JP2005032124A - Confidential symbol, authentication means, article using the same, authentication method and authentication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a symbol difficult to copy and excellent in confidentiality, thereby obtaining an authentication means difficult be forged. <P>SOLUTION: There are provided a confidential symbol in which a plurality of light emitting parts (1) which emit light upon irradiation of an electromagnetic wave are arranged to form a cipher, and the light emitting parts are constituted of a bar-like body having a long side (a) which is longer than the light emission wave length and a short side (b) which is shorter than the light emission wave length; an authentication means having an authentication region in which a light emitting region having the plurality of the light emitting parts arranged in parallel are arranged in one or more places; an article having the authentication means; an authentication method which detects the light emission of the light emitting parts via a straight polarizer by irradiating the authentication means with a non-polarized electromagnetic wave or detects the light emission of the light emitting parts by irradiating the authentication means with the electromagnetic wave as straight polarized light; and an authentication device comprising a light source which irradiates the authentication means with a non-polarized electromagnetic wave and a light receiving part which detects the light emission of the light emitting parts via a straight polarizer, or a light source which irradiates the authentication means with the electromagnetic wave as straight polarized light and a light receiving part which detects the light emission of the light emitting parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a covert sign, authentication means, an article used therefor, an authentication method thereof, and an authentication apparatus that are difficult to forge and are suitable for various articles such as cards.

Credit cards and the like have been reported to increase damage caused by counterfeit cards, and authentication means that are difficult to counterfeit are required. Conventionally, as an authentication means for confirming the authenticity of a credit card or an ID card, a magnetic recording, a hologram image, a latent image formed on a retardation film on a reflection layer, or an azimuth angle of an optical axis of a retardation layer is used. What changed and formed a latent image was known. The latent image provided on the retardation layer is irradiated with polarized light and observed through a polarizer.
US Pat. No. 5,393,099 US Pat. No. 5,547,790 JP 2001-232978 A Special table 2001-525080 gazette

  However, in hologram images formed by providing a highly reflective metal thin film made of aluminum or the like on the micron-order unevenness, the uneven pattern can be visually observed, and it is easy to manufacture a counterfeit product with a cutting device, and is easily forged There was a point.

  Also, in the method of providing a latent image on a retardation film, it is difficult to make a sharp boundary of a strain or to form a fine pattern because the retardation of the film is based on a deviation in the orientation of the polymer. There is a problem that it can be easily formed by processing or the like and easily forged.

  Furthermore, even in a latent image in which the azimuth angle of the optical axis of the retardation layer is changed, the polarization state can be easily analyzed simply by examining the change in light intensity by rotating the polarizing plate that observes it. There was a problem that it could be easily duplicated and easily counterfeited simply by irradiating with ultraviolet rays.

  On the other hand, a barcode formed by forming an absorption / non-absorption pattern of light with an array of millimeter-order bars is not suitable for applications requiring security because the pattern can be easily recognized visually. In some cases, the current one-dimensional bar code has a problem that it cannot cope with an increase in the number of recorded information such as the number of conferences and varieties.

  In view of the above, an object of the present invention is to obtain a sign that is difficult to counterfeit and has excellent concealment, and that is difficult to forge.

  In the present invention, a plurality of light emitting portions that emit light upon irradiation with electromagnetic waves from the outside are arranged to form a code, and the light emitting portions are longer than the light emission wavelength and shorter than the light emission wavelength based on the planar shape. An authentication unit having a secret symbol formed of a rod-like body having a short side, and an authentication region in which a plurality of the light emitting units are arranged in parallel on the long side and arranged in one place or two or more places; An article having the authentication means is also provided.

  Further, the present invention irradiates the authentication means with a non-polarized electromagnetic wave and detects the light emission of the light emitting part forming the authentication means via a linear polarizer, or irradiates the authentication means with the electromagnetic wave as linearly polarized light. An authentication method for detecting light emission of the light emitting unit, a light source for irradiating the authentication unit with non-polarized electromagnetic waves, and a light receiving unit for detecting light emission of the light emitting unit forming the authentication unit via a linear polarizer There is provided an authentication device including at least an authentication device, and a light source that irradiates the authentication unit with electromagnetic waves as linearly polarized light, and a light receiving unit that detects light emitted from a light emitting unit forming the authentication unit.

  The light emitting part emits light when irradiated with electromagnetic waves such as ultraviolet rays and visible light, and the light emission is linearly polarized light having a vibration surface in the long side direction even when irradiated with non-polarized electromagnetic waves based on the shape characteristics of the light emitting part. When observed without a polarizer, the linearly polarized light is visually recognized as uniform light emission, and when observed through the polarizer, a difference in brightness is visually recognized depending on the direction of polarization.

  In addition, when the electromagnetic wave is irradiated as linearly polarized light, the light emission intensity (brightness) visually changes depending on the direction of the polarized light. Depending on the crossing angle formed by the vibration direction of the electromagnetic wave and the long side direction of the light emitter, for example, the crossing angle A combination of 0 degrees and 90 degrees can create a light emission / non-light emission state.

