JP2007188602A - Recording medium and reading and writing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium which has a magnetic recording layer and a heat sensitive recording layer wherein recording is irreversibly performed and wherein a forgery is hardly made and authentication is reliably performed and which has high reliability of rewritten recorded information and irreversibly recorded information of the heat sensitive recording layer when information of the magnetic recording layer is rewritten and recorded and when information recording of the heat sensitive recording layer is performed and to provide a reading and writing device of the recording medium. <P>SOLUTION: In the recording medium 1 wherein at least the magnetic recording layer 7 and the heat sensitive recording layer 4 are sequentially layered on one surface of a base material 10, an amorphous ferromagnetic film 2 having peculiar magnetic characteristics is provided at a part of the other surface of the base material 10. Authentication is performed by reading the peculiar magnetic characteristics of the amorphous ferromagnetic film of the recording medium and information is recorded in the magnetic recording layer by a magnetic recording means and information is recorded in the heat sensitive recording layer by an irreversibly recording means only when the determination result is a truth. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording medium having a thermal recording layer that is irreversibly recorded with a magnetic recording layer, and a read / write device for the recording medium. Specifically, when it is difficult to create a counterfeit product, authenticity determination is reliably performed, information on the magnetic recording layer is rewritten and recorded, and information recording on the thermal recording layer is performed. The present invention relates to a recording medium with high reliability of irreversible recording information on a recording layer and a reading / writing device thereof.

  Conventionally, as disclosed in Patent Document 1, as an information recording card, a heat-destructive recording layer can record irreversible information as a card in which a base material, a magnetic recording layer, a heat-sensitive destruction recording layer, and a hologram layer are sequentially laminated. What is provided as a visible information recording part is known. Further, as disclosed in Patent Document 2, a thermal printing sheet (card) is proposed in which a magnetic layer is provided on the back surface of a base material, and a thermosensitive coloring layer and a hologram forming layer are provided on the surface of the base material. Such an information recording card can record inherent information irreversibly by using a magnetic recording layer, a hologram layer, and a heat-sensitive destructive recording layer, which is a heat-sensitive recording layer, or a heat-sensitive coloring layer. It is described that these information recording cards have an effect of improving the forgery prevention property.

However, as for the security of holograms (diffraction gratings), counterfeit products have come out in recent years, and the anti-counterfeit effect is not perfect only by visual authentication. Further, in recent years, it is easy to rewrite magnetic recording data only by reading the data of the magnetic recording layer, and it is not possible to reliably add additional information.
JP-A-8-80680 JP 2005-66871 A

  Therefore, according to the present invention, it is difficult to produce a counterfeit product in a recording medium having a heat-sensitive recording layer that is irreversibly recorded with the magnetic recording layer, authenticity determination is performed reliably, and information on the magnetic recording layer is stored. To provide a recording medium with high reliability of rewritable recording information and irreversible recording information of a thermosensitive recording layer and recording / reading apparatus of the recording medium when rewriting and recording information of the thermosensitive recording layer With the goal.

  In view of the above situation, the present invention has been intensively researched and developed, and the present invention has found a recording medium that has solved the above-described problems and a reading / writing device for the recording medium. That is, the invention described in claim 1 is a recording medium in which at least a magnetic recording layer and a thermosensitive recording layer are sequentially laminated on one surface of a base material, and a unique magnetic property is formed on a part of the other surface of the base material. A recording medium is provided with an amorphous ferromagnetic film having characteristics.

  A second aspect of the present invention is a recording medium in which the amorphous ferromagnetic film according to the first aspect is formed as a read code, and the anti-counterfeiting property is further improved. A third aspect of the present invention is a recording medium in which a colored layer is further formed on the amorphous ferromagnetic film according to the first or second aspect. Appearance is unrecognizable and anti-counterfeiting is further enhanced. A fourth aspect of the invention is a recording medium in which a hologram forming layer is further formed on the amorphous ferromagnetic film according to the first aspect, and the anti-counterfeiting property is further improved.

  According to a fifth aspect of the present invention, there is provided a reading and writing apparatus for a recording medium according to any one of the first to fourth aspects, wherein means for reading the intrinsic magnetic characteristics of the amorphous ferromagnetic film of the recording medium (ferromagnetic reading means); It has means for recording information on the magnetic recording layer of the medium (magnetic recording means) and means for recording information on the thermosensitive recording layer irreversibly recorded on the recording medium (irreversible recording means). Read / write characterized in that authentication is performed and information is recorded on the magnetic recording layer by the magnetic recording means and information is recorded on the thermosensitive recording layer by the irreversible recording means only when the determination result is authentic. Device.

