 10 and the second sheet 20 in various ways. The intermediate sheet 30 may be impregnated or coated with the first sheet 10 or the second sheet 20 in advance. Alternatively, it may be adhered to the first sheet 10 and the second sheet 20 by an adhesive layer in the form of a liquid or film. Alternatively, the first sheet 10, the intermediate sheet 30, and the second sheet 20 may be stacked in order and then assembled together by pressing at high temperature and/or high pressure.

The first sheet 10 includes a first silver coin 41 . Although FIG. 1 shows the first silver coin 41 as a separate layer formed on the underside of the first sheet 10 for convenience of explanation, the first silver coin 41 may be a silver coin image formed on the first sheet 10 itself. And, the formation position is not limited to the bottom.

The first silver coin 41 can be formed in a variety of ways. For example, the first silver coin 41 may be formed by etching or pressing in the manufacturing process of the first sheet 10 . For example, if the first sheet 10 is a paper sheet, it may be formed by creating pulp regions of reduced or increased thickness in the papermaking step. In addition, it can be formed by adjusting the transmittance by mechanical means and/or chemical means of applying a specific material after sheet production. That is, in the present invention, the formation method or structure of the first silver coin 41 is not limited.

3 is an exemplary plan view of a first silver coin according to a first embodiment of the present invention. The first silver coin 41 may be embodied in various forms, such as an image, a combination of an image and a text, in addition to the text illustrated in FIG. 3 . When the security sheet 1 is viewed from the top side, that is, the second sheet 20, the first silver coin 41 can be observed as a normal character string ABCD, as shown in FIG. When viewed from the bottom, it may be formed in the form of a character string with left and right reversed.

Effects of the security sheet according to the first embodiment of the present invention will be described with reference to FIG. 4 . 4 is a view for explaining visual effects when observing the security sheet according to the first embodiment of the present invention from various directions.

Referring to FIG. 4 , when viewed from the upper surface of the security sheet 1 , that is, from the second sheet 20 under transmitted light, the first silver coin 41 may be observed with different sharpness depending on the viewing direction. The first direction 51 is a direction parallel to the inclined surface 33 of the intermediate sheet 30, the third direction 53 is a direction perpendicular to the inclined surface 33, and the second direction 52 is a first direction ( 51) and the third direction 53, that is, assuming a direction forming an angle of 45 degrees with the inclined surface 33, the amount of transmitted light blocked by the intermediate sheet 30 when viewed from the first direction 51. Since this is small, the first silver coin 41 is observed relatively distinctly. In addition, when viewed from the second direction 52, part of the transmitted light is blocked by the intermediate sheet 30, and thus the first silver coin 41 is observed as a relatively faint image. On the other hand, when observing from the third direction 53, most of the transmitted light is blocked by the intermediate sheet 30, so that the first silver coin 41 is hardly observed. Light transmittance in the third direction 53 may be less than 5%.

As described above, according to the first embodiment of the present invention, it is possible to obtain a visual effect in which the sharpness of the silver coin is changed according to the observation direction, which provides a visual effect such as a silver coin image appearing and disappearing when the observation direction is changed. . As a result, the security of the silver coin can be further improved.

A security sheet according to a second embodiment of the present invention will be described with reference to FIGS. 5 to 7 . In describing the second embodiment, descriptions of parts overlapping with those of the first embodiment will be omitted, and description will be made focusing on differences.

5 is a cross-sectional view of a security sheet according to a second embodiment of the present invention. Referring to FIG. 5 , in the security sheet 2 according to the second embodiment of the present invention, the middle sheet 30 covers only a part of the area where the first silver coins 41 are formed in a direction perpendicular to the security sheet 2 . It is different from the security sheet 1 according to the first embodiment in that it is disposed.

Referring to FIG. 6 , which is an exemplary plan view of the first silver coin according to the second embodiment of the present invention, the first silver coin 41 may be formed of a string similarly to the first embodiment, and only some of the characters are included in the security sheet ( 2) may overlap with the intermediate sheet 30 in a direction perpendicular to it. That is, the characters 'B' and 'C' may overlap with the intermediate sheet 30, and the characters 'A' and 'D' may not overlap with the intermediate sheet 30.

