JPH09288802A - Magnetic card, its recording method and its collating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent forgery of data, etc., for showing the using state, etc., by performing one-directional magnetical recording. SOLUTION: A part of a recording surface 11 of a prepaid card 10 is made to be a one-directional recording area 13 by using a magnetic material capable of magnetic recording only under the demagnetizing state at ordinary temp., and is moreover divided into a 1st recording area 131 and a 2nd recording area 132 , and at the manufacturing time, the one-directional recording area 13 is initialized into the demagnetizing state. At the time of issuing the card, a specific data for this card is recorded in the 1st recording area 131 , and also the specific data is recorded in a reading commencement part of the 2nd recording area 132 . Then, whenever the card is used, the data recorded in the 1st and 2nd recording areas 131 and 132 are read out and collated after demagnetizing an already recorded part out of the one-directional recording area 13. Afterward, a frequency data showing used frequency is additionally recorded in the 2nd recording area 132 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card suitable for use in a magnetic card such as a so-called prepaid card, a recording method therefor, and a matching method therefor.

[0002]

2. Description of the Related Art Conventionally, a technique for recording magnetic data has been widely used in magnetic recording media such as ID cards and prepaid cards. However, in recent years, many cases have been reported in which data is tampered with by taking advantage of the magnetic recording property of "rewritable". Therefore, in order to prevent these cases, for example, in prepaid cards,
Data indicating the frequency of use is recorded on the recording medium itself separately from the magnetic data, and at the time of use, both records are compared and verified to verify the presence or absence of tampering. In this case, in the method of recording on the recording medium itself, punching of punch holes, destruction by metal discharge, thermal destruction of low melting point metal, etc., and once recording, it cannot be physically returned to the original state. A recording method for creating a state (hereinafter, referred to as "unidirectional recording") is used.

[0003]

However, such conventional one-way recording is, for example, an aluminum discharge breakdown recording,
Since it uses recording materials and recording methods that are essentially unrelated to magnetic recording, such as tin vapor deposition film destruction recording and punch hole recording, it is not only a device required for reading and writing but also a recording medium. It was a cause of inviting high cost of itself. Further, at the time of reading / recording, there is a problem that the recording medium itself is stained (print residue, burrs due to perforation, etc.), and maintenance of a device required for reading / recording is indispensable. It is also pointed out that the most common method of punching punch holes according to the frequency of use is powerless with respect to a means for shielding the punch holes with a protective tape or the like. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic card that solves the above problems by using magnetic recording for unidirectional recording, a recording method therefor, and a matching method. To do.

[0004]

In order to solve the above problems, the present invention has a first recording area using a magnetic material capable of magnetic recording only in a demagnetized state, and before data recording. In addition, the first recording area is initialized to a demagnetized state, and the data to be recorded is additionally recorded in the first recording area at the time of recording. Such magnetic materials include
For example, Mn-Bi exists, and once data is recorded in a demagnetized state, the data cannot be erased at room temperature. Therefore, if, for example, data indicating the usage frequency of the card is additionally recorded in the recording area, it becomes impossible to return the usage frequency to the previous state. Further, before use, the card stores data unique to the recording area, and demagnetizes the recording area for each use to determine the presence or absence of data. It is possible to determine whether or not. This is because if the recording area is subjected to DC degaussing with a permanent magnet or AC degaussing with a high frequency twice or more the recording frequency, the illegally recorded data will be erased, but the additionally recorded data will not be erased. This is because.

[0005]

Embodiments of the present invention will be described below with reference to the drawings.

<1: First Embodiment> This embodiment is applied to a prepaid card in which a predetermined amount of money information is not recorded as an initial state as a magnetic card.
FIG. 4 is a plan view showing the structure of the recording surface. As shown in the figure, the recording surface 11 of the prepaid card 10 has a rewritable area 12 made of a normal magnetic material for performing rewritable magnetic recording and a unidirectional recording for performing unidirectional recording magnetically. It is divided into a recording area 13.

