JP4548720B2 - Identification medium, article provided with identification medium, and optical identification device - Google Patents

Description

  The present invention relates to an identification medium capable of identifying the authenticity (authenticity) of an article by a visual effect.

  For daily necessities and clothing, identification cards and various tickets, fake products that resemble the real thing appear on the market and become a problem. Under such circumstances, there is a need for a technology that can identify the authenticity of an article in order to guarantee performance, reliability, safety, or maintain brand power.

  As a technique for identifying the authenticity of an article, a method of performing printing using a special ink on an article to be identified, or a method of attaching a small piece having special optical reflection characteristics to the article is known.

  The method of printing special ink is to check the authenticity by printing a predetermined character or design using ink that fluoresces against ultraviolet light, and then highlighting the design or character when irradiated with ultraviolet light. Is the method. Also known is a method in which authenticity is identified with a magnetic sensor by applying ink mixed with magnetic particles or magnetic particles.

  As small pieces having optical reflection characteristics, those utilizing optical characteristics exhibited by cholesteric liquid crystals are known. This technique is disclosed in Patent Document 1, for example. A seal having a hologram function is also known.

JP-A-4-14496

  An identification medium using special ink or cholesteric liquid crystal has a risk of being obtained and forging the identification medium. In particular, the level of counterfeit technology has recently increased, and it has become difficult to ensure the authenticity determination function simply by using special ink or cholesteric liquid crystal. This also applies to an identification medium using a hologram.

  An object of the present invention is to provide an identification means that is difficult to forge and has a high authenticity determination function.

  First, the optical characteristics exhibited by the polarizing fiber used in the present invention will be described. FIG. 8 is a conceptual diagram showing an example of the structure of a polarizing fiber used in the present invention. Conceptually, this polarizing fiber has a structure in which a dye (polarized substance) 103 exists along the main chain 102 so as to be entangled with the main chain 102 of the polymer material constituting the fiber 101.

  In this structure, as shown in FIG. 8A, the polarizing fiber 101 is viewed through a polarizing plate 105 that selectively transmits linearly polarized light in the X-axis direction (linearly polarized light having an electric field component 108 in the X-axis direction) 106. Think about the case.

  In this case, the linearly polarized light component in the X-axis direction is selectively reflected from the polarizing fiber 101 that has been irradiated with white light. This is because since the dye 103 extends in the X-axis direction, polarized light in the X-axis direction is efficiently reflected. When the fiber 101 is viewed through the polarizing plate 105, the linearly polarized light 106 in the X-axis direction passes through the polarizing plate 105, so that the fiber 101 can be seen with the color of the dye 103.

  On the other hand, when the fiber 101 is viewed through the polarizing plate 109 that transmits linearly polarized light in the Y-axis direction (linearly polarized light having the electric field component 112 in the Y-axis direction) 110 as shown in FIG. It becomes like this.

  First, the polarizing plate 109 selectively transmits the linearly polarized light component 110 in the Y-axis direction, but does not transmit the linearly polarized light component in the X-axis direction orthogonal thereto. The linearly polarized light component 106 in the X-axis direction is selectively reflected from the polarizing fiber 101 struck with white light, but the reflection of the linearly polarized light component in the Y-axis direction is weak.

  Therefore, when the fiber 101 is observed through the polarizing plate 109, the reflected light from the dye 103 is difficult to transmit through the polarizing plate 109, and thus the fiber 101 looks dark.

  Based on this principle, when the fiber 101 is viewed through the polarizing plate, the appearance of the fiber 101 changes depending on the selection of the polarization direction of the polarizing plate. In the present specification, a fiber having optical characteristics such as the fiber 101 is referred to as a polarizing fiber.

The present invention relates to an identification medium using the principle of the above optical characteristics. That is, in the identification medium of the present invention , two layers of paper materials containing polymer fibers are laminated, and the polymer fibers are added with a direct dye composed of a dichroic organic dye and stretched in the longitudinal direction. In each of the two layers of paper material, the polymer fibers are aligned in the direction of orientation, and a pattern is formed using the distribution region of the oriented polymer fibers, and the pattern is It is a watermark, characterized in that the orientation directions of the polymer fibers in the two-layer paper material are different.

  In the present invention, the above-described polarizing fiber may be distributed as it is on the base material or in the base material, or a woven fabric using this polarizing fiber may be distributed on the base material or in the base material. .

  Since the above-mentioned polarizing fiber selectively reflects only a specific linearly polarized light component, when the plane in which the polarizing fiber is distributed is viewed through the linear polarizing filter, the polarization fiber is polarized by the relative rotation angle between the plane and the polarizing filter. The reflected light from the fibers changes and the visible pattern changes. By using this change, an identification function can be obtained.

  As a method for obtaining the identification function, there is a method of irradiating light through a linear polarizing filter and directly observing it, or further observing through a polarizing plate, in addition to the method described above.