According to this structure, a different visual effect from that of the first embodiment can be obtained. 7 is a view for explaining visual effects when the security sheet 2 according to the second embodiment of the present invention is observed from various directions under transmitted light. Referring to FIG. 7 , 'A' and 'D', which are letters that do not overlap with the intermediate sheet 30 in the direction perpendicular to the security sheet 2, are not affected by the transmitted light being blocked by the intermediate sheet 30, It is clearly observed regardless of the direction of observation. On the other hand, the characters 'B' and 'C' overlapping the intermediate sheet 30 are observed relatively distinctly when observed in the first direction 51 parallel to the inclined surface 33, and the second perpendicular to the inclined surface 33. It is hardly observed when observed in the third direction 53, and is observed with relatively faint clarity when observed in the second direction intermediate between the first direction 51 and the third direction 53.

As described above, according to the second embodiment of the present invention, a visual effect in which the sharpness of a part of a silver coin is changed according to the direction in which the security sheet 2 is observed can be obtained, which is equivalent to the change in the image of the silver coin itself. provide an effect. As a result, the security of the silver coin can be further improved.

A security sheet according to a third embodiment of the present invention will be described with reference to FIGS. 8 to 11 . In the description of the third embodiment, descriptions of overlapping parts with the first and second embodiments will be omitted, and description will focus on differences.

The security sheet 3 according to the third embodiment of the present invention is different from the second embodiment in that silver coins are also formed on the second sheet 20 .

That is, the security sheet 3 according to the third embodiment of the present invention includes the first sheet 10 including the first silver coin 41, the intermediate layer 30 and the second silver coin 42. A sheet 20 may be included. Since the silver coins are formed on the first sheet 10 and the second sheet 20, respectively, a visual effect as if the silver coin image changes according to the viewing direction can be provided, as in the second embodiment, and in some cases An effect observed by merging the first silver coin 41 and the second silver coin 42 may be provided.

Fig. 9 is an exemplary plan view of the security sheet 3 according to the third embodiment. As shown in FIG. 9 , the first silver coins 41 formed on the first sheet 10 are formed to overlap the middle sheet 30 in a direction perpendicular to the security sheet 3, and formed on the second sheet 20. The second silver coin 42 may be formed so as not to overlap the intermediate sheet 30 in a direction perpendicular to the security sheet 3 . In this case, when observed from the upper surface of the security sheet 3 under transmitted light, that is, in the direction of the second sheet 20, substantially the same visual effect as that of the second embodiment may be provided. That is, as shown in FIG. 7 , the second silver coins 42 'A' and 'D' formed on the second sheet 20 so as not to overlap the middle sheet 30 are clearly observed regardless of the observation direction. On the other hand, 'B' and 'C' characters, which are the first silver coins 41 formed to overlap with the intermediate sheet 30 on the first sheet 10, can be observed in a first direction 51 parallel to the inclined plane 33. It is relatively clearly observed when observed, rarely observed when observed in the third direction 53 perpendicular to the inclined surface 33, and observed in the second direction intermediate between the first direction 51 and the third direction 53. When it does, it is faintly observed.

10 and 11 are diagrams for explaining another embodiment of the third embodiment of the present invention. Unlike the embodiments described with reference to FIGS. 8 and 9 , the embodiments of FIGS. 10 and 11 are formed such that a portion of the first silver coin 41 does not overlap with the intermediate sheet 30 in the vertical direction of the security sheet 3 . can For example, as illustrated in FIG. 10 , when the silver coin of the '○' image is formed as a part of the first silver coin 41 at a position that does not overlap with the intermediate sheet 30, the '○' image is the intermediate sheet 30 ), so it can be clearly observed regardless of the viewing direction. That is, as shown in FIG. 11, in the case of 'B' and 'C' characters formed to overlap with the intermediate sheet 30, the light blocking effect by the intermediate sheet 30 is relatively low in the first direction 51. , observed distinctly in the second direction 52, observed faintly in the third direction 53, and hardly observed in the third direction 53, while the '○' image formed not to overlap with the intermediate sheet 30 is independent of the observation direction. always clearly observed. At this time, it can be observed as being merged with the second silver coin 42 formed on the second sheet 20 . That is, the letters 'A' and 'D' of the second silver coin 42 and the '○' image of the first silver coin 41 may be observed in a merged form.

