KR20130010301A - Anti-counterfeit hologram film having watermark have recorded thoreon multiple images, manufacturing method thereof and method for detection of watermark - Google Patents

Abstract

PURPOSE: A hologram film for counterfeit prevention with watermarks of a plurality of images, a manufacturing method and a watermark identifying method are provided to block a copy of a watermark with enhancement of security for the watermark. CONSTITUTION: A watermark(20) is formed on four corners in a hologram thin film(10). An image is impressed on the watermark. The image is displayed as a number for enhancing security. The image is hidden by a background pattern. A separate filter(30) is overlapped on the watermark. The hidden watermark is identified by controlling a relative location of the separate filter.

Description

Anti-counterfeiting hologram film with watermark of multiple images, manufacturing method and watermark identification method

The present invention relates to a forgery preventing hologram film having a watermark in which multiple images are recorded, a manufacturing method thereof, and a method for identifying the watermark by a filter.

In general, a hologram is one that can have a single wavelength and a single frequency for a long time, and phase information of a coherent laser beam is recorded to realize various colors, three-dimensional shapes, or dynamic images. A unique image of a hologram is generated and Because the reproducing process is optical, it is not easy to duplicate, because only a part of the optical information is printed when it is copied by the existing color copier or precision scanner, and it is used as a means of preventing forgery. It is commercialized in the form.

1 is a schematic diagram of a hologram pattern (interference pattern) by enlarging a cross section of a general embossed hologram film, and has a sine wave shape having a depth (B) and a length (A) of several hundreds to thousands of nm in the hologram. A hologram pattern of fine convexities is recorded. That is, the hologram pattern is indented into the uneven shape on the surface of the hologram receiving layer 1 of the hologram film, and the metal deposition layer of Al, Ag, ZnS, ZnO, SiO2, etc. (2) to facilitate the observation of the reflected light reflected from the unevenness on the receiving layer (2). ) Is applied by vacuum deposition to a thin film.

In addition, in order to form a more complex and three-dimensional image into a hologram, additional irregularities are formed between the patterns as shown in FIG. 1, or hologram stickers and hologram stamping foils, such as labels and stamping foils, which are mass-produced through a precision embossing process. A release layer, a colored layer, an adhesive layer or an adhesive layer, and / or a hologram protective layer may be further stacked on and under the hologram receiving layer 1.

As an example in which a hologram is applied, Patent Document 1 discloses a label for preventing copying and a method of manufacturing the same, and Patent Document 2 discloses a scratch hologram sticker and a method of manufacturing the same.

On the other hand, the hologram is manufactured by using a holographic glass disc using a photoresist photosensitive agent used in semiconductor wafer fabrication, and using a plated metal plate of electroplating and a metal disc for the production of a metal disc of the hologram glass disc, such as the embossed hologram described above. The unevenness of the disc is transferred to PET, OPP, PVC, PC, etc. by heat and pressure to produce a hologram film.

However, such a hologram is attached to a product in the form of a sticker label or a stamping foil, and has an excellent function of preventing the manufacture or distribution of a counterfeit or a replica, but a conventional hologram can be identified by the naked eye, and thus is almost similar. There is a possibility of forgery, and there was a problem that it is not easy for ordinary consumers to distinguish such forged holograms.

In particular, forgery techniques for embossed types of holograms have been advanced year by year, and the availability of holographic materials has become easier, and at first glance, similar holographic labels or stickers have been forged and actually overlooked.

On the other hand, in order to prevent the forgery of the hologram, even in the production of holograms, efforts are being made to use advanced technology or to recognize images that are difficult to forge, but this leads to an increase in the manufacturing cost of the hologram, which in turn causes the hologram to be used. In addition to increasing the manufacturing cost of the product, there is a problem that mass production of holograms is not easy. Furthermore, in terms of hologram-applied sticker labels, etc. should not only be easily forged on their own, but also should be easily distinguishable from forged holograms, the increase in the difficulty of copying to prevent duplication is the fact that the non-expert There is a limit that can make it difficult to identify and rather obscure the distinction between forged holograms and genuine ones.