  In the present invention, a paper material is selected as a base material on which a polarizing fiber or a woven fabric cut product is distributed, and the polarized fiber or a woven fabric cut product is incorporated into the paper base material by a paper basket. It is preferable to adopt.

  Examples of the paper material include pulp as in the case of constituting ordinary paper. In addition to pulp, ceramic fibers, organic fibers other than pulp, and materials obtained by mixing organic fibers and inorganic fibers can be used. Of course, the paper material may contain raw materials other than the fibrous material.

  According to this aspect, since the polarizing fiber has a structure in which paper is made in a paper material, an identification medium that is difficult to forge can be obtained. In particular, the optical properties of the polarizing fiber itself are organic and are processed into an extremely thin fiber shape. Therefore, it is difficult to counterfeit those having the same optical properties.

  In addition, when a polarizing fiber is made in the paper structure, a pattern constituted by the polarizing fiber can function as a “watermark”. For example, when this watermark is viewed through a polarizing filter that selectively transmits linearly polarized light, if the polarizing filter and the paper are relatively rotated, the appearance of the pattern due to the polarizing fiber changes.

  That is, when this watermark is viewed through the polarizing filter, the polarizing fiber extended in the direction corresponding to the polarization direction of the polarizing filter shows strong reflection, so that its presence appears to be emphasized. Then, when the polarizing filter is turned, the extension direction of the polarizing fiber that appears to be emphasized changes accordingly. Thereby, the appearance of the polarizing fiber changes. It is possible to determine authenticity by discriminating this difference in appearance by visual recognition or image recognition. This effect can be obtained in the same manner when a cut product obtained by cutting a fabric woven with polarizing fibers is distributed.

  The distribution of the polarizing fiber or the cut fabric of the woven fabric using the polarizing fiber may be distributed in a random direction or may be aligned in a predetermined direction. Here, the orientation of the cut product is grasped as the orientation of the oriented fiber in the fabric constituting the cut product.

  In the state in which the polarizing fiber or the cut material is distributed in a random direction, the first state in which the linear fiber is distributed in a random state, the state in which the fiber is bent without being in a linear state Since these are distributed at random, the second state whose orientation is not uniform when viewed as a whole, and the third state in which these two states are combined are included.

  In the situation where the polarizing fiber or the cut material is distributed in a random direction, when viewed through the polarizing plate, the portion that appears to be emphasized changes depending on the direction of the fiber by turning the polarizing plate, According to the change, the appearance of the pattern formed by the polarizing fiber or the cut material changes.

  At this time, if the pattern is configured using the distribution region of the polarizing fiber or the cut material, the pattern of the fiber in the pattern changes when the polarizing plate is turned.

  In addition to the method of dispersing and holding the polarizing fiber and the cut material in the paper-made material, the present invention includes a polarizing fiber and a cut material (for example, a layer structure such as a pressure-sensitive adhesive layer, an adhesive layer, or a paint layer). A polarizing fiber woven fabric cut product) may be dispersed and held. In addition, a light-transmitting thin plate material such as a PET film can also be used as a base material for distributing the polarizing fiber and the cut material of the woven fabric.

  Resin materials such as PET film are easy to perform any coloration, hologram formation, arbitrary pattern printing, etc., so that the optical action is combined with the optical identification function exhibited by the polarizing fiber to further enhance discrimination Optical function can be obtained. In particular, by using a light-transmitting material that transmits visible light, a “watermark” using a polarizing fiber can be formed.

  The pressure-sensitive adhesive layer or the adhesive layer can be used when fixing to a base material constituting the identification medium itself or when fixing the identification medium to an appropriate article. In particular, when an adhesive layer is used, if the adhesive layer is forcibly peeled off, the adhesive layer peels off or breaks, thereby destroying the pattern or pattern made up of polarizing fibers and cut materials, which is difficult to regenerate. It will be something. This makes it difficult to reuse or illegally use the identification medium.

  The adhesive layer refers to a layer that does not cure and maintains adhesive strength. On the other hand, the adhesive layer refers to a material that hardens after bonding and exhibits an adhesive force, but does not exhibit a function again like an adhesive layer when peeled off once.

  In this invention, it is preferable to set it as the structure by which a predetermined | prescribed pattern is formed using the area | region where the cut material of the textile fabric using a polarizing fiber or a polarizing fiber is distributed at random. According to this aspect, the symbol can be used as an identification target, and a higher authenticity determination function can be obtained. In addition, as a design, a character, some design, a picture, or these combinations can mention.

  Moreover, in this invention, you may comprise a some pattern using the polarizing fiber of a different color. According to this aspect, when the polarizing filter is rotated, it is possible to observe a change in appearance so that different patterns are emphasized. Moreover, you may mix and use the polarizing fiber which colors several different colors.