  According to the light emitting section, by arranging a plurality of the light emitting portions with different long side directions, combinations having different polarization vibration directions can be formed, and a pattern based on a difference in brightness of polarized light emission can be formed. In that case, since the short side of the light emitting part is shorter than the emission wavelength, the formation of the light emitting element requires submicron-order fine patterning to limit counterfeiting, and it is difficult to recognize individual light emitting parts with the naked eye. The whole is recognized as a homogeneous light emitter, and the light emission pattern is also difficult to recognize and the pattern is difficult to analyze, making it difficult to imitate.

  Further, according to the above-described light emitting portion, light having different wavelengths can be selected by selecting the forming material and the irradiation electromagnetic wave, the irradiation electromagnetic wave and the emission wavelength are concealed, and the emission wavelength and the emission wavelength are different. It is possible to form a code or the like based on the difference in wavelength by laminating the portions, and to form a highly confidential symbol by devising the arrangement of the light emitting portion and the light emitting pattern, and it is difficult to imitate or duplicate.

  Furthermore, in the above-described lamination method, information can be recorded in multiple layers in the same plane, and the information recording amount is excellent. In addition, the change in polarization direction can also be used as information in the bar code system, and the information recording capacity can be greatly increased compared to the conventional binary recording bar code.

  The covert sign according to the present invention is a code formed by arranging a plurality of light emitting portions that emit light upon irradiation with electromagnetic waves from the outside. An example thereof is shown in FIG. FIG. 1 is an enlarged plan view of an example of a light emitting region 10 that forms an authentication means, where 1 is a light emitting portion and 2 is a non-light emitting portion. As is apparent from the figure, the light emitting section 1 is formed of a rod-like body 1 having a long side a longer than the emission wavelength and a short side b shorter than the emission wavelength based on the planar shape. As a result, light can be emitted as linearly polarized light having a vibration surface in the long side direction.

  The light-emitting portion can be formed using one or two or more suitable light-emitting materials that emit light when irradiated with electromagnetic waves from the outside, and the material is not particularly limited. In particular, a material that emits light energy such as fluorescence or phosphorescence when excited by irradiation with ultraviolet rays or visible light, particularly a material that emits light having a visible light region, particularly a central wavelength in the range of 390 to 700 nm, is preferably used.

  Incidentally, examples of the light-emitting material include terphenyl, quaterphenyl, polyphenylene 1,7H-benzimidazo (2,1-a) benz (de) isoquinolin-7-one (BBQ), Oxazoles and oxalates such as 2- (4-biphenylyl) -5-phenyl-1,3,4-oxadiazole (PBD) and 1,4-bis (5-phenyloxazol-2-yl) benzene (POPOP) And diazole derivatives.

  Further, 7-hydroxycoumarin, 7-hydroxy-4-methylcoumarin (4-MC), 7-diethylamino-4-methylcoumarin (DAMC), coumarin derivatives such as coumarin 120, quinolinol derivatives, phthalocyanine derivatives, fluorene and derivatives thereof, Anthracene and derivatives thereof are also examples of the light-emitting material.

  Furthermore, xanthene (pyronine, rhodamine, and fluorescein) dyes such as rhodamine 6G and rhodamine 110, oxazine dyes such as cresyl violet and oxazine 1, stilbene dyes such as trans-4,4′-diphenylstilbene, cyanine Examples of the light-emitting material include dyes, polyacetylene compounds, phenylene vinylene compounds, phenylene ethynylene compounds, five-membered and six-membered heterocyclic compounds, and the like.

  The above-mentioned luminescent material can be preferably used in a method of dispersing in a matrix made of a polymer, for example, and applying it to a supporting substrate such as cards or a sticker. The amount of the luminescent material used can be appropriately determined, but is generally 1 to 500 parts by weight, especially 5 to 250 parts by weight, especially 10 to 100 parts by weight per 100 parts by weight of the matrix polymer. When the luminescent material is used at a high concentration, concentration quenching may occur, and if necessary, it may be dispersed in the matrix polymer as a dendrimer having the luminescent material as a core.

  As the matrix polymer, one or more suitable ones can be used, and the type of the polymer is not particularly limited. In particular, those that are excellent in transparency to electromagnetic waves to be irradiated are preferable. Examples thereof include polymethyl methacrylate and polyacrylate, polycarbonate and polyvinyl alcohol, polyvinyl pyrrolidone and hydroxyethyl cellulose, cellulose acetate butyrate and cellulose propionate.

  Polyvinyl chloride, polyethylene terephthalate, poly α-naphthalene methacrylate, polyvinyl naphthalene, poly n-butyl methacrylate, polycyclohexyl methacrylate, poly (4-methylpentene), epoxy resin, polysulfone, polyethersulfone, polyetherketone, polyarylate Polyamide, polyimide, polyetherimide, polyethersulfone, polyacrylonitrile, and polyethylene are also examples of the matrix polymer.

