JP2003320772A - Medium having image changing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium having an image changing function which can repeat visualizing without necessity of a special unit or the like for visualizing the latent image without increasing a cost of forming the latent image such as a hidden character or the like difficult to be duplicated by a color copier and which has excellent heat resistance and light resistance. <P>SOLUTION: A card 1 has the image changing function formed of parallel lines made of a transparent resin having a latent image pattern 22 and a non- latent image part 24 surrounding the pattern 22 and having the same shape as that of the pattern 22 on the partial region of a base material 10. In this card 1, the parallel lines for forming the pattern 22 are formed at a gradient of 90° with respect to the parallel lines of the non-latent image part 24. A parallel-line pattern 20 made of this transparent resin is formed of an ultraviolet curing ink and cured. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium having a latent image formed of hidden characters or patterns and having a function of being visualized according to a viewing angle. For example, cards, securities, or a brand. The present invention relates to a medium having an image changing function that can be added to a product that requires anti-counterfeiting such as a product.

[0002]

2. Description of the Related Art Conventionally, there are various methods for forming a latent image. For example, there is pencil out printing (Deco Matte), in which a transparent ink medium with a filler is printed, and when the portion is rubbed with a pencil, pencil dust adheres to the printed portion and hidden characters appear, but this latent image is It is used as a play rather than as a full-fledged latent image because you can see it when you look closely. Further, for example, the irreversible thermosensitive coloring ink is an ink that is colored by applying heat,
Some use white or colorless transparent ink,
It is effective as a latent image, but it requires a heat source device to visualize the latent image and cannot erase what has been once displayed, so its application is limited. There is a problem that is. Further, there is a method of printing a white ink containing a filler harder than a metal such as titanium oxide on a white paper and rubbing with a coin or the like to visualize a latent image, and providing a matte varnish on this. Although it can be made invisible by visual observation, its application is limited because it can be visualized only once. On the other hand, a reversible thermosensitive ink (thermochromic ink) is a medium that can be repeatedly visualized. The thermochromic ink is an ink that reversibly develops color when heat is applied, and when heat is applied, the color is developed or decolored, and when left for a while, it returns to its original state. This ink is also used as a latent image or in the form of hiding the image, but its use is limited due to poor resistance, particularly heat resistance. In addition, there is photochromic ink as a medium that can be visualized repeatedly, and this photochromic ink is
It is an ink that develops color when irradiated with light, especially ultraviolet rays. It is used as a latent image because of white or colorless transparent ink, but its use is limited due to its low resistance, especially light resistance. Fluorescent ink is an ink that emits light when irradiated with ultraviolet rays and is used as a latent image because it has white or colorless transparent ink. This fluorescent ink is classified into an organic type and an inorganic type. The organic type emits light when it is contained in a printing ink in a very small amount, but its use is limited due to its weak light resistance. Further, it is necessary to add a large amount of the inorganic type to the printing ink (about 10 to 20%), and the latent image will be visually recognizable, so it is necessary to devise the design and the like. Furthermore, a method of forming a latent image by using moire (interference fringes) such as halftone dots is a method of forming a latent image on a transparent film of halftone dots arranged in order by partially changing the pitch or angle of the halftone dots. Moire is generated by superimposing it on the image, and the image appears. In this case, there is a problem that a simple display medium can be used repeatedly but a complicated image cannot be formed. Further, the latent image formed by the magnetic ink is magnetized by forming an image by a method of magnetizing a magnetic layer having a magnetically recordable coercive force (about 300 Oe or more) in a pattern, and sprinkling iron powder on the magnetic layer. It is a method to display an image by utilizing the property that iron powder gathers in the part,
In this method, the process of displaying the latent image is complicated,
Further, the rewriting of the image is possible, so that the use is limited. In addition, a latent image is formed by forming an image with an ink that absorbs infrared light by utilizing the infrared region, covering the image so that it is not visible, and providing a layer that transmits light in the infrared region. However, in order to display this latent image, an infrared camera or the like is necessary, which is a large scale for the device. In addition, there is ink (IV ink) that is white or colorless in the visible light range but has absorption in the infrared range,
This also requires an infrared camera or the like as described above.

