KR20200030311A - A security document comprising of lens array and printed images and a preparation method thereof - Google Patents

Abstract

The present invention relates to a method of implementing an apparatus so that authenticity of a security document for a purpose of preventing forgery and alteration can be easily confirmed. The apparatus of the present invention can be manufactured by printing dots or very fine characters, figures, and the like in a certain space on the printing surface, and then adhering a transparent film thereon and applying pressure using an uneven plate to be combined with each other. There is an effect that printed images move or disappear depending on the direction of viewing through a lens of the film formed of the uneven plate, and an advantage for which the color changes. A user can easily check the authenticity of the security document according to the present invention, thereby having a function as the security apparatus against illegal forgery and alteration.

Description

A security document comprising of lens array and printed images and a preparation method thereof

The present invention relates to a security document for preventing forgery including a security element capable of preventing forgery and a method for manufacturing the same, and it is easy to confirm the authenticity of an ID, passport, security, or security document, and effectively prevents forgery or tampering. To do this, after printing dots, very fine characters, figures, etc. on the printing surface, and then forming a transparent film, and then forming a lens using an uneven plate, a security document that implements a security element that changes shape or color And a method for manufacturing the same.

In general, various security factors have been applied to prevent forgery and alteration in security documents such as banknotes, securities, and identification cards.

An example of such a security element is an optical element that can easily identify the authenticity with the naked eye. According to the trend of miniaturization of electronic devices, an area that cannot be miniaturized with a general lens, such as an optical element applied to a camera of a mobile phone A small diffraction optical element has been developed in the industry and plays a large role in industry. However, most of these diffractive optical elements are not suitable for use as a security element applied to a security document because the size is about a few millimeters to a few centimeters.

In addition, with recent rapid development of optical lithography and electron beam lithography technologies, miniaturization of various devices has been developed mainly in the semiconductor field. A method of forming a pattern to be manufactured with a mask first and exposing it with an ultraviolet light source or an electron beam to form a fine pattern in a photosensitive medium such as photoresist is used, and through the technique of thermal reflow, microscopic micro It has also been possible to manufacture a security element using a lens array, but the microlens produced in this way has the disadvantage of being difficult to apply in the form of a thin film because it must always form a spherical surface with a thickness of several tens of μm.

As a security element, in US Pat. No. 4,892,336, which is a conventional technology in which such a micro-optical security element is applied as a security element, a lenticular lens as a refractive optical element is applied to one side of a transparent film and a printing pattern is applied to the other side as a security element. Although it has been suggested to be used, there is a disadvantage in that the manufacturing process and method are very complex and the process cost is high.

In the security document including the identification card, products that apply the technology to appear one by one depending on the direction of viewing two or more images have been commercialized, and the technology implemented in this way is commonly referred to as a 'lenticular'.

This is for giving a decorative effect in fancy goods, and can be easily implemented by attaching a film formed with a transparent lens to a printing surface.

However, in the case of security lenticular technology for the purpose of preventing forgery, the protective layer, the issuing layer, and the printed surface are attached to each other by thermal compression of the mirror plate, and in this process, the protective layer and the issuing layer are combined with each other so that peeling is impossible. Therefore, security can be greatly improved, and additionally, it is possible to print variable data on the issuing layer through the protection layer, so security can be greatly improved.

The lenticular technology using an existing lens may be implemented by thermally compressing a lens on a surface on which a picture or pattern is printed as shown in FIG. 1 (a), and red and blue on the printing surface as shown in FIG. 1 (a). If the color is located, it has a very good lenticular effect.

However, in the case of forming a thermocompression step after a flat plate printing step, since each step is performed in different process steps, a design error inevitably occurs, and as a result, a flat plate printed figure as shown in FIG. 1 (b). Alternatively, since the position of the drawing is not arranged at the exact position of the center of the lens, and is formed to be deviated, unlike the case of FIG. 1 (a), in the case of FIG. 1 (b), it is different in the a direction and the b direction. There is a problem in that defective products in which colors cannot be identified are made.

In addition, when the image is printed on the lower surface of the film layer on which the lens is formed, the lens (a) and the image (b) can be interlocked as shown in FIG. 2. The letter 'A' described in b) is expanded to provide an effect (c) in which a three-dimensional effect is felt when the observer looks at it. This method of implementation is implemented in the form of a three-dimensional partial exposure hidden line on the front of the Bank of Korea Bank of Korea, Oman, and is applied to bank notes of other countries.

