Display medium for authenticity determination and method for manufacturing display medium for authenticity determination

Abstract

To provide a display medium for authenticity determination capable of freely varying a shape and a place of a display for authenticity determination according to demand and desire of a user, and a method for manufacturing the display medium for authenticity determination.SOLUTION: An authenticity determination display medium according to the present disclosure is an authenticity determination display medium having an authenticity determination unit for determining authenticity of a medium includes: a first layer having a non-copyable portion on which low-density printing for copy prevention is performed; a second layer having no non-copyable portion; and a thermochromic ink layer which is a layer provided between the first layer and the second layer and includes thermochromic ink that becomes transparent in response to heat application, where the authenticity determination unit is formed by removing, with a laser, the non-copyable portion in the first layer or part of the second layer overlapping with the non-copyable portion of the first layer.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to an authenticity determination display medium having a function of determining that a medium has been copied, and a method for manufacturing the authenticity determination display medium.

Background Art

[0002] In information display (storage) media such as cards, there are known cards having an authenticity determination function for determining whether the card has been forged. In such a card, for example, when the card surface is printed with a copying device or the like, a predetermined pattern such as characters emerges, and thus the authenticity of the card can be determined.

[0003] For example, there is known a technique of displaying authenticity determination information by changing the color by applying heat at a specific temperature (for example, Patent Document 1). Also, there is known a technique of making characters or the like emerge when copying with a copying device or the like by changing the thickness of the lines printed on the card or the density of the halftone dots of the background pattern (for example, Patent Documents 2 and 3). Further, there is known a technique of making an image formed by relief printing emerge by performing printing on the surface of an irradiation object by laser irradiation (for example, Patent Document 4).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] According to the prior art, when copying onto a medium using a copying device or the like, characters or the like that float up can be printed, so authenticity determination can be performed based on such display.

[0006] However, printing on a medium is usually performed according to plate making. For this reason, in the case of a medium such as an identity card where different displays are made for each sheet, there is a problem that the shape of the display for authenticity determination, the location where the display is printed, etc. cannot be made variable for each card.

[0007] Also, in a method of performing copy determination based on changes such as the thickness of a halftone or the density of the screen of a background pattern as in the prior art, since it is necessary to display a halftone or a background pattern to form a display for performing copy determination, there is a problem that the design is limited. Specifically, in the prior art, it is difficult to apply a so-called solid design in which, for example, a card is almost entirely filled with one color.

[0008] Therefore, the present disclosure proposes an authenticity determination display medium and a method for manufacturing an authenticity determination display medium that can freely vary the shape and location of the display for authenticity determination and can apply a flexible design.

Means for Solving the Problem

[0009] In order to solve the above problems, an authenticity determination display medium according to the present disclosure is an authenticity determination display medium having an authenticity determination unit for determining the authenticity of a medium, including a first layer having a non-copyable portion subjected to low-density printing for copy prevention, a second layer not having the non-copyable portion, and a layer provided between the first layer and the second layer and including a thermochromic ink layer containing a thermochromic ink that becomes transparent in response to heat application. The authenticity determination unit is formed by removing, with a laser, the non-copyable portion in the first layer or a part of the second layer that overlaps the non-copyable portion of the first layer.

Effects of the Invention

[0010] According to one aspect of the embodiment, in the information display medium, the shape and location of the display for authenticity determination can be freely changed, and a flexible design can be applied.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following embodiments, the same parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0013] (1. Embodiment) (1-1. Regarding the method of forming the authenticity determination unit) First, a method of forming a region (authenticity determination unit) for preventing duplication by combining thin lines and thick lines, which is a premise of the technology according to the present disclosure, will be described with reference to FIGS. 1 to 3.

[0014] FIG. 1 is a diagram for explaining the authenticity determination unit of the present disclosure. FIG. 1 shows an example of a forgery-proof card 10 having the authenticity determination unit according to the present disclosure. As shown in FIG. 1, a ten-thousand line pattern (a collection of regularly arranged parallel lines) is printed on the forgery-proof card 10 as a ground pattern. Further, the forgery-proof card 10 has an authenticity determination unit consisting of the characters "OK".