  The present invention can also be understood as an article provided with the above-described identification medium. The article to be identified is not particularly limited, and examples thereof include an article made of paper such as a passport, a certificate, an important document, a banknote, a gift certificate, an invitation ticket, an admission ticket, and a cash voucher. In addition, cards, clothing, daily necessities, storage media, electrical appliances, machine parts, electronic parts, and other various products can be listed. Moreover, you may utilize this invention for the package and packaging material of these articles | goods. Moreover, you may utilize the identification medium of this invention for the tag, price tag, etc. which are attached to goods.

  The present invention can also be understood as an optical identification device that includes an imaging unit that captures the above-described identification medium and an authenticity determination unit that performs authenticity determination using the captured image. In this case, authenticity determination using an image processing technique can be performed.

  The main polymer of the polarizing fiber used in the present invention is not particularly limited as long as it can be melt-spun. However, as a preferable polymer material, it is preferable to employ a material that is excellent in affinity and transparency with the dye constituting the polarizability-expressing substance and that can be easily melt-spun and stretched.

  Examples of such a polymer include polyesters such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyethylene terephthalate, and polybutylene terephthalate. Among them, the ethylene-vinyl alcohol copolymer can obtain a fiber having a smooth surface by melt spinning, and can use a dichroic direct dye having a low polarization property and a high polarization performance as a polarization developing substance. preferable.

  A polarization-expressing substance is a substance that absorbs light on a vibrating surface in a specific direction when light is incident on the substance and creates polarized light that is polarized in a direction perpendicular to the direction. Examples of the polarization-expressing substance include a direct dye composed of a dichroic organic dye (dichroic direct dye). Examples of the dichroic direct dyes include those selected from azo series, tolidine series, dianisidine series, benzidine series, and stilbel series. These dichroic direct dyes may be used alone or in combination.

  There is an appropriate range for the content of the dichroic direct dye to the polymer. If the concentration of the dichroic direct dye relative to the polymer is low, sufficient polarization characteristics cannot be obtained. On the other hand, if the concentration of the dichroic direct dye relative to the polymer is large, the light transmittance decreases and the contrast between light and darkness decreases. . Considering such a phenomenon, the content of the dichroic direct dye is preferably in the range of 0.02 to 1.0% by weight, particularly 0.05 to 0.8% by weight of the polymer.

  As the cross-sectional structure of the polarizing fiber, various shapes such as a circle, an ellipse, and a flat shape can be adopted. Although the fiber diameter of a polarizing fiber is restrict | limited by the objective, generally it can select from the range of 10 micrometers-several hundred micrometers. The fiber may be monofilament or multifermented.

  As a method of adding a polarizability-expressing substance to the fiber, a method of mixing a polymer and a polarizability-expressing substance in advance before fiberization, or immersing the fiber after fiberization in a solution or dispersion containing the polarizability-expressing substance. There are methods (so-called dyeing) and the like. The former method is preferred for aligning the polarizing expression substance more effectively.

  For spinning, a known melt spinning method can be employed. However, in view of the heat resistance of the polarizability-expressing substance, it is important to perform melting at a temperature as low as possible within the range of its melting point plus 30 ° C. and further shorten the residence time at the time of melting.

  The polarizing fiber obtained by spinning is subjected to a stretching treatment in order to develop polarization characteristics. This stretching temperature is preferably selected from a temperature range of the glass transition temperature (Tg) to Tg + 60 ° C. of the polymer.

  According to the present invention, it is possible to obtain an identification means that is difficult to forge and has a high authenticity determination function. That is, according to the present invention, since the identification medium is configured using the optical function indicated by the polarizing fiber, it is possible to perform authenticity determination using changes in the appearance of the fiber. Since the appearance of the fiber is a unique optical phenomenon, it is difficult to counterfeit and the discrimination ability can be increased. In particular, since the fiber distribution state is difficult to reproduce, an identification medium having a high identification function and difficulty in counterfeiting can be obtained.

1. First Embodiment In the present embodiment, a polarizing fiber exhibiting polarization characteristics is obtained by adding a polarizability-expressing substance to a polymer constituting the fiber and drawing it after spinning. Then, the polarizing fiber is cut into an appropriate length, and is spread into a thin paper and randomly dispersed to obtain a paper having an identification function.

  The polarizing fiber exhibits different optical characteristics for linearly polarized light having an electric field component in the polymer stretching direction (fiber extending direction) and linearly polarized light orthogonal to the linearly polarized light. Therefore, when the paper is viewed through the polarizing plate, the intensity from the polarizing fiber changes depending on the orientation (rotational position) of the polarizing plate, and the appearance of the randomly positioned polarizing fiber changes. A function as an identification medium can be obtained by utilizing this change in appearance.

(Production method of the first embodiment)
(Production method of polarizing fiber)
First, a method for producing a polarizing fiber will be described. Here, an example will be described in which polyester is used as the polymer and dichroic direct dye is used as the polarizing material. First, as a blue dichroic direct dye, 0.2% by weight of trade name “DIRECT DARKGREEN BA” manufactured by Sumitomo Chemical Co., Ltd. was dissolved in ethylene glycol to prepare a green pigment solution.