On the other hand, with the recent widespread use of copying machines using electrophotographic technology, if a recent color copying machine is used, it is extremely difficult for anyone to easily distinguish a manuscript or a copy. It can be easily created. Thus, while color copying is convenient, there is an increasing problem that securities such as stock certificates, bonds, promissory notes and checks, and printed matter such as admission tickets and boarding passes are easily forged. As a means for restraining such copying and improving security, forgery prevention technology by various copying is applied to the securities and the like. For example, copy protection technology using the base material itself such as watermarked paper, colored paper, and paper with chips, printing of tint block, color pattern, stick color pattern, logo line, and special ink such as fluorescent ink, decolorizing ink, etc. There is a copy protection technique by special printing using the above, and a copy protection technique called a digital watermark created by including information indicating that the print document is a copy prohibited object. However, these techniques have problems that they are complicated and the cost is high.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art. The problem is that hidden characters and hidden characters that are difficult to forge or copy by a commercially available color copying machine or the like are used. The cost of forming a latent image such as a pattern is low, and the latent image is visualized (including true / false judgment)
It is an object of the present invention to provide a medium having an image changing function which is excellent in heat resistance and light resistance because it can be repeatedly visualized without requiring a special device or the like.

[0005]

In order to achieve the above object in the present invention, first, in the invention of claim 1, the latent image pattern portion and the latent image pattern portion are provided in at least a partial area or the entire area of one surface of the base material. A medium having an image changing function, in which the surrounding non-latent image portion is formed by a line made of a transparent resin of the same shape, and the line forming the latent image pattern part is a line of the non-latent image part. On the other hand, the medium having an image changing function is characterized in that it is formed at an inclination of 45 to 135 °, preferably 90 °.

According to the first aspect of the present invention, the latent image pattern portion and the non-latent image portion are formed on the base material with the lines made of transparent resin of the same shape to form a medium having an image changing function. The manufacturing cost does not increase, and the heat resistance and light resistance are excellent.
Further, since each of the lines forming the latent image pattern portion and the non-latent image portion is formed with an inclination of 45 to 135 °, preferably 90 °, these latent image pattern portion and non-latent image portion are formed. There is a difference in the amount of reflected light at the top (top) of the line
The visualization of the latent image pattern portion can be visually confirmed by the change in the angle of reflection from the light source, which makes it difficult to copy (counterfeit) by a copying machine, does not require a special device for the visualization, and can be repeated. It is possible to provide a medium having a possible image changing function. The inclination of the lines forming the latent image pattern portion and the non-latent image portion is 4
If the angle is less than 5 ° and exceeds 135 °, there is no difference in the amount of reflected light on the top surfaces of the lines on both sides, and in visualizing the latent image pattern portion, a visible image pattern lacking in contrast is not preferable.

According to a second aspect of the present invention, the medium having an image changing function according to the first aspect is characterized in that the line has a thickness in the range of 5 to 10 μm.

According to the second aspect of the invention, by setting the thickness of the parallel lines in the range of 5 to 10 μm, the tops (top faces) of the parallel lines of the latent image pattern portion and the non-latent image portion are formed. There is a difference in the amount of reflected light, so that the latent image pattern portion can be a medium having an image changing function for obtaining a visible image pattern with high contrast due to a change in viewing angle. The thickness of this line is
If it is less than 5 μm, the top of the line (top surface) becomes flat,
There is no difference in the amount of reflected light at the top (top surface) of the lines of the latent image pattern part and the non-latent image part. As a result, the latent image pattern part becomes a visible image pattern without contrast due to the change of the viewing angle. If the thickness exceeds 10 μm, when products are stacked, they will tilt, which will interfere with manufacturing, storage, or transportation, and if applied to cards, malfunctions will occur when transported by vending machines, etc. It is not preferable because it may occur or it may be difficult to form by printing or the like which can be performed at low cost.

Further, in the invention of claim 3, the line width of the line is in the range of 50 to 200 μm, and the interval thereof is substantially the same as the line width. This is a medium having the image changing function.

According to the third aspect of the present invention, the line width of the parallel lines is in the range of 50 to 200 μm, and the interval (the white portion between the parallel lines) is defined as the line width. By making the lines substantially the same, the lines can also have a uniform thickness, and if the line width of the lines is less than 50 μm, reproducibility due to printing or the like becomes difficult, and the above-mentioned thickness becomes small. When the line width of the line exceeds 200 μm, the line formed is too conspicuous, the latent image pattern part is visually recognized even in the normal case, and when applied to a card etc., It is not preferable because it has a problem that it is inferior in abrasion resistance and the like in conveyance suitability in a reading machine or the like.

Furthermore, in the invention of claim 4, the line made of the transparent resin is formed of an ultraviolet curable ink,
The medium having an image changing function according to claim 1, characterized in that the medium is cured by irradiation with ultraviolet rays.

