JP2009059429A - Information recording card, information reading device, and information reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information recording card, information reading device, and information reading method to obtain high security effect with a simple configuration. <P>SOLUTION: The information recording card has a recording section made of a thin film magnetic body, and having a plurality of magnetized domains for generating magnetization vertically to the film surface arranged in a two dimensional manner to record the information corresponding to the direction of the magnetization of each magnetized domain. The card reads the information recorded on the recording section by radiating linearly polarized light beams to a plurality of the magnetized domains included in the information recording card to transmit the component in the preset vibration direction of the light transmitted or reflected through or on each magnetized domain respectively so that the component of the transmitted light in the vibration direction corresponding to each magnetized domain is individually received and signal processing is carried out by using the intensity of the received light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information recording card for magnetically recording predetermined information, an information reading apparatus and an information reading method for reading information recorded by the information recording card.

  Conventionally, in the case of magnetic recording type information recording cards, in addition to the recording method being publicly known, data can be easily viewed using magnetic powder or the like, so that forgery or alteration is possible. There was a problem that it was easy to be done.

  As a technique for solving such a problem of the magnetic recording information recording card, a technique relating to a magneto-optical information recording card is known (see, for example, Patent Documents 1 and 2). Magneto-optical information recording cards are generally less susceptible to external magnetic fields and recorded information is less likely to change. For this reason, it is considered that the magneto-optical information recording card can prevent counterfeiting and tampering and can improve the security as compared with the magnetic recording information recording card.

Japanese Patent Laid-Open No. 58-14306 JP-A-10-134422

  However, in order to read the information recorded on the magneto-optical information recording card, a lens and other optical components for irradiating the information recording card with laser light are necessary, and the configuration for reading the information is complicated. I had to be. Further, as in the case of the magnetic recording type, a mechanism for transporting the information recording card is necessary when reading, and the configuration is complicated in this sense.

  The present invention has been made in view of the above, and an object of the present invention is to provide an information recording card, an information reading apparatus, and an information reading method capable of obtaining a high security effect with a simple configuration.

  In order to solve the above-described problems and achieve the object, an information recording card according to the present invention is an information recording card capable of magnetically recording predetermined information and optically reading the recorded information. A plurality of magnetization regions that are made of a thin-film magnetic material and generate magnetization in a direction perpendicular to the film surface of the magnetic material, and record information corresponding to the magnetization direction of each magnetization region. A recording unit is provided.

  The information recording card according to the present invention is characterized in that, in the above invention, the diameter of the film surface of the magnetized region is not less than a dimensional tolerance of the information recording card.

  The information recording card according to the present invention is characterized in that, in the above invention, the recording unit is embedded in a main body of the information recording card.

  Further, the information recording card according to the present invention is 180 degrees with respect to each of the three axes including an axis orthogonal to the surface and orthogonal to each other at one point inside the information recording card. It has a rotationally symmetric shape, and the recording unit records identification information that identifies the arrangement of the information recording cards that move with each other by rotating 180 degrees around at least one of the three axes. It is characterized by that.

  In the information recording card according to the present invention as set forth in the invention described above, the magnetic body includes a magneto-optical material that produces a magneto-optical effect.

  In the information recording card according to the present invention as set forth in the invention described above, the magneto-optical material is an amorphous alloy of a rare earth and a transition metal.

  In the information recording card according to the present invention as set forth in the invention described above, the magneto-optical material is a magnetic garnet thin film.

  An information reading apparatus according to the present invention comprises a thin film-like magnetic material, and a plurality of magnetization regions that generate magnetization in a direction perpendicular to the film surface are two-dimensionally arranged, and information corresponding to the magnetization direction of each magnetization region. An information recording card having a recording unit for recording the information is an information reading device that reads information recorded by the recording unit, the holding unit holding the information recording card, and the information recording card held by the holding unit A light projecting unit that projects light, a polarizing unit that is provided between the light projecting unit and the holding unit, and converts the light projected by the light projecting unit into linearly polarized light; Transmitting means for transmitting a component in a predetermined vibration direction of light transmitted or reflected by each of the plurality of magnetized regions of the recording unit of the information recording card, and individually receiving the light transmitted by the transmitting means. Light receiving means Signal processing means for performing signal processing using the intensity of light individually received by the light receiving means, and the light linearly polarized by the polarizing means collectively irradiates the plurality of magnetization regions. Features.

  In the information reading apparatus according to the present invention, in the above invention, the transmission means is on the same plane with respect to the vibration direction of the linearly polarized light, among the vibration direction components of the light transmitted or reflected by the magnetization regions. The two vibration direction components rotated by the same angle in opposite directions are transmitted respectively, and the signal processing means calculates the intensity difference between the two vibration direction components of the light transmitted or reflected through the same magnetized region. Then, a signal corresponding to the sign of the calculated intensity difference is generated and output.

