JP3020978B2 - Card-shaped recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial Application Field) The present invention is capable of multi-value recording of necessary information on a magnetic layer such as a prepaid card, a credit card, or the like, or multi-value recording information. The present invention relates to a card-shaped recording medium which can be read and cannot be falsified.

(Prior Art) Conventionally, information recorded on a card-shaped recording medium, for example, the balance, the number of times of use, and the like, are often magnetically recorded on a magnetic stripe provided on a normal medium. Further, there has been a device in which a magnetic substance is embedded in a recording medium and the surface thereof is covered with an invisible member so that the embedded magnetic substance is punched out each time the recording medium is used (for example, Japanese Patent Publication No. 48-16595). ).

Further, a recording medium using a magnetic stripe has a drawback that the amount of information that can be recorded is small, so that a magnetic layer 4 is formed on the entire surface of a card mother layer (for example, PET) 41 as shown in FIG.
A card-shaped recording medium 40 having two layers has appeared.

Generally, a card-shaped recording medium having a magnetic layer is used with high versatility. Usually, only one type of magnetic material is used for the magnetic layer, and the magnetization characteristics of the magnetic material are determined by the magnetic flux density Φ with respect to the magnetization H. Given by the relationship
For example, a magnetic hysteresis curve C shown in FIG. 21 is obtained.

That is, the recording on the magnetic layer is performed by the binary information of the positive and negative values regarding the residual magnetic flux of the magnetic flux density Φ by applying a magnetic field by the magnetic head. In the example of FIG. Is recorded. Further, at the time of reading, the magnetic layer on which such binary information is recorded is brought into contact with the magnetic head gap, and a signal of V = α · dφ / dt (where α is a constant) is obtained from the coil by transport,
Binary encoded information of "0" and "1" is obtained.

(Problems to be Solved by the Invention) However, there is a risk that any of the information recorded on each of the recording media may be easily falsified. That is, when recording on a magnetic stripe or a magnetic layer, the recorded information can be decrypted by collecting and analyzing the recorded information from a large number of media, and for example, it is easy to give a new value to a medium having no value. . Further, in a recording medium described in Japanese Patent Publication No. 48-16595, the value can be easily recovered by embedding and gluing a magnetic substance in a punched and perforated portion.

Therefore, for a card-shaped recording medium having a magnetic layer, falsification prevention and higher security are achieved by performing multi-value recording than by binary recording, but multi-value recording is performed on one type of magnetic material. Is theoretically possible, but practically impossible. This is because, when recording information, it is difficult to keep the degree of contact on the contact surface between the magnetic head and the magnetic layer completely uniform because there is a limit in processing accuracy, and the current during recording on the magnetic head is reduced. Maintaining high accuracy is problematic in terms of cost. Further, in the case of a magnetic layer composed of one kind of magnetic material, as shown in FIG. 21, even if a change ΔH in magnetizing force, which is a deviation of the magnetic field at the time of recording, cannot be avoided to a certain extent, this deviation in ΔH causes a residual magnetic flux. In the case of Φ, a large deviation such as ΔΦ occurs. With respect to the magnetic hysteresis curve C usually shown by one type of magnetic material, the residual magnetic flux is represented by multi-values of three or more values (hereinafter, multi-value means three or more values). This is because the residual magnetic flux cannot be maintained accurately even if the above-mentioned method is used, and excessive multi-value recording only impairs the guarantee of stability at the time of reading. For this reason, multi-value recording is considered to be virtually impossible. However, under the present circumstances, binary recording is used, while leaving problems in recording density and security.

Therefore, the magnetic layer of the card-shaped recording medium is made into two layers, and two magnetic layers are constituted by magnetic materials having different coercive forces, respectively.
There is one in which recording of each layer can be recorded with independent binary information. However, information recording of each layer is limited to binary recording, and true recording is performed on one magnetic layer and false recording is performed on the other magnetic layer. this is,
Since false recording is performed on the low-coercivity magnetic layer, a true recording can be read / written by applying a bias magnetic field to the magnetic head to erase the recording on the low-coercivity layer, for example. Still, it leaves a problem in terms of security.

The present invention has been made in view of the above circumstances,
SUMMARY OF THE INVENTION It is an object of the present invention to falsify recording information by providing a single magnetic layer formed by mixing various kinds of magnetic materials having different coercive forces and forming a layer on the entire surface (or a part) of a card so that multi-value recording can be performed. To provide a card-shaped recording medium which is impossible.