However, although these technologies have the effect of floating in space and two images changing as the shape moves, additional research and development is needed to use two colors or to apply images with different personalities to specific locations at the same time.

U.S. Patent No. 4,892,336

The present invention is to more effectively solve the problems of the existing prior art, and includes a sheet layer formed by flat panel printing, images such as lines, dots, and characters, and a transparent protective layer thermally compressed onto the sheet layer. Regarding a security document, a mirror steel plate in which concave or convex lens irregularities are formed is positioned on a position corresponding to an image formed on a sheet layer, on top of the transparent protective layer, and simpler by using a separate pressing means. By forming the lens array in a manner, it is intended to provide a security document for forgery prevention including an effective forgery prevention security element.

Another object of the present invention, by optimizing the positional relationship between the lens array formed to produce a security element for preventing such forgery and the flat plate printed image formed on the bottom, when viewing the printed image through the lens, the viewing direction In order to realize the three-dimensional effect of moving the image in a simple and effective manner.

A security document according to an embodiment of the present invention for achieving the problems of the prior art and the object of the present invention as described above includes: a sheet layer on which a picture or character is formed through flat panel printing; and a transparent protective layer thermally compressed onto the sheet layer; It includes, on the upper portion of the transparent protective layer, characterized in that the concave or convex lens is formed at regular intervals through the compression of the mirror steel plate.

In addition, optionally, a transparent issuing layer may be positioned between the sheet layer and the transparent protective layer, and it is preferable that an additional printed image is formed on the issuing layer.

When the distance between the center points of the concave or convex lenses is L, the distance between the center points of the pictures or letters formed on the sheet layer is more than 0.5L and less than 3L (however, the distance between the center points of the pictures or letters is not L) It is preferred to have.

On the other hand, at least two different pictures or letters are formed on the sheet layer, and the distance between the center points of each is different from each other, but a value of more than 0.5L and less than 3L (however, the distance between the center points of the picture or text is L). More preferred).

The concave or convex lens formed on the top of the transparent protective layer is a three-dimensional structure having a circular or polygonal shape on the underside, and when the cross-sectional area of the underside of the lens is S, the area of the figure or character formed on the sheet layer is 0.3S. It is more preferable to have a value of 0.8S or more.

In addition, when the distance between the center points of the concave or convex lenses is L, the distance between the center points of the pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of the pictures or letters is L). No), and the center point of the picture or character may be arranged to move to the left or right at a predetermined interval when viewed based on the formed lens train, wherein the predetermined interval is the distance L between the center points of the lens Smaller is preferred.

In addition, when the distance between the center points of the concave or convex lenses is L, the distance between the center points of the pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of the pictures or letters is L). No), and the center point of the picture or letter is arranged to move to the left or right at a predetermined interval when viewed based on the formed lens train, and the predetermined interval is a value less than the distance L between the center points of the lens. It is possible to decrease along the heat of adjacent lenses.

In addition, when the distance between the center points of the concave or convex lenses is L, the distance between the center points of the pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of the pictures or letters is L). And not), the center point of the picture or letter may be arranged to move to the left or right at a predetermined interval, and to move upwards or downwards at the same time when viewed based on the formed lens train.

In the security document according to an embodiment of the present invention, the sheet layer may be a composite sheet layer in which a plurality of sheet layers each having different pictures or characters formed through flat plate printing are stacked, and the transparent issuing layer formed with a printed image may be used. It is preferable that the transparent region is located, and the printed image layer formed on the lower sheet layer is observed through the transparent region layer in the upper lens.

As another embodiment of the present invention, a method of manufacturing a security document may be mentioned. A flat plate printing step of forming a picture or character on a sheet layer through a flat plate printing method; After the transparent protective layer is placed on the sheet layer on which a picture or character is printed, a pressing step of thermocompression bonding; And a lens forming step of forming a lens at regular intervals by pressing a mirror steel plate on top of the genital transparent protective layer.