  In the information reading apparatus according to the present invention as set forth in the invention described above, the diameter of the film surface of the magnetized region is equal to or larger than a dimensional tolerance of the information recording card.

  The information reading method according to the present invention includes a thin film-like magnetic material, and a plurality of magnetization regions that generate magnetization in a direction perpendicular to the film surface are two-dimensionally arranged, and information corresponding to the magnetization direction of each magnetization region. An information recording method for reading information recorded on the recording unit by an information recording card having a recording unit for recording the information, wherein the linearly polarized light is collectively applied to the plurality of magnetization regions of the information recording card Irradiate, and the irradiated light transmits the component in the predetermined vibration direction of the light transmitted or reflected through each magnetization region, and individually receives the component in the vibration direction of the transmitted light in association with each magnetization region. The signal processing using the intensity of the received light is performed.

  According to the present invention, a plurality of magnetization regions that are made of a thin-film magnetic material and generate magnetization in a direction perpendicular to the film surface are two-dimensionally arranged, and information corresponding to the magnetization direction of each magnetization region is recorded. When an information recording card provided with a recording unit reads information recorded by the recording unit, a plurality of magnetization regions provided in the information recording card are collectively irradiated with linearly polarized light, and the irradiated light is applied to each magnetization region. The component of the vibration direction of the light that has been transmitted or reflected is transmitted, the component of the transmitted light in the vibration direction is individually received in association with each magnetization region, and the signal using the intensity of the received light By performing the processing, it is possible to read information recorded by the magnetized region that is not easily affected by the external magnetic field without using a complicated configuration such as an optical component such as a lens or a transport mechanism. Therefore, a high security effect can be obtained with a simple configuration.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described below with reference to the accompanying drawings. Note that the drawings referred to in the following description are merely schematic, and when the same object is shown in different drawings, dimensions, scales, and the like may be different.

(Embodiment 1)
FIG. 1 is a diagram showing an overall configuration of an information reading system including an information recording card and an information reading device according to Embodiment 1 of the present invention. An information reading system 100 shown in FIG. 1 includes an information recording card 1 that magnetically records predetermined information, and an information reading device 2 that optically reads information recorded on the information recording card 1.

  FIG. 2 is a diagram showing the configuration of the information recording card 1, and is a cross-sectional view taken along line AA in FIG. The information recording card 1 includes a thin base plate 11 and a recording unit 12 that is provided at a substantially central portion of the base 11 and magnetically records predetermined information.

  The substrate 11 is realized using a resin such as polycarbonate, acrylic resin, or polyvinyl chloride. When reading information with visible light, the resin applied to the substrate 11 must be transparent.

  The recording unit 12 includes a thin-film magneto-optical layer 121 that magnetically records predetermined information, and a protective layer 122 that surrounds the magneto-optical layer 121 to prevent oxidation of the magneto-optical layer 121 and the like. It is embedded in the intermediate portion of the base material 11 in the plate thickness direction. The magneto-optical layer 121 is composed of an amorphous alloy (eg, TbFeCo) of a rare earth (Gd, Tb, etc.) and a transition metal (Fe, Co, etc.), a magnetic garnet thin film (eg, yttrium / iron garnet (YIG)), etc. It is realized using a magneto-optical material that produces an effect. Information recorded by the magneto-optical layer 121 can be optically read from the outside. The protective layer 122 has a property of transmitting light, and is realized by, for example, silicon nitride. Note that at least one surface of the recording unit 12 may be exposed on the surface of the substrate 11. Note that when a material having a high degree of barrier is applied as the base material 11 of the information recording card 1, it is not necessary to provide a protective layer for the recording unit 12.

  Information recorded by the recording unit 12 is not rewritten such as information for identifying whether the information recording card 1 is a legitimate card or information for identifying the owner of the information recording card 1. Information is assumed, but other information can be recorded.

  FIG. 3 is a diagram showing the configuration of the magneto-optical layer 121, and is a plan view seen from the direction of arrow B in FIG. In the magneto-optical layer 121, a plurality of magnetization regions M are formed in a two-dimensional square lattice. The magnetization region M generates magnetization in a direction perpendicular to the film surface, and forms a perpendicular magnetization film.

  Even if the information recording card 1 moves by the dimensional tolerance of the card (based on “JIS X 6301 identification card—physical characteristics”), the diameter of the magnetization region M forming the magneto-optical layer 121 is the information reading device 2. It is desirable that the size does not affect the reading of the image, specifically about 1 mm or more.

  Information writing to the magnetized region M is performed according to the same principle as information writing to a conventional magneto-optical disk or the like using laser light. However, in the information recording card 1, the size of the magnetization region M to be written is significantly larger than the magnetization region of a normal magneto-optical disk (in the case of a normal magnetization region, about several tens of μm). For this reason, in order to accurately write desired information to the magnetization region M without damaging the periphery of the magnetization region M, a considerably advanced technique is required. Therefore, the information recording card 1 according to the first embodiment is very difficult to falsify or forge the recorded information as compared with a normal magneto-optical disk or the like.