In addition, the present invention provides a method of forming a latent image by embossing directly on the surface of a plastic card such as an ID card or a credit card. However, the latent image can be observed by the naked eye by tilting the plastic card at an angle. Is not prevented in principle, and there is a limit in that it is not possible to take advantage of the hologram which gives a luxurious feeling by expressing various colors and images.

Patent Document 1: Republic of Korea Patent Publication No. 2003-0021843

Patent Document 2: Republic of Korea Patent Publication No. 2001-0084963

Accordingly, the present invention was able to solve the above problems by applying a watermark or latent image having multiple images that are not visually identified to the hologram, and the present invention was completed based on this.

Accordingly, an object of the present invention is to prevent the forgery of the hologram by applying a watermark or latent image that is not visually identified to the hologram, and also to make the watermark visible and simple by a separate means. It is to provide a hologram film to easily identify the authenticity.

Another object of the present invention is to provide a method for producing the hologram film.

In addition, another object of the present invention to provide a method for identifying a watermark formed on the hologram film by a filter recognizer.

The anti-counterfeiting hologram film of the present invention for achieving the above object, in the anti-counterfeiting hologram film having a watermark, the first key pattern formed with an arbitrary pattern and the letters, numbers, or shapes to hide the first The first image in which the first latent image pattern is disposed side by side at a position spaced apart from the key pattern in one direction, and the second key pattern on which an arbitrary pattern is formed, and letters, numbers, or shapes to be hidden A watermark including a second image in which a second latent image pattern arranged side by side at a position spaced apart from each other by a second key pattern and a predetermined interval is inscribed, wherein the first image and the second image are disposed at different angles; And a background pattern in which an arbitrary pattern is imprinted at a portion except the watermark.

In one preferred embodiment of the present invention, the first key pattern and the first latent image pattern is the same or different from each other, the anti-counterfeit hologram having a watermark of multiple images, characterized in that formed of any one selected from dotted lines, lines, or dots. film.

In a preferred embodiment of the present invention, the second key pattern and the second latent image pattern is characterized by being formed of any one selected from the same or different from each other dotted lines, lines, or dots.

In another preferred embodiment of the present invention, the key pattern is a dotted line, the latent image pattern is full line, wherein the dotted line is 100 with a line thickness of 0.015 to 0.030 mm, an interval of 0.05 to 0.07 mm, and a length of 0.10 to 0.25 mm. A screen tone with a screen tone of ˜400 lines and a screen concentration of 12-14%, and the line has a screen thickness of 100 to 400 lines with a line thickness of 0.05 to 0.01 mm and an interval of 0.15 to 0.25 mm, and a screen concentration of 14 to 16%. It is characterized by.

In a preferred embodiment of the present invention, the second image is characterized in that it is disposed at an angle of 85 to 110 degrees in the clockwise direction with respect to the horizontal direction of the first image.

In a preferred embodiment of the present invention, the watermark is located at a position where a predetermined interval is spaced apart from the third key pattern in which a random pattern is formed and a letter, number, or shape to be hidden in one direction with the third key pattern. The third latent image pattern disposed side by side may further include a third image, wherein the third image is disposed at an angle different from that of the first image and the second image.

Method of manufacturing a forgery prevention hologram film having a watermark of multiple images for achieving another object of the present invention, in the method of manufacturing a forgery prevention hologram film having a watermark, and hides the first key pattern formed with an arbitrary pattern Providing a first image in which a first latent image pattern in which letters, numbers, or shapes are arranged side by side at a spaced distance from the first key pattern in one direction, and a first pattern on which an arbitrary pattern is formed Providing a second image of a second key pattern and a second latent image pattern in which a letter, number, or shape to be hidden is arranged side by side at a position spaced apart from the second key pattern by a predetermined distance in one direction; Placing the first image and the second image at different angles to form a watermark; And forming a background pattern in which a predetermined pattern is imprinted at a portion except the watermark.

In a preferred embodiment of the present invention, the first key pattern and the first latent image pattern may be formed of any one selected from dotted lines, lines, or dots.

In a preferred embodiment of the present invention, the second key pattern and the second latent image pattern may be formed of any one selected from the same or different from each other, such as dotted lines, lines, or dots.