Of these, in the rewritable area 12, transaction data indicating the transaction status of the card is recorded each time a ticket is issued or each time it is used. The unidirectional recording area 13 further includes a first recording area 131 and a second recording area 132.
It is divided into Here, in the first recording area 131, unique data unique to the card, such as the card type and ID, is recorded when the ticket is issued. In addition, the second recording area 132
In that area, limit number data indicating a limit number (amount of money, issuance frequency) usable in the card is recorded as unique data in one area. In this case, one area is preferably the head area when the external magnetic head scans the second recording area 132. Further, in the second recording area 132, following this one area, frequency data indicating the frequency of using the card is additionally recorded for each use. Therefore, in the present embodiment, the card specific data is recorded in the first recording area 131 and the head area of the second recording area 132, while the frequency data corresponding to the usage frequency of the card is recorded in the first area. The second recording area 13 2 will be additionally recorded in areas other than the head area.

Here, the difference between the issue frequency indicated by the limit data of the peculiar data and the usage degree indicated by the frequency data indicates the balance frequency that can be used thereafter.
Also, the usage frequency indicated by the transaction data recorded in the rewritable area 12 and the usage frequency indicated by the frequency data additionally recorded in the second recording area 132 should originally match. In addition, in the recording layer of the rewritable area 12,
In order to rewrite the data, general magnetic materials such as iron oxide substances such as barium ferrite and γ-ferrite,
A crystalline simple metal such as carbonyl iron is used, and a magnetic thin film having the following magnetic characteristics is used for the recording layer of the unidirectional recording region 13 in order to magnetically perform unidirectional recording. .

<1-1: Magnetic Thin Film> That is, when the magnetic thin film is magnetized in a demagnetized state (unmagnetized state) with an apparent coercive force of about 600 to 1000 [Oe] at room temperature. , Its initial magnetization characteristic saturates in a magnetic field less than half the coercive force, but the coercive force at that time is 10 [kOe] or more. On the other hand, in this magnetic thin film, the magnitude of magnetization becomes small and the coercive force becomes about 200 [Oe] in a low temperature environment of −180 ° C. or less, but the magnetization direction does not change. Thereafter, even when the temperature is returned to room temperature and an external magnetic field is applied, the magnetization direction cannot be accurately changed.

In such a magnetic thin film, the coercive force from the demagnetized state at room temperature is about 600 to 1000 [Oe] as described above, so that a general magnetic head such as a magnetic head such as permalloy or sendust is used. It can be used for magnetic recording. Also, once magnetically recorded, its coercive force is 10 [kO
e] or more, but the strength of the external magnetic field from the magnetic head or the like is at most about 5 to 6 [kOe], so the magnetization direction of the magnetic thin film cannot be changed.

Therefore, once magnetic recording is performed using a general magnetic head in a demagnetized state of such a magnetic thin film at room temperature, the contents cannot be erased and rewritten. Can not. Therefore, such a magnetic thin film can be magnetically recorded only in a demagnetized state at room temperature. The magnetic material having the characteristics described above includes, for example, Mn-Bi, which is thinned by deposition (evaporation, sputtering, etc.), printing or the like and used as the magnetic thin film in the present embodiment. The demagnetization method for the above magnetic material is as follows. That is, if such a magnetic material is in a magnetized state, it is first cooled to an ultralow temperature (for example, −180 ° C.), and then an AC magnetic field with a peak magnetic field of about 500 to 1500 [Oe] or attenuation from the outside. Apply a magnetic field. Thereby, demagnetization or initialization can be performed.