  The recording medium of the present invention has a structure in which at least a magnetic recording layer and a thermosensitive recording layer are sequentially laminated on one surface of a base material, and an amorphous strong material having inherent magnetic properties is formed on a part of the other surface of the base material. A magnetic film is provided. By reading the intrinsic magnetic properties of the amorphous ferromagnetic film of this recording medium, an authenticity judgment is made. Only when the judgment result is authentic, information is recorded on the magnetic recording layer by the magnetic recording means, and irreversible. It is used by recording information on the heat-sensitive recording layer by a recording means, and it is difficult to produce a forged product of this recording medium, and authenticity determination is reliably performed, and information on the magnetic recording layer is rewritten and recorded. At the time of recording information on the thermal recording layer, the reliability of the rewritable recording information and the irreversible recording information on the thermal recording layer is very high.

  FIG. 1 is a schematic plan view showing an embodiment of a recording medium 1 of the present invention. On the surface side of the recording medium 1, characters, patterns and the like are formed on the entire surface of the recording medium 1 by a pattern printing layer 3. In addition, an amorphous ferromagnetic film 2 having inherent magnetic properties is partially provided on the picture print layer 3. A thermal recording layer 4 is provided on the entire surface of the recording medium 1 on the back side of the recording medium 1, and various characters are formed on the thermal recording layer 4 by the character printing layer 5. In the figure, the area indicated by the dotted line is the scanning area of the print head, and in this area, the thermal recording layer 4 is colored by the heating of the print head, and a recording section for visible information recorded irreversibly. 6 is formed.

  FIG. 2 is a schematic cross-sectional view taken along the line XX of the recording medium 1 shown in FIG. 1. The magnetic recording layer 7, the colored printing layer 8, and the thermosensitive recording layer 4 are provided on one surface of the substrate 10. The character printing layer 5 is partially provided on the heat-sensitive recording layer 4 in order. In addition, the pattern printed layer 3 and the protective layer 9 are laminated on the other surface of the base material 10, and the amorphous ferromagnetic film 2 having unique magnetic properties is provided on a part of the protective layer. is there. The main purpose of the colored printing layer 8 is to make the hue of the magnetic recording layer 7 easier to read in the color recording portion of the heat-sensitive recording layer. However, the material selection of the heat-sensitive recording layer, the adjustment of the thickness thereof, etc. However, it is not necessarily provided. In order to form an amorphous ferromagnetic film on a part of the protective layer, a printing method such as screen printing or letterpress printing can be used. However, a thermal transfer foil provided with an amorphous ferromagnetic film on a support so as to be peeled off. It is preferable to form an amorphous ferromagnetic film in an arbitrary shape by a thermal transfer method using a heating means such as a thermal head.

  FIG. 3 is a schematic cross-sectional view showing one embodiment of a thermal transfer foil 11 used for forming an amorphous ferromagnetic film by a thermal transfer method. On the support 12, a release layer 13, a colored layer 14, The anchor layer 15, the amorphous ferromagnetic film 2, and the adhesive layer 16 are sequentially stacked. When the image is transferred to a recording medium using the illustrated transfer foil, an adhesive layer, an amorphous ferromagnetic film, an anchor layer, a colored layer, and a release layer are sequentially laminated on a part of the recording medium.

  FIG. 4 is a schematic cross-sectional view showing another embodiment of the thermal transfer foil 11 used for forming the amorphous ferromagnetic film by the thermal transfer method. The release layer 13 and the OP layer 17 are formed on the support 12. The hologram forming layer 18, the metal reflection layer 19, the amorphous ferromagnetic film 2, and the adhesive layer 16 are sequentially laminated. When transferred to a recording medium using the transfer foil shown in the figure, an adhesive layer, an amorphous ferromagnetic film, a metal reflective layer, a hologram forming layer, an OP layer, and a release layer are sequentially laminated on a part of the recording medium. It becomes.