In another preferred embodiment of the present invention, the key pattern is a dotted line, the latent image pattern is full line, wherein the dotted line has a line thickness of 0.015 to 0.030 mm, an interval of 0.05 to 0.07 mm, a length of 0.10 to 0.25 mm 100 to 400 lines of screen tone and 12 to 14% of screen concentration. The line is 100 to 400 lines of screen thickness of 0.05 to 0.01 mm with a thickness of 0.15 to 0.25 mm and a screen concentration of 14 to 16%. It is characterized by having.

In a preferred embodiment of the present invention, the second image is characterized in that it is arranged at an angle of 85 degrees to 110 degrees clockwise with respect to the horizontal direction of the first image.

In a preferred embodiment of the present invention, the watermark forming step is a third key pattern formed with a random pattern and a letter, number, or shape to be hidden is spaced a predetermined distance in one direction with the third key pattern The method may further include providing a third image having a third latent image pattern disposed side by side at an angle, wherein the third image is disposed at a different angle from the first image and the second image.

A method of identifying a watermark of a hologram film for achieving another object of the present invention is:

A first image in which a first latent image pattern in which a first key pattern on which a random pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced a predetermined distance from the first key pattern in one direction; And a second image in which a second latent image pattern in which a second key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced apart from the second key pattern by a predetermined distance in one direction A watermark including the first image and the second image at different angles; And

A method of identifying a watermark of the anti-counterfeiting hologram film having a watermark of a multi-image including a; a background pattern of a pattern imprinted in a portion other than the watermark.

A filter formed in the same pattern as the key pattern corresponding to the first and second images, respectively, is achieved by placing the filter on the watermark.

Multiple images of the watermark formed on the hologram film according to the present invention are not easily identified with the naked eye, and even if the security of the watermark is further enhanced to mimic a hologram other than the watermark, the reproduction of the watermark is fundamentally impossible. Done.

In addition, the watermark can be easily identified by the filter recognizer to which the key pattern is applied, so that the authenticity of the security product with the hologram film according to the present invention can be easily distinguished.

1 is a schematic diagram illustrating a hologram pattern by enlarging a cross section of a general embossed hologram film.
2 is a diagram schematically showing an example of a hologram film and a filter having a watermark according to an embodiment of the present invention.
3 is a view schematically illustrating a first key pattern of a watermark according to an embodiment of the present invention. FIG. 3A is a plan view of a key pattern perceived in the watermark from above, and FIG. 3B is a partially enlarged view of FIG. 3A. to be.
4 is a view schematically illustrating a second key pattern of a watermark according to an embodiment of the present invention. FIG. 4A is a plan view of a key pattern perceived by the watermark from above, and FIG. 4B is a partially enlarged view of FIG. 4A. to be.
5 is a view schematically showing an image of a watermark according to an embodiment of the present invention, FIG. 5A is a plan view of a first image, and FIG. 5B is a plan view of a second image.
FIG. 6 is a view briefly showing that a background pattern is inscribed on a watermark in which the key pattern and the image of FIGS. 3 and 4 are inscribed.
7A is a plan view of a filter for confirming a first image, and FIG. 7B is a plan view of a filter for confirming a second image.
8A illustrates a state in which the first image is identified by overlapping the filter of FIG. 7A with FIG. 6, and FIG. 8B illustrates a state in which the second image is identified by overlapping the filter of FIG. 7B in FIG. 6.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In general, a holographic film generally uses a synthetic resin film (eg, PET) having a thickness of about 250 μm or less. In addition, a medium such as a photosensitive plate or a metal thin film may be used. In addition, as described above, referring to FIG. 1, the hologram film generally has a concave-convex shape between the hologram receiving layer 1 and the metal deposition layer 2 coated thereon. A protective layer, a colored layer, a release paper, etc. can be laminated | stacked.

Therefore, in the present invention, the hologram film refers to a general medium on which the image information of the hologram is recorded, and the finished product film also provided a hologram film so that the interference pattern of the hologram can be imprinted into an uneven shape through embossing. It seems to correspond.