(Means for Solving the Problems) The present invention relates to a card-shaped recording medium, and an object of the present invention is to provide at least two types of coercive forces having different coercive forces on the entire upper surface or a part of a card base layer. 1 consisting of a mixture of magnetic materials
This is achieved by providing one magnetic layer so that multi-level recording can be performed on this magnetic layer. Alternatively, the coercive force is 3
This is achieved by providing a magnetic layer composed of two or more types of magnetic materials that differ by a factor of two or more so that multi-level recording can be performed on this magnetic layer. Alternatively, a magnetic layer composed of two or more magnetic materials having different coercive forces is provided on the entire upper surface or a part of the upper surface of the card mother layer, and the upper surface of the magnetic layer is turned from ferromagnetic to non-magnetic by heating of a heat supply unit. This is achieved by providing a recording member that causes a magnetic transformation of magnetism. Alternatively, a magnetic layer made of two or more magnetic materials having different coercive forces is provided on the entire upper surface or a part of the card base layer, and mechanical deformation is performed on the upper surface side of the magnetic layer or the lower surface side of the card base layer. This is achieved by providing a recording member which causes magnetic transformation from non-magnetic to ferromagnetic.

(Function) In the card-shaped recording medium of the present invention, in order to enable multi-value recording of information, the magnetic layer is composed of at least two or more magnetic materials having different coercive forces from each other. This is because the magnetization characteristics of a single magnetic material have two values on a magnetic hysteresis curve, and the magnetic layer having different coercive forces is mixed and formed (or provided) to obtain a residual magnetic flux value. Is multi-valued.

The larger the difference in coercive force between the magnetic materials, the easier the multi-value recording is, but a difference of about three times or more is sufficient. Also,
The residual magnetic flux of one type of magnetic material has two values, whereas the n type of magnetic material has 2n values. However, in use, the mixing ratio (or the lamination ratio) is adjusted to determine the positive or negative of the predetermined magnetizing force. In order to make a specific residual magnetic flux correspond to the value, the (n + 1) value is used to rationalize the magnetic hysteresis characteristics.

(Embodiment) FIG. 1 shows the appearance of a card-shaped recording medium 10 according to an embodiment (first embodiment) of the present invention, and has a rectangular card structure as in the case of a magnetic card or the like. And PET,
On the entire upper surface of the card base layer 1 made of paper or the like, there is provided a magnetic layer 2 formed by mixing at least two magnetic materials having coercive forces different from each other by at least three times. A metal layer 3 made of austenitic stainless steel which has been made ferromagnetic is formed by vapor deposition, sputtering, or foil sticking. The metal layer 3 is provided with an ID recording section 4 and a frequency recording section 5 as shown in FIG. 2, and a printing section 6 as shown in FIG.
The main recording section 7 is assigned to the magnetic layer 2.

The magnetic layer 2 and the metal layer 3 of such a card-shaped recording medium 10 will be described below.

The magnetic layer 2 is not formed of one kind of magnetic material, but is formed by mixing or forming two kinds of magnetic materials having different coercive forces. FIG. 4 shows this magnetic layer 2
Shows the magnetic hysteresis characteristics of the magnetization characteristic given by a magnetic flux Φ for magnetizing force H, not only two values of the positive and negative remanent flux D1 or D3 greatest when magnetizing force H _d or H _a, residual magnetic flux D2 by magnetizing force _{H b} or _{H c} appears. H _b or H _c is low coercivity portion saturation magnetic field over Δ
It has a width of H. The residual magnetic flux has a total of three values. FIG. 5 shows the magnetic properties of the magnetic material of the magnetic layer 2, wherein the magnetic flux (density) properties are expressed by the magnetic susceptibility x with respect to the magnetic force H.
With respect to the coercive force, the magnetic material A is about five times as high as the magnetic material B, and by adjusting the current of the write head from the magnetization characteristics shown in FIG. The residual magnetic fluxes D1 to D3 can be recorded. The difference in coercive force of the magnetic material constituting the magnetic layer 2 may be three times or more,
It is desirable that the value be twice or more in order to perform multi-value recording. The magnetic layer 2 can also be formed by layering magnetic materials (multilayering) in addition to mixing and forming a plurality of magnetic materials. In this case, the orientation of each magnetic material is improved, and FIG. Has a somewhat sharper shape than the case where the inflection portion E shown in FIG.