(Base material)
As the base material 10 in the recording medium of the present invention, high-quality paper, coated paper, recycled paper, synthetic paper and the like can be used, and further, synthetic resin films such as polyethylene terephthalate, polyethylene, polypropylene and vinyl chloride can also be used. . These base materials are preferably colored and concealed in white or the like in order to make it easy to identify the pattern of the pattern printing layer. These substrates have a thickness of about 16 to 50 μm. When transferring an amorphous ferromagnetic film from a transfer foil, the heat transfer efficiency during thermal transfer, the handling and storage of recording media, and the like. It is preferably used because of its ease.

(Thermosensitive recording layer)
The heat-sensitive recording layer 4 is for recording the color of the heated portion by heating with a thermal head or laser irradiation, and irreversibly records unique information. The heat-sensitive recording layer contains a heat-sensitive color-developing material, and specifically includes an electron-donating dye precursor and an electron-accepting compound that develop color by a thermal melting reaction, and further, if necessary, a sensitizer and a color fading. Inhibitors, fillers such as pigments and lubricants, dispersants, binders and the like are included.

  The heat-sensitive recording layer is formed as a layer by coating or printing on the substrate. Examples of the method for forming the thermosensitive recording layer include gravure, roll coating, spray coating, dipping, and others. As the electron-donating dye precursor, one that is applied to this kind of heat-sensitive material as a leuco dye, one that develops color in yellow, cyan, magenta, or the like is selected. Specific examples of the electron-donating dye precursor include triphenylmethane, fluorane, phenothiazine, auramine, spiropyran, and indinophthalide, and are appropriately selected according to the color to be colored.

  The above-mentioned electron-accepting compound is a developer combined with an electron-donating dye precursor, such as a phenolic substance such as bisphenol A, octylphosphonic acid, nonylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, tetradecyl. Examples thereof include organic acids such as phosphonic acid, octadecylphosphonic acid and erotic tetradecanoic acid, metal complex compounds, thiodiphenylurea, and quinones.

  Examples of the sensitizer include stearic acid amide, behenic acid amide, methylene bis stearic acid amide, dibenzyl oxalate, tolylbiphenyl ether, and fatty acid amides. Examples of the anti-fading agent include analogs of color developers blocked with hydroxyl groups, organometallic salts such as zinc salts, and hindered phenols. When the pigment is used in combination, the white pigment has an effect of scattering visible light and near infrared light to the surroundings, promotes near infrared light absorption into the light absorbent and increases heat generation efficiency. Examples of the pigment include calcium carbonate, aluminum hydroxide, silicate, zeolite, silica, kaolin clay, and urea formalin resin.

  In forming the heat-sensitive recording layer, an ink or a paint is prepared in order to form a layer made of the above materials. As a binder for ink or paint, a water-soluble resin is the main component, and examples thereof include polyvinyl alcohol, starch, methyl cellulose, hydroxyethyl cellulose, gelatin, casein, urea resin, melanin resin, amide resin, and polyurethane resin. Moreover, various adjuvants can be added as needed.

As the heat-sensitive recording layer, those having a color hue such as black, brown, amber, red, red, orange, red purple, and blue can be used. The thickness of the thermosensitive recording layer is about 1.0 to 20 g / m ² when dried.

(Amorphous ferromagnetic film)
As the amorphous ferromagnetic film 2, an amorphous ferromagnetic material mainly composed of cobalt (Co), iron (Fe), and nickel (Ni) is formed by a vacuum film forming method such as vapor deposition, sputtering, or ion plating. It can be formed on a support of a heat-sensitive magnetic transfer foil. Such an amorphous ferromagnetic film can be provided with a thickness of about 10 nm to 300 nm (0.01 μm to 0.3 μm). As the amorphous ferromagnet, a material having unique hysteresis characteristics of Hc (holding force), μ (magnetic permeability), Bm (saturation magnetic flux density), and BH characteristics (hysteresis curve) is used.

  That is, with reference to FIG. 6 showing a hysteresis curve of a magnetic material, the amorphous ferromagnetic material used in the present invention is preferably a material having a high angle ratio magnetic characteristic as shown in FIG. Such a ferromagnetic material exhibits unique characteristics in Hc (coercive force) and Bm (saturation magnetic flux density). From the magnetic characteristics, the magnetic field strength normally applied and the magnetic flux density of the magnetic material magnetized by the magnetic field are Since it has a non-linear BH characteristic (hysteresis curve), it can be clearly distinguished from a general magnetic material as shown in FIG. The ferromagnetic material used in the present invention preferably has an Hc of 40 to 4000 A / m (0.5 to 50 oersted) and an Rsq (square ratio) of 0.7 to 1.0. The squareness ratio Rsq is represented by Rsq = Br (residual magnetic flux density) / Bm (saturated magnetic flux density).