  Further, hydrogenated products and copolymers of polycyclopentadiene, hydrogenated products and copolymers of polycyclohexadiene, styrene / maleic anhydride copolymers, styrene / acrylonitrile copolymers, tetrafluoroethylene / hexafluoropropylene copolymers Polymers, benzocyclobutane copolymers, derivatives thereof, and the like are also examples of the matrix polymer.

  On the other hand, the light emitting material may be made of a polymer. Incidentally, examples include polyparaphenylene derivatives, polythiophene derivatives, polyacetylene derivatives, polyvinylcarbazole derivatives, polyfluorene derivatives, polysilane derivatives, and the like. The light-emitting material made of a polymer can be preferably used, for example, by a method of coating a support substrate such as a card or a sticker seal as a solution in a solvent.

The light emitting material may be made of an inorganic substance. By the way, as an example, Ca ₁₀ (PO ₄ ) ₆ (F, Cl) ₂ : Sb, Mn, BaMg ₂ Al ₁₆ O ₂₇ : Eu, CeMgAl ₁₁ O ₁₉ : Tb, Y ₂ O ₃ : Eu, Y (V , P) O ₄ : Eu and Zn ₂ SiO ₄ : Mn. A luminescent material made of an inorganic substance can be preferably used in a method of coating an inorganic substance on a support substrate such as a card or a sticking seal by a thin film forming method such as a vacuum deposition method or a sputtering method.

  For example, the light emitting part is formed by partially removing a coating film or a coating film made of a light emitting material provided on a support substrate by an ablation processing method using a laser beam or a photolithography method, so that the light emitting portion is longer than the emission wavelength. It can be performed by a method of patterning by processing into a state of a rod-like body having a long long side and a short side shorter than the emission wavelength. For the patterning, a mask on which a processing pattern is formed may be used as necessary. In laser light irradiation and photolithography exposure, the irradiation width of the irradiation light can be reduced through a lens or the like as necessary.

  The long side length of the light emitting portion formed of the rod-shaped body formed by the patterning is set to be 2 times or more, particularly 3 times or more, particularly 5 times or more of the wavelength λ emitted by irradiation with electromagnetic waves. It is more preferable than this point. The upper limit of the long side length is arbitrary and can be appropriately determined depending on the size of the application target such as cards and the like, and may be a length of about 1 to 20 mm. In general, an increase in the amount of information per unit area is increased. For example, it is 500 μm or less, in particular 100 μm or less, particularly 10 μm or less.

  The short side length of the light emitting part is 0.05 to 0.8 times, particularly 0.1 to 0.6 times, especially 0.2 to 0. It is preferable to make it 4 times. The thickness of the light emitting part is generally 10 nm to 10 μm, in particular 30 nm to 5 μm, particularly 60 nm to 1 μm.

  The covert sign can be formed as a code formed by arbitrarily arranging a plurality of light emitting portions. Incidentally, in the example of FIG. 1, the light emitting portions 1 are arranged in parallel in the horizontal direction of the short side direction, and are also arranged in the vertical direction of the long side direction to form the light emitting region 10. Accordingly, the light emitting units are arranged in a discontinuous state.

  When arranging light emitting parts of the same type that exhibit the same emission wavelength under the same electromagnetic wave irradiation, the nearest light emission is used in order to clarify the difference in the polarization characteristics etc. of linearly polarized light emitted by clarifying the separation of each light emitting part. It is preferable to provide an interval of more than the emission wavelength, especially 1.5 times or more of the emission wavelength, especially 2 times or more of the intervals. If the interval, particularly the interval in the short side direction of the light emitting part is too narrow, it becomes difficult to clearly form the boundary of the light emitting part, and the polarization degree of light emission may be lowered.

  On the other hand, when a plurality of light emitting portions are arranged in the same direction and each light emitting portion forms a region (light emitting region) that emits linearly polarized light in the same vibration direction, uniform light emission in that region, that is, light emission The distance between the light emitting portions in the same light emitting region is preferably 100 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less, in order to prevent the light emission from being sparse due to the interval between the portions being too wide. The formation of the light emitting region is advantageous for improving the detection accuracy of the light emission characteristics by increasing the polarization degree and light emission intensity of linearly polarized light.

  The arrangement form of the plurality of light emitting sections, and thus the encryption form, is arbitrary as described above, and is an appropriate encryption formed by arranging the light emitting sections in one or more directions of vertical, horizontal, diagonal or thickness. be able to. Incidentally, as an example of the arrangement, a plurality of light emitting units 1 are arranged in parallel with the short side direction and / or the long side direction of the light emitting unit as shown in FIG. , Different ring shapes, ring shapes, polygonal shapes, waveform shapes, other graphic forms, various character forms, other symbol forms, etc. Good.