<1-2: Additional Recording Method> Next, a method of additionally recording frequency data in the unidirectional recording area 13 made of the above-mentioned magnetic thin film will be described with reference to FIG.
It is assumed that the frequency data is recorded in a demagnetized state at room temperature. If the usage frequency is "1",
As shown in FIG. 2A, one set of magnetic blocks B1 whose magnetic directions are opposite to each other is recorded as frequency data in the second recording area 132 following the limit number data recorded first in the scanning direction. To be done. Note that the limit number data is omitted in the figure. Next, when the usage frequency becomes "2", as shown in FIG. 2B, the same magnetic block B2
Is recorded as frequency data adjacent to the previously recorded magnetic block B1. Hereinafter, each time the number of times of use increases, a similar magnetic block is similarly created in the second recording area 13.
In 2, the data is sequentially recorded as frequency data along the scanning direction. On the other hand, a portion of the second recording area 132 where no limit number data and frequency data are recorded is kept in a demagnetized state due to initialization.

Therefore, the usage frequency of the prepaid card 10 can be obtained by the following method. That is, first, the second recording area 132 is scanned by the magnetic head to detect positive and negative magnetic peak points of the magnetic block recorded following the limit number data, and then the number is n. In this case, (n-1) / 2 is calculated and the number of magnetically inverted magnetic blocks is detected to obtain the usage frequency. However, if there is no magnetic peak point, the frequency of use is “0”.

<1-3: Operation> Next, the operation of the prepaid card according to the present embodiment will be described with reference to FIG. When this prepaid card 10 is manufactured at the factory,
First, in step S1, at least the unidirectional recording area 13 is initialized to a demagnetized state by the above-mentioned ultra-low temperature environment / AC magnetic field. Thereafter, the initialized prepaid card 10 is shipped from the factory in a state of being magnetically shielded, and delivered to a store or the like where the card is used.

Next, when the prepaid card 10 is issued, in step S2, the first recording area 131 of the unidirectional recording area 13 contains unique data such as the card type and ID. While the data is directionally recorded, the limit number data is unidirectionally recorded as unique data in the head area of the second recording area 132. Therefore, at this time, the peculiar data is recorded in the first recording area 131 and the head area of the second recording area 132 while the demagnetized state is recorded in the areas other than the head area of the second recording area 132. Is maintained. Next, in step S3, data indicating that the transaction count of the card is zero is recorded in the rewritable area 12 as transaction data.

Each time the prepaid card 10 is used, data is read / written (recorded) in the rewritable area 12 and the unidirectional recording area 13 in accordance with the usage status. Done. Specifically, the processes of the following steps S4 to S12 are executed. First, in step S4, the prepaid card 10 used is read and
It is inserted into the writing device. Next, in step S5, the first recording area 131 of the unidirectional recording area 13
Is demagnetized by the magnetic head. Here, in the present embodiment, tampering with the prepaid card 10 is detected in steps S6 and S7 assuming the following tampering.

The proper frequency data of the prepaid card recorded at the time of issuing the ticket or before the present time is transferred to a magnetic tape or the like made of an ordinary magnetic material, and the frequency data of the card base material is recorded on this magnetic tape. The magnetic recording medium is affixed to an appropriate position, and another magnetic recording medium in which data can be rewritten by a magnetic head or the like is used. Alternatively, the frequency data is similarly transferred to a magnetic card available on the market. The recorded frequency data itself is rewritten to data before the ticket is issued or before the present time. In any case, the frequency data is magnetically tampered with at the time of ticketing or before the current time.

Considering a case here, in the present embodiment, the coercive force of the magnetic thin film at room temperature is sufficiently stronger than the magnetic field of the magnetic head. The unique data once recorded in 131 should not be erased by the degaussing process (step S5) by the magnetic head. Therefore, in the case of a legitimate prepaid card, the unique data is still recorded in the first recording area 131 even after the degaussing process, whereas in the case of an unauthorized prepaid card, all the data on the transferred tape or the like is erased. To be done. Therefore, after the degaussing process in step S5, it is determined in step S6 whether or not the unique data is recorded in the first recording area 131, and if it is not recorded, it is detected that the case is illegal due to the case. You can