  In FIG. 3, the magnetized region M has a circular surface (film surface), but the surface of the magnetized region M may have a shape other than a circle (polygon, ellipse, etc.). Further, the arrangement of the magnetized regions M shown in FIG. 3 is merely an example, and may be arranged in a staggered pattern.

  The surface shape of the recording unit 12 may be a shape other than a square (rectangle, polygon, circle, etc.), and the arrangement position thereof can be changed.

  When forming the recording part 12 of the information recording card 1 having the above configuration, the protective layer 122, the magneto-optical layer 121, and the protective layer 122 are sequentially laminated on a part of the resin that forms the base material 11. . This lamination can be performed by sputtering, for example. Note that a transparent UV curable resin may be applied as a hard coat layer to the surface of the last laminated protective layer 122.

  FIG. 4 is a diagram illustrating a configuration of the information reading device 2. The information reading device 2 is a device that irradiates the information recording card 1 to be read with light and optically reads information recorded on the information recording card 1 using transmitted light of the irradiated light. Specifically, the information reading device 2 includes a card insertion slot 20 as a holding unit that holds the information recording card 1 in a stationary state, and a light source that is a light projecting unit that projects light to be emitted to the information recording card 1. 21, a linear polarizing plate 22 that is provided between the card insertion slot 20 and the light source 21 and linearly polarizes light emitted from the light source 21, and is opposed to the linear polarizing plate 22 across the card insertion slot 20. A linearly polarizing plate 23 that is a transmitting means that transmits a component in a predetermined vibration direction of light transmitted through the information recording card 1 and a light receiving unit that receives the light transmitted through the linear polarizing plate 23. An element 24 and a signal processing unit 25 (signal processing means) that performs predetermined signal processing on a signal detected by the light receiving element 24 are provided.

  The light source 21 is realized using a light emitting diode (LED). In the first embodiment, since the diameter of the magnetized region M in which information to be read is recorded is as large as the dimensional tolerance of the information recording card 1, it is not necessary to use laser light as the light source 21. Further, since the light emitted from the light source 21 is transmitted through the recording unit 12 of the information recording card 1, the distance between the light source 21 and the information recording card 1 and the distance between the light source 21 and the light receiving element 24 are made smaller than before. can do. As a result, the light emitted from the light source 21 reaches the light receiving element 24 without spreading too much, and optical components such as a condensing lens and a polarizing beam splitter are not necessary. Therefore, the number of parts can be reduced, and downsizing of the apparatus can be realized. Further, it is possible to realize cost reduction by not using expensive optical components.

  FIG. 5 is a plan view showing the configuration of the linearly polarizing plate 23. The linear polarizing plate 23 shown in the figure has a configuration in which two types of strip-shaped first polarizing plate 231 and second polarizing plate 232 having different transmission axes are arranged alternately along the short direction of each polarizing plate. Have Light that has passed through the same magnetization region M (indicated by a broken line in FIG. 5) of the recording unit 12 of the information recording card 1 is incident on the first polarizing plate 231 and the second polarizing plate 232 that make a pair adjacent to each other.

  FIG. 6 is a plan view showing the configuration of the light receiving element 24. The light receiving element 24 shown in the figure transmits the magnetization region M provided in the information recording card 1 and detects the light polarized by the linear polarizing plate 23. Therefore, the light receiving element 24 corresponds to each of the plurality of magnetization regions M, and the first light receiving unit 241 and the second light receiving unit 242 that detect light transmitted through the first polarizing plate 231 and the second polarizing plate 232, respectively. Are arranged on the base material in pairs. In other words, the light receiving element 24 receives the light transmitted through one magnetization region M by the first light receiving unit 241 and the second light receiving unit 242 that make a pair adjacent to each other. For this reason, the total number of the first light receiving parts 241 and the second light receiving parts 242 is twice as many as the magnetization region M. 6 indicates the boundary between the first polarizing plate 231 and the second polarizing plate 232 when the linear polarizing plate 23 is viewed on the light receiving element 24.

  As described above, the diameter of the magnetization region M of the recording unit 12 of the information recording card 1 is determined based on the dimensional tolerance of the card. For this reason, even if the magnetized region M moves by a dimensional tolerance, the correspondence relationship between the magnetized region M and the light receiving element 24 does not change and does not affect the reading of information recorded by the recording unit 12.

  FIG. 7 is a diagram schematically showing an outline of optical reading of information in the information reading apparatus 2 having the above configuration. First, the non-polarized light emitted from the light source 21 is linearly polarized by the linear polarizing plate 22. In FIG. 7, arrows L0 and the like schematically represent the vibration direction of the electric field constituting the light.