  Further, the light emitting part is in an arrangement form in which two layers or three or more layers are laminated, that is, an arrangement form in which two or more layers of the same or different kinds of light emitting parts are overlapped with the same or different dimensions in the thickness direction. Also good. The superimposition may be in a state where the upper layer covers the entire lower-layer light-emitting portion, or in a state where the upper and lower layers partially overlap, and the upper layer may be in a state of being overlapped with the long side of the lower-layer light-emitting portion. The long sides of the light emitting units may be parallel or may intersect.

  The covert sign may be formed by an arrangement of a plurality of light emitting portions having different light emission wavelengths. The arrangement form may conform to the above. In particular, when the combination of the light emitting portions for emitting light and the light emitting portions that differ from each other, that is, the combination of the light emitting portions that can clearly distinguish these wavelengths, even in the case of the above-described stacked arrangement, The light emission / non-light emission of each light emitting unit can be controlled, the amount of information recorded by multilayer recording can be increased, and the difficulty of copying and the confidentiality of information can be enhanced.

  Light emission having different wavelengths can be distinguished by being separated by, for example, a filter or a dichroic mirror showing selective transmission of wavelengths. A combination of light emitting portions having different irradiation wavelengths and emission wavelengths can be achieved by selecting a light emitting material. In this case, the difference in emission wavelengths can also be used for forming information. In a combination of light emitting portions having different irradiation wavelengths and emission wavelengths, it is advantageous for increasing the amount of information recording to have a combination of light emitting portions in which the irradiation (absorption) wavelength region and the light emission wavelength region are as narrow as possible.

  The above-described arrangement form may be achieved in units of light emitting units, or may be achieved in a plurality of arrangements in units of the above-described light emitting regions. That is, the light emitting region is a region in which a plurality of light emitting units are arranged in the same direction and each light emitting unit emits linearly polarized light having the same vibration direction, and the vertical, horizontal, diagonal, or thickness of the light emitting region is a unit. Or the arrangement | positioning form mentioned above may be achieved based on arrangement | positioning of two or more directions.

  The covert symbol with the light emitting region as a unit improves the luminance by summing up the light emitted by the linearly polarized light in the same vibration direction by the light emitting units in the region, and obtains bright light emission to improve the symbol detection accuracy. The size of the light emitting area is arbitrary, and can be appropriately determined depending on the size of the application target such as cards. In general, the size of the light emitting region in which light emitting portions of 2 to 10,000, especially 5 to 1,000, particularly 10 to 100, are present.

  Therefore, the covert symbol can be formed as a bar code in which the light emitting portions or light emitting regions are arranged in one or more directions of vertical, horizontal, diagonal, or thickness. The barcode has a light emitting part or light emitting area arranged in one direction of length, width, diagonal or thickness, and the light emitting part or light emitting area is in two or more directions of vertical, horizontal, diagonal or thickness. It can be in the form of an array.

  Incidentally, in the example of FIG. 1, the light emitting units are arranged in multiple stages (vertical arrangement) with the horizontal arrangement of the light emitting units as a unit, and the light emitting units are formed in a form in which they are arranged in two directions, vertical and horizontal. Note that the arrangement in the thickness direction means that the light emitting portions or light emitting regions are partially or entirely overlapped as in the above-described stacked arrangement, and the light emitting portions or light emitting regions in the overlapping form are vertically, horizontally, or obliquely arranged. A barcode or the like arranged in one direction or two or more directions can also be formed.

  The covert sign can be preferably used to form a sign that requires confidentiality or covertness such as an authentication means. For the formation of the authentication means, it is preferable to form the authentication area by arranging the light emitting area as a unit at one place or two or more places in view of the authentication accuracy.

  The authentication area can be formed, for example, by combining two or more kinds of light emitting areas having different arrangement directions of the light emitting portion long sides, as in the arrangement example of the light emitting areas described above. Accordingly, it is possible to form a linearly polarized light emission pattern having a different vibration direction based on the difference in the direction of the long side of the light emitting unit. The authentication means may be formed of the same kind or different kind of authentication areas arranged at two or three or more places.

  The arrangement direction of the light emitting portions in the light emitting region is, for example, a parallel relationship (0 degree) or orthogonal with respect to a direction in which the long side of the light emitting portion in one light emitting region can be arbitrarily selected as a combination of a plurality of light emitting regions forming the authentication region By normalizing the direction of the long side of the light emitting part in each light emitting region in advance, as in the case of a combination of two or more types of light emitting regions having a relationship (90 degrees) or 45 degrees or 135 degrees, The direction can be detected more easily.

  It is also possible to use any combination of the directions of the long side of the light emitting unit without the above-mentioned normalization, encrypt the combination, and record it as a light emitting unit or a light emitting region. According to this, the confidentiality or concealment of the authentication means can be improved, and the detectability of the polarization direction can also be improved.