[0015] The authenticity determination unit is also referred to as an anti-copying character or the like. As shown in the enlarged portion 20 of the forgery-proof card 10 in FIG. 1, the authenticity determination unit is formed by thin lines 24 which are thinner than the thick lines 22, rather than the thick lines 22 which form the ground pattern.

[0016] In the present disclosure, the thick line 22 is a line that can be read by a copying device or the like and is also displayed on the copied medium. On the other hand, the thin line 24 is a line that cannot be read by a copying device or the like and becomes blank on the copied medium. As an example, the thick line 22 has a width of 74 μm for each line and an interval of 169.4 μm between the ten-thousand lines. Also, the thin line 24 has a width of 22.5 μm for each line and an interval of 99.2 μm between the ten-thousand lines. Note that the definitions of the thick line 22 and the thin line 24 may vary depending on the reading performance of a copying device or the like. For example, when copying with an arbitrary copying device or the like, a line that can be read may be defined as a thick line, and a line that cannot be read may be defined as a thin line. That is, if the forgery-proof card 10 satisfies the condition that one of the printed portions such as the thick line 22 and the thin line 24 is readable by a copying device and the other printed portion is unreadable by the copying device, it can be provided with an authenticity determination unit.

[0017] Also, for the authenticity determination unit such as an anti-copying character, it is desirable that the ratio of the widths and intervals of the thick line 22 and the thin line 24 is closer in order to make it difficult for a person to visually recognize. Note that if one of the printing areas is readable and the other printing area is unreadable, and the densities (the ratio of the printed portion to the non-printed portion) of both printing areas are close, the ground pattern of the forgery-proof card 10 may be a halftone dot instead of a ten-thousand line pattern. Hereinafter, a portion that becomes unreadable when copied with an arbitrary copying device or the like may be referred to as an "uncopyable portion", and a region where such low-density printing such as unreadable ten-thousand line patterns is performed may be referred to as a "low-density region".

[0018] That is, in the example of FIG. 1, the anti-counterfeiting card 10 has characters "OK" formed by thin lines 24, and the other regions are formed by thick lines 22. In this case, if the anti-counterfeiting card 10 is genuine, when the characters "OK" are copied by a copying device or the like, they will float as blanks. On the other hand, if it is a counterfeit card, since the anti-copying characters "OK" are not included (or not formed as thin lines 24), the characters "OK" will not float when copied by a copying device or the like. Thus, the user can determine the authenticity of the anti-counterfeiting card 10.

[0019] The anti-counterfeiting card 10 according to the embodiment is manufactured based on the process described below with reference to FIG. 2. FIG. 2 is a diagram showing an example of a method for forming an authenticity determination portion.

[0020] The anti-counterfeiting card 10 is manufactured by laminating a layer printed with thick lines and a layer printed with thin lines.

[0021] First, a thin line layer 30 printed with thin lines is overlaid on a thick line layer 32 printed with thick lines. That is, in the example shown in FIG. 2, the thick line layer 32 serves as the base of the anti-counterfeiting card 10. An intermediate layer is provided between the thin line layer 30 and the thick line layer 32. The intermediate layer includes, for example, a concealment layer having a role of concealing the base and a transparent over-sheet layer having a role of protection. Due to the presence of the concealment layer in the middle, when the thin line layer 30 is superimposed on the thick line layer 32, the thick line layer 32 becomes invisible, and only the printing of the thin line layer 30 is visible. Such a state is the coupon face 34 shown in FIG. 2.

[0022] Subsequently, the process of adding an authenticity determination portion 38 to the coupon face 34 will be described. In the example of FIG. 2, the authenticity determination portion 38 is assumed to have a character shape of "T". A laser irradiator is used to form the authenticity determination portion 38. Note that the shape of the authenticity determination portion 38 can be arbitrarily set. For example, the manufacturer may set the check number (check digit) of the ID number printed on the card as the authenticity determination portion 38.