On the other hand, considering the case, in the present embodiment, the frequency data recorded in the second recording area 132 cannot be rewritten. The reason is that, in the second recording area 132, the area where the frequency data is recorded is in a demagnetized state at the time of ticketing, and in the present embodiment, the frequency data cannot be erased at room temperature and can only be additionally recorded. This is because. That is, the frequency data recorded in the second recording area 132 is irreversible and cannot be restored to the frequency data at the time of issuance or the frequency data prior to the present time. Even if the transaction data recorded in the rewritable area 12 is rewritten, the usage frequency indicated by the transaction data recorded in the rewritable area 12 and the frequency data recorded in the second recording area 132 are indicated. The usage frequency will not match. Therefore, in step S7, the transaction data is read from the rewritable area 12 and the frequency data is read from the second recording area 132, and the usage frequency indicated by the transaction data and the usage frequency indicated by the frequency data are read. It is possible to determine whether they match, and if they do not match, it can be detected that the case is fraudulent.

When the prepaid card 10 is detected as an illegal one as a result of such discrimination, a message to that effect is displayed and the prepaid card 10 is judged to be in error, and the subsequent processing is disabled. . On the other hand, when it is detected that the prepaid card 10 is valid, the processing procedure proceeds to the next step S8, and the second recording area 132
Reading the limit count data from the first area of the second record area to obtain the difference from the count data read from the second recording area 132, that is, the balance frequency that can be used thereafter is calculated, and whether the balance count is zero or not. Determine whether. If the result of this determination is "Yes", a message to that effect is displayed, and
The use of this prepaid card 10 is terminated. on the other hand,
If the determination result is "No", in the next step S9, the user is permitted to purchase a product or the like having the balance frequency equal to or less than the obtained balance frequency. Then, when the user actually purchases the product etc., the frequency data corresponding to the purchase amount is additionally recorded in the second recording area 132 in step S10, and subsequently, the transaction data in the rewritable area 12 in step S11. Is rewritten to a value according to the transaction frequency.
Then, in step S12, the prepaid card 10 is returned to the user. After that, prepaid card 1
Whenever a purchase using 0 is made, step S
The processing of 4 to S12 will be executed.

According to the prepaid card according to the present embodiment as described above, since the unidirectional recording is magnetically performed, the device required for reading and writing can be shared with that of general magnetic recording, and the whole system can be used. The cost can be kept low. In addition, since the recording medium is not contaminated during reading and writing, maintenance of the device required for reading and writing becomes almost unnecessary. Furthermore, since the frequency data can only be additionally recorded and cannot be erased at room temperature, it is almost impossible to falsify the frequency data, and the security can be improved.

<1-4: Modification of First Embodiment> In the above-described first embodiment, the second recording area 132
Since it is not possible to rewrite the frequency data recorded in, it is considered that the damage due to the case does not substantially occur. Therefore, as shown in FIG. 5, the collation between the frequency data and the transaction data may be abolished, and the fraud may be determined only by the presence or absence of the unique data after the degaussing process. Since this configuration corresponds to a second embodiment described later, it will be described in detail there. In step S5, the target of the degaussing process is the first recording area 13
Although only 1, the area in which the limit number data is recorded and the area in which the frequency data is additionally recorded in the second recording area 132 may be the target of the degaussing process.
At this time, regarding the above-mentioned area of the second recording area 132,
There are two possible cases, one is for the degaussing process together with the first recording area 131, and the other is for the degaussing process alone. Here, when both areas are to be degaussed,
The presence / absence of unique data in the first recording area 131 and the presence / absence of limit number data in the second recording area 132 are detected, and the frequency data in the second recording area 132 and the transaction data in the rewritable area 12 are collated. By doing so, the reliability of discrimination can be further improved. On the other hand, when the above-mentioned area of the second recording area 132 is to be the target of the degaussing processing alone, the second recording area 1
While detecting the presence or absence of the limit number data in 32,
The same effect can be obtained by collating the frequency data in the second recording area 132 with the transaction data in the rewritable area 12. Further, in the above-described first embodiment, when the ticket is issued, the limit number data is to be recorded in the head area of the second recording area 132, but this is recorded in the first recording area 131. Then, the second recording area 1
Only frequency data may be recorded in 32.