  Next, Kuraray Co., Ltd. product name Eval Chip “ES-G110A” was dissolved at 180 ° C., and the above dye solution was mixed therein so that the dye concentration in the polymer was 0.3%. The mixture was kneaded with a twin-screw kneader, and the kneaded product was vacuum dried at a temperature of 105 ° C. to obtain green colored polymer chips. As the material, in addition to those described above, a thermoplastic resin such as a polyester resin or a nylon resin can also be used.

  This colored polymer chip was spun from a 6-hole die with a diameter of 0.2 mm at a temperature of 180 ° C. and a winding speed of 500 m / min, and further stretched 2.5 times with a drawing machine having a roller temperature of 70 ° C. and a plate temperature of 120 ° C. And 175 dtex polarizing fiber was obtained. When the polarizing fiber was obtained, it was cut into a length of 15 mm to obtain a fiber piece.

  This fiber had a strength of 3.1 (cN / dtex) and an elongation of 26%. When a plurality of the polarizing fibers are arranged in parallel to obtain a 1 × 1 cm sheet-like molded product and the degree of polarization and transmittance are measured, the degree of polarization is 71% and the transmittance is 41%. The measurement of the degree of polarization is performed in accordance with the polarization degree measurement method of the polarizing plate of EJAJ standard LD-201, and the measurement of the transmittance is for light in the visible light wavelength region. The measurement was performed in accordance with the transmittance measurement method.

(Method for producing identification medium)
Next, a method for producing an identification medium made of paper having a structure in which the above-described polarizing fiber is encased in a paper material will be described. FIG. 1 is a conceptual diagram showing an outline of an apparatus for producing a paper material in which polarizing fibers are randomly inserted. In FIG. 1, a feed roll 11, a take-up roll 12, a paperboard base cloth 13, a first paperboard circular mesh 14, a first slurry container 15, a first pulp solution (first paper raw material slurry) 16, second paper web 17, second slurry container 18, second pulp solution (second paper raw material slurry) 19, peeled intermediate paper material 20, drying device 21, post-processing device A (calendar) 22, a manufactured paper material 23, and a take-up roll 24 on which the obtained paper material 23 is taken up are shown.

  The paperboard base cloth 13 is a blanket-like woven cloth. Paper pulp is performed by thinly attaching the pulp solution to the surface of the paper cloth base cloth 13 in the form of a film. The paper webs 14 and 17 have a drum-like rotatable structure, and have a net structure for attaching a pulp solution to the surface thereof.

  The first pulp solution 16 is purely for paper bottles and is a pulp solution used for ordinary paper bottles. The second pulp solution 19 is a pulp solution obtained by adding the above-described polarizing fiber cut pieces to the first pulp solution 16.

  In the apparatus shown in FIG. 1, the paper base fabric 13 is fed from the feed roll 11 to the take-up roll 12, and at that time, the first paper web 14 and the second paper web 17 are simultaneously rotated. To do. A first pulp solution 16 and a second pulp solution 19 are respectively formed on the surfaces of the first paperboard circular mesh 14 and the second paperboard circular mesh 17 that rotate in accordance with the movement of the paperboard base cloth 13. It adheres and is sequentially copied onto the surface of the paper cloth base cloth 13. In this way, the paper material in the intermediate state that has been paper-cured adheres to the surface of the paper stock base fabric 13 in layers.

  The intermediate paper material adhering to the layer is peeled off from the surface of the base paper cloth 13 at the portion of the take-up roll 12 as indicated by reference numeral 20, transported by the roll transport mechanism, and dried by the drying device 21. A drying process is performed in By performing this drying process, moisture is removed from the paper material 20 in the intermediate state.

  The paper material dried in the drying device 21 is subjected to pressure in a post-processing device (calendar) 22, formed into a predetermined thickness, and subjected to a polishing process. In this way, the paper material 23 in which the pulp material is laminated in two layers is manufactured, and the paper material 23 is wound around the winding roll 24.

Here, the conditions of the above production steps are set so that the thickness of the first layer obtained by the pulp solution 16 is finally 50 μm and the thickness of the second layer obtained by the pulp solution 19 is finally 50 μm. did. The basis weight of the pulp material of the first layer and the second layer is 45 g / m ^2, and the basis weight of the polarizing fiber in the second layer is 0.8 g / m ^2. The solution was adjusted.

  FIG. 2 is a cross-sectional view showing an outline of the obtained paper material having a two-layer structure. FIG. 2 shows a structure in which the first layer 201 and the second layer 202 are stacked. Here, the first layer 201 is a layer made of a normal paper material, and the second layer 202 is a layer in which polarizing fiber pieces are randomly mixed in the paper material constituting the first layer 201.