(Magnetic recording layer)
The magnetic recording layer 7 is composed of γ-Fe ₂ O ₃ , Co-coated γ-Fe ₂ O ₃ , Fe ₃ O ₄ , CrO ₂ , Fe, Fe—Cr, Fe—Co, Co—Cr, Co—Ni, and MnAl. A dispersion obtained by dispersing conventionally known magnetic fine particles such as Ba ferrite and Sr ferrite in an appropriate resin or ink vehicle is applied onto a substrate by a conventionally known coating method such as a gravure method, a roll method or a knife edge method. Can be formed. Also, the magnetic recording layer is formed on the substrate by using a metal such as Fe, Fe-Cr, Fe-Co, Co-Cr, or an alloy thereof, or an oxide thereof, by vacuum deposition, sputtering, plating, or the like. You can also

  When the magnetic recording layer is formed by a coating method, the film thickness is about 1 to 100 μm, preferably about 5 to 20 μm. When the magnetic recording layer is formed by vacuum deposition, sputtering, or plating, the film thickness is about 100 to 1 μm, preferably about 500 to 2000.

Resin or ink vehicle in which magnetic fine particles such as γ-Fe ₂ O ₃ are dispersed include butyral resin, vinyl chloride / vinyl acetate copolymer resin, urethane resin, polyester resin, cellulose resin, acrylic resin, styrene / male An acid copolymer resin or the like is used, and a rubber-based resin such as nitrile rubber or a urethane elastomer is added as necessary. In addition, surfactants, silane coupling agents, plasticizers, waxes, silicone oils, carbon and other pigments can be added to the dispersion in which the magnetic fine particles are dispersed in the resin. .

(Picture printing layer)
The pattern printing layer 3 is composed of cellulose derivatives such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate, and cellulose acetate, styrene resins such as polystyrene and poly-α-methylstyrene, styrene copolymer resins, polymethyl methacrylate, poly Acrylic resins or methacrylic resins, such as ethyl methacrylate, polyethyl acrylate, and polybutyl acrylate, or copolymers, rosin, rosin-modified maleic acid resin, rosin-modified phenol resin, polymerized rosin ester resin such as polymerized rosin, polyacetic acid Various pigments and dyes are added to binders such as vinyl resin, coumarone resin, vinyl toluene resin, vinyl chloride resin, polyester resin, polyurethane resin and butyral resin according to the color to be colored. If necessary, add a plasticizer, stabilizer, wax, grease, desiccant, drying aid, curing agent, thickener, dispersant, and then color paint or kneaded with a solvent or diluent. Using ink, it can be formed in a desired portion by a coating method such as a normal gravure method, a roll method, a knife edge method, and an offset method, or a printing method. The pattern print layer may be formed in a single color, or may be formed in a desired pattern, characters, background pattern, pattern, or the like using a plurality of colored paints or inks.

  The above pattern printing layer is formed between the base material and the amorphous ferromagnetic film, but the above pattern printing is also applied to the colored printing layer 8 and the character printing layer 5 provided on the other surface of the base material. It can be provided by the same material and formation method described for the layers.

(Protective layer)
The protective layer 9 can be formed by laminating a synthetic resin film, using an extrusion coating method, or applying a synthetic resin paint. Synthetic resins constituting the protective layer can be widely used in the same manner as the synthetic resins used in forming the colored printing layer in consideration of application or adhesion to other layers. In particular, the use of a thermosetting synthetic resin is advantageous in terms of surface hardness and prevention of contamination. Furthermore, if a paint containing an ultraviolet curable synthetic resin is used, curing after application can be performed instantaneously. preferable. In addition, silicone or the like can be added to the protective layer to make the surface peelable.

(Thermal transfer foil)
In order to form the amorphous ferromagnetic film of the recording medium in the present invention, the thermal transfer foil 11 which is detachably provided on the support is used, the heating means such as a thermal head is used, and the thermal transfer method is used. An amorphous ferromagnetic film can be formed in a shape. As the support 12 of the thermal transfer foil, a synthetic resin film as described in the base material of the recording medium can be used, and the thickness thereof is about 5 to 300 μm, preferably about 10 to 50 μm. . And it is preferable to form the amorphous ferromagnetic film described above on this support through a release layer.