[0023] With respect to the coupon face 34, the laser irradiator irradiates, for example, a carbon dioxide laser (CO 2 laser) to remove the fine line layer 30 and the concealment layer. The coupon face 36 is the state of the card after the coupon face 34 has been irradiated with a laser and the authenticity determination portion 38 has been formed.

[0024] Due to the removal of the concealment layer, the thick line layer 32, which is the base, appears on the surface in the authenticity determination portion 38 of the coupon face 36. When the coupon face 36 is copied, a copy such as the coupon face 40 shown in FIG. 2 is made. That is, in the coupon face 40, the printing area corresponding to the fine line layer 30 is not copied, and only the thick line layer 32 corresponding to the authenticity determination portion 38 is copied, so that the shape of "T" emerges.

[0025] The manufacturing method shown in FIG. 2 will be described using FIG. 3, which shows a cross-section of the card. FIG. 3 is a cross-sectional view of the anti-counterfeiting card 10 in which the authenticity determination portion is formed.

[0026] As shown in FIG. 3, the anti-counterfeiting card 10 is composed of, in order from the bottom, a core material 46, which is a main constituent member of the card (e.g., plastic, etc.), a thick line layer 32 in which thick lines are printed as myriad lines, a transparent over-sheet 44, a concealment layer 42, and a fine line layer 30 in which fine lines are printed as myriad lines, which are laminated and joined to each other. In an actual card, a coat layer (protection layer) for protecting the card surface may be provided on the upper layer of the fine line layer 30, and a printing layer (design layer) for applying a design to the card may be provided on the upper layer of the concealment layer 42. However, in FIG. 3 and FIGS. 4 and the like described later, these illustrations are omitted.

[0027] The laser irradiator irradiates a laser on a portion of the surface of the anti-counterfeiting card 10 corresponding to the authenticity determination unit 38 to remove the fine line layer 30 and the concealment layer 42. The removed portion 48 removed by the laser corresponds to the authenticity determination unit 38 having the character shape of "T" as shown in FIG. 2. In the embodiment, for example, the fine line layer 30 has a thickness of about 2 μm and the concealment layer 42 has a thickness of about 2 μm. To form the authenticity determination unit 38 by laser removal for such a layer with such a thickness, a high degree of adjustment is required including errors. In this regard, in the manufacturing method according to the embodiment, by interposing a transparent oversheet 44 formed with a certain thickness (for example, about 50 to 100 μm), the adjustment of the laser irradiation can be facilitated. That is, in the manufacturing method according to the embodiment, by adjusting the laser irradiation to remove a part of the transparent oversheet 44, the fine line layer 30 and the concealment layer 42 can be surely removed and the thick line layer 32 can be prevented from being removed. As a result, in the anti-counterfeiting card 10 after laser irradiation, the thick line layer 32 can be seen while the transparent oversheet 44 remains.

[0028] As described above, in the first example, the fine line layer 30 is disposed on the first layer of the surface of the anti-counterfeiting card 10, and the authenticity determination unit 38 is formed by removing, with a laser, a non-reproducible portion that is an arbitrary part thereof and a part of the concealment layer 42 corresponding to the non-reproducible portion.

[0029] (1-2. Configuration example of anti-counterfeiting card according to the present disclosure) As described above, since the authenticity determination unit is formed by combining a fine line and a thick line in upper and lower layers, either the fine line or the thick line will appear on the surface of the card. For this reason, it is difficult to apply a so-called solid design to the card having the authenticity determination unit with a single color on the surface. Then, for the issuer of the card, the design space is narrowed and flexible expression may be hindered.

[0030] Therefore, the anti-counterfeiting card 60 according to the embodiment solves the above problems with the configuration shown in FIG. 4. FIG. 4 is a cross-sectional view of the anti-counterfeiting card 60 according to the embodiment.

[0031] As shown in FIG. 4, the anti-counterfeiting card 60 includes a fine line layer 30, a transparent over-sheet 44, a thick line layer 32, and a core material 46, similar to the structure of the anti-counterfeiting card 10 shown in FIG. 3.