2 is a view showing an embodiment of a hologram film having a watermark according to the present invention. Referring to FIG. 2, at four corners of a holographic thin film in which a flat or three-dimensional hologram using an interference light of a laser is indented, an image 21 represented by the number “10000” for enhancing the security of the hologram is inscribed. A watermark 20 is formed. At this time, the hologram including the image 21 is embossed by applying heat and pressure to the film for hologram 10 using a mold manufactured in advance, such as an embossed hologram.

As such, the image 21 perceived on the hologram film 10 is hidden by the background pattern and is not normally identified with the naked eye, and a separate filter 30 is overlapped on the watermark so that the filter may be separated from the watermark. The hidden watermark can be identified by adjusting the relative position.

The reason why the image 21 having the same pattern as the key pattern is clearly displayed on the key pattern is that the image 21 is inscribed so as to be shifted with a predetermined interval in one direction with respect to the key pattern.

The watermark, background pattern, and other holograms (that is, the holograms on the hologram film), in which the key pattern and the image are imprinted as described above, are synthesized in a holistic pattern by a graphic program. The irregularities of the disc are transferred to the hologram film by heat and pressure.

Looking specifically at the transition process, by designing an image including a watermark to be transferred to the holographic film through computer graphics work, the image is exposed to a laser light such as photolithography on a glass plate coated with a high-resolution photosensitive agent By using the photographing to create a glass master (Glass Master), the surface of the glass master is plated to produce a nickel mold, which is a holographic disc.

At this time, the metal to be plated on the surface of the glass master is usually used nickel, by depositing silver or nickel on the glass master to add conductivity, nickel plating is carried out the process of peeling the nickel plate to about 200 ~ 300㎛ to the nickel mold Is made. Nickel mold is printed by applying heat and pressure to the hologram film by using electroplated nickel shim again.

According to the present invention, at least two images composed of a key pattern and a latent image pattern corresponding thereto are arranged at different angles to form a watermark, and easily identified using a filter corresponding to each image. In other words, the image is composed of a key pattern on which a random pattern is formed and a latent image pattern arranged side by side at a position spaced apart from the key pattern by a predetermined interval in one direction. The two images are placed at different angles to form a watermark.

According to an exemplary embodiment of the present invention, the watermark is located at a position where a predetermined interval is spaced apart from the first key pattern in which a random pattern is formed and a letter, number, or shape to be hidden in one direction with the first key pattern. A first image in which a first latent image pattern arranged side by side is recognized, and a second key pattern on which an arbitrary pattern is formed, and a letter, number, or shape to be hidden is spaced apart from the second key pattern in one direction by a predetermined distance The second latent image pattern disposed side by side includes a second image inscribed, and the first image and the second image are disposed at different angles. The watermark thus formed has almost no blank area formed in the watermark so that the multiple images are not easily visually identified. However, in the case where a blank area is partially formed in the portion except for the watermark, a background pattern of an arbitrary pattern may be formed.

Looking at the manufacturing method of the anti-counterfeiting hologram film having the watermark of the multi-image having such a structure, first, the first key pattern formed with a random pattern and the letters, numbers, or shapes to hide the first key pattern And a first image in which a first latent image pattern arranged side by side at a position spaced apart at a predetermined interval in one direction is provided, and then a second key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden are described above. The second latent image pattern disposed side by side at a position spaced apart from the second key pattern by a predetermined distance may be provided to the second image. The first image and the second image provided as described above are arranged at different angles to form a watermark, and then a background pattern in which an arbitrary pattern is imprinted is formed on a portion other than the watermark, thereby forming a watermark. The anti-counterfeiting hologram film provided with a watermark is manufactured.

According to an exemplary embodiment of the present disclosure, the first key pattern and the first latent image pattern may be formed of any one pattern selected from dotted lines, lines, or dots, and may be the same as or different from each other. In addition, the second key pattern and the second latent image pattern may also be formed in any pattern selected from the same or different from each other in dotted lines, lines, or dots. As such, in the present invention, multiple images may be designed by not only using a single pattern but by mixing various patterns to form an image.