  The linearly polarized light having the vibration direction L0 irradiates the entire recording unit 12 of the information recording card 1 at a time and enters all the magnetization regions M at once. As shown in FIG. 8, the oscillation direction of the light incident on each magnetization region M is rotated according to the magnetization direction of the magnetization region M (Faraday effect). In FIG. 8, the transmission axis P <b> 1 is the transmission axis of the linearly polarizing plate 22. Further, the transmission axis P 2 is the transmission axis of the first polarizing plate 231, and the transmission axis P 3 is the transmission axis of the second polarizing plate 232. Here, in order to accurately detect the magnetization direction of the magnetization region M, the intensity of the light detected through the first polarizing plate 231 and the intensity of the light detected through the second polarizing plate 232. It is desirable that the absolute value of the difference be equal regardless of the magnetization direction of the magnetization region M. Therefore, in the first embodiment, the angle formed by the transmission axis P1 of the linear polarizing plate 22 and the transmission axis P2 of the first polarizing plate 231 is the transmission axis P3 of the linear polarizing plate 22 and the transmission axis P3 of the second polarizing plate 232. Is set to be equal to the angle formed by (in FIG. 8, this angle is α).

  As described above, the magnetization direction of the magnetization region M is directed to one of two directions opposite to each other. Hereinafter, these two magnetizations are referred to as upward and downward. In FIG. 8, the vibration direction of the linearly polarized light after passing through the magnetization region M having upward magnetization is L1, and the vibration direction of the linearly polarized light after passing through the magnetization region M having downward magnetization is L2. The vibration directions L1 and L2 are directions rotated by the same angle θ (Faraday rotation angle) in the opposite directions on the same plane with respect to the vibration direction L0 of the linearly polarized light incident on the magnetization region M.

FIG. 9 is a diagram illustrating light components transmitted through the first polarizing plate 231 and the second polarizing plate 232 when transmitted through the magnetization region M having upward magnetization. In FIG. 9, when the amplitude of the transmitted light having the vibration direction L1 is I, the intensity of the component L12 in the vibration direction parallel to the transmission axis P2 of this transmitted light is I ² cos ² (α−θ). On the other hand, the intensity of the component L13 in the vibration direction parallel to the transmission axis P3 of the transmitted light transmitted through the magnetization region M having upward magnetization is
I ² cos ² (α + θ). When the difference in intensity between the two vibration direction components L12 and L13 is ΔI,
ΔI = I ² cos ² (α−θ) −I ² cos ² (α + θ)
= I ² sin2α · sin2θ (1)
It is. On the other hand, in the case of the transmitted light that has passed through the magnetization region M having downward magnetization, the absolute value of ΔI is the same as the absolute value of Equation (1), but the sign of ΔI is the same as that of Equation (1). Vice versa.

  Here, the Faraday rotation angle θ is an amount determined by the characteristics of the magnetization region M and the like. Therefore, it can be seen that α = 45 (degrees) is required to maximize the intensity difference ΔI. This is the case when the transmission axis P2 and the transmission axis P3 are orthogonal.

  Light that has passed through the same magnetization region M and has passed through the first polarizing plate 231 and the second polarizing plate 232 is received by the first light receiving unit 241 and the second light receiving unit 242 that form a pair adjacent to each other. Thereafter, the light received by the first light receiving unit 241 and the second light receiving unit 242 is photoelectrically converted and sent to the signal processing unit 25.

  The signal processing unit 25 calculates the intensity difference ΔI of the light transmitted through the same magnetized region M and received by the paired first light receiving unit 241 and second light receiving unit 242 according to the equation (1). A signal of 0 or 1 is output according to the sign (±) of ΔI.

  By the way, the intensity of light from the light source 21 is almost uniform within the range of the magnetized region M, but is not uniform when viewed in the entire recording unit 12, and reaches at the central portion and the peripheral portion of the recording unit 12. A difference occurs in the intensity of the light to be transmitted. In the first embodiment, since the information associated with the magnetization region M is detected using the difference in intensity of the light received by the pair of the first light receiving unit 241 and the second light receiving unit 242, the light intensity Can be canceled by calculating the intensity difference. As a result, the magnetization direction of each magnetization region M can be accurately detected regardless of the non-uniformity of the intensity of light reaching each magnetization region M.

  The signal output from the signal processing unit 25 may be transmitted as it is to the information processing terminal, or information stored in advance in the information reading device 2 (for example, an ID for personal identification). You may make it perform collation.

  According to the first embodiment of the present invention described above, a plurality of magnetization regions that are made of a thin film-like magnetic material and generate magnetization in a direction perpendicular to the film surface are arranged two-dimensionally, and the magnetization of each magnetization region is When an information recording card having a recording unit that records information corresponding to a direction reads information recorded by the recording unit, a plurality of magnetization regions included in the information recording card are collectively irradiated with linearly polarized light, The irradiated light transmits a component in a predetermined vibration direction of the light transmitted or reflected through each magnetization region, and individually receives the component in the vibration direction of the transmitted light in association with each magnetization region. By performing signal processing using the intensity of light, information recorded by a magnetized region that is not easily affected by an external magnetic field can be read without using a complicated configuration such as an optical component such as a lens or a transport mechanism.Therefore, a high security effect can be obtained with a simple configuration.