By the way, when the magnetic layer 2 is formed using magnetic materials having different coercive forces, a magnetic hysteresis curve showing the magnetization characteristics usually has 2n residual magnetic fluxes for n types of magnetic materials. That is, in the case of the two magnetic body mixed generated magnetic layer, a residual magnetic flux D1 or D4 corresponding to the magnetizing force H _d or H _a as shown in Figure 6, corresponding to the magnetizing force H _c or H _b There exist a total of four values of the residual magnetic flux D2 or D3, but in practical terms, the residual magnetic flux of (n + 1) value (where 0
It is preferable to use only). For example, residual magnetic flux
Assuming that D3 (FIG. 4) or D4 (FIG. 6) is the initial value, and comparing the (n + 1) value in FIG. 4 and the 2n value in FIG. 6 respectively, the residual magnetic flux D2 (the to record FIG. 4) is multiplied by the magnetic field of the magnetizing force H _c, the residual magnetic flux D1 (fourth
Figure) may be Torisare the respective magnetic fields to record over a magnetic field of force H _d. However, when the 2n values of recording, for example, the residual magnetic flux D3 (FIG. 6), once the magnetizing force H _d This is because the magnetic field of the magnetizing force _Hb must be applied subsequently to the application of the magnetic field, and then the magnetic field must be removed, resulting in a troublesome recording method. Therefore, when the magnetic layer 2 is mixedly formed or layered with three types of magnetic materials,
As shown in FIG. 7, it is sufficient if the configuration is such that four values (1 to 4) of residual magnetic flux can be obtained.

To the magnetic layer 2 configured as described above, by adjusting the magnetic head in the initial state, after applying the magnetic field of force H _a on a magnetic hysteresis curve shown in FIG. 4, deprived of the magnetic field Leave in the state of residual magnetic flux D3,
Obtaining a residual magnetic flux D2 or D1 respectively over magnetizing force H _c or H _d in recording. Also in the case of rewriting, after reading the ternary information, it is only necessary to initialize by applying _a magnetic field of the magnetizing force Ha and then follow the hysteresis curve.

When reading such ternary information by FM method,
Assuming that the residual magnetic flux D3 shown in FIG. 4 is in an initial state, a description will be given with reference to a time chart shown in FIG. First, by conveying the card-shaped recording medium 10 at a constant speed, a dΦ / dt signal as shown in FIG. 3A is obtained by a magnetic head, and the dΦ / dt signal is integrated as shown in FIG. Thus, reproduction information is obtained in three values of "0", "1", and "2" as shown in FIG. When recording information in three values, the reverse process may be performed.

 Next, the metal layer 3 will be described.

It is known that martensite is obtained when steel is quenched from the austenitic region at a critical cooling rate or higher. The temperature at which martensite is generated is called the _Ms point, and depends on the chemical composition of the steel. However, martensite may be induced also by processing the unstable austenite, but its occurrence temperature is shifted to higher temperatures than M _s point, martensite does not occur due to too high a processing than M _s point. This point is called the _Md point, and the formation of martensite caused by processing is called processing-induced transformation. In this case, stress is applied to process austenite, and martensitic transformation is induced and progresses by the processing strain. Large plasticity occurs as the martensitic transformation progresses, and this is due to the transformation-induced plasticity.
It is named ced plasticity (TRIP), and this transformation-induced plasticity is a type of superplasticity. That is, austenite → martensitic transformation occurs by processing,
The stress concentration that caused the work-induced transformation is alleviated by the occurrence of the transformation, resulting in a fairly large ductility.

By the way, stainless steel is classified as shown in Table 1 below.

Austenitic stainless steel is 301, 304, 316, 321
The stainless steel as the metal layer 3 'used in the second embodiment described later is a stainless steel having a metastable austenite phase at room temperature, that is, the _Md point is higher than room temperature, and _Ms The point is austenitic stainless steel below room temperature. By subjecting the austenitic stainless steel to mechanical deformation such as rolling, embossing, and punching at room temperature, the non-magnetic austenite undergoes magnetic transformation into ferromagnetic martensite. Irreversible. It returns to non-magnetic at about 400 ° C to 1000 ° C depending on the carbon content.