  The thicknesses of the first layer 201 and the second layer 202 can be arbitrarily selected from the range of about 20 μm to 90 μm, respectively. Moreover, the basic weight of a pulp and the basic weight of a polarizing fiber can be adjusted arbitrarily.

  The paper material having a two-layer structure shown in FIG. 2 is substantially white and has an optical characteristic that allows the polarizing fibers randomly mixed in the second layer 202 to be confirmed when transmitted through a light beam.

  Here, the paper material having a two-layer structure shown in FIG. 2 was cut into an appropriate size, and a test paper using this as a watermark was produced.

(Function of the embodiment)
FIG. 3 is a perspective view showing an outline of the test sheet and a conceptual diagram for explaining a state of appearance. FIG. 3A is a perspective view showing an outline of the test paper, FIG. 3B is a conceptual diagram illustrating how the watermark portion is seen, and FIGS. 3C and 3D are views. It is a conceptual diagram explaining how to look when visually observed through a polarizing plate.

  FIG. 3 shows an identification medium 301 having a “watermark” 302. The identification medium 301 shown in FIG. 3 is formed by cutting the paper material having the two-layer structure shown in FIG. 2 into a square, and further removing the first layer (ordinary paper material) into a square shape at the center. In the structure, the second layer (the layer in which the polarizing fiber is inserted) is exposed on the front and back sides.

  When the identification medium 301 shown in FIG. 3 is directly observed visually from the first layer 201 side under natural light, a “watermark” 302 constituted by the second layer can be observed. When this “watermark” 302 is directly viewed, the randomly distributed green polarizing fibers 303 can be observed as conceptually shown in FIG.

  Here, when a polarizing plate that selectively transmits linearly polarized light in a predetermined direction is inserted between the eyes and the identification medium 301 and observation is performed through the polarizing plate, as shown in FIG. The specific direction component of the polarizing fiber 303 appears to be emphasized. That is, the portion of the polarizing fiber 303 that extends in a predetermined direction (a direction that matches the polarization direction in FIG. 3C) is emphasized and looks thick, and then the polarizing fiber has a component (cosine component) in this predetermined direction. The part 303 looks a little thick. The portion of the polarizing fiber 303 extending in a direction perpendicular to the predetermined direction is weakly reflected and appears thin.

  According to this optical function, by rotating the polarizing plate, the highlighted portion of the polarizing fiber changes continuously as shown in (D). That is, it is observed that the pattern formed by the polarizing fibers changes as the polarizing plate rotates. By utilizing this fact, an authenticity determination function can be obtained.

  As a method for obtaining the above-described function, light may be irradiated through a polarizing plate, and the irradiated state may be observed. That is, the polarization fiber may be irradiated with linearly polarized light in a predetermined polarization state. Also in this case, by rotating the polarizing plate, the appearance of the polarizing fiber changes, and it can be observed as a pattern change.

  Further, for example, when the “watermark” 302 is held over sunlight and further viewed through the polarizing plate, it is possible to observe a state in which the appearance of the polarizing fiber 303 varies greatly depending on the direction of the polarizing plate. This is because the linearly polarized light component in the predetermined direction in the predetermined wavelength band contained in the sunlight is selectively reflected by the polarizing fiber 303, so that the reflected component contributes to the appearance of the reflected light depending on the orientation of the polarizing plate. This is because a difference appears in

  The “watermark” using the present invention exemplified above has an advantage of showing an optical function different from the “watermark” conventionally used for bills and the like.

  Here, an example of a method of transmitting light and observing the transmitted light (that is, a method of using as a “watermark”) has been described as one method of using a paper material into which a polarizing fiber is inserted as an identification means. In addition to the method using transmitted light, there is a method using reflected light. For example, in the paper material having a two-layer structure shown in FIG. 2, the first layer (ordinary paper layer) is placed behind and the second layer (the layer in which the polarizing fiber is inserted) is observed. When the reflected light is observed, the same discrimination effect as that of the “watermark” can be obtained.

2. Second Embodiment An appropriate symbol may be formed using the “watermark” exemplified in the first embodiment. In this way, the symbol is constituted by the “watermark”. For example, when the symbol is observed through the polarizing plate, the appearance of the symbol changes by turning the polarizing plate. By using this change, it is possible to identify authentication or the like.

  In this aspect, a layer of a normal paper material may be disposed on the base other than the watermark, and the transmitted light may be observed in the watermark portion and the reflected light may be observed in other portions. In this way, it is possible to observe more complicated changes in the design.

3. Third Embodiment Polarizing fibers may be oriented and distributed in paper. In this case, in the observation using the polarizing plate, there is a significant difference in the appearance of the polarizing fiber, so that the distinguishability can be further increased. As a method for orienting the polarizing fiber into the paper, a method using a long net can be mentioned. Hereinafter, a method using this long network will be described.