  Further, as described above, it is possible to form an authentication pattern consisting of a light / dark difference due to the difference in the arrangement direction of the light emitting portion long sides in the plurality of light emitting regions forming the authentication region. By the way, when the light emission in the authentication region composed of the light emission region by the combination of 0 degree, 45 degrees, and 90 degrees is observed through a polarizer having the absorption axis as the 0 degree direction, the light intensity transmitted through the polarizer is ideal. Specifically, it becomes 0%, 50%, and 100%, and a light / dark pattern having three values of darkness, medium, and light can be formed.

  Therefore, in the above example, ternary recording and reading based on the difference in brightness can be achieved. Note that the direction of the long side of the light emitting portion in the light emitting region specified as 0 degree or 45 degrees is preferably within an error range of 5 degrees or less from the viewpoint of detection accuracy by clarifying the difference in brightness.

  The above-described light emission pattern having a light and dark difference by two or more light emitting areas having different arrangement directions of the light emitting portion long sides can be used as an authentication pattern for a barcode formed of the light emitting areas. As described above, the barcode may be one in which the light emitting areas are arranged in one or more directions of vertical, horizontal, diagonal, or thickness to form an authentication pattern.

  An example of the authentication pattern based on the above-described difference in brightness is shown in FIG. This means that the lateral direction is 0 degree, the light emitting area 10a whose long side direction is 0 degree, the light emitting area 10b that is 45 degrees, and the light emitting area 10c that is 90 degrees are 10a, 10b, 10c, and 10b. An authentication region is formed by arranging in the order of 10a, and a light emission pattern is observed through a polarizer having a transmission axis in the direction of 0 degrees.

  As is apparent from the figure, the light transmittance changes in accordance with the arrangement order of the light emitting regions 10a to 10c, and light, intermediate, dark, intermediate and bright light emission patterns are formed. When observed without using a polarizer, no difference in brightness appears in 10a, 10b, and 10c, and light emission of uniform brightness is exhibited in each light emitting region. By changing the transmission axis direction of the polarizer for pattern detection or preparing a plurality of ones having different transmission axis directions, it is possible to detect a more complicated polarization axis and perform multi-value recording.

  As described above, the direction of the vibration plane of the linearly polarized light in the light emission pattern can be easily and freely controlled by changing the long side direction of the light emitter. In addition, an authentication pattern using the polarization direction as information can be formed by a combination of light emitting regions having different long side directions of the light emitter.

  Further, when a barcode is formed by a combination of light emitting regions having different long side directions of the light emitter, information based on the polarization direction can be recorded in addition to the barcode information by the conventional binary recording, and such multi-values can be recorded. By achieving information recording, the recording capacity can be dramatically increased. In addition, by applying the above-described lamination method in which the light emitting portions having different emission wavelengths are superimposed, information multi-layer recording within a certain section is achieved, and the information recording capacity is further increased.

  The light-emitting portion exhibits light emission characteristics that emits linearly polarized light having a vibration surface in the long side direction when irradiated with electromagnetic waves, as a result of the fact that light cannot vibrate in the short side direction and can vibrate only in the long side direction. The emitted light appears to be light with uniform brightness in normal observations that do not pass through the polarizer with non-polarized light, but the characteristics of polarized light emission are manifested through observation through the polarizer and irradiation with linearly polarized light. Can do.

  Even if a polarizer is laminated on a light emitting material to form a mechanism of polarized light emission, it is not suitable as an authentication means unless the polarization direction can be controlled. Incidentally, in the elliptically polarized light via the retardation layer, the brightness hardly changes even if the transmission axis of the polarizer is changed. The authentication means is required to emit linearly polarized light as in the light emitting unit according to the present invention and to have a large polarization contrast in each of the long side and the short side. This makes it possible to write and read information with high accuracy and facilitate authentication.

In the observation of light emission through the polarizer, the maximum transmittance of light is shown when the transmission axis direction of the polarizer and the long side direction of the light emitting part are parallel, and the transmission axis direction and the short side direction of the light emitting part are The minimum light transmittance is shown when parallel. Also, in the arrangement angle between them, when the angle of the transmission axis of the polarizer is θp, the angle of the long side direction of the light emitting part is θ1, and the light emission intensity of the light emitting part not passing through the polarizer is I0, the transmission intensity I is , I = I0 · {cos (θp−θ1)} ² . Therefore, by rotating the polarizer relative to the emitted light, the polarization direction in the light emitting part or the light emitting region can be easily determined.

  An authentication method according to the present invention is to irradiate an authentication means comprising the light emitting part or light emitting region with a non-polarized electromagnetic wave and detect light emitted from the light emitting part forming the authentication means via a linear polarizer, or The authentication means is irradiated with electromagnetic waves as linearly polarized light to detect the light emission of the light emitting section.

