JPH05770B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to magnetic cards.

[Problems to be solved by conventional technology and invention]

In recent years, with the widespread use of magnetic cards such as cash cards and credit cards, crimes such as counterfeiting and misuse of cards have occurred.

Here, an example of a method for forging a card in the case of a cash card is as follows.

1. Forgery by someone inside the bank The magnetic recording medium of the cash card (usually formed in a stripe shape, commonly known as a magnetic stripe) contains the bank code number, deposit account number, and PIN number that the user Information is recorded magnetically. Card counterfeiting is extremely easy for people inside the bank, especially those involved in card issuance, because they can obtain the user information. That is, forgery can be easily carried out by erasing the card owned by the forger using a magnetic recording device, and then magnetically recording the user information on the card of another person to be counterfeited using the device. In this case, the recording conditions such as the position of the first magnetic recording (barcode) (distance from the edge of the magnetic recording medium to the first magnetic recording symbol) and magnetic recording density (number of bits) can be determined by the person in charge of card issuing. Since he is very knowledgeable, he can forge it without any problem.

2. In the case of forgery by an external party: User information cannot be easily obtained by an external party. However, by secretly watching the operations of a person withdrawing cash from an automatic teller machine, they learned the PIN number of the withdrawer's card, and also learned the balance statement (the one sent from the machine along with the cash) that the withdrawer had discarded. (often thrown away) and find out the bank code number and deposit account number written on the statement. Therefore, it is possible to perform forgery by putting a card owned by the forger into a magnetic recording device, erasing his or her own user information, and newly magnetically recording the other person's user information obtained as described above. In this case, when the counterfeiter's card is soaked in developer, the magnetic recording symbol (barcode) appears as an image, and if you look at it, you can see the location of the first magnetic recording symbol, the magnetic recording density (number of bits), etc. Since the conditions can be determined, magnetic recording can be performed exactly the same as on another person's card.

As mentioned above, since information can be easily erased or newly recorded on magnetic recording cards, no effective means for preventing counterfeiting has been established so far.

In view of the above points, it is an object of the present invention to provide a magnetic card that can accurately prevent card forgery.

[Means to solve the problem]

In order to solve the above problems, the present invention has the configuration shown below.

That is, the present invention has the following features: (1) A low coercive force magnetic layer and a high coercive force magnetic layer each having a card-specific information recording area and a user information recording area are laminated, and the low coercive force magnetic layer and the high coercive force magnetic layer are laminated. A magnetic card characterized in that a multilayer magnetic recording medium having a coercive force different from that of the other layers by a factor of three or more is formed on a card base material.

(2) A low coercive force magnetic layer and a high coercive force magnetic layer each having a card specific information recording area and a user information recording area are laminated, and the coercive force of the low coercive force magnetic layer and the high coercive force magnetic layer is A magnetic card formed by forming a multi-layer magnetic recording medium with a magnetic recording capacity of 3 times or more on a card base material, characterized in that card-specific information is magnetically recorded in a card-specific information recording area of a high coercive force magnetic layer. magnetic card.

The main points are as follows.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 and 2, reference numeral 1 indicates a magnetic card according to the first aspect of the present invention, and this magnetic card 1 has a multilayer magnetic recording medium 4 comprising a low coercive force magnetic layer 2 and a high coercive force magnetic layer 3. The magnetic material has a coercive force of at least 3 between the low coercive force magnetic layer 2 and the high coercive force magnetic layer 3.
It's more than twice as different. That is, the coercive force in the high coercive force magnetic layer 3 has a value more than three times the coercive force in the low coercive force magnetic layer 2. The coercive force of the magnetic layers 2 and 3 can be arbitrarily selected, and various combinations of the two are possible. Generally, the coercive force of the magnetic layers standardized in magnetic recording systems is 300.
There are Oe, 650 Oe, and 3000 Oe, and 650 Oe is currently used for cash cards. Therefore, also in the present invention, a magnetic layer 2 having a coercive force of 650 Oe, for example, can be used. In this case, since the magnetic layer 3 needs to have a coercive force three times or more the coercive force of 650 Oe of the magnetic layer 2, a magnetic layer 3 having a coercive force of 3000 Oe, for example, can be used.

Further, each of the magnetic layers 2 and 3 includes a card specific information recording area 6a and a user information recording area 7a (low coercive force magnetic layer), and a card specific information recording area 6b and user information recording area 7b (high coercive force magnetic layer). layer) is provided.

The recording medium 4 is formed in a striped shape as shown in FIG.
The area of the recording medium 4 is not limited to the striped shape, and the area of the recording medium 4 can be arbitrarily selected.
It is also possible to have a structure in which the longitudinal ends of the card base material 5 and the ends of the card base material 5 are not aligned with each other.

3 to 6 show other embodiments of the first invention.