<2: Second Embodiment> In the prepaid card 10 according to the first embodiment described above, the frequency data is additionally recorded as magnetic blocks whose magnetic directions are opposite to each other. In the embodiment, the region length is magnetized. Further, the second embodiment is such that the rewritable area 12 in the first embodiment is used.
It is also an example of not having. FIG. 4A shows this second
3 is a plan view showing a recording surface 21 of the prepaid card 20 according to the embodiment. FIG. As shown in this figure, on the recording surface 21, a unidirectional recording area 23 for magnetically performing unidirectional recording, and guide patterns 24 arranged at equal intervals along the scanning direction of the magnetic head are formed. It is provided. The guide pattern 24 can be detected optically or magnetically, and when the usable transaction limit of the prepaid card 20 is set to "10", as shown in FIG.
It is composed of eleven bars including a bar 240 for detecting the start position and bars 241 to 2410 corresponding to each usage frequency. Then, in the second embodiment, the guide pattern 24 and the unidirectional recording area 23 are simultaneously read in the scanning direction.

<2-1: Additional Recording Method> Next, the additional data recording method of the frequency data in the other mode will be described. 6 and 7 are diagrams for explaining the concept of this system. The second embodiment has the following points in common with the first embodiment. That is, first,
The point that the unidirectional recording area 23 is initialized to a demagnetized state at the time of manufacturing, and secondly, at the time of issuance, the limit number data indicating the usable maximum number of the card is magnetically recorded in the unidirectional recording area 23. At the point of being recorded in the head area of the head in the scanning direction, and thirdly, at the time of use, before reading the data, the area of the unidirectional recording area 23 where the data has already been recorded is demagnetized. First and second
It is common in the embodiments.

First, when the guide pattern 24 is read,
The guide pattern output corresponding to the reading is shown in FIG.
Obtained as shown in (a). At the time of initialization immediately after manufacturing, the unidirectional recording area 23 is initialized to the demagnetized state, and as a result, nothing is recorded in that area as shown in FIG. Next, at the time of ticketing, as shown in FIG. 6B, the bar 240 for detecting the start position is read, and the falling portion P of the read signal is detected.
Then, the frequency data is additionally recorded in the unidirectional recording area 23 until the time point Q when the time ΔT2 elapses after the falling portion P is detected. Only the frequency data recorded at this time is recorded at the time of ticketing and does not indicate the frequency that has already been used, and therefore has the meaning of the unique data in the above-described embodiment. At the time of issuing a ticket, the frequency of use is naturally zero.

Next, at the time of use, when checking the usage frequency of the card (at the time of reading), as shown in FIG. 7A, the guide pattern 24 and the unidirectional recording area 23 are read at the same time. The bar number n of the guide pattern is counted until the next time point R. That is, in the read signal of the guide pattern, the time ΔT1 (where ΔT1>
Even if ΔT2) has elapsed, the bar number n of the guide pattern is counted until time R when the frequency data is not detected in the read signal of the unidirectional recording area 23. If the number n of bars counted at this time is used, the usable balance frequency is (11-n) frequency and the usage frequency is (n-1). In the example shown in FIG. 7A, since the number of bars counted up to the time point R is “3”, the balance frequency is “8” and the usage frequency is “2”. To be detected.

Next, at the time of use, at the time of additionally recording frequency data corresponding to the usage frequency on the card (at the time of recording)
, The frequency data is as shown in FIG.
From the next time point S to time point U, additional recording is performed in the unidirectional recording area 23. That is, from the time S when the time ΔT1 has elapsed after the trailing portion is detected, the trailing portion of the bar that is the number of bars counted during the previous reading is added to the bar. The frequency data is additionally recorded until the time point U when the time ΔT2 is detected.