On the other hand, the austenitic stainless steel as the metal layer 3 used in the first embodiment undergoes magnetic transformation due to mechanical deformation below the _Md point, resulting in a ferromagnetic martensite structure. The ferromagnetic martensite structure undergoes magnetic transformation by heating with a heat supply means such as a laser beam or a thermal head, and becomes a nonmagnetic austenite structure again at room temperature. FIG. 9 shows this state, and shows a card-like austenitic stainless steel made of ferromagnetic martensite.
When the thermal head 11 is pressed against the surface and heated, the heated portion 12 is demagnetized, and the depth D of the demagnetized portion substantially depends on the heating energy. Therefore, by moving over the ferromagnetic stainless steel 10 while controlling the heating energy of the thermal head 11, information corresponding to a ternary (0, 1, 2) state as shown in FIG. 10, for example, is obtained. Can be recorded. The same applies to the case where a laser beam is used instead of the thermal head 11. In the case of a laser beam, the beam diameter and shape can be arbitrarily changed in addition to the energy. FIG. 12 (A) shows a state in which the recess 21 of the austenitic stainless steel 20 is made ferromagnetic by embossing, and FIG. 12 (B) shows a state in which the periphery of the hole formed by the punch hole 22 becomes ferromagnetic. This shows the situation. In this manner, another magnetic recording can be performed by forming a non-magnetic portion in the ferromagnetic layer on the card in a binary or multi-valued manner or by forming a ferromagnetic portion in the non-magnetic layer. it can.

In the first embodiment, a metastable austenite structure can be obtained at room temperature as described above, and at the room temperature, it is made ferromagnetic by a special method, for example, strong processing or film formation such as vapor deposition or sputtering. A metal or alloy that causes magnetic transformation from magnetic to non-magnetic is deposited on the card base layer 1.
The metal layer 3 is provided on the upper surface side of the magnetic layer provided on the entire upper surface or a part of the magnetic layer. The recording of information on the metal layer 3 is performed by a heat supply means such as a thermal head as described with reference to FIG. 9, and the ID recording section 4 is made ferromagnetic by the heat supply means at the time of card production or issuance. The metal layer 3 is locally heated to form a nonmagnetic mark 4A as shown in FIG. The mark 4A is coded according to the number, interval, shape, etc., and the ID recording unit 4 records card price information, issuer information, etc., and records the non-magnetic mark 4A with a magnetic head or a magnetoresistive (MR) element. Position, shape (width, size, etc.),
Read the number. In the frequency recording section 5, the metal layer 3 is locally heated by the heat supply means in accordance with the frequency of use to form non-magnetic points or bars as in the frequency recording information 52 in FIG. Is not destroyed, so that high-density recording is possible. As the use frequency increases, the frequency record information 52 becomes longer accordingly. Then, the position, number or length of the non-magnetic point is read by a magnetic head or a magneto-resistive element, and another punch hole 51 may be formed in parallel for user's visual observation.

In FIG. 2, the mark 4A and the frequency record information 52 are clearly shown. However, if only the transformation is performed from ferromagnetic to non-magnetic, the transformed part can hardly be recognized by eyes.

Further, the surface of the metal layer 3 is locally heated in accordance with the printing shape by the heat supply means in accordance with the frequency of use of the printing portion 6, and a blue oxide film is formed on the surface, so that the remaining amount and the use date can be visually checked. Print on. That is, when the surface of the recording layer 3 is heated for a long time by the heat supply means or at a high temperature, the surface of the silver-white recording layer 3 changes to blue via a golden color and is printed as shown in FIG.

FIG. 11 shows that a primary coil 32 and a secondary coil 33 are
Is shown, the read portion of the magnetic head 30 is located in the ferromagnetic portion (or the mixed portion of ferromagnetic and non-magnetic) or the non-magnetic portion of the metal layer 3. With secondary coil 33
Output V _OUT of the metal layer 3
The information in the recording unit 4 and the frequency recording unit 5 can be read. That is, the card-shaped recording medium 10 of this embodiment performs the magnetic recording of the information after the multi-level recording can be performed on the magnetic layer 2 and the heat supply means on the metal layer 3 by the heat supply means. Necessary information is recorded.

In the above embodiment, the magnetic layer 2 is formed on the entire surface of the card base material.
And the metal layer 3 is layered on the entire upper surface of the magnetic layer 2, but may be provided on a part of the card.