According to the invention of claim 4, the line made of the transparent resin is formed by a screen printing method using an ultraviolet curable ink and is immediately cured by irradiation with ultraviolet rays. The top of the line (top surface) does not become flat due to leveling etc. unlike ordinary evaporative drying type ink, and a sharp acute angle can be formed. Therefore, the lines of latent image pattern part and non-latent image part The difference in the amount of reflected light on the top (top surface) of the image becomes larger, and as a result, the latent image pattern portion can be a medium having an image changing function that becomes a visible image pattern of higher contrast due to the change of the viewing angle.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As a medium having an image changing function of the present invention, for example, as shown in the plan view of FIG.
0) has an image changing function in which a line portion pattern (20) made of transparent resin is applied to one side of a white plastic sheet for a card and a printing portion (12) made of characters and a partial region thereof. A card (1), wherein the invention according to claim 1 is, for example, as shown in a plan enlarged view of FIG. 2, the line pattern (20) has a latent image pattern portion ( 22) and its surroundings, this latent image pattern portion (2
2) and a non-latent image part (24) surrounding it,
The angle at which the line forming the latent image pattern portion (22) and the line forming the non-latent image portion (24) intersect is 90 °.

The line pattern (20) consisting of the latent image pattern portion (22) and the non-latent image portion (24) around the latent image pattern portion (22) is formed in a partial area on both front and back surfaces though not shown. Alternatively, it may be formed on the entire surface of one side or both sides.

Further, the invention according to claim 2 is, for example, as shown in the enlarged side sectional view of FIG. 3 showing the BB cross section of FIG. 2, the latent image pattern portion (22) and the periphery thereof. The thickness (D) of the lines forming the non-latent image portion (24) is 5 to
The invention according to claim 3 has a range of 10 μm,
For example, as shown in the enlarged side cross-sectional view of FIG. 3, the line width (W) of the lines forming the latent image pattern portion (22) and the non-latent image portion (24) is in the range of 50 to 200 μm. Things
The line spacing (S) is approximately the same as the line width (W).

Further, the invention according to claim 4 is
For example, as shown in the enlarged side sectional view of FIG. 3, the line pattern (20) made of a transparent resin forming the latent image pattern portion (22) and the non-latent image portion (24) is an ultraviolet curable screen ink. And a card (1) having an image changing function, which is formed by a screen printing method and is cured by irradiation of ultraviolet rays such as a xenon lamp.

As described above, for example, as shown in the enlarged side sectional view of FIG. 3, the line of the latent image pattern portion (22) and the line 90 °
The light (62) from the light source (60) on the non-latent image part (24) side is reflected by the line pattern (20) consisting of the lines of the non-latent image part (24) intersecting at an angle of When the light (62) hits the latent image pattern portion (22) composed of lines extending in the direction of (62), the light (62) is regularly reflected on the line top (top surface) of the latent image pattern part (22), It is visible as a bright pattern to the human eye (64) facing the light source (60). On the other hand, at the top (top surface) of the non-latent image part (24) formed by lines parallel to the direction of the light (62), the light source (6
The light (62) from the light source (0) is diffusely reflected and is visually recognized as a dark pattern by the human eye (64) facing the light source (60). Therefore, when viewed from directly above the line pattern (20) shown in FIG. 2, there is no difference in the amount of reflected light from the latent image pattern portion (22) made of a transparent resin and the non-latent image portion (24). Although indistinguishable, when the reflection of light from the upper direction of the parallel line pattern (20) is viewed from the lower side, the latent image pattern portion (22) is visually recognized as a whitish "T" character.

Contrary to this, for example, when the card (1) having the image changing function shown in FIG. 2 is rotated leftward by 90 ° and viewed under the same conditions as described above, the latent image pattern portion (2
2) will be visually recognized as the letter "T" with the blackish left side as the sky. Also in this case, when the line pattern (20) is viewed from directly above, the latent image pattern portion (22) cannot be visually recognized even if the existence of the line pattern (20) can be recognized.

Line pattern (20) according to the present invention.
Examples of the UV-curable screen ink for forming a polymer include polymers such as polyurethane acrylate, polyester acrylate, and alkyd acrylate, a photoreactive diluent such as long-chain aliphatic acrylate, arlyacrylate, and benzyl acrylate; , A benzophenone-based or acetophenone-based photopolymerization initiator, and an aliphatic amine-based or aromatic amine-based photosensitizer, etc., which are formed by a screen printing method using such an ink. Is immediately cured by UV irradiation from a xenon lamp, etc.
The line pattern (20) of 0 μm can be obtained. The UV-curable screen ink does not necessarily have to be colorless and transparent, and may have the same effect (transparency and surface reflectivity) as the transparent ink, for example, a colored transparent ink containing a bright pigment. May be

Further, as the base material according to the present invention, in addition to high-quality paper, OCR paper, etc., in the case of the card (1) having the image changing function shown in FIG. 1, a plastic sheet is suitable,
For example, vinyl chloride (PV
C), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) or ABS sheets, and the like. Especially, vinyl chloride is often used because of its embossability, and in recent years it has been incinerated. Due to problems and the like, the above resins, including amorphous PET, have been devised and used.