According to another preferred embodiment of the present invention, it is preferable that the key pattern is a dotted line and the latent image pattern is full in terms of identification of a latent image by a filter (lenticular viewer) that is an identification device. In the present invention, the dotted line is a filter having a screen tone of 100 to 400 lines having a line thickness of 0.015 to 0.030 mm, an interval of 0.05 to 0.07 mm, and a length of 0.10 to 0.25 mm, and a screen concentration of 12 to 14%. It is preferable in terms of the identification of the latent image by (Lenticular Viewer), and the full line is identified as having a screen player of 100 to 400 lines with a line thickness of 0.05 to 0.01 mm and an interval of 0.15 to 0.25 mm, and a screen concentration of 14 to 16%. It is preferable at the point of identification of the latent image by the filter (lenticular viewer) which is an apparatus.

In addition, the images are arranged at different angles to form a watermark. For example, the second image is disposed at an angle of 85 to 110 degrees in a clockwise direction with respect to the horizontal direction of the first image. It is preferable at the point of identification of the latent image by a filter (lenticular viewer). The watermark may include a third latent image pattern disposed side by side at a position where a third key pattern on which a random pattern is formed and a letter, number, or shape to be hidden are spaced apart from the third key pattern by a predetermined distance in one direction. The third image may further include an engraved third image. In this case, the third image may be disposed at a different angle from the first image and the second image.

On the other hand, the method for identifying the watermark of the holographic film according to the present invention is hidden by placing a filter formed in the same pattern as the key pattern corresponding to the first and second images, respectively, at a proper position on the watermark to correspond to the key pattern. The latent image pattern may be displayed to easily distinguish the authenticity of the security product having the hologram film attached thereto.

The anti-counterfeiting hologram according to the present invention is applied to a product such as a sticker label, a printing label, a stamping foil by stamping on a PET film, PVC film, OPP film, Hot Stamping Foil, ABS, PMMA, etc. The reliability of the attached product can be improved.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are not intended to limit the scope of the present invention.

Example 1

The first key pattern is a screen tone bow of 175 lines having a line thickness of 0.015 mm, a thickness of 0.05 mm, and a length of 0.10 mm, and a dotted line having a screen concentration of 12%, as shown in FIGS. 3A and 3B. A first latent image of the character as shown in Fig. 5A at a position where a screen line of 0.05 lines and a screen line having a thickness of 0.15 mm and a screen concentration of 14% are separated and spaced at a predetermined interval in one direction with respect to the first key pattern. The pattern was constructed to form the first image.

The second key pattern is a screen tone bow of 190 lines having a line thickness of 0.020 mm, an interval of 0.06 mm, and a length of 0.20 mm, and a dotted line having a screen density of 13%. The second latent image pattern is formed of line thickness. A second latent image having the shape as shown in FIG. 5B at a position where a screen bow of 110 lines having a thickness of 0.07 mm and a distance of 0.20 mm and a screen density of 15% are spaced apart at predetermined intervals in one direction with respect to the second key pattern. The pattern was constructed to form a second image.

The watermark was manufactured by arranging the second image thus formed at an angle of 90 degrees clockwise with respect to the horizontal direction of the first image, and forming a background pattern with dotted lines on portions other than the first image and the second image.

The watermark thus prepared is a glass master by photographing an image synthesized in a general pattern by a graphic program on a glass plate coated with a high-resolution photosensitive agent using an exposure machine to make a glass master, plate the surface of the glass master, and manufacture a nickel mold, which is a holographic disc. It was. The mold was used to print the hologram film while applying heat and pressure to transfer the image to the hologram film.

As described above, the hologram film having the watermark of the multi-image manufactured as described above could not be identified with the naked eye.

Meanwhile, after forming a filter as shown in FIGS. 7A and 7B having the same pattern as the first key pattern and the second key pattern, respectively, corresponding to the first and second images, the individual filter corresponding to each image is watered. As a result of identifying by placing on a mark, the watermark of the hologram film could be identified as shown in FIGS. 8A and 8B.