Further, in the above description, the ternary recording is performed on the recording portion of the austenitic stainless steel 13 which has been made ferromagnetic, but it is also possible to record multi-valued information of two or more values. . It is also possible to provide a protective layer, a soft magnetic layer for concealing magnetic recording, a color printing layer, a printing layer, or a layer for aesthetics on each recording member so that each recording layer is invisible from the outside. It is. Further, the main recording section 7 of the magnetic layer 2 can be read and written through the upper layer by a magnetic head adjusted so that multi-value recording can be performed. Therefore, the modes of such magnetic recording and frequency recording are not limited to the present embodiment, but can be variously changed.

FIG. 13 shows the appearance of a card-shaped recording medium 50 as a second embodiment, corresponding to the first embodiment. The basic difference from the card-shaped recording medium 10 of the first embodiment is that, instead of the ferromagnetic austenitic stainless steel as the metal layer 3, a nonmagnetic austenitic stainless steel metal layer 3 'is used. It is a point. A magnetic layer 2 composed of a mixture of two magnetic materials is provided on the entire upper surface of a card base layer 1 made of PET, paper, or the like, and the entire lower surface of the card base layer 1 is made of non-magnetic austenitic stainless steel. The metal layer 3 ′ has a configuration in which the metal layer 3 ′ is layered by attaching a foil or the like. Further, a coating layer for protecting the magnetic layer 2 is provided on the entire upper surface of the magnetic layer 2.
51 is layered, and its surface is a printing surface for printing the remaining amount, the date of use, and the like visually. A protective layer 52 made of PET, paper, or the like for concealing the metal layer 3 'is provided on the entire lower surface of the metal layer 3', and the required printing is made in advance on the surface. An ID recording section 4 and a frequency recording section 5 are assigned to the metal layer 3 ′, and a main recording section 7 is assigned to the magnetic layer 2. The recording on the metal layer 3 ′ is performed by perforation (punch hole) or by embossing. That is, the metal layer 3 '
When the non-magnetic austenitic stainless steel is subjected to mechanical deformation, magnetic transformation occurs only around the perforated portion H (or embossed portion) as shown in FIG. If a head or a magnetoresistive element (MR) is used, the position and the number of the perforated portions H (or embossed portions) can be read.

FIG. 14 shows an example of a magnetic head 60 for detecting ferromagnetism near the perforated portion H when the recording unit is transported in a direction perpendicular to the plane of the paper, in which magnetoresistive (MR) elements 62 and 63 are connected in series. connected to, and applies a DC bias D _B therebetween,
It is magnetized by the permanent magnet 61. In this case, the MR element 62 acts for canceling, and the output V _OUT of the MR element 63 changes due to the ferromagnetic portion near the perforated portion H, so that the recorded information in the recording portion can be read.

FIG. 15 shows an example in which information in the storage section is read by the magnetic head 80, and FIG. 16 shows that after the magnetizing section S magnetizes the ferromagnetic section S, the recording medium is conveyed and the output coil 83 is turned on. An example in which reading is performed with a wound magnetic head 80 is shown. In this case, since the ferromagnetic portion S is magnetized and magnetized by the magnet 84, the output coil when the ferromagnetic portion S comes to the position of the magnetic head 80 is formed.
The output voltage V _{OUT at} 83 changes, whereby the ferromagnetic portion S can be detected. 17 to 19 show examples of a detection device using a magnetoresistive element (MR element).
The figure shows the MR element for detection (MR1) 70 and the MR element for cancellation (M
R2) is placed in the magnetic field of the electromagnet 72 for detection. In FIG. 18, one MR element 73 is placed in the magnetic field of the electromagnet 74 and driven via the resistor 75. 19 is an example in which two MR elements 76 and 77 are separated via an electromagnet 78.

By appropriately selecting such a magnetic head and a magnetic detection device, the position and the number of the perforated portions H (or embossed portions) can be read as the recording information of the ID recording unit 4 and the frequency recording unit 5. .

The metal layer 3 'of the card-shaped recording medium 50 shown in FIG.
May be provided on the entire surface of the magnetic layer 2 or may be provided together with the metal layer 3 of the first embodiment.