As described above, according to the third embodiment of the present invention, it is possible to obtain a visual effect in which the sharpness of a part of a silver coin is changed according to the direction in which the security sheet 3 is observed, which is as if the image of the silver coin itself changes. provide an effect. In addition, it is possible to provide an effect in which the silver coin images respectively formed on both sides of the security sheet 3 are partially merged with each other. As a result, the security of the silver coin can be further improved.

A security sheet according to a fourth embodiment of the present invention will be described with reference to FIGS. 12 to 14 . In the description of the fourth embodiment, descriptions of overlapping parts with other embodiments will be omitted, and description will focus on the parts with differences.

The fourth embodiment of the present invention differs in the configuration of the intermediate sheet 30 compared to other embodiments.

Referring to FIG. 12 , the security sheet 4 according to the fourth embodiment of the present invention includes a first sheet 10 including a first silver coin 41, an intermediate sheet 30 and a second sheet 20. can be configured to include 12 shows that the intermediate sheet 30 is disposed on the entire area of the joint surface between the first sheet 10 and the second sheet 20, but the intermediate sheet 30 is the first sheet ( 10) and the second sheet 20 may be disposed on only a partial area of the bonding surface. In addition, although it is shown in FIG. 12 that no silver coins are formed on the second sheet 20, this is exemplary, and like the third embodiment, the second sheet 20 may also include silver coins.

13 is a partially enlarged cross-sectional view of an intermediate sheet according to a fourth embodiment of the present invention. Referring to FIG. 13 , the intermediate sheet 30 may include a base layer 31 and a pattern layer 32 . The pattern layer 32 is formed on one surface of the base layer 31 and may include a plurality of repeated inclination patterns having an inclined surface 33 inclined at a predetermined inclination angle θ with respect to the base layer 32. . At this time, the inclination angle is not constant throughout the intermediate sheet 30, and regions having different inclination angles may be mixed. For example, the intermediate sheet 30 may include a first region Region I in which the inclined surface 33 is inclined at a first angle and a second region Region II inclined at a second angle. The first angle and the second angle are not limited to specific values, and absolute values of inclination angles of the first area and the second area may be the same. That is, the first area and the second area may have left-right symmetric shapes with slant patterns.

A light blocking layer 34 may be formed on the inclined surface 33 . The light blocking layer 34 blocks transmission of light, and the light blocking rate may be 70% or more, preferably 80% or more, and particularly preferably 90% or more. For example, a preferable range of the light blocking rate of the light blocking layer 34 may be 70 to 95%.

The first sheet 10 may include a first silver coin 41 . At this time, a partial area of the first silver coins 41 overlaps the first region I of the intermediate sheet 30 in the vertical direction, and another partial area of the first silver coins 41 overlaps the intermediate sheet 30 in the vertical direction. ) may overlap with the second region (Region II).

14 is a view for explaining visual effects when the security sheet according to the fourth embodiment of the present invention is observed from various directions under transmitted light. At this time, the first silver coin 41 is the same as in the first embodiment of FIG. 3, except that the letter 'A' and the letter 'B' overlap the second area of the middle sheet 30 in the vertical direction of the security sheet 4 It is assumed that the 'C' character and the 'D' character overlap the first area of the intermediate sheet 30.

Referring to FIG. 14 , when viewed from the upper surface of the security sheet 4 , that is, from the second sheet 20 under transmitted light, the first silver coin 41 may be observed differently depending on the viewing direction. When observed in a first direction 51 parallel to the inclined surface 33 of the first region of the intermediate sheet 30, the 'C' character and the 'D' character overlapping the first region of the first silver coin 41 is clearly observed, whereas the 'A' and 'B' characters overlapping the second area are hardly observed due to the light blocking effect of the second area of the intermediate sheet 30 . Conversely, when observing from the third direction 53 parallel to the inclined surface 33 of the second area of the intermediate sheet 30, the 'A' character overlapping the second area of the first silver coin 41 and ' While the character B' is clearly observed, the characters 'C' and 'D' overlapping the first area are hardly observed due to the light blocking effect of the first area of the intermediate sheet 30 . In addition, when viewed from the second direction 52, part of the transmitted light is blocked by the intermediate sheet 30, and thus the first silver coin 41 is observed as a relatively faint image.