  The authentication method includes, for example, an authentication device including at least a light source that irradiates non-polarized electromagnetic waves to the authentication unit and a light receiving unit that detects light emitted from a light emitting unit forming the authentication unit via a linear polarizer, It can be implemented by an authentication device or the like that includes at least a light source that irradiates the means with electromagnetic waves as linearly polarized light and a light receiving unit that detects light emission of the light emitting unit forming the authentication unit.

  As the light source for irradiating non-polarized electromagnetic waves, an appropriate light source such as a light source that irradiates ultraviolet rays such as a high-pressure mercury lamp or a xenon lamp, or a light source that emits visible light such as an incandescent lamp or a cathode tube can be used. A light emitting diode or the like can also be used. As the light source for irradiating the electromagnetic wave as linearly polarized light, an appropriate light source such as a combination of the non-polarized light source and a linear polarizer, or a laser emitting linearly polarized light composed of ultraviolet rays, visible light, or the like can be used.

  As a light-receiving unit that detects light emitted from the light-emitting unit through a linear polarizer as necessary, for example, a luminance meter, a photomultiplier tube, a device that can detect a light-dark difference, such as a CCD, and in particular, a device that can quantitate Can be used. A light receiving portion that can identify the light emission pattern of the light emitting portion forming the authentication means is preferable.

  Linear polarizers include absorbing polarizers such as polyvinyl alcohol stretched films dyed with dichroic substances such as iodine, and reflective polarizers such as multilayer laminates of stretched films and quarter-wave plates An appropriate material such as a liquid crystal layer can be used.

  When detecting the light emission pattern or the authentication pattern in the authentication means, an authentication device having a pinhole or slit disposed between the light receiving unit and the authentication means and the operation means is used to pass the pinhole or slit through the operation means. It is also possible to adopt a method in which the light emitting unit that is disposed between the light receiving unit and the authentication unit detects light emitted from the light emitting unit forming the authentication unit through the pinhole or slit. The purpose of the pinholes and slits is to improve detection accuracy by preventing light from adjoining or nearby light emitting portions or light emitting regions.

  The authentication means according to the present invention can be a bar code that can be read only through a polarizer, and can be preferably applied to various articles that require authentication. In that case, the authentication means may be directly formed at an appropriate position such as the surface of the article, or may be attached as a sticker seal in which the authentication means is provided on the support base material.

  The supporting base material of the sticker seal includes various polymers such as those exemplified in the matrix polymer, papers, thin leaves such as films and sheets made of ceramics and metals, plates and rods, etc. An appropriate form can be used. The support substrate may be either a transparent body or an opaque body, and may be light reflective. The sticker seal can be adhered to the article through an adhesive means such as a pressure-sensitive adhesive or an adhesive as necessary.

  As an article provided with an authentication means, for example, various cards such as a financial card such as a credit card or a prepaid card, an identification card such as an ID card, an electronic such as software or a program recording medium, LCD, CVD, DVD, etc. Examples include parts, electrical products, support base materials for sticking seals, documents that require authentication, and sent items.

  Incidentally, FIG. 3 illustrates a credit card using the authentication means according to the present invention. Reference numeral 100 denotes an authentication means directly formed in one area of the credit card. In normal observation, light emission of uniform brightness according to the shape of the authentication area consisting of the light emission areas shown in a lattice shape is visually observed, but when viewed through a polarizer as extracted by an arrow, the light emission area The image specified in the long side direction of the light emitting part is visually observed. Such an authentication means can change the pattern for each card and can also be used as an individual authentication means.

  FIG. 4 shows an example in which the authentication means according to the present invention is formed as a sticker seal 110 and bonded to an electrical product through an adhesive layer. The example shows a DVD player. When the sticker is peeled off, part or all of it remains on the article as an adherend so that it can be determined whether or not it has been peeled off in advance. . In that case, a specific message or information can be left on the seal on the peeling side or the remaining side.

  The above-mentioned sticker seal is formed by, for example, providing a light emitting region or authentication means on the surface of the seal with an adhesive means for an article (adhered body), and partially changing the adhesive force of the adhesive means to obtain the light emitting region or authentication. If the adhesive strength at a part or all of the position corresponding to the means is made higher than the adhesion strength between the light emitting area or the authentication means and the transparent base material supporting the light emitting area, and the seal is peeled off, the light emitting area portion of the high adhesive strength Or the method by which an authentication means part and a transparent base material isolate | separate and remain in articles | goods etc. can be performed.

  Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited thereto.

  Spin a 0.6% by weight tetrachloroethane solution of MEH-PPV (poly (2-methoxy, 5- (2'-ethylhexyloxy) -1,4-phenylenevinylene)), a light-emitting polymer, on a glass substrate. It was coated and dried by heating to form a thin film having a thickness of 150 nm.