  Further, according to the first embodiment, since the diameter of the film surface of the magnetized region is equal to or larger than the dimensional tolerance of the information recording card, a significantly larger magnetized region is formed as compared with the magnetized region in the conventional magneto-optical system. can do. As a result, the tolerance for the movement of the information recording card is increased, and the mechanism for reading can be simplified.

  Furthermore, according to the first embodiment, since the configuration of the information reading apparatus is simple, downsizing is easy, there are few failures, and maintenance work can be greatly reduced.

  Further, according to the first embodiment, since the information recorded on the information recording card is read while the card is stationary, an error or the like when transporting the card as in the conventional case does not occur, and it is stable. Can be read. Also, if an error should occur, retry can be performed in a stationary state, which is convenient.

(Embodiment 2)
FIG. 10 is a diagram showing the configuration of the information reading apparatus according to Embodiment 2 of the present invention. An information reading device 3 shown in the figure is a device that irradiates light to an information recording card 1 to be read and optically reads information recorded on the information recording card 1 using transmitted light of the irradiated light. is there. Specifically, the information reading device 3 includes a card insertion slot 30 as a holding unit that holds the information recording card 1 in a stationary state, one or a plurality of light sources 21 (only one light source 21 is illustrated in FIG. 10), , A light guide plate 31 that uniformly emits light generated by one or a plurality of light sources 21, and a polarization unit that is provided between the card insertion slot 30 and the light guide plate 31 and linearly polarizes light emitted from the light guide plate 31. The linear polarizing plate 22 and the straight line which is provided on the side facing the linear polarizing plate 22 across the card insertion slot 30 and is a transmission means for transmitting the component in the predetermined vibration direction of the light transmitted through the information recording card 1 A polarizing plate 32, a light receiving element 33 that is a light receiving unit that receives light transmitted through the linear polarizing plate 32, and a signal processing unit 34 that performs predetermined signal processing on a signal detected by the light receiving element 33. In the second embodiment, one or a plurality of light sources 21 and a light guide plate 31 have a function as light projecting means.

  The linearly polarizing plate 32 is formed of a single plate similarly to the linearly polarizing plate 22, and is disposed so that the transmission axes thereof are not parallel to the linearly polarizing plate 22.

  FIG. 11 is a plan view showing the configuration of the light receiving element 33. The light receiving element 33 shown in the figure has a plurality of light receiving portions 331 that individually transmit the plurality of magnetization regions M included in the recording unit 12 of the information recording card 1 and individually receive the light polarized by the linear polarizing plate 32. . The light receiving unit 331 is provided in a two-dimensional square lattice shape at a position corresponding to each of the plurality of magnetization regions M. Thus, in the information reading apparatus 3, since the light guide plate 31 that emits uniform light is provided, it is not necessary to provide two polarizing plates for one magnetization region M as in the first embodiment. .

  The information reading method performed by the information reading device 5 having the above configuration is the same as the information reading method according to the first embodiment described above.

  According to the second embodiment of the present invention described above, a high security effect can be obtained with a simple configuration as in the first embodiment described above.

  Further, according to the second embodiment, by using the light guide plate, the light intensity that reaches the light receiving element through the recording portion of the information recording card can be made uniform, so that it passes through one magnetization region. It is possible to measure light with a single light receiving unit. For this reason, the structure of a light receiving element can be simplified.

(Embodiment 3)
FIG. 12 is a diagram showing a configuration of an information reading system configured using the information recording card and the information recording apparatus according to Embodiment 3 of the present invention. An information reading system 200 shown in FIG. 1 includes an information recording card 4 that magnetically records predetermined information, and an information reading device 5 that optically reads information recorded by the information recording card 4. The third embodiment is characterized in that information recorded by the information recording card 4 is read by using reflected light of light emitted by the information reading device 5.

  FIG. 13 is a cross-sectional view showing the configuration of the information recording card 4. The information recording card 4 includes a thin base plate 41 and a recording portion 42 provided at a substantially central portion of the base 41 and on which predetermined information is magnetically recorded.

  The base material 41 is realized by the same resin as the base material 11 of the information recording card 1.

  The recording unit 42 includes a magneto-optical layer 421 that magnetically records predetermined information, a reflection layer 422 that is stacked on the magneto-optical layer 421 and reflects light transmitted through the magneto-optical layer 421, and the magneto-optical layer 421 and the reflection layer. And a protective layer 423 that surrounds the periphery of the layer 422 and prevents the magneto-optical layer 421 from being oxidized, and is embedded in an intermediate portion of the substrate 11 in the thickness direction.