  FIG. 4 is a conceptual diagram showing an outline of an apparatus for producing a paper material in which polarizing fibers are oriented and inserted. In FIG. 4, a feed roll 401, a take-up roll 402, a belt-like net member (long net) 403, a pulp solution dropping nozzle 404, a pulp solution supply pipe 405, an intermediate paper material 406, a drying device 407, a post-treatment Shown is apparatus 408, manufactured paper material 409, and take-up roll 410 on which the resulting paper material 409 is wound.

  Here, from the pulp solution supply pipe 405, a normal pulp solution for pulp is mixed with polarized fiber cut pieces.

  In this apparatus, while the belt-shaped net member 403 fed from the feed roll 401 is being conveyed to the take-up roll 402, the pulp solution is placed on the belt-shaped net member 403 in a moving state from the pulp solution dropping nozzle 404. Is dropped. At this time, since the belt-shaped net member 403 moves in one direction, the paper material in an intermediate state in which the axial directions of the polarizing fibers are aligned to some extent in the direction along the moving direction adheres on the net member 403. .

  The adhered intermediate paper material is peeled off from the mesh member 403 at the portion of the take-up roll 402 as indicated by reference numeral 406. The peeled intermediate paper material 406 is dried by a drying device 407 and further processed into a paper material 409 by a post-processing device 408. Then, the obtained paper material 409 is taken up by a take-up roll 410. In this way, it is possible to obtain a paper in which the polarizing fibers are wound in an oriented state.

  When this method is used, it is possible to obtain a state in which the transparent fibers are aligned in an orientation state in which the directions of the polarizing fibers are aligned in one direction. In addition, by applying this method, an identification medium in which polarizing fibers are oriented in two directions can be obtained as described below. This example will be described below.

  First, a paper material in which the polarizing fibers are oriented in one direction is prepared by the above-described method, and the paper material is cut into a quadrilateral. Two pieces of the cut pieces are prepared and bonded together with the orientation directions different by 90 °. By doing so, it is possible to obtain a paper material in which polarizing fibers are oriented in two orthogonal directions.

  FIG. 5 is a conceptual diagram showing how the paper is inserted as a “watermark” when the polarization fibers are aligned (orientated). In FIG. 5, when the test specimen is viewed over white light, (A) is directly viewed, (B) is through a polarizing plate that selectively transmits the electric field component in the X-axis direction in the figure. (C) conceptually shows the state when viewed through a polarizing plate that selectively transmits the electric field component in the Y-axis direction in the figure.

  FIG. 5 conceptually simplifies the state in which the polarizing fibers 502 oriented in the X-axis and the polarizing fibers 503 oriented in the Y-axis direction are distributed in the “watermark” 501 for the sake of simplicity. It is shown.

  When the “watermark” 501 is viewed directly, the polarizing fibers 502 and 503 can be observed as they are as shown in FIG. When the “watermark” 501 is viewed through a polarizing plate that selectively transmits the electric field component in the X-axis direction, the reflected light from the polarizing fiber 502 extended in the X-axis direction is relatively as shown in FIG. The reflected light from the polarizing fiber 503 extending in the Y-axis direction appears weak. In other words, the X-axis oriented polarizing fiber 502 appears to float relatively more than the case of (A), and conversely the Y-axis oriented polarizing fiber 503 appears weaker.

  The reason why the reflected light from the polarizing fiber 502 extending in the X-axis direction looks relatively strong is that components other than linearly polarized light (X-axis polarized light) having an electric field component in the X-axis direction are blocked by the polarizing plate. This is because the portions other than the portion of the polarizing fiber 502 extending in the axial direction appear relatively dark, whereby the polarizing fiber 502 extending in the X-axis direction can be recognized relatively strongly.

  When the “watermark” 501 is viewed through a polarizing plate that selectively transmits the electric field component in the Y-axis direction, as shown in (C), it extends in the Y-axis direction, contrary to the case of (B). The reflected light from the polarizing fiber 503 appears relatively strong, and the reflected light from the polarizing fiber 502 extended in the X-axis direction appears weak.

  Thus, depending on the presence or absence of the polarizing plate and the angle of the polarizing plate, the pattern formed by the polarizing fiber changes, and identification can be performed using this change.

  As an application example of this aspect, an aspect in which a pattern is configured using a distribution region of oriented polarizing fibers can be cited. In this aspect, when the design is viewed through the polarizing plate, it is possible to select a case where the design looks emphasized and a case where the design is difficult to see by rotating the polarizing plate. That is, it is possible to obtain an optical function in which the pattern appears to be raised depending on the angle of the polarizing plate, or vice versa. By using this optical function, it is possible to easily determine the authenticity. In addition, although it is not clear by direct view, an identification function can be realized in which a predetermined pattern emerges when observed through a polarizing plate.