In the case of a card (1) having an image changing function, for example, a printing section (12) is formed on the outermost layer on the front and back surfaces of the card.
It is also possible to provide a protective layer for protecting the like, and as the protective layer, it is common to thermally laminate a transparent vinyl chloride film having a thickness of 5 to 15 μm, but other acrylics, polyesters (including PET) Resins such as resins that have excellent heat resistance and toughness as the main component, and are mixed with silicon and ethylene wax at a ratio of 1 to 5% by weight considering the slipperiness of machinery, etc. It can also be formed by coating with. However, the line pattern (20) should not be covered with this protective layer. This is because it affects the amount of reflected light in the line pattern (20).

[0022]

Since the present invention has the above-mentioned constitution, it has the following effects. That is, in the invention according to claim 1, the latent image pattern portion and the non-latent image portion surrounding the latent image pattern portion are formed by a line made of a transparent resin of the same shape in at least a partial region or the entire region of one surface of the substrate. Since it is a medium having an image changing function, the manufacturing cost does not increase, and the heat resistance and light resistance are excellent, and each of the lines forming the latent image pattern portion and the non-latent image portion is 45 to 135 °. Since it is formed in a range of 90 °, preferably 90 °, the peaks (top surface) of lines in these latent image pattern portion and non-latent image portion
There is a difference in the amount of light reflected by the light source, and the visualization of this latent image pattern portion can be visually recognized by the change in the angle of reflection from the light source, making it difficult to copy (counterfeit) with a copying machine. It is possible to provide a medium that does not require a device and has a repeatable image changing function.

Further, in the invention according to claim 2,
By setting the thickness of the parallel lines in the range of 5 to 10 μm, the tops of the parallel lines of the latent image pattern part and the non-latent image part (top surface)
However, the latent image pattern portion can be a medium having an image changing function for obtaining a high-contrast visible image pattern due to a change in viewing angle.

In the invention according to claim 3,
The line width of the line is in the range of 50 to 200 μm, and the interval (the white portion between lines) is made substantially the same as the line width. If the line width of the lines is less than 50 μm, the reproducibility due to printing or the like becomes difficult, and the above thickness cannot be removed, resulting in non-uniformity. Is 200
If it exceeds μm, the lines formed are too conspicuous, and the latent image pattern portion becomes visible even under normal conditions, which is not preferable.

Further, in the invention according to claim 4, the line made of the transparent resin is formed by a screen printing method using an ultraviolet curable ink, and is immediately cured by irradiation with ultraviolet rays. The top of the line (top)
However, unlike normal evaporation-drying type ink, it does not become flat due to leveling etc. and can form a sharp acute angle,
Therefore, the top of the line of the latent image pattern part and the non-latent image part (top surface)
The difference in the amount of reflected light is further increased, and as a result, the latent image pattern portion in the line pattern becomes a medium having an image changing function of becoming a visible image pattern of higher contrast due to the change of the viewing angle.

Therefore, according to the present invention, a latent image formed of hidden characters or patterns is formed, and in a medium having an image changing function which becomes visible depending on the viewing angle, for example, forgery of cards, securities, brand products, etc. As a medium having an image change function that can be added to products requiring prevention, it exhibits excellent practical effects.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a medium having an image changing function of the present invention.

2 is an enlarged front view of FIG. 1 showing an embodiment of a medium having an image changing function of the present invention.

3 is an explanatory view showing an embodiment of a medium having an image changing function of the present invention, and is a cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

1. Card with image change function 10 ... Base material 12 ... Printing section 20 ... Line pattern 22 ... Latent image pattern section 24..Non-latent image part 60 ... light source 62 ... light 64 ... eyes D: Line pattern thickness S: Line spacing W: Line width of line

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Claims (4)

[Claims] 1. An image changing function in which a latent image pattern portion and a non-latent image portion surrounding the latent image pattern portion are formed by lines made of transparent resin of the same shape on at least a partial area or the entire area of one surface of a substrate. In the medium, the lines forming the latent image pattern portion are formed in a range of 45 to 135 °, preferably 90 ° with respect to the lines of the non-latent image portion. A medium having an image changing function. 2. The medium having an image changing function according to claim 1, wherein the line has a thickness in the range of 5 to 10 μm. 3. The medium having an image changing function according to claim 1, wherein the line width of the lines is in the range of 50 to 200 μm, and the interval between them is substantially the same as the line width. . 4. A medium having an image changing function according to claim 1, 2 or 3, wherein the lines made of the transparent resin are formed of an ultraviolet curable screen ink and are cured by irradiation of ultraviolet rays. .