  Next, for the thin film, stripes a to d each having a light transmitting portion and a shielding portion having long sides formed in directions of 0 °, 90 °, 45 °, and 135 ° as shown in FIG. Is irradiated with a KrF excimer laser beam having a wavelength of 248 nm through a mask having a period of 15 μm, and the irradiated image is reduced and projected to 1/30 through a lens and ablated, and the short side length is smaller than the emission wavelength. A 2 mm vertical and horizontal light emitting region having a 12 μm light emitting portion with a period of 0.5 μm in a state where the long sides are parallel to each other was formed.

  The issuance area is formed in such a manner that the glass substrate is fed 2 mm at a time, but the mask is changed and the exposure is repeated, and the light emitting area is formed in the order of a, b, c, d, a, b, c, d based on the mask. An authentication means composed of an authentication area arranged was formed on a glass substrate. In addition, the period and short side length of the light emission part in each issue area | region were confirmed by electron microscope observation.

  In accordance with the first embodiment, an authentication means including an authentication area in which light emitting areas are arranged in the order of a, c, b, d, a, c, b, and d based on a mask was formed on a glass substrate.

Comparative Example 1
In accordance with Example 1, an authentication means comprising an authentication region in which the MEH-PPV thin film provided on the glass substrate was not patterned by ablation processing with a mask was formed.

Comparative Example 2
Using a mask having a stripe period of 60 μm, a light emitting region having a light emitting part having a short side length of 1 μm larger than the light emission wavelength and a long side in parallel with a period of 2 μm is set to a, b, c, d based on the mask. , A, b, c, and d, authentication means including authentication areas arranged in the order is formed according to the first embodiment.

Evaluation test When irradiated with ultraviolet rays from the lower surface of the glass substrate to the authentication areas of the examples and comparative examples, the generated fluorescence was visually observed as it was. The difference in the light emission pattern could not be confirmed.

  Next, when the fluorescence by ultraviolet irradiation was visually observed in Example 1 through a polarizer, bright light in the region a was obtained when the transmission axis of the polarizer and the long side direction of the light emitting portion of a were parallel. And light was not visible in the region b. In addition, in the areas c and d, light (dark) having an intermediate brightness between the areas a and b was visually observed.

  On the other hand, in the observation in which the transmission axis of the polarizer is perpendicular to the long side direction of the light emitting portion a, bright light can be seen in the region b, and light cannot be seen in the region a. Further, dark light was visually perceived in the areas c and d. Furthermore, when the transmission axis of the polarizer is set to a crossing angle of 45 degrees with respect to the long side direction of the light emitting part a, bright light can be seen in the area c and light cannot be seen in the area d. It was. Further, dark light was visually perceived in the areas a and b.

  Next, in an observation in which the transmission axis of the polarizer is set to a crossing angle of 135 degrees with respect to the long side direction of the light emitting part a, bright light can be seen in the area d and light cannot be seen in the area c. It was. Further, dark light was visually perceived in the areas a and b. As described above, in Example 1, four values can be recorded per one light emitting region according to the long side direction of the light emitting part, and the light emission pattern due to the difference in the polarization direction can be clearly discriminated by observation through the polarizer. I understand.

  The observation result similar to the above is obtained also in Example 2, and it can be confirmed that the light emission pattern is different from that in Example 1 by observation through a polarizer, and different information is recorded in Examples 1 and 2. I was able to confirm. On the other hand, in Comparative Examples 1 and 2, when observing in the same manner as described above, the same level of light can be seen in all cases regardless of the angle between the transmission axis of the polarizer and the long side direction of the light emitting portion, and the light emission pattern. Could not get the difference. From this, it can be seen that the light emission by the comparative example is not linearly polarized light.

  On the other hand, when the authentication region of Example 1 was irradiated with non-polarized ultraviolet laser light from the lower surface of the glass substrate, and the fluorescence intensity by the light emitting region was observed through the polarizer while moving the glass substrate, the light, dark, intermediate Intermediate, bright, dark, intermediate, and intermediate emission patterns were observed, and the pattern order could be read. In the same observation according to Example 2, bright, intermediate, dark, intermediate, bright, intermediate, dark, and intermediate light emission patterns were observed, and it was possible to read that the pattern order was different from that of Example 1. However, in the same observation using the comparative example, the brightness of the light emission did not change, and it was impossible to visually recognize that there was a pattern in the light emission.

  In addition, an ultraviolet laser beam consisting of linearly polarized light whose oscillation direction is 0 degrees (corresponding to the mask a region) is irradiated from the lower surface of the glass substrate to the authentication region of Example 1, and the intensity of fluorescence by the light emitting region is moved while moving the glass substrate. When observed, bright, dark, intermediate, intermediate, bright, dark, intermediate, and intermediate emission patterns were observed, and the order of the patterns could be read. In the same observation according to Example 2, bright, intermediate, dark, intermediate, bright, intermediate, dark, and intermediate light emission patterns were observed, and it was possible to read that the pattern order was different from that of Example 1. However, in the same observation using the comparative example, the brightness of the light emission did not change, and it was impossible to visually recognize that there was a pattern in the light emission.