  The release layer 13 is for facilitating the peeling of the amorphous ferromagnetic film from the support, and also has a role of protecting the amorphous ferromagnetic film to some extent after transfer. As a material of this layer, a resin having sufficient transparency, friction resistance, stain resistance, and solvent resistance, for example, (meth) acrylate resin, vinyl chloride resin, vinyl acetate resin, urethane A simple resin, a melanin resin, a polyester resin, a mixture and a copolymer are used. In addition, an ink prepared by dissolving or dispersing a wax, a silicone wax, a silicone resin, a fluororesin, or the like in a suitable solvent is applied and dried on a substrate by a known means. It can be carried out. The thickness of such a release layer is preferably about 0.5 to 5 μm, more preferably 1 to 3 μm.

  Further, in the thermal transfer foil, in order for the transfer part including the amorphous ferromagnetic film to improve the adhesion to the recording medium, an adhesive layer 17 is provided on the amorphous ferromagnetic film, that is, on the outermost surface of the thermal transfer foil. be able to. This adhesive layer may be composed of a vinyl acetate hot-melt resin, an acrylic resin, a vinyl resin, a polyester resin, a urethane resin, an amide resin, an epoxy resin, etc. The pressure-sensitive adhesive can be composed of acrylic or rubber-based ones. The coating thickness may be within 1 to several μm. Usually, when the adhesive layer is a pressure-sensitive adhesive layer, after applying the pressure-sensitive adhesive to the protective release paper provided on the transfer foil, the protective release paper and the transfer foil are integrated, and the transfer foil is used. Further, when the release paper is removed, the pressure sensitive adhesive is transferred onto the amorphous ferromagnetic film so that it can be used.

  An anchor layer 15 can be provided between the colored layer 14 of the thermal transfer foil and the amorphous ferromagnetic film 2 to increase the adhesion between the colored layer and the amorphous ferromagnetic film. Also, when manufacturing a thermal transfer foil, an amorphous ferromagnetic film is formed on the anchor layer. The surface on which the anchor layer is formed is smoothed, and an amorphous ferromagnetic film is formed on the amorphous ferromagnetic film. A film can be formed to improve the accuracy of mechanical reading of the amorphous ferromagnetic film. The binder resin used for the anchor layer includes polyester resin, vinyl chloride / vinyl acetate copolymer resin, polyurethane resin, polyvinyl butyral resin, acrylic resin, cellulose resin, styrene / maleic acid copolymer resin, rubber resin, polychlorinated resin. Vinylidene resin, polyamide resin or the like is used. These binder resins can be dissolved in a solvent and formed on a substrate by a conventionally known coating method such as a gravure method, a roll method, or a knife edge method.

(Hologram forming layer)
In the recording medium of the present invention, it is preferable that a hologram forming layer 18 is further formed on the amorphous ferromagnetic film. As one method for forming the hologram forming layer 18 on the recording medium, a thermal transfer foil is used. Is convenient and preferably performed. The hologram forming layer can be made of a resin material that can reproduce the fine pattern of the hologram. In general, thermoplastic resins such as polyvinyl chloride resin, acrylic resin, polystyrene, polycarbonate, etc., unsaturated polyester resin, melamine, epoxy, acrylate, etc. are used alone or in combination with the above thermoplastic resin. It can be used in admixture with a polymerizable resin. Furthermore, a thermoformable substance having a radically polymerizable unsaturated group, or a radically polymerizable unsaturated group monomer is added to these, and an ionizing radiation curable resin is radiation curable. Can be used. The film thickness of such a hologram forming layer is preferably in the range of 0.1 to 6 μm, and more preferably in the range of 1 to 4 μm.

  The size and shape of the hologram image formed on the hologram forming layer is not particularly limited because it varies depending on the required mode. As a method for forming a hologram image, a conventionally known method, for example, an original plate provided with an uneven pattern of interference fringes of a hologram is used, and fine unevenness is formed by an embossing method or the like. The hologram image may be a planar hologram or a volume hologram. In the case of a planar hologram, a relief hologram is preferable from the viewpoint of mass productivity and cost. In addition, Fresnel holograms, Fraunhofer holograms, lensless Fourier transform holograms, laser reproduction holograms such as image holograms, white light reproduction holograms such as rainbow holograms, color holograms utilizing these principles, computer holograms, hologram displays, multi A flex hologram, a holographic stereogram, a holographic diffraction grating, or the like can be used.