The security document according to the present invention, by observing a flat-panel printed image formed on the lower portion of the lens array through the lens array formed through the compression of the mirror steel plate, it is possible to more easily implement a three-dimensional effect of moving the image according to the viewing angle It has advantages, and optimizes the arrangement and shape of the lens array and flat-panel printed image to overcome printing errors caused by different production processes (flat plate printing and crimping of mirrored steel plates, etc.) and gives movement to the shape of the image. By providing a security element that can be done, there is an effect that can greatly improve the security of the security document.

The problems and effects to be solved of the present invention will be more clearly understood through preferred embodiments described below.

1 schematically shows a conventional lenticular lens (a) and a structure (b) of defective products generated during the manufacturing process.
Figure 2 is a schematic view showing the configuration of the conventional commercialized three-dimensional partial exposure hidden line.
3 schematically shows a stacked structure of a security document according to an embodiment of the present invention.
4 is a diagram schematically showing an example of a mirror steel plate used in the present invention.
5 to 14 are views schematically showing embodiments of various types of security documents according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or dictionary meanings, but should be interpreted as meanings and concepts corresponding to the technical spirit of the present invention.

Throughout this specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated.

Each step may be performed differently from the specified order, unless a specific order is explicitly stated in the context. That is, each step may be performed in the same order as specified, or may be performed substantially simultaneously, or in the opposite order.

As described in the prior art, in the conventional lenticular, since a print image and a lens are configured to interlock with each other, a problem in which an effect is not created frequently occurs due to an undesired print alignment as shown in FIG. 1 (b). . Therefore, there is a difficulty that the product can be implemented only when the alignment interval between the lens and the printed image is possible within nano units.

Accordingly, the present invention is intended to implement such a technique in a real product under realistic constraints that an image is formed in general offset printing and the print alignment between the lens and the image is very inaccurate, effectively preventing the moire phenomenon between the offset image and the lens array. Must use it. In addition, in order to squeeze a precise lens through a mirror steel plate, precision processing technology is required to produce a mirror steel plate, and in order to realize offset printing, a printing plate is produced using a CTP (computer engraving machine) of 5000 dpi or higher. It is preferred to use.

The security document according to the present invention is produced through the following process.

① Flat plate printing on the sheet layer: The flat plate printed image can form letters, pictures, etc. of a specific shape using dots, lines, etc. It is desirable to print in consideration of the lens size and focal length to be formed in a subsequent step. . In addition, a color applied to flat panel printing may be applied from a single color to at least two or more mixed colors.

② A security document is formed by thermally compressing the transparent issuing layer and the protective layer on the sheet plate's flat-panel printing surface. The issuing layer can be selectively used as needed.

③ Using the mirror steel plate equipped with the form of a template capable of forming concave and / or convex lenses, the protection is applied by pressurizing or applying heat to the security document on which the protective layer, the issuing layer and the printing sheet are laminated. An array of lenses with a certain distance is formed on the top of the layer.

④ A lens array is formed on the transparent protective layer, and the security document of the present invention can be manufactured through an image printed on the sheet layer. If necessary, printing is further performed on the transparent issuing layer to further perform lens array and transparency. As the printed image of the issuing layer, the picture or the text on the sheet layer influence each other, it can act as a security element of the security document.

3 schematically shows a security document according to an embodiment of the present invention, the mirror steel plate 100 is for forming an array of lenses 120 on the upper portion of the protective layer 110, a plurality of lenses ( 120) are spaced apart at regular intervals so that they can be formed at regular intervals, and the radius of curvature (R) of the lens in consideration of the focal length with the printed image, picture or text formed on the issuing layer 130 and the sheet layer 140 This is decided.

The protective layer 110 is a transparent layer that is located at the top of the security document to protect the issuing layer 130 and the printing layer 140, etc., the lens 120 by the mirror steel plate 100 Is formed on the top.

The issuance layer 130 is a layer positioned between the sheet layer 140 and the protective layer 110 constituting the security document of the present invention, and is a layer that is printed after thermal compression of the security document, and the sheet layer 140 Is a layer on which a printed image is formed with a flat sheet located at the bottom of the secure document of the present invention.

In addition, the identification numbers 150 and 160 of FIG. 3 are print images formed between the issuing layer 130 and the protective layer 110 and prints formed between the issuing layer 130 and the sheet layer 140, respectively. As an image, mainly implemented by flat panel printing, an image of a size exceeding the diameter of the lens 120 may also be applied.