  As described above, in the embodiment according to the present invention, light emission by linearly polarized light is obtained, and the light emission pattern by the difference in the polarization direction is obtained by controlling the polarization direction by the long side direction of the light emitting unit, and the difference in the light emission pattern is also clear. It can be distinguished that it is effective as an authentication means. However, it can be seen that the light emission pattern cannot be formed in the comparative example and cannot be used as an authentication means.

  After forming the light emitting region by the mask b according to the first embodiment, an N region is superimposed on the region through the mask a to form an authentication region, and the authentication region is irradiated with ultraviolet rays from the lower surface of the glass substrate. Then, when the fluorescence was visually observed through a polarizer, an N-shaped light emitting region was observed in a black background when the transmission axis of the polarizer and the long side direction of the light emitting part a were parallel. Further, in the relationship in which the transmission axis of the polarizer and the long side direction of the light emitting part a are orthogonal, an N character was observed in black in a bright light emitting region. Further, in the relationship where the transmission axis of the polarizer and the long side direction of the light emitting part a crossed at 45 degrees, light emission with uniform brightness was observed and the N-character was not visually recognized.

  As described above, the authentication means according to the present invention can be easily attached to the surface of cards such as credits, etc., which realizes linearly polarized light emission by patterning of the emission wavelength or less and the difference in vibration plane of the linearly polarized light. Since encryption information can be recorded in the light emission pattern itself by using it, forgery is difficult, and since the light emission pattern can be read through a polarizer or linearly polarized light, various dimensions of barcodes can be easily formed.

An enlarged explanatory plan view of a light emitting area comprising a light emitting portion Expansion explanation plan view of authentication area consisting of light emitting area Credit card explanation top view Description perspective view of application example of sticker seal Description plan view of the mask

Explanation of symbols

1: Light emitting part a: Long side b: Short side 2: Non-light emitting part 10, 10a, 10b, 10c: Light emitting area 100: Authentication area (authentication means)
110: Affixed sticker

Patent applicant Nitto Denko Corporation
Agent Tsutomu Fujimoto

Claims (15)

  A plurality of light emitting portions that emit light by external electromagnetic wave irradiation are arranged to form a code, and the light emitting portion has a long side longer than the emission wavelength and a shorter side shorter than the emission wavelength based on the planar shape. A covert sign made of sticks.   The authentication means which has an authentication area | region formed by arrange | positioning the light emission area | region which the some of the light emission part of Claim 1 arranged in parallel based on the long side in one place or two places or more.   3. The authentication unit according to claim 2, wherein the authentication area is formed by a combination of two or more types of light emitting areas having different arrangement directions of the light emitting section long sides.   4. The authentication area according to claim 2 or 3, wherein the authentication area includes a plurality of light emitting areas, and the arrangement direction of the light emitting parts in the light emitting areas is based on a direction in which the long sides of the light emitting parts in one light emitting area can be arbitrarily selected, or Authentication means in an orthogonal relationship or a 45 or 135 degree cross relationship.   The authentication means according to any one of claims 2 to 4, wherein two or more types of light emitting areas having different arrangement directions of the light emitting portion long sides form an authentication pattern by the difference in the arrangement direction of the light emitting portion long sides.   6. The authentication means according to claim 5, wherein the authentication pattern is a bar code in which the light emitting areas are arranged in one or more directions of vertical, horizontal, diagonal, or thickness.   An article comprising the authentication means according to one of claims 2 to 6.   The article according to claim 7, wherein the authentication means is adhered as a sticking seal, or the authentication means is formed on the surface.   The product according to claim 7 or 8, comprising a credit card, an ID card, a prepaid card, a sticker, an electronic component, or an electrical product.   The authentication means according to one of claims 2 to 6 is irradiated with non-polarized electromagnetic waves, and the light emitted from the light-emitting portion forming the authentication means is detected through a linear polarizer, or the authentication means has electromagnetic waves. The authentication method which detects light emission of the said light emission part by irradiating as a linearly polarized light.   The authentication unit according to any one of claims 2 to 6 includes at least a light source that irradiates a non-polarized electromagnetic wave and a light receiving unit that detects light emitted from a light emitting unit forming the authentication unit via a linear polarizer. Authentication device to perform.   7. An authentication apparatus comprising at least a light source that irradiates the authentication means according to one of claims 2 to 6 with electromagnetic waves as linearly polarized light, and a light receiving part that detects light emission of a light emitting part forming the authentication means.   The authentication device according to claim 12, wherein the light source includes a laser that emits linearly polarized light or a linear polarizer.   14. The authentication device according to claim 11, wherein the light receiving unit identifies the light emission pattern of the light emitting unit forming the authentication unit. The light emission which has a pinhole or slit arranged between the light receiving part and the authentication means and its operation means, and forms the authentication means through the pinhole or slit in each of claims 11 to 14 Authentication device that detects light emission of the light at the light receiving part.

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