[0032] The transparent over-sheet 44 is a layer located at the center of the anti-counterfeiting card 60 and is formed of, for example, a transparent resin, film, or the like. The core material 46 is a resin constituting the card and is, for example, a base material mainly composed of an opaque white resin as a whole. The core material 46 is, as an example, 560 μm thick and is formed of a known opaque resin such as polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene terephthalate glycol (PET-G), or polycarbonate (PC).

[0033] Furthermore, the anti-counterfeiting card 60 includes a temperature-indicating ink layer 50 containing temperature-indicating ink at a position below the fine line layer 30 and above the thick line layer 32. That is, the anti-counterfeiting card 60 is composed of the fine line layer 30, the temperature-indicating ink layer 50, and the thick line layer 32 laminated and bonded to each other.

[0034] The temperature-indicating ink layer 50 is a layer formed by applying temperature-indicating ink that changes to transparent by heat application. The temperature-indicating ink not only becomes transparent by heat application but also can vary its color depending on the film thickness and properties, and can exhibit various colors.

[0035] FIG. 5 shows a top view (plan view) and a cross-sectional view of the surface of the anti-counterfeiting card 60. FIG. 5 is a diagram for explaining the anti-counterfeiting card 60 according to the embodiment.

[0036] In the embodiment, the inks used for the fine line layer 30, the temperature indicating ink layer 50, and the thick line layer 32 shall be of the same color or similar colors to such an extent that they cannot be distinguished visually. For this reason, when the temperature indicating ink layer 50 is in an opaque state, when looking at the anti-counterfeiting card 60 from the surface, since the fine line layer 30 and the temperature indicating ink layer 50 are of the same color, it is visually recognized as a solid design. This is because the fine lines drawn in the fine line layer 30 and the temperature indicating ink in the temperature indicating ink layer 50 are of the same color, making it difficult for humans to visually recognize the fine lines. Also, due to the fact that the temperature indicating ink layer 50 is opaque, the thick line layer 32 does not appear visually.

[0037] In the embodiment, a process for forming the authenticity determination unit 62 is performed on the anti-counterfeiting card 60 in the state of the left part of FIG. 5.

[0038] Specifically, with respect to the anti-counterfeiting card 60, the laser irradiator irradiates a CO 2 laser or the like on the region of the fine line layer 30 where the authenticity determination unit 62 is to be formed. The right part of FIG. 5 shows the state where the authenticity determination unit 62 is formed on the anti-counterfeiting card 60.

[0039] As shown in the plan view of the right part of FIG. 5, the authenticity determination unit 62 is in the shape of the character "T". As shown in the plan view of the right part of FIG. 5, in the region corresponding to the authenticity determination unit 62, the fine line layer 30 has been removed, so the thin fine lines have been removed. That is, in the authenticity determination unit 62, the temperature indicating ink layer 50 appears, and the fine lines of the fine line layer 30 do not exist. However, since the fine line layer 30 and the temperature indicating ink are of the same color, it is difficult for the user to visually recognize the authenticity determination unit 62. That is, the user cannot recognize visually that the authenticity determination unit 62 is formed on the anti-counterfeiting card 60. Note that there may be a slight step in the removal unit 64 in the authenticity determination unit 62, but the card manufacturer can also form the anti-counterfeiting card 60 so that no step occurs by filling the region corresponding to the authenticity determination unit 62 with a transparent sheet, resin, or the like.

[0040] (1-3. Example of authenticity determination function) Next, the authenticity determination process by the authenticity determination unit 62 will be described with reference to FIG. 6. FIG. 6 is a diagram for explaining the authenticity determination function of the anti-counterfeiting card 60 according to the embodiment.