Here, for example, a case will be described in which a prepaid card 20 having a usage frequency of "2" is used to purchase a product having a usage frequency of "1". First, as shown in FIG. 7A, the number of bars up to the time point R during reading is counted as "3", so that the usage frequency is obtained as "2". After that, as shown in FIG. 7B, at the time of recording, from the point S at which the frequency data is further time ΔT1 has elapsed since the falling portion of the bar 242 corresponding to the previous usage frequency “2” was detected. , Is additionally recorded until a time T when a time ΔT2 has elapsed after the falling portion of the bar 243 corresponding to the usage number “3” to which the usage number “1” is added is detected.

<2-2: Operation> The operation of the second embodiment in such a recording system is as shown in FIG. In the present embodiment, the rewritable area 12 in the first embodiment is not provided, and thus the processing relating to transaction data is excluded in the operation shown in FIG. In addition, the target of the degaussing process in step S5 is the unidirectional recording area 2
It is possible to limit the area in which the frequency data is recorded, or to set the whole area of the unidirectional recording area 23. Now, in the second embodiment, if the card to be used is valid, the data recorded in the unidirectional recording area 23 should not be erased by the degaussing process in step S5. Even if the card is unused after the ticket issuance, the limit data and the frequency data corresponding to the start position detecting bar 2410 should be recorded in the unidirectional recording area 23 when the ticket is issued. . Therefore, in the case of a valid card, at least the limit number data and the frequency data corresponding to the start position detecting bar 2410 are still recorded in the one-way recording area 23 even after the degaussing process. If the card is one in which the frequency data has been tampered with, such as by attaching a magnetic tape or the like to the unidirectional recording area 23, all the transferred data is erased. Therefore, after the degaussing process in step S5,
6, it is determined whether or not the limit number data and the frequency data having the first unique data meaning are recorded in the one-way recording area 23, and if they are not recorded, it can be detected as illegal. it can.

Further, in such a recording method, when the prepaid card 20 is used up to the issuance frequency of "10", the frequency data is the time from the falling portion of the bar 2410 corresponding to the usage frequency "10". Until ΔT2 elapses, all bars 240 in the guide pattern 24
.About.2410 will be recorded. When the frequency data is recorded corresponding to all the bars 240 to 2410, the number of guide patterns up to the time point R is counted as "11", the usage frequency is "10", and the balance frequency is "0". Is detected, it is determined that all prepaid cards have been used, and the use of the prepaid card 20 is completed.

<2-3: Modification of Second Embodiment> The second embodiment described above does not have the rewritable area 12 of the first embodiment, but in the present invention, rewriting is possible. The existence of the region 12 is not denied, and may be provided separately. In the second embodiment, the limit number data and the frequency data are recorded in the unidirectional recording area 13. However, a plurality of unidirectional recording areas 13 are provided and only one of them is limited. It is also possible to record the number data and record the frequency data in the other area.

<3: Others> In the first and second embodiments described above, since the magnetic card is applied to the prepaid card, the frequency data is recorded in the unidirectional recording areas 13 and 23. When the magnetic card of the present invention is applied to a card other than a prepaid card, it may be considered that frequency data need not be recorded. If the frequency data is not recorded, it is sufficient to record only the unique data that is unique to the card, and if the unique data is still recorded even if the area is degaussed, it is determined that the card is valid. . Further, in the present invention, a person who can know the magnetic characteristics of the magnetic material used for the recording layer de-magnetizes the regions 13 and 23 in which the unidirectional recording is to be performed by the above-described method to falsify the frequency data. (Erase) is theoretically possible. However, in order to bring it into the demagnetized state, an environment for cooling the recording layer to about −180 ° C., equipment for applying an AC magnetic field, and the like are required, and therefore it is considered practically impossible.