  The magneto-optical layer 421 has the same configuration as the magneto-optical layer 121 of the information recording card 1 according to the first embodiment (see FIG. 3), an amorphous alloy of a rare earth and a transition metal, a magnetic garnet thin film, etc. This is realized using the magneto-optical material. Information recorded by the magneto-optical layer 421 can be optically read from the outside. The reflective layer 422 is realized by, for example, aluminum. Further, the protective layer 423 is realized using silicon nitride in the same manner as the protective layer 122.

  The information reading device 5 includes a card insertion slot 50 as a holding unit that holds the information recording card 4 in a stationary state, a light source 21 that is a light projecting unit that projects light to irradiate the information recording card 4, and a light source 21. Is provided between the linear polarizing plate 22 which is a polarizing means for linearly polarizing the light emitted from the card, the card insertion slot 50 and the linear polarizing plate 22, and transmits light linearly polarized by the linear polarizing plate 22. A mirror 51 that reflects the light reflected by the information recording card 4 and returned; a linear polarizing plate 23 that is a transmission means that transmits a component in a predetermined vibration direction of the light reflected by the mirror 51; A light receiving element 24 that is a light receiving unit that receives light transmitted through the plate 23 and a signal processing unit 25 that performs predetermined signal processing on a signal detected by the light receiving element 24 are provided.

  In the information reading system 200 having the above configuration, when the information reading device 5 irradiates and linearly polarized light is reflected by the recording unit 42 of the information recording card 4, the polarization axis depends on the magnetization state of the magnetization region M. Rotates (magnetic Kerr effect). For this reason, the information reading device 5 is recorded in each magnetization region M based on the sign of the intensity difference between the components in the two vibration directions transmitted through the linearly polarizing plate 23, as in the first embodiment. Information can be detected.

  According to the third embodiment of the present invention described above, a high security effect can be obtained with a simple configuration as in the first and second embodiments described above.

  In the third embodiment, the case where linearly polarized light is incident in a direction orthogonal to the surface of the magnetization region M of the information recording card 4 is described. However, the incident angle of the linearly polarized light with respect to the magnetization region M is It is not limited to.

(Embodiment 4)
FIG. 14 is a diagram showing a configuration of an information recording card according to Embodiment 4 of the present invention. The information recording card 6 shown in the figure includes a thin base plate 61 and a recording portion 62 provided at the center of the base 61 and on which predetermined information is magnetically recorded. While the surface of the base material 61 is rectangular, the surface of the recording unit 62 is square, and the center of the rectangle coincides with the center of the square. Each side of the square is parallel to any one of the sides of the rectangle.

  The configuration of the base material 61 is the same as the configuration of the base material 11 of the information recording card 1 described above. The recording unit 62 includes a thin-film magneto-optical layer 621 that magnetically records predetermined information, and a protective layer 622 that surrounds the magneto-optical layer 621 and prevents the magneto-optical layer 621 from being oxidized. The base material 61 is embedded in an intermediate portion in the plate thickness direction. Information recorded by the magneto-optical layer 621 can be optically read by using any of the information reading devices 2, 3 and 5 described in the first to third embodiments.

  The information recording card 6 is three axes including an axis (z axis) passing through the center of the rectangle formed by the surface of the base material 61 and orthogonal to the surface of the base material 61, and orthogonal to each other at the center of gravity of the information recording card 6. Each of the three axes (x-axis, y-axis, and z-axis) is 180 degrees rotationally symmetric. For this reason, the information recording card 6 has four arrangements that can move to each other by rotating 180 degrees around at least one of three axes orthogonal to each other. Hereinafter, these four arrangements will be described.

  FIG. 15 is a view of the recording unit 62 of the information recording card 6 shown in FIG. 14 as viewed from the positive z-axis direction. The vertical direction is parallel to the x-axis (positive downward), and the horizontal direction is the y-axis (rightward). Parallel to (positive). In FIG. 15, a magneto-optical material is not laminated at a location corresponding to the magnetized region in the upper left corner, and instead, a protective layer 622 penetrates up and down to form a non-magnetized region.

  FIG. 16 is a diagram showing a configuration of the magneto-optical layer 621 when the information recording card 6 is rotated 180 degrees around the x axis from the state shown in FIG. 14, and is viewed from the positive direction of the z axis as in FIG. It is a figure. In FIG. 16, the left and right positions of the non-magnetized region through which the protective layer 622 passes are reversed with respect to the position of the non-magnetized region of FIG.

  FIG. 17 is a diagram showing a configuration of the magneto-optical layer 621 when the information recording card 6 is rotated 180 degrees around the y-axis from the state shown in FIG. 14, and is viewed from the positive direction of the z-axis as in FIG. It is a figure. In FIG. 17, the position of the non-magnetized region through which the protective layer 622 penetrates is upside down with respect to the position of the non-magnetized region of FIG.