[0041] When the authenticity determination function of the anti-counterfeiting card 60 is to be expressed, for example, the user exposes the anti-counterfeiting card 60 to the heat source 56 or irradiates the anti-counterfeiting card 60 with light that can serve as the heat source 56 to make the temperature-sensitive ink in the temperature-sensitive ink layer 50 transparent. For example, the user may apply heat to the anti-counterfeiting card 60 by a method such as warming the anti-counterfeiting card 60 with body temperature to make the temperature-sensitive ink transparent. In the cross-sectional view of FIG. 6, an example is shown where the heat source 56 is located on the upper surface of the anti-counterfeiting card 10. However, the direction of heat application is not limited to the upper surface. As long as heat that can make the temperature-sensitive ink transparent can be applied, such as from the lower surface or the side surface, the direction does not matter.

[0042] The left part of FIG. 6 shows that heat has been applied and a part of the temperature-sensitive ink layer 50 has become transparent. In the transparent part of the temperature-sensitive ink layer 50, the lines drawn on the thick line layer 32 located in the lower layer of the temperature-sensitive ink layer 50 appear. As shown in the plan view of the left part of FIG. 6, in the transparent part of the temperature-sensitive ink layer 50, both the lines of the thin line layer 30 and the lines of the thick line layer 32 appear. However, as described above, since both are drawn so that their densities are close, it is difficult for the user to recognize the authenticity determination unit 62.

[0043] When the anti-counterfeiting card 60 is copied in such a state, the copied image 70 shown in the right part of FIG. 6 is obtained. That is, only the thick line display 72 corresponding to the authenticity determination unit 62 is recognized in the copied image 70, and the thin lines drawn on the thin line layer 30 are not reproduced by the copy and thus are not recognized by the user.

[0044] As described above, according to the technology of the embodiment, the shape and location of the display for authenticity determination can be freely formed on the card face, and by performing the authenticity determination process using the transparency of the temperature-sensitive ink layer 50, designs that were difficult in the past, such as solid designs, can be applied to the card.

[0045] (2. Variations of the Embodiment) (2-1. Card Configuration) Subsequently, different configuration examples of the anti-counterfeiting card according to the present disclosure are shown. FIG. 7 is a diagram showing an anti-counterfeiting card 80 according to a variation.

[0046] In the anti-counterfeiting card 80 according to the variation, the fine line layer 30 serves as a base. That is, in the anti-counterfeiting card 80, a thick line layer 32 printed with thick lines is overlaid on the fine line layer 30 printed with fine lines. Further, similar to the anti-counterfeiting card 60, a thermochromic ink layer 50 is provided between the fine line layer 30 and the thick line layer 32 in the anti-counterfeiting card 80. For this reason, in the anti-counterfeiting card 80, the fine line layer 30 is concealed by the thermochromic ink layer 50 and does not appear.

[0047] Also in the example of FIG. 7, similar to FIG. 5, the authenticity determination portion 82 is formed by a laser. The authenticity determination portion 82 has the character shape of "T". The authenticity determination portion 82 corresponds to the removal portion 84 in the cross-sectional view.

[0048] On the left side of FIG. 7, the user applies heat to the thermochromic ink with a heat source 56 to make the thermochromic ink layer 50 transparent. At the portion where the thermochromic ink layer 50 becomes transparent, the fine lines drawn on the fine line layer 30 located in the lower layer of the thermochromic ink layer 50 appear.

[0049] As shown in the plan view of the left part of FIG. 7, since a part of the thick line layer 32 is removed and the thermochromic ink layer 50 becomes transparent, the fine line layer 30 which is the base appears on the surface in the authenticity determination portion 82. However, as described above, the density of the fine lines and the thick lines is drawn to be close, and because of the same color system, it is difficult for the user to recognize the authenticity determination portion 82.

[0050] When the anti-counterfeiting card 80 is copied in such a state, a copied image 90 shown in the right part of FIG. 7 is obtained. That is, since the fine lines located in the authenticity determination portion 82 are not reproduced in the corresponding copy, a display in which the character shape of "T" is white-out appears in the copied image 90.

[0051] Thus, in the technology according to the present disclosure, the authenticity determination unit may be formed of a copyable portion (thick line) or a non-copyable portion (thin line). When configured such that two types of lines, i.e., thick lines and thin lines, are visible as in the modification example, the density of the thick line layer 32 is lowered or the density of the thin line layer 30 is increased, so that the densities of the two become closer and it becomes more difficult to visually recognize the authenticity determination unit.