4 is a schematic view of the mirror steel plate 100 as viewed from above and a cross-section (a plane cut along a straight line a), when a lens is cut in the center, a round intaglio groove or a round embossed groove is formed. A plurality of layers can be pressed together with pressure to a secure document having a stacked structure to form an array of lenses 120.

[ Example  One]

An embodiment of the security document of the present invention is schematically presented in FIG. 5. In FIG. 5, 'a' denotes a flat plate printed image 160, and 'b' denotes a lens 120 formed using a mirror steel plate 100, where the observer's observation direction is (c) to (d). As it is changed or changed from (d) to (c), a three-dimensional effect in which the flat-panel printed image moves can be realized.

However, in order to realize the stereoscopic effect of moving the printed image, there are certain restrictions on the arrangement of the lens array and the printed image. That is, when the distance between the center points of the lens 120 constituting the lens array is referred to as 'L', i) the distance between the centers of the printed image is the same as the distance 'L' between the center points of the lens 120 If, ii) when the distance between the centers of the printed images is 3L or more, and iii) when the distance between the centers of the printed images is 0.5L or less, the stereoscopic effect of moving the flat-panel printed image is not realized (see Table 1). .

Ratio of the distance between the lens center point and the center of the printed image Drawing Remark 3 or more

Orange: print image
Gray: lens 1 case
0.5 or less

In (a) of FIG. 6, the number of formed lenses and the number of printed images are the same, so that the distance between the lens center points and the distance between the centers of the printed images is the same, and their ratio is 1, so that the flatbed printed image moves This is the case when the stereoscopic effect is not realized.

In (a) of FIG. 6, in the case of 'a' and many 'c' having fewer printed images than the number of lenses, the three-dimensional effect of the implemented image due to the difference in the quantity of the lens and the printed image (protruding or entering) ) Occurs.

FIG. 6 (b) schematically shows an example of another arrangement form between the lens and the printed image. In FIG. 6 (b), “a” is an orange-printed image, and the spacing is more dense than that of the lens. 'B' is a blue print image and is applied at the same intervals as the lens. As mentioned above, while the orange image has motion and three-dimensional effect, the blue color does not have this effect, but when the characters or figures composed of orange and blue with three-dimensional effect are combined, the three-dimensional effect and movement are contrasted. Can be maximized.

6 (c) of FIG. 6 schematically shows an example of another arrangement form between a lens and a printed image according to the present invention, which is a combination of a lens and two different color flat images. The orange color of the flat image is applied at a narrower distance than the lens, and the blue color is the opposite. When this combination is made, a three-dimensional effect (a protruding effect or an entering effect) is formed in the orange and blue colors of the flat image.

[ Example  2]

In the process of arranging the lens and the printed image, when the diameter or cross-sectional area of the lens (A) is referred to as 'S', the cross-sectional area of the printed (orange) printed image is 30% (a) and 80% of 'S' ( b) must be maintained within the range to achieve the effect of three-dimensional effect and movement (see Fig. 7 (a)).

7 (b) shows various structures and shapes of lenses in the present invention. The black area a means the lowest part of the lens, and the white area b is the highest part of the lens. Due to various three-dimensional cross-sectional shapes, it is possible to control various effects on the printed image.

The effect is realized through the lens according to the position of the printed images (orange color), so there is a morphological limitation. Fig. 7 (c) shows that various shapes of the cross-section structure of such a lens can be used, from square to octagonal and circular, and a printed image of a long shape in one direction is used as shown in Fig. 7 (d). In the case, the stereoscopic effect is weakened.

[ Example  3]

In FIG. 8 (a), as the center of the orange-colored print image goes from 'a' to 'b' (based on the column of the lens array), the position is shifted to the right at predetermined intervals, such as' a ',' b 'Is the same distance from each other. When a plurality of lenses and printed images are arranged as shown in FIG. 8 (a), an image as shown in FIG. 8 (b) is created, and the security document including the printed images and the lens array is tilted or according to a viewing direction. As it moves, it becomes possible to realize a three-dimensional effect.