  18 is a diagram showing the configuration of the magneto-optical layer 621 when the information recording card 6 is rotated 180 degrees around the z-axis from the state shown in FIG. 14, and is viewed from the positive direction of the z-axis as in FIG. It is a figure. In FIG. 18, the position of the non-magnetized region through which the protective layer 622 penetrates is inverted both vertically and horizontally with respect to the position of the non-magnetized region of FIG.

  As is clear from FIGS. 15 to 18, the arrangement of the information recording card 6 can be identified by the position of the non-magnetized region. Hereinafter, a case where the information recording card 6 having such rotational symmetry is inserted into the information reading device 2 to read information will be considered. In this case, the intensity of light emitted from the light source 21 and transmitted through the linearly polarizing plate 22 and then transmitted through the non-magnetized region is transmitted through the magnetized region M after exiting from the light source 21 and transmitted through the linearly polarizing plate 22. Greater than light intensity. Therefore, the signal processing unit 25 of the information reading device 2 can detect the position of the non-magnetized region of the recording unit 12 according to the intensity of the light received by the light receiving element 24.

  In the fourth embodiment, the position of the non-magnetized region detected by the signal processing unit 25 is used as identification information for identifying the four arrangements of the information recording card 6 classified based on the rotational symmetry described above. That is, the signal processing unit 25 changes the signal processing content of the light transmitted through the magnetized region M of the recording unit 62 according to the position of the non-magnetized region detected based on the intensity of the light received by the light receiving element 24. To do. For example, the magnetization directions of the individual magnetization regions M are the same in FIGS. 15 and 18, but FIGS. 16 and 17 are reversed with respect to the magnetization directions in FIG. Therefore, the signal processing unit 25 performs a process of determining the positive direction of magnetization according to the position of the non-magnetized region, that is, the arrangement of the information recording card 6.

  According to the fourth embodiment of the present invention described above, since the card insertion direction in the information reading device can be identified by providing a non-magnetized region in the recording unit, the user of the information recording card can use the information reading device. When the information reading card is inserted into the card, the card can be inserted without being conscious of the insertion direction. Therefore, it is possible to significantly improve the convenience for the user.

  In addition, if the surface of the base material of the information recording card is also square, the information recording card will have higher rotational symmetry. In this case, there are eight equivalent insertion methods for the information recording card. In order to identify all the eight types of non-magnetized regions, at least two non-magnetized regions may be provided.

  As another method of providing a non-magnetized region in the recording unit, a predetermined number (for example, three) of magnetized regions M among the plurality of magnetized regions M included in the information recording card 1 according to the first embodiment. The magnetization corresponding to the start code or the end code may be applied.

  In the above description, the case where the information recording card 6 has rotational symmetry with respect to three axes has been described. However, for example, the information recording card 6 may have rotational symmetry only with respect to the z-axis in FIG. In this case, it is possible to prevent the information recording card 6 from being read when the information recording card 6 is turned upside down.

  Note that the information recorded by the information recording card 6 can be read in the same manner as described above even if the information reading device 3 or 5 is used.

(Other embodiments)
So far, the first to fourth embodiments have been described in detail as the best mode for carrying out the present invention, but the present invention should not be limited by these embodiments. For example, it is possible to read information by projecting light of an infrared ray by a light projecting unit of the information reading apparatus. In this case, a visible light blocking resin that blocks visible light and transmits infrared light may be applied as the base material of the information recording card. When infrared light is used in this way, the recording unit can be hidden from the surface of the information recording card by adopting a configuration in which the recording unit is embedded in the base material. As a result, a desired design can be applied to the surface of the information recording card including the recording unit, and the degree of freedom in design is also increased.

  As described above, the present invention can include various embodiments and the like not described herein, and various design changes and the like can be made without departing from the technical idea specified by the claims. It is possible to apply.

It is a figure which shows the structure of the information reading system comprised using the information recording card | curd and Embodiment 1 which concern on Embodiment 1 of this invention. It is a figure which shows the structure of the information recording card | curd which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the magneto-optical layer with which the information recording card | curd which concerns on Embodiment 1 of this invention is provided. It is a figure which shows the structure of the information reader which concerns on Embodiment 1 of this invention. It is a top view which shows the structure of the linearly polarizing plate with which the information reading apparatus which concerns on Embodiment 1 of this invention is provided. It is a top view which shows the structure of the light receiving element with which the information reading apparatus which concerns on Embodiment 1 of this invention is provided. It is a figure which shows typically the outline | summary of the reading of the information currently recorded on the magnetization area | region. It is a figure which shows rotation of the vibration direction by the magneto-optical effect (Faraday effect) of the light which permeate | transmitted the magnetization area | region. It is a figure which shows the component of the vibration direction of the light which permeate | transmitted two polarizing plates. It is a figure which shows the structure of the information reader which concerns on Embodiment 2 of this invention. It is a top view which shows the structure of the light receiving element with which the information reading apparatus which concerns on Embodiment 2 of this invention is provided. It is a figure which shows the structure of the information reading system comprised using the information recording card | curd and information recording apparatus which concern on Embodiment 3 of this invention. It is a figure which shows the structure of the information recording card | curd which concerns on Embodiment 3 of this invention. It is a figure which shows the structure of the information recording card | curd which concerns on Embodiment 4 of this invention. It is a figure which shows the structure (1st example) of the recording part according to arrangement | positioning of the information recording card | curd which concerns on Embodiment 4 of this invention. It is a figure which shows the structure (2nd example) of the recording part according to arrangement | positioning of the information recording card | curd which concerns on Embodiment 4 of this invention. It is a figure which shows the structure (3rd example) of the recording part according to arrangement | positioning of the information recording card | curd which concerns on Embodiment 4 of this invention. It is a figure which shows the structure (4th example) of the recording part according to arrangement | positioning of the information recording card | curd which concerns on Embodiment 4 of this invention.