4). Fourth Embodiment Hereinafter, an example of an identification medium functioning as a seal using the present invention will be described. FIG. 6 is a cross-sectional view schematically showing a cross-sectional structure of an identification medium that functions as a seal. Hereinafter, an outline of a manufacturing process of the present embodiment will be described.

  First, a separator (release paper) 601 is prepared, an adhesive is applied thereon, and an adhesive layer 602 is formed. Next, the polarizing fiber is dispersed on the exposed surface of the adhesive layer 602, and the polarizing fiber 603 is fixed to the surface using the adhesive force of the adhesive layer 602. At this time, a predetermined pattern may be formed using a range in which the polarizing fibers 603 are dispersed. In this way, the state shown in FIG.

  Next, the PET film 604 is bonded to the surface of the adhesive layer 602 on the side where the polarizing fiber 603 is fixed. In this way, an identification medium including a separator 601, an adhesive layer 602, a polarizing fiber 603 on the surface of the adhesive layer, and a PET film 604 in a state in which the polarizing fiber 603 is pressed against the adhesive layer 602 as shown in FIG. 6B is obtained. be able to.

  This identification medium can peel the separator 601 and affix the exposed adhesive layer 601 to an appropriate member. When this identification medium is observed from the PET film 604 side, the polarizing fiber 603 can be observed through the PET film.

  For example, in the case where a red color is used as the polarizing fiber and a black material is selected as the adhesive layer 601, when the polarizing filter is rotated when the identification medium is observed through the polarizing filter, the polarizing fiber 603 is obtained. The red pattern constituted by appears to change according to the rotation of the polarizing filter.

  Further, by coloring the adhesive layer 601 to a color other than red, it is possible to obtain an optical characteristic in which a red fiber pattern changes in accordance with the rotation of the polarizing filter in a predetermined background color.

  This aspect is convenient because the identification medium can be used as a seal. In addition, by adjusting the adhesive strength of the adhesive layer 602, a configuration is realized in which the PET film 604 is peeled off and the design and pattern of the polarizing fiber 603 are destroyed when the one pasted is to be peeled off. be able to. In this way, an identification medium that is difficult to reuse can be obtained.

5. Fifth Embodiment The present embodiment relates to a configuration in which an ultraviolet curable resin layer in which polarizing fibers are mixed is provided on the surface of a light transmissive resin film. First, an OPP film (biaxially stretched polypropylene film) is prepared as a light transmissive resin film, and an ultraviolet curable resin mixed with polarizing fibers is applied to one surface thereof.

  Then, the polarizing fiber is fixed on the OPP film by irradiating ultraviolet rays and curing the ultraviolet curable resin. In this way, an identification medium having a resin layer in which the polarizing fibers are distributed and fixed on the light-transmitting resin film can be obtained.

  In this aspect, by using a transparent or predetermined color as the ultraviolet curable resin, a combination of colors with the color of the polarizing fiber can be arbitrarily selected.

6). Sixth Embodiment As an identification method using a polarizing fiber, a configuration in which the color of the polarizing fiber is the same as the color of the background can be mentioned. In this case, when the polarizing plate is rotated in the state observed through the polarizing plate, the color of the background does not change, but the polarization of the portion where the relationship in which the extending direction of the polarizing fiber and the polarizing plate are perpendicular is established. The reflection from the fiber becomes weak and this part is observed in gray. When the polarizing plate is rotated, this gray part appears and disappears one after another. Moreover, since it is difficult to see the polarizing fiber when directly observed, it is possible to observe the difference in appearance depending on the presence or absence of the polarizing filter.

7). Seventh Embodiment In the examples described in the present specification, two or more types of polarizing fibers having different colors may be used. In this case, (1) these fibers are mixed, (2) the symbols are used separately, (3) the mixing ratio is controlled to give a predetermined color, and (4) the colors are combined with these methods. A method of giving a design can be selected.

  By combining a plurality of colors, the identification ability can be enhanced. In addition, by realizing a delicate hue, it is possible to provide an identification medium having a high anti-counterfeit ability.

8). Eighth Embodiment In the example described in the present specification, a woven fabric woven with a polarizing fiber may be cut into an elongated shape instead of the polarizing fiber. In this case, the cut piece exhibits the same function as the polarizing fiber.

9. Ninth Embodiment An identification medium using the present invention can be automatically identified by image recognition in addition to a method of identifying by observation through a polarizing filter or observation by irradiating polarized light.

  FIG. 7 is a conceptual diagram showing an example of an apparatus for determining the authenticity of an identification medium using the present invention. FIG. 7 shows an authenticity determination device 801 including a stage 802, an authenticity determination target article 803, a visible light irradiation device 804, a camera 805, a polarizing filter 806, a determination unit 807, a memory 808, and an output unit 809. .

  The stage 802 is a stage on which the authenticity determination target article 803 is placed. The authenticity determination target article 803 is, for example, an identification card to which an identification medium shown in FIGS. 2 and 6 is attached. The polarizing filter 806 has a function of selectively transmitting predetermined linearly polarized light. The determination unit 807 has a function of analyzing an image captured by the camera 805 and determining authenticity. The memory 808 is a storage unit that stores data referred to in the determination process performed in the determination unit 807.