Effects of the Invention As described above, according to the card-shaped recording medium of the present invention,
By forming or layering magnetic materials having different coercive forces from each other to form a magnetic layer, there is provided a novel card capable of recording information at high density and with multiple values. That is, magnetic recording is different from the conventional writing method,
Since the technology for multi-values is introduced, measures for preventing unauthorized use such as skimming (data copying) and refreshing (data change) of information are taken, and security can be remarkably improved. In addition, due to the nature of using multi-valued residual magnetic flux, for example, the residual magnetic flux of strong coercive force of the magnetic material is used for dummy information, and the necessary information is recorded in the residual magnetic flux of weak coercive force, and it is more than weak coercive force for reading. It can be used with a concealment function such as that performed by Further, a non-magnetic portion can be formed by applying heat to a metal layer made of ferromagnetic austenitic stainless steel or a similar alloy having an effect on the magnetic layer, whereby information can be recorded. Such cards have also been realized. Since the transformed non-magnetic portion does not become ferromagnetic unless subjected to strong processing, it is extremely difficult to return such a recording member to its original state, and it becomes virtually impossible to tamper with card data. The magnetic transformation is not visible from the outside and cannot be copied. In a metal layer using nonmagnetic austenitic stainless steel, a ferromagnetic portion can be formed by perforation or the like, and the ferromagnetic portion returns to its original nonmagnetic state unless heated to several hundred degrees Celsius or more. Therefore, an excellent recording medium having high stability can be provided.

In the card of the first embodiment, since a ferromagnetic metal layer is provided on the upper surface of the magnetic layer, for example, after performing multi-level magnetic recording on the main recording portion of the magnetic layer, another card is separately provided on the upper metal layer. If the dummy information is recorded, the security of using the card can be ultimately improved.

[Brief description of the drawings]

FIG. 1 is an external view showing a card-shaped recording medium as a first embodiment of the present invention, FIGS. 2 and 3 are diagrams showing a part of the card-shaped recording medium, and FIG. 4 is related to the card-shaped recording medium of the present invention. FIG. 5 shows an example of a magnetic hysteresis curve of a magnetic layer, FIG. 5 shows a characteristic diagram of the magnetic material, FIG. 6 shows a magnetic hysteresis curve of another magnetic layer, and FIG. 7 shows a residual magnetic flux of another magnetic layer. FIG. 8 is a time chart for explaining reading of multi-valued information from a magnetic layer, and FIG. 9 is a diagram showing a state of heating a ferromagnetic austenitic stainless steel. The figure showing the
FIG. 10 is a diagram showing a state in which magnetic transformation is caused by heating,
FIG. 11 is a structural view showing an example of a magnetic head suitable for a card-shaped recording medium according to the present invention, and FIGS. 12 (A) and (B) illustrate how a non-magnetic material undergoes ferromagnetic transformation by mechanical treatment. FIG. 13 is an external view showing a second embodiment of the card-shaped recording medium of the present invention, and FIGS. 14 to 16 are other magnetic heads suitable for the card-shaped recording medium of the present invention. FIGS. 17 to 19 are diagrams showing examples of a magnetoresistive element suitable for the card-shaped recording medium of the present invention, FIG. 20 is a diagram showing an example of a conventional card, and FIG. FIG. 4 is a magnetic hysteresis curve diagram of the magnetic layer of FIG. 1 ... card mother layer, 2 ... magnetic layer, 3, 3 '... metal layer, 4 ... ID
Recording section, 5 ... frequency recording section, 6 ... printing section, 7 ... main recording section,
10, 40, 50 ... card-shaped recording medium, 30 ... magnetic head.

Claims (4)

(57) [Claims] 1. A single magnetic layer comprising a mixture of two or more magnetic materials having different coercive forces is provided on the entire upper surface or a part of the card base layer, and multi-value recording can be performed on the magnetic layer. A card-shaped recording medium characterized by the above. 2. A magnetic layer comprising two or more magnetic materials, each having a coercive force different by at least three times, is provided on the entire upper surface or a part of the card base layer, and multi-value recording can be performed on this magnetic layer. A card-shaped recording medium characterized by the following. 3. A magnetic layer composed of two or more magnetic materials having different coercive forces is provided on the entire upper surface or a part of the upper surface of the card base layer, and the upper surface of the magnetic layer is heated by a heat supply means. A card-shaped recording medium, comprising a recording member which causes a magnetic transformation from magnetic to non-magnetic. 4. A magnetic layer comprising two or more magnetic materials having different coercive forces is provided on the entire upper surface or a part of the card base layer, and on the upper surface side of the magnetic layer or the lower surface side of the card base layer. A card-shaped recording medium characterized by comprising a recording member which causes a magnetic transformation from non-magnetic to ferromagnetic by mechanical deformation.