As described above, according to the fourth embodiment of the present invention, a visual effect in which the sharpness of the silver coin is changed according to the direction of observation and a visual effect in which the image of the silver coin itself is changed is provided. As a result, the security of the silver coin can be further improved.

A security sheet according to embodiments of the present invention may be applied to various items requiring security. The article may be printing paper, writing paper, art paper, letter paper, wrapping paper, identification card, passport, banknote, hidden line, check, gift certificate, admission ticket, ticket, certificate, warranty, security label, etc., but is not limited thereto.

Although described above with reference to the limited embodiments and drawings, these are only examples, and it will be apparent to those skilled in the art that various modifications and implementations are possible within the scope of the technical idea of the present invention. For example, all or part of each embodiment may be selectively combined and implemented, thereby providing various visual effects not specifically described in the embodiments. Therefore, the protection scope of the present invention should be defined by the description of the claims and their equivalents.

1, 2, 3, 4: Security seat
10: first sheet
20: second sheet
30: middle seat
31: base layer
32: pattern layer
33: slope
34: light blocking layer
41: 1st silver coin
42: Second silver coin
51 to 53: 1st to 3rd directions

Claims (17)

A security sheet in which silver coins are observed differently depending on the direction,
a first sheet containing first silver coins, a second sheet and an intermediate sheet disposed between the first sheet and the second sheet;
The first sheet and the second sheet are transparent or translucent sheets,
The middle sheet,
A transparent or translucent substrate layer and a pattern layer formed on one surface of the substrate layer and having an inclined surface inclined at a predetermined angle with respect to the substrate layer, wherein an inclined pattern is repeatedly formed,
A light blocking layer is formed on the inclined surface,
the intermediate sheet is disposed so as to overlap at least a portion of the formation area of the first silver coin in a vertical direction of the security sheet;
When observing from the second direction, when a direction parallel to the inclined surface is referred to as a first direction, a direction forming an angle of 45 degrees with the inclined surface is referred to as a second direction, and a direction perpendicular to the inclined surface is referred to as a third direction, the first direction The security sheet, characterized in that the silver coin is observed with lower clarity than when viewed from the first direction and with higher clarity than when observed from the third direction. According to claim 1,
The security sheet, characterized in that the middle sheet overlaps the entire formation area of the first silver coin in the vertical direction of the security sheet. delete delete According to claim 1,
The security sheet according to claim 1 , wherein the middle sheet overlaps a part of the area where the first silver coin is formed and does not overlap the other part in the vertical direction of the security sheet. delete According to claim 1,
Wherein the second sheet comprises a second silver coin. According to claim 7,
The security sheet of claim 1, wherein the second silver coin includes an area that does not overlap with the intermediate sheet in a vertical direction of the security sheet. According to claim 7,
When viewed from the direction of the second sheet under transmitted light, at least a portion of the first silver coin and the second silver coin are merged and observed. According to claim 1,
The pattern layer of the intermediate sheet includes a first region in which inclined patterns having inclined surfaces inclined at a first angle are repeatedly formed, and a second region in which inclined patterns having inclined surfaces inclined at a second angle are repeatedly formed;
The security sheet, characterized in that the first angle and the second angle are different from each other. According to claim 10,
The security sheet, characterized in that the inclination pattern of the first area and the inclination pattern of the second area are symmetrical to each other. According to claim 10,
The security sheet according to claim 1 , wherein a part of the area where the first silver coin is formed overlaps the first area in a vertical direction, and another part of the area where the first silver coin is formed vertically overlaps the second area. According to claim 12,
When viewed from the second sheet direction under transmitted light, the observed image of the first silver coin changes according to the viewing direction. According to claim 1,
A security sheet, characterized in that the light blocking rate of the light blocking layer is in the range of 70% or more and 95% or less. According to claim 1,
The light blocking layer is a security sheet, characterized in that a metal thin film or an insulating thin film made of one or more layers. According to claim 1,
Security sheet, characterized in that the base layer is a polymer film An article comprising a security sheet according to claim 1 .

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