[0052] (2-2. Display medium for authenticity determination) In the above embodiment, the anti-counterfeiting card 60 and the anti-counterfeiting card 80 are exemplified as the display medium for authenticity determination. However, the display medium for authenticity determination is not limited to a card, and any medium may be used as long as it is a medium on which the above-described printing is possible. Further, the display medium for authenticity determination according to the present disclosure can be used in all industries such as the manufacture, sale, and use of information display media used for authenticity determination.

[0053] (2-3. Printing mode) The display medium for authenticity determination may be printed with halftone dots or the like instead of the lines printed on the thick line layer 32 and the thin line layer 30 exemplified in the embodiment. That is, as long as the display medium for authenticity determination has a configuration in which a layer having a non-copyable portion (low-density region) and a layer having no non-copyable portion are laminated, any printing mode may be employed, not limited to lines or halftone dots.

[0054] (2-4. Configuration of medium) In the above embodiment, an example is shown in which the authenticity determination unit is formed only on one side of the anti-counterfeiting card 60. However, the anti-counterfeiting card 60 may be configured such that the authenticity determination unit is also exposed on the back surface. For example, the anti-counterfeiting card 60 can form the authenticity determination unit at a desired position on the front or back surface by adopting a configuration in which the respective layers shown in FIG. 4 are laminated on the front and back surfaces with the core material 46 as the center.

[0055] (2-5. Mode of thermochromic ink) In the above embodiment, an ink that becomes transparent at a predetermined temperature is exemplified as the thermochromic ink. However, the thermochromic ink may not only be a transparentizing one, but also have a property that its color changes by heat application.

[0056] (3. Other Embodiments) The processes according to the above-described embodiments may be implemented in various different forms other than the above embodiments.

[0057] For example, among the processes described in the above embodiments, all or part of the processes described as being automatically performed can be manually performed, or all or part of the processes described as being manually performed can be automatically performed by a known method. In addition, the processing procedures, specific names, and information including various data and parameters shown in the above documents and drawings can be arbitrarily changed unless otherwise specified. For example, the various information shown in each figure is not limited to the illustrated information.

[0058] Also, each component of each illustrated device is a functional concept and does not necessarily have to be physically configured as shown. That is, the specific form of the distribution and integration of each device is not limited to that shown, and all or part of it can be functionally or physically distributed and integrated in any unit according to various loads, usage situations, etc.

[0059] Also, the above-described embodiments and modifications can be appropriately combined within a range that does not conflict with the processing content.

[0060] Also, the effects described in this specification are merely examples and are not limiting, and there may be other effects.

[0061] (4. Effects of the Display Medium for Genuine / Fake Determination According to the Present Disclosure) As described above, the authenticity determination display medium according to the present disclosure (the anti-counterfeiting card 60 or the anti-counterfeiting card 80 in the embodiment) has an authenticity determination unit (the authenticity determination unit 62 or the like in the embodiment) for determining the authenticity of the medium. Further, the authenticity determination display medium has a first layer (the fine line layer 30 or the like in the embodiment) having a non-reproducible portion subjected to low-density printing for anti-copying, a second layer (the thick line layer 32 in the embodiment) having no non-reproducible portion, and a layer provided between the first layer and the second layer and including a thermochromic ink layer (the thermochromic ink layer 50 in the embodiment) containing a thermochromic ink that becomes transparent in response to heat application. The authenticity determination unit according to the authenticity determination display medium is formed by removing, with a laser, a non-reproducible portion in the first layer or a part of the second layer that overlaps the non-reproducible portion of the first layer.