1: hologram receiving layer 2: metal deposition layer
10: hologram film 20: watermark
21: images
30: Filter (Lenticular Viewer)

Claims (13)

In the anti-counterfeiting hologram film having a watermark,
A first image in which a first latent image pattern in which a first key pattern on which a random pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced a predetermined distance from the first key pattern in one direction; And a second image in which a second latent image pattern in which a second key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced apart from the second key pattern by a predetermined distance in one direction A watermark including the first image and the second image at different angles; And
Anti-counterfeit hologram film having a watermark of a multi-image including a; a background pattern in which a random pattern is imprinted on a portion excluding the watermark. The anti-counterfeiting hologram film of claim 1, wherein the first key pattern and the first latent image pattern are formed of any one selected from dotted lines, lines, or dots. The anti-counterfeiting hologram film of claim 1, wherein the second key pattern and the second latent image pattern are formed of any one selected from dotted lines, lines, or dots. The method according to claim 2 or 3, wherein the key pattern is a dotted line, the latent image pattern is full line, wherein the dotted line is of 100 to 400 lines having a line thickness of 0.015 to 0.030 mm, an interval of 0.05 to 0.07 mm and a length of 0.10 to 0.25 mm. Screen tone and screen density of 12-14%, wherein the line is characterized by having a screen thickness of 100-400 lines with a line thickness of 0.05-0.01 mm and an interval of 0.15-0.25 mm and a screen concentration of 14-16%. Anti-counterfeiting hologram film having a watermark of multiple images. The anti-counterfeiting hologram film of claim 1, wherein the second image is disposed at an angle of 85 to 110 degrees in a clockwise direction with respect to a horizontal direction of the first image. The method of claim 1, wherein the watermark is a third key pattern in which an arbitrary pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced apart from the third key pattern by a predetermined interval in one direction. The anti-counterfeiting hologram film having a watermark of multiple images, wherein the latent image pattern further includes a third image in which the third image is engraved, wherein the third image is disposed at a different angle from the first image and the second image. In the manufacturing method of the anti-counterfeiting hologram film having a watermark,
A first image in which a first latent image pattern in which a first key pattern on which a random pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced a predetermined distance from the first key pattern in one direction is removed. And a second latent image pattern in which a second key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced a predetermined distance apart in one direction from the second key pattern. Providing a second image, wherein the first image and the second image are disposed at different angles to form a watermark; And
Forming a background pattern in which a predetermined pattern is imprinted on the portion except the watermark; Method of manufacturing a forgery prevention hologram film having a watermark of a multi-image comprising a. The method of claim 7, wherein the first key pattern and the first latent image pattern are the same or different from each other and are formed of any one selected from dotted lines, lines, or dots. . The method of claim 7, wherein the second key pattern and the second latent image pattern are the same or different from each other, and are formed of any one selected from dotted lines, lines, or dots. . The method according to claim 8 or 9, wherein the key pattern is a dotted line, the latent image pattern is full line, wherein the dotted line is of 100 to 400 lines of line thickness 0.015 ~ 0.030 mm, interval 0.05 ~ 0.07 mm, length 0.10 ~ 0.25 mm Screen tone and screen density of 12-14%, wherein the line is characterized by having a screen thickness of 100-400 lines with a line thickness of 0.05-0.01 mm and an interval of 0.15-0.25 mm and a screen concentration of 14-16%. Method of manufacturing a forgery prevention holographic film having a watermark of multiple images. The method of claim 7, wherein the second image is disposed at an angle of 85 degrees to 110 degrees in a clockwise direction with respect to a horizontal direction of the first image. 9. The method of claim 7, wherein the forming of the watermark is arranged side by side at a position where a predetermined interval is spaced apart from the third key pattern in one direction from a third key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden. And providing a third image having a third latent image pattern imprinted therein, wherein the third image is disposed at a different angle from the first image and the second image. Method of producing a holographic film for preventing forgery. A first image in which a first latent image pattern in which a first key pattern on which a random pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced a predetermined distance from the first key pattern in one direction; And a second image in which a second latent image pattern in which a second key pattern on which an arbitrary pattern is formed and a letter, number, or shape to be hidden are arranged side by side at a position spaced apart from the second key pattern by a predetermined distance in one direction A watermark including the first image and the second image at different angles; And
A method of identifying a watermark of the anti-counterfeiting hologram film having a watermark of a multi-image including a; a background pattern of a pattern imprinted in a portion other than the watermark.
And identifying a watermark of the hologram film by placing a filter formed in the same watermark as a key pattern corresponding to the first and second images, respectively.

Images