  Further, the metal reflection layer 19 can be provided between the hologram forming layer and the amorphous ferromagnetic film, so that the amorphous ferromagnetic film can be concealed and the visibility of the hologram image in the hologram forming layer is improved. be able to. The metal reflection layer is made of a nonmagnetic metal or nonmetal. For example, aluminum (Al), copper (Cu), zinc (Zn), tin (Sn), silver (Ag), gold (Au), silicon (Si), titanium (Ti), vanadium (V), Chromium (Cr) or an alloy thereof, or an oxide, nitride, or oxynitride powder thereof can be used. The metal reflective layer can be formed of the above metal or non-metal with a film thickness of about 100 to 1 μm by a method such as vacuum deposition or sputtering.

  In the heat-sensitive transfer foil shown in FIG. 4, an OP layer 17 is provided between the release layer and the hologram forming layer. This OP layer has a function of protecting the hologram forming layer, and the above picture pattern is provided. It can be formed by the same method as the pattern print layer, using the resin described in the print layer and excluding the colorant.

(Read / write device)
The reading / writing apparatus of the present invention is a reading / writing apparatus for the recording medium described above, and means for reading the intrinsic magnetic characteristics of the amorphous ferromagnetic film of the recording medium (ferromagnetic reading means) and the magnetic property of the recording medium. A means for recording information on the recording layer (magnetic recording means) and a means for recording information on the heat-sensitive recording layer (irreversible recording means) recorded on the recording medium (irreversible recording means) have an authenticity judgment by the ferromagnetic reading means. Only when the determination result is authentic, information is recorded on the magnetic recording layer by the magnetic recording means, and information is recorded on the thermosensitive recording layer by the irreversible recording means.

  The reading / writing apparatus of the present invention will be described using the apparatus shown in FIG. 5 as an example. Reading as means for reading the unique magnetic properties of the amorphous ferromagnetic film of the recording medium, such as a plurality of conveying roller pairs 21, 30, 31, 32 as conveying means for conveying the card-like recording medium 1 A head 22; a transport roller 23 that transports the recording medium 1 while pressing the recording medium 1 against the head 22; a timing sensor 24 for detecting the timing of magnetic recording; and means for recording information on the magnetic recording layer of the recording medium 1 As a magnetic head 25, a conveyance roller 26 for conveying the recording medium 1 while pressing the recording medium 1 against the head 25, a timing sensor 27 for detecting the timing of thermal recording, and recording information on the thermal recording layer of the recording medium 1. Read / write composed of a thermal head 28 as means for performing the operation, a platen roller 29 for conveying the recording medium 1 while pressing the recording medium 1 against the head 28, etc. Device, which is 20.

  In the configuration as described above, a series of reading and writing (recording) operations are performed while the recording medium 1 is being conveyed by rotating the conveyance roller pair 21 by a driving force of a conveyance motor (not shown). That is, first, the read head 22 reads the presence / absence of the intrinsic magnetic characteristics of the amorphous ferromagnetic film of the recording medium 1 or the magnetically recorded information of the ferromagnetic film, and determines the magnetic characteristics of the ferromagnetic film. Only when the information recorded or magnetically recorded on the ferromagnetic film is detected, the process proceeds to the means for recording information on the magnetic recording layer of the next recording medium. If the magnetic characteristics inherent to the amorphous ferromagnetic film of the recording medium 1 are not recognized by the read head 22 or information recorded on the ferromagnetic film cannot be detected, the magnetic recording layer of the recording medium The operation stops without proceeding to the means for recording information (magnetic head 25).

  A signal corresponding to the information to be written to the magnetic recording layer is sent from a control device (not shown) to the magnetic head 25 as means for recording information on the magnetic recording layer of the recording medium. Further, based on the position data read by the timing sensor 24 in advance, the position and direction to be shifted when writing to the magnetic recording layer are determined. After information is recorded on the magnetic recording layer of the recording medium, information is recorded on the thermal recording layer of the recording medium by the thermal head 28. A signal corresponding to information to be recorded on the thermal recording layer is sent to the thermal head 28 from a control device (not shown). Further, based on the position data read by the timing sensor 27 in advance, the position and direction to be shifted when recording on the thermosensitive recording layer are determined.