[0062] In this way, in the authenticity determination display medium according to the present disclosure, the first layer having a non-reproducible portion and the second layer having a reproducible portion are laminated, and by removing one of them with a laser, the authenticity determination unit is formed. Further, in the authenticity determination display medium, a thermochromic ink layer is provided between the first layer and the second layer, so that the visualization state in the medium can be changed. Thereby, in the authenticity determination display medium, the shape and location of the display for authenticity determination can be freely formed on the card face, and by performing the authenticity determination process using the transparency of the thermochromic ink layer, it is possible to apply a design that has been difficult in the past, such as a solid design.

[0063] In the authenticity determination display medium, the first layer is disposed above the thermochromic ink layer, and the second layer is disposed below the thermochromic ink layer. In this case, the authenticity determination unit is formed by removing, with a laser, a part of the non-reproducible portion in the first layer that corresponds to the authenticity determination unit. Alternatively, in the authenticity determination display medium, the first layer may be disposed below the thermochromic ink layer, and the second layer may be disposed above the thermochromic ink layer. In this case, the authenticity determination unit is formed by removing, with a laser, a part of the second layer that overlaps the non-reproducible portion of the first layer and corresponds to the authenticity determination unit.

[0064] Thus, with respect to the first layer and the second layer, regardless of which is disposed above the temperature-indicating ink layer, the authenticity determination unit can be freely formed in the display medium for authenticity determination according to the present disclosure.

[0065] In addition, in the display medium for authenticity determination, the pattern of the low-density printing in the first layer, the temperature-indicating ink of the temperature-indicating ink layer, and the pattern applied to the second layer may be formed in the same color.

[0066] Thereby, even after the authenticity determination unit is formed by laser removal, the display medium for authenticity determination does not give the user a feeling of change in appearance, so that the aesthetic property can be kept high.

[0067] As described above, the embodiments of the present application have been described in detail with reference to the drawings. However, these are merely examples, and the present invention can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art, starting from the aspects described in the column of the disclosure of the invention.

Explanation of Reference Numerals

[0068] 30 Thin line layer 32 Thick line layer 42 Concealing layer 44 Transparent over-sheet 46 Core material 50 Temperature-indicating ink layer 60 Anti-counterfeiting card

Claims

1. A display medium for authenticity determination having an authenticity determination unit for determining the authenticity of a medium, comprising a first layer having a non-reproducible portion subjected to low-density printing for anti-copying, a second layer having no such non-reproducible portion, and a temperature-indicating ink layer provided between the first layer and the second layer and containing a temperature-indicating ink that becomes transparent in response to heat application. The authenticity determination unit is formed by removing, with a laser, the non-reproducible portion in the first layer or a part of the second layer that overlaps the non-reproducible portion of the first layer. A display medium for authenticity determination, characterized by the above.

2. The first layer is disposed above the temperature-indicating ink layer, and the second layer is disposed below the temperature-indicating ink layer. The authenticity determination unit is formed by removing, with a laser, a part of the non-reproducible portion in the first layer that corresponds to the authenticity determination unit. The display medium for authenticity determination according to Claim 1, characterized by the above.

3. The first layer is disposed below the temperature-indicating ink layer, and the second layer is disposed above the temperature-indicating ink layer. The authenticity determination unit is formed by removing, with a laser, a part of the second layer that overlaps the non-reproducible portion of the first layer and corresponds to the authenticity determination unit. The display medium for authenticity determination according to Claim 1, characterized by the above.

4. The pattern of the low-density printing, the temperature-indicating ink of the temperature-indicating ink layer, and the pattern applied to the second layer are formed in the same color. The display medium for authenticity determination according to Claim 1, characterized by the above.

5. A method for manufacturing a display medium for authenticity determination having an authenticity determination unit for determining the authenticity of a medium, comprising bonding together a first layer having a non-reproducible portion subjected to low-density printing for anti-copying, a second layer having no such non-reproducible portion, and a temperature-indicating ink layer provided between the first layer and the second layer and containing a temperature-indicating ink that becomes transparent in response to heat application. The authenticity determination unit is formed by removing, with a laser, the non-reproducible portion in the first layer or a part of the second layer that overlaps the non-reproducible portion of the first layer. A method for manufacturing a display medium for authenticity determination, characterized by the above.

Images