Explanation of symbols

1, 4, 6 Information recording card 2, 3, 5 Information reader 11, 41, 61 Base material 12, 42, 62 Recording unit 20, 30, 50 Card insertion slot 21 Light source 22, 23, 32 Linearly polarizing plate 24, 33 Photodetector 25, 34 Signal processor 31 Light guide plate 51 Mirror 100, 200 Information reading system 121, 421, 621 Magneto-optical layer 122, 423, 622 Protective layer 231 First polarizing plate 232 Second polarizing plate 241 First light receiving portion 242 Second light receiving portion 331 Light receiving portion 422 Reflecting layer M Magnetized region

Claims (11)

An information recording card that magnetically records predetermined information and is capable of optically reading the recorded information,
A recording unit made of a thin-film magnetic material, in which a plurality of magnetization regions that generate magnetization in a direction perpendicular to the film surface of the magnetic material are two-dimensionally arranged, and information corresponding to the magnetization direction of each magnetization region is recorded An information recording card comprising:   2. The information recording card according to claim 1, wherein the diameter of the film surface of the magnetized region is equal to or larger than a dimensional tolerance of the information recording card.   The information recording card according to claim 1, wherein the recording unit is embedded in a main body of the information recording card. Three axes including an axis orthogonal to the surface, and a shape that is rotationally symmetrical by 180 degrees with respect to each of the three axes orthogonal to each other at one point inside the information recording card,
The recording unit records identification information that identifies the arrangement of the information recording cards that move with each other by rotating 180 degrees around at least one of the three axes. The information recording card according to any one of claims 1 to 3.   The information recording card according to claim 1, wherein the magnetic body includes a magneto-optical material that generates a magneto-optical effect.   6. The information recording card according to claim 5, wherein the magneto-optical material is an amorphous alloy of a rare earth and a transition metal.   6. The information recording card according to claim 5, wherein the magneto-optical material is a magnetic garnet thin film. Information comprising a recording unit that is made of a thin-film magnetic material, and in which a plurality of magnetization regions that generate magnetization in a direction perpendicular to the film surface are two-dimensionally arranged and records information corresponding to the magnetization direction of each magnetization region An information reader for reading information recorded by the recording card in the recording unit,
Holding means for holding the information recording card;
A light projecting means for projecting light onto the information recording card held by the holding means;
Polarizing means provided between the light projecting means and the holding means, and linearly polarized light projected by the light projecting means;
Transmitting means for transmitting each of the components in a predetermined vibration direction of the light transmitted or reflected by each of the plurality of magnetization regions of the recording unit of the information recording card held by the holding means;
A light receiving means for individually receiving the light transmitted by the transmission means;
Signal processing means for performing signal processing using the intensity of light individually received by the light receiving means;
With
The information reading apparatus according to claim 1, wherein the light linearly polarized by the polarizing means irradiates the plurality of magnetization regions at once. The transmission means includes components of two vibration directions rotated by the same angle in the opposite directions on the same plane with respect to the vibration direction of the linearly polarized light, among the vibration direction components of the light transmitted or reflected by each magnetization region. Each through
The signal processing means calculates an intensity difference between the two vibration direction components of light transmitted or reflected through the same magnetized region, and generates and outputs a signal corresponding to the sign of the calculated intensity difference. The information reading apparatus according to claim 8.   10. The information reading device according to claim 8, wherein the diameter of the film surface of the magnetized region is equal to or larger than a dimensional tolerance of the information recording card. Information comprising a recording unit that is made of a thin-film magnetic material, and in which a plurality of magnetization regions that generate magnetization in a direction perpendicular to the film surface are two-dimensionally arranged and records information corresponding to the magnetization direction of each magnetization region An information reading method for reading information recorded by the recording card in the recording unit,
Irradiating linearly polarized light to the plurality of magnetized regions included in the information recording card at once,
The irradiated light transmits the components in the predetermined vibration direction of the light transmitted or reflected by each magnetized region,
The component of the vibration direction of the transmitted light is individually received in association with each magnetization region,
An information reading method characterized by performing signal processing using the intensity of the received light.

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