In the embodiment shown in FIG.
It has a structure in which a release layer 8 is provided on the surface of the . Note that 9 in the figure indicates an adhesive layer (heat seal type). The magnetic card 1 having such a structure can be manufactured by a transfer method. For example, as shown in FIG. A magnetic transfer tape formed by sequentially laminating adhesive layers 9 is brought into close contact with the card base material 5 via the adhesive layer 9, heated and pressed to perform thermal transfer, and then the support 10 is peeled off, and further heated and pressed to form a card. Embed them in the base material 5 so that they are flush with each other. The support 10 is made of, for example, a 25μ thick polyester film, and the release layer 8 is made of, for example,
3μ thick polyester resin, butyral resin, etc.
For example, vinyl chloride resin or the like can be used as the card base material 5. The thickness of the adhesive layer 9 is usually 5 to 10 microns. The thickness of the magnetic layers 2 and 3 is usually 10 to 15 μm, and those having a residual magnetic flux of 1.4 maxwell/cm are usually used.

In the embodiment shown in FIG. 4, magnetic layer 2 and magnetic layer 3 are
interaction between the two (for example, magnetic layer 2
When laminating the magnetic layer 3 and the magnetic layer 3, a barrier layer 11 with a thickness of, for example, 10 μm or less is interposed between the magnetic layer 2 and the magnetic layer 3 to prevent the surface of the lower layer from being dissolved by a solvent and becoming uneven. It is something that As the barrier layer 11, a synthetic resin film, aluminum foil, etc. can be used.

In the embodiment shown in FIG. 5, a protective layer 1 made of a synthetic resin film is provided on the upper surfaces of the magnetic layer 2 and the magnetic layer 3.
2 is provided. Such a magnetic card 1 can be manufactured by a coating method,
Magnetic layer 3, magnetic layer 2, protective layer 1 on card base material 5
2 are sequentially coated and heated and pressed to embed them in the card base material 5 so that they are flush with each other.

Moreover, in the embodiment shown in FIG.
is attached to the card base material 5 by an adhesive layer 14. Such a magnetic card 1 can be manufactured by a lamination method, in which a magnetic layer 3, a magnetic layer 2, and a protective layer 12 are sequentially laminated on a base film 13. It is attached to the card base material 5 through the adhesive layer 14 so that
This can be obtained by embedding them in the same plane and making them flush with each other. The barrier layer 11 can also be provided between the magnetic layers 2 and 3 in the structures shown in FIGS. 5 and 6.

Incidentally, FIGS. 3 to 6 show longitudinal sectional views taken along the line Y--Y in FIG. 1.

The magnetic card according to the second invention of the present invention is the magnetic card according to the first invention, in which card-specific information is magnetically recorded on the high coercive force magnetic layer.

Below, the coercive force of magnetic layer 2 is 650 Oe, and magnetic layer 3 is 650 Oe.
The second example is when the coercive force is 3000 Oe.
The case of magnetically recording card-specific information on a magnetic card in the invention will be described.

After manufacturing the magnetic card 1 of the first invention having the multilayer magnetic recording medium 4, the magnetic card manufacturer magnetically records the card specific information a on the recording medium 4 by applying the magnetic card 1 to a magnetic recording device. In this case, the card unique information a is recorded in each card unique information recording area 6a, 6b provided in the recording medium 4 in advance. The magnetic layer on which the card specific information a is to be recorded is not the low coercive force magnetic layer 2 but the high coercive force magnetic layer 3. Generally, when performing magnetic recording on a magnetic layer, it is necessary to apply a magnetic field that is at least three times the coercive force of the magnetic layer. Therefore, in this case, card specific information a
9000 Oe to 10000 Oe to record on the magnetic layer 3
It is necessary to apply a magnetic field of Oe. At this time, information a is also recorded on the magnetic layer 2 at the same time (FIG. 8B).
The card specific information a to be recorded can be any card number, card symbol, etc., but must be information that specifies the card. Therefore, a certain card-specific information a is given only to a certain card, and other card-specific information is given to other cards.

Next, the magnetic card manufacturer erases the information a recorded on the magnetic layer 2 using a magnetic recording device. Generally, in order to erase information recorded on a magnetic layer, it is necessary to apply a magnetic field at least three times the coercive force of the magnetic layer, as in the case of recording. Therefore, in this case, to erase information a from the magnetic layer 2, 2000
It is necessary to apply a magnetic field of Oe. Suppose now that information a is erased from the magnetic layer 2 by applying a magnetic field of 2000 Oe. Here, since a magnetic field of at least 9000 Oe is required to erase even the information a of the magnetic layer 3,
The information a of the magnetic layer 3 is not erased, but only the information a of the magnetic layer 2 is erased. In this case, if the coercive force of the magnetic layer 3 is less than three times the coercive force of the magnetic layer 2, the magnetic layer 3 will be affected and may be demagnetized.
In the present invention, the coercive force of the magnetic layer 3 is more than three times the coercive force of the magnetic layer 2, so this problem does not occur. Thus, a magnetic card 1a according to the second aspect of the present invention is obtained in which the card specific information a is recorded only in the magnetic layer 3 (FIG. 8C).