When the position of each print image is applied differently by adding a blue image to the orange print image in FIG. 8 (a), each color moves in a different direction as shown in FIG. 8 (c). In addition, when making a difference in the number of printed images, it is possible to form a different three-dimensional effect (a protruding effect or an entering effect).

FIG. 9 (a) is configured such that the center of the orange print image is spread from the 'a' to the 'I' direction (a), and the 'b' has the same position from 'a' to 'I'. . That is, when viewed based on the formed lens row, the center of the printed image is arranged to move to the left or right at a predetermined interval, and the predetermined interval has a value less than the interval L between the center points of the lens, and It is arranged in a decreasing form along the heat.

When the lens and the printed image are arranged as shown in FIG. 9 (a) in this way, an effect in which a difference in tilt between the left and right occurs as shown in FIG. 9 (b) can be implemented.

FIG. 10 (a) shows a form arranged in a manner similar to that of FIG. 9 (a) as described above. As the orange print image descends from the 'A' to the 'I' direction, the curve of the red line (c) as in 'a' And 'b' does not change the interval. When configured in this way, it has the effect of three-dimensional effect and movement as shown in Fig. 10 (b).

When the arrangement form presented in FIGS. 9 (a) and 10 (b) is combined, the effect of the three-dimensional effect and movement using characters may be implemented as shown in FIG. 11, (a), (b), and ( c) can be used in various ways. In addition, it can be implemented in various colors, and it can make a difference in the three-dimensional effect that pops in and out by applying more or less quantity difference with the lens.

FIG. 12 schematically shows the arrangement of the lens array and the printed image as another modified example.

In Fig. 12 (a), the orange print image is arranged such that the position moves as 'a' and 'b' as it goes down from 'A' to 'I'. It is arranged to move to the left or right at an interval of, and the predetermined interval has a value smaller than the interval L between the center points of the lens.

In addition, when viewed in the direction from 'da' to 'la', it is formed to generate a predetermined position difference, such as 'c' and 'd'. When a lens and a printed image are created and printed in this arrangement, an image as shown in FIG. 12 (b) may be created. Depending on the viewing direction, motion and three-dimensional effects are realized.

Compared to the previously described arrangement structure, the arrangement structure shown in FIG. 12 (a) is characterized in that the position between the lens and the printed image is generated in two or four directions, and FIG. 8 ( If combined to be added to the arrangement structure of a) to 11 (a), it is possible to form or implement even more various effects and three-dimensional effects.

[ Example  4]

13 schematically shows a cross-sectional structure of a security document according to another embodiment of the present invention, a mirror steel plate 100 capable of forming a lens array, a transparent protective layer 110 in which a lens array is implemented, and red printing It includes a transparent layer 131 on which the image 170 is formed, and a forming layer 141 on which the purple print image 180 is printed.

When a security document is manufactured to have such a stacked structure, a three-dimensional effect by the red print image 170 and an effect according to the purple print image 180 may be made different.

Particularly, when a plurality of colors are to be printed on the same printing layer to realize various three-dimensional effects, it may be difficult to implement a vivid effect due to color mixing and ink bleeding, as shown in FIG. After the printing is performed, the sheet layer on which the print image is formed is separated into a plurality of sheets, and then stacked and combined to provide a result having a more vivid three-dimensional effect.

[Example 5]

'A' in FIG. 14A schematically shows a cross-sectional structure of the lens 120 array and the sheet layer 140 that are thermally compressed to form one security document, and 'I' means another security document. . 120 denotes a lens formed on the protective layer 110, 140 denotes a printed sheet layer on which a printed image is formed, and 200 denotes a hole formed on the printed sheet layer 140. .

After physically forming the hole 200 in the printed sheet layer 140, a separate transparent material is inserted, or light passes through an area except the hole 200 at the top or bottom of the printed sheet layer 140. It is also possible to form a hole structure that forms a substantially transparent area, not a physical hole, by printing opaquely.

Reference numeral 190 in FIG. 14 (a) denotes a printed image formed in a separate document 'b' different from a secure document of 'a', and a printed image 190 formed in a separate document 'b' It is preferable that the lens 120 array formed in the document 'A' is arranged to be interlocked as in Examples 1 to 3 above, and as it is arranged in this form, the user overlaps the document 'A' and 'B' with each other. With the arrangement, the printed image 190 of the 'B' document can exhibit the effect of three-dimensional effect, movement, and color conversion by the lens 120 array of the 'A' document (see FIG. 14 (b)).