  The output unit 809 is an information output unit that displays the result of the determination process performed by the determination unit 807. As the output unit 809, a display or an alarm buzzer can be employed.

  Hereinafter, an example of the operation of the authenticity determination device 801 will be specifically described. Here, an example in which authentication determination processing is performed on the identification medium shown in FIG. 2 will be described.

  First, in advance, an image of a pattern indicated by the identification medium at a plurality of predetermined rotation angles of the polarizing filter 806 is stored in the memory 808 in advance.

  For authenticity determination, the authenticity determination target article 803 is placed on the stage 802. Then, the visible light irradiation device 804 emits white light, and an identification medium (not shown) on the authenticity determination target article 803 is imaged by the camera 805. This imaging is performed at every predetermined rotation angle of the polarizing filter 806.

  The determination unit 807 compares the image captured by the camera 805 with the image stored in the memory 808, and determines that the authenticity determination is genuine if it is within the allowable level range even if the same or different. Otherwise, it is determined as a freight. This determination result is displayed on the output unit 809.

  In this embodiment, an image captured by the camera 805 can be displayed on the output unit, and visual confirmation can be used together.

  The present invention can be applied to an identification medium capable of performing authenticity determination by visual observation or image processing.

It is a conceptual diagram which shows the outline | summary of the apparatus which produces the paper material which penetrated the polarizing fiber at random. It is sectional drawing which shows the outline | summary of the paper material of the two-layer structure using invention. FIG. 5 is a perspective view illustrating an outline of a test sheet using the invention and a conceptual diagram illustrating a state of appearance. It is a conceptual diagram which shows the outline | summary of the apparatus which produces the paper material which orientated and polarized fiber. It is a conceptual diagram which shows how it looks at the time of using as a "watermark" the paper rolled in in the state (orientated state) in which the direction of the polarizing fiber was uniform. It is sectional drawing which shows the outline of the cross-section of the identification medium using the invention which functions as a seal | sticker. It is a conceptual diagram which shows an example of the apparatus which performs the authenticity determination of the identification medium using this invention. It is a conceptual diagram which shows an example of the structure of the polarizing fiber utilized by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Fiber (polarizing fiber), 102 ... Main chain of polymer material, 103 ... Dye (polarization expressing substance), 105 ... Polarizing plate, 106 ... Linearly polarized light in X-axis direction, 108 ... Electric field component in X-axis direction, 109 DESCRIPTION OF SYMBOLS ... Polarizing plate, 110 ... Linearly polarized light in the Y-axis direction, 112 ... Electric field component in the Y-axis direction, 11 ... Sending roll, 12 ... Winding roll, 13 ... Base cloth for paper basket, 14 ... First paper board , 15 ... 1st slurry container, 16 ... 1st pulp solution (1st paper raw material slurry), 17 ... 2nd net for paper baskets, 18 ... 2nd slurry container, 19 ... 2nd pulp solution (Second paper raw material slurry), 20 ... paper material in an intermediate state, 21 ... drying device, 22 ... post-treatment device, 23 ... produced paper material, 24 ... winding roll on which the paper material 23 is wound, 406 ... paper material produced, 407 ... drying device, 408 ... Processing device 409 ... manufactured paper material 410 ... take-up roll around which paper material 409 is wound, 201 ... first layer of paper, 202 ... second layer of paper, 301 ... identification medium, 302 ... watermark, 303 DESCRIPTION OF SYMBOLS: Polarizing fiber, 401 ... Sending out roll, 402 ... Winding roll, 403 ... Belt-like net member (long mesh), 404 ... Pulp solution dropping nozzle, 405 ... Pulp solution supply pipe, 501 ... Watermark, 502 ... Oriented Polarizing fiber, 503... Oriented polarizing fiber, 601. Separator (release paper), 602... Adhesive layer, 603... Polarizing fiber, 604... PET film, 801. ... Visible light irradiation device, 805 ... Camera, 806 ... Polarizing filter, 807 ... Determination part, 808 ... Memory, 809 ... Output part.

Claims (3)

  Two layers of paper material containing polymer fibers are laminated,
  The polymer fiber is added with a direct dye composed of a dichroic organic pigment and stretched in the longitudinal direction.
In each of the two layers of paper material, the polymer fibers are aligned in the direction of orientation, and a pattern is constructed using the distribution region of the oriented polymer fibers,
The design is a watermark,
An identification medium, wherein the orientation directions of the polymer fibers in the two-layer paper material are different. An article comprising the identification medium according to claim 1 . Imaging means for imaging the identification medium according to claim 1 ;
An optical discriminating apparatus comprising: an authenticity determining unit that performs authenticity determination using the captured image.

Images