[0033]

As described above, according to the present invention,
Since the unidirectional recording is performed by magnetic recording, which is an original recording method, it is possible to reduce the cost not only in the apparatus itself but also in the recording medium alone. Further, in comparison with a conventional method such as punching of a punch hole, the recording medium is not stained at the time of reading / writing, so that the apparatus required for reading / writing can be maintenance-free.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a prepaid card according to a first embodiment of the present invention.

FIG. 2A and FIG. 2B are diagrams for explaining a recording method of frequency data in a recording area of the same prepaid card.

FIG. 3 is a flowchart showing an operation of the prepaid card according to the same embodiment.

FIG. 4A is a plan view showing a configuration of a prepaid card according to another embodiment of the present invention, and FIG. 4B is a view showing a guide pattern thereof.

FIG. 5 is a flowchart showing an operation of the prepaid card according to the embodiment.

6A and 6B are diagrams showing a read / write signal of a guide pattern and frequency data of the same prepaid card, respectively.

FIGS. 7A and 7B are diagrams showing a read / write signal of a guide pattern and frequency data of the same prepaid card, respectively.

[Explanation of symbols]

 10, 20 ... Prepaid card (magnetic card), 13, 23 ... Unidirectional recording area (recording area), 131 ... First recording area, 132 ... Second recording area

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G11B 5/80 G07F 7/08 Z

Claims (8)

[Claims] 1. A first recording area is formed by using a magnetic material that can be magnetically recorded only in a demagnetized state at room temperature, the first recording area is initialized to a demagnetized state before recording, and at the time of recording. A magnetic card, wherein data is additionally recorded on the first recording area. 2. The magnetic card according to claim 1, wherein the second recording area is formed by using a magnetic material capable of rewriting magnetic recording. 3. The magnetic material according to claim 1, wherein the initial magnetization characteristic from the demagnetized state at room temperature is saturated in a magnetic field of half the coercive force or less, and the coercive force is 10 [kOe] or more. The magnetic card according to claim 1, wherein the magnetic card is provided. 4. The data recorded in the first recording area indicates the usage frequency of the card, and the usage frequency and the magnetic reversal are recorded in association with each other. The magnetic card described in 1. 5. The data recorded in the first recording area indicates the usage frequency of the card, and the usage frequency and the area length are recorded in correspondence with each other. The magnetic card described in 1. 6. A magnetic card having a recording area formed by using a magnetic material capable of magnetic recording only in a demagnetized state at room temperature, wherein the recording area is initialized to a demagnetized state, and before use, A magnetic card characterized by recording data specific to the card in the recording area, degaussing the recording area each time it is used, and judging that the card is illegal if no data is recorded in the area. Matching method. 7. A magnetic card in which a recording area is formed by using a magnetic material capable of magnetically recording only in a demagnetized state at room temperature, wherein the recording area includes at least a unique information recording area and a write-once information recording area. Are assigned to each other to initialize the unique information recording area and the additional write information recording area to a demagnetized state, and when the ticket is issued, the unique data of the card is recorded in the unique information record area. A recording method for a magnetic card, characterized by additionally recording data indicating a usage state of the card in an area. 8. A magnetic card comprising a unidirectional recording area made of a magnetic material capable of magnetic recording only in a demagnetized state at room temperature and a rewritable area made of a magnetic material rewritable for magnetic recording. At least a write-once information recording area is allocated to the unidirectional recording area, the write-once information recording area and the rewritable area are initialized to a demagnetized state, and the card is used for the rewritable area when a ticket is issued. The first data indicating the status is recorded, and the second data indicating the usage status of the card is additionally recorded in the additional write information recording area for each use, while the second data indicating the usage status is recorded in the rewritable area according to the usage status If the contents of the second data additionally recorded in the additional recording information recording area and the first data recorded in the rewritable area do not match before use, the first data is updated. , The Matching method of a magnetic card, characterized in that to determine the de invalid.