When the security document is produced in this way, the security of the security document is required because the separate lens 120 array of the other document 'A' and the printed image 190 of the document 'B' must be simultaneously forged or tampered with. It can be greatly improved.

The size and curvature radius R of the lens 120 formed in the 'A' document is preferably determined according to the printed image 190 printed on the 'B' document, and has a diameter of about 30 to 300 μm. It is preferably formed of.

The print image 190 is preferably made of very small caustics, and it is possible to make face images or text information related to a document through differences in the caustics. In particular, text information related to a security document is applied by changing the position of the print image 190 that can be linked to the lens 120, and this can be confirmed through the lens 120, 'c' in FIG. 14 (c). As described above, various information elements related to a document can be implemented in a photographic image to effectively prevent image tampering.

As described above, although specific embodiments have been described in the detailed description of the present invention, various modifications are possible without departing from the scope of the present invention. .

100: mirror steel plate 110: protective layer
120: lens 130: issuing layer
131: transparent layer 140: sheet layer
141: forming layer 150, 160: printed image
170, 180: Print image 190: Print image
200: hole

Claims (11)

Sheet layer on which pictures or characters are formed through flatbed printing; and
Includes a transparent protective layer heat-pressed over the sheet layer;
A security document characterized in that a concave or convex lens is formed at regular intervals through compression of a mirror steel plate on the upper portion of the transparent protective layer. According to claim 1,
A transparent issuing layer is positioned between the sheet layer and the transparent protective layer,
The issuing layer, characterized in that the print image is further formed, a secure document. According to claim 1,
When the distance between the center points of concave or convex lenses is L, the distance between the center points of pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of pictures or letters is not L) Secure document, characterized by having a. According to claim 3,
At least two different pictures or letters are formed on the sheet layer, and the distance between the center points of each is different from each other, but a value of more than 0.5L and less than 3L (however, the distance between the center points of the picture or text is not L) Secure document, characterized by having a. According to claim 1,
The concave or convex lens is a three-dimensional structure with a circular or polygonal shape on the underside.
When the bottom cross-sectional area of the lens is S, the area of the picture or character formed on the sheet layer has a value of 0.3S or more and 0.8S or less, a security document. According to claim 3,
When the distance between the center points of concave or convex lenses is L, the distance between the center points of pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of pictures or letters is not L) Have
The central point of the picture or letter is arranged to move to the left or right at a predetermined interval when viewed based on the formed lens row, the predetermined distance being smaller than the distance L between the center points of the lens, security document . According to claim 3,
When the distance between the center points of concave or convex lenses is L, the distance between the center points of pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of pictures or letters is not L) Have
The center point of the picture or letter is arranged to move to the left or right at a predetermined interval when viewed based on the formed lens row, the predetermined interval having a value less than the distance L between the center points of the lens, and Secure document, characterized by decreasing along the heat. According to claim 3,
When the distance between the center points of concave or convex lenses is L, the distance between the center points of pictures or letters formed on the sheet layer is greater than 0.5L and less than 3L (however, the distance between the center points of pictures or letters is not L) Have
The center point of the picture or character is arranged to be moved to the left or right at a predetermined interval and at the same time to move upward or downward when viewed based on the formed lens row, the predetermined interval being less than the distance L between the center points of the lens Security document, characterized by a small one. According to claim 1,
The sheet layer is a security document, characterized in that a composite sheet layer in which a plurality of sheet layers, each having different pictures or characters, respectively, are formed through flat plate printing. According to claim 2,
A secure document, characterized in that a transparent area is located on a transparent issuing layer on which a printed image is formed, and the printed image layer formed on the lower sheet layer can be observed through the transparent area layer in the upper lens. In the method of manufacturing a security document,
A flat plate printing step of forming a picture or character on a sheet layer through a flat plate printing method;
Placing a transparent protective layer on the sheet layer on which the picture or character is printed, and then compressing by thermal compression; And
A method of manufacturing a security document comprising; a lens forming step of forming a lens at regular intervals by pressing a mirror steel plate on top of the genital transparent protective layer.

Images