  Although not shown in FIG. 5, the read head 22 can detect whether or not the amorphous ferromagnetic film of the recording medium 1 has the inherent magnetic characteristics, or whether the magnetically recorded information on the ferromagnetic film can be read and detected. As a result, the read data is transmitted from the read head 22 to the computer, and the computer that has received the read data has the intrinsic magnetic characteristics of the ferromagnetic film and the magnetic property of the ferromagnetic film. Only when the recorded information can be read, it is determined to be genuine, and otherwise, it is determined not to be authentic, that is, authenticity determination is performed.

  Only when it is determined to be authentic by the above authenticity determination, the process proceeds to a means for recording information on the magnetic recording layer of the next recording medium and a means for recording information on the thermal recording layer of the recording medium. If it is not determined, the process does not proceed to the next step and stops. The result of the authenticity determination can be displayed as determination information by display means such as a display. In this case, if the authentication is determined to be fake, the authentication information may be displayed on the display unit and an alarm buzzer may be sounded.

  FIG. 1 shows an embodiment in which information is recorded on the heat-sensitive recording layer by the recording medium reading / writing apparatus described above. The illustrated recording medium is in the form of a card, and the date of use, the remaining number, and the like are recorded on the thermal recording layer on the card surface. The numbers such as “040403” and “8000” shown in the figure are the recording unit 6 as variable information recorded irreversibly. Note that the XX cross-sectional view of the heat-sensitive recording printing layer (region) on the back surface and the amorphous ferromagnetic film shown in FIG. 1 can be, for example, a schematic diagram as shown in FIG.

1 is a schematic plan view showing an embodiment of a recording medium of the present invention. It is a schematic sectional drawing in the cut surface of XX of the recording medium shown in FIG. It is a schematic sectional drawing which shows one embodiment of the thermal transfer foil used in order to form an amorphous ferromagnetic film by a thermal transfer system. It is a schematic sectional drawing which shows other embodiment of the thermal transfer foil used in order to form an amorphous ferromagnetic film by a thermal transfer system. It is the schematic which shows one Embodiment of the reading / writing apparatus of the recording medium of this invention. It is a graph which shows the hysteresis curve of a magnetic material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording medium 2 Amorphous ferromagnetic film 3 Picture printing layer 4 Thermal recording layer 5 Character printing layer 6 Recording part 7 Magnetic recording layer 8 Colored printing layer 9 Protective layer 10 Base material 11 Thermal transfer foil 12 Support body 13 Peeling layer 14 Coloring Layer 15 Anchor layer 16 Adhesive layer 17 OP layer 18 Hologram forming layer 19 Metal reflecting layer 20 Read / write device 21, 30, 31, 32 Conveying roller pair 22 Read head 23 Conveying roller 24 Timing sensor 25 Magnetic head 26 Conveying Roller 27 Timing sensor 28 Thermal head 29 Platen roller

Claims (5)

  In a recording medium in which at least a magnetic recording layer and a thermosensitive recording layer are sequentially laminated on one surface of a substrate, an amorphous ferromagnetic film having inherent magnetic properties is provided on a part of the other surface of the substrate. A recording medium characterized by the above.   The recording medium according to claim 1, wherein the amorphous ferromagnetic film is formed as a read code.   The recording medium according to claim 1, wherein a colored layer is further formed on the amorphous ferromagnetic film.   The recording medium according to claim 1, further comprising a hologram forming layer formed on the amorphous ferromagnetic film. 5. A recording medium reading and writing apparatus according to claim 1, wherein means (ferromagnetic reading means) for reading the intrinsic magnetic characteristics of the amorphous ferromagnetic film of the recording medium, and magnetism of the recording medium. A means for recording information on the recording layer (magnetic recording means) and a means for recording information on the heat-sensitive recording layer (irreversible recording means) recorded on the recording medium (irreversible recording means) have an authenticity judgment by the ferromagnetic reading means. And a read / write device which records information on the magnetic recording layer by the magnetic recording means and records information on the thermosensitive recording layer by the irreversible recording means only when the determination result is authentic.

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