Next, a method of obtaining a card to be finally used using the magnetic card 1a of the second invention will be described.

A magnetic card issuer (for example, a bank, credit card company, etc.) places the magnetic card 1a on a magnetic recording device and magnetically records the user information b in the conventional manner. In this case, the user information recording area 7 of the recording medium 4
will be recorded. In FIGS. 1 and 2, the area to the left of the dotted line 15 shown on the recording medium 4 is given as the user information recording area 7. Currently, the magnetic recording devices installed in banks, credit card companies, etc. have a magnetic field of about 2000 Oe, so when magnetic card issuers record user information, the information b is recorded only on the magnetic layer 2, and the magnetic field is about 2000 Oe. It is not recorded in layer 3. User information b may be the same type as before; for example, in the case of a cash card,
Banks, code numbers, deposit account numbers, PIN numbers, etc. are used as user information b. Thus, a magnetic card 1 is issued in which card specific information a is recorded in the high coercive force magnetic layer 3 of the card specific information recording area 6 and user information b is recorded in the low coercive force magnetic layer 2 of the user information recording area 7. (Figure 9).

Next, the principle of counterfeit prevention will be described by taking as an example the case where the magnetic card of the present invention is used as a cash card.

First, we will discuss the case where someone inside the bank uses an unissued card to forge a card. In an unissued card, as shown in FIG. 10A, no user information is recorded in the magnetic layer 2, but card specific information a is recorded in the magnetic layer 3. Here, it is assumed that "1" is recorded as the card specific information a. It is assumed that the card counterfeiter uses this card to record the unique card information and user information of another person, which the card forger came to know in the course of his/her work. Here, it is assumed that the other person's card specific information a is "2". in this case,
As mentioned above, the magnetic recording device installed in banks has a magnetic field of about 2000 Oe, so the card specific information a is recorded with "2" and "1" superimposed one above the other (Figure 10B) . When a counterfeiter attempts to withdraw cash by using this counterfeit card from an automatic teller machine installed at a bank, the waveforms of the card-specific information "1" and "2" are synthesized in the magnetic reader, causing noise. occurs, and as a result,
The device cannot read the card-specific information and no cash withdrawal will take place. In addition, if card unique information "2" is not recorded in the recording area, the combination of card unique information a and user information b will be different, so the device will generate an inappropriate signal, and similarly, it will not be possible to withdraw cash. will not be performed. Furthermore, as will be described later, the card specific information "1" cannot be erased initially.

Next, we will discuss the case where someone inside the bank or someone outside the bank uses their own card for forgery. The card owned by the counterfeiter has card specific information a and user information b, as shown in Figure 11A.
It is assumed here that the card specific information a is "3". A counterfeiter attempts to erase the information recorded on his own card and newly record information on another person's card. Here, as mentioned above, since the magnetic recording device that can be used by bank officials or outsiders has a magnetic field of about 2000 Oe, the user information b recorded on the magnetic layer 2 can be erased, but the The card specific information "3" recorded on the card remains without being erased (FIG. 11B). Assume that card specific information a and user information b of another person's card, which were known by some means, are recorded on this card. Here, the other person's card specific information a
Assume that is "2" as described above. For the same reason as mentioned above, the information a and b are recorded only in the magnetic layer 2, and the card specific information "2" and "3" are recorded vertically overlapping each other (FIG. 11C). Even if this card is used, a magnetic reader cannot read it for the same reason as mentioned above, so crimes are prevented.

Next, specific examples of the present invention will be shown.

Specific Example After magnetically recording predetermined card-specific information in the card-specific information recording area of a multilayer magnetic recording medium of a magnetic card using a magnetic recording device with a magnetic field of 10,000 Oe, the low coercive force magnetic layer is recorded with a magnetic field of 2,000 Oe. card-specific information has been deleted. Then 2000
Predetermined user information was recorded in the user information recording area using the Oe magnetic field. The user information was erased using a magnetic field of 2000 Oe, and user information and card specific information different from the user information and card specific information were recorded using the same 2000 Oe magnetic field. When this magnetic card was placed in a magnetic reader, noise was observed and the card could not be read.

〔Effect of the invention〕

As explained above, the magnetic card of the first aspect of the present invention has a low coercive force magnetic layer and a high coercive force magnetic layer each having a card specific information recording area and a user information recording area, and has a low coercive force magnetic layer and a high coercive force magnetic layer. The magnetic card of the second invention is formed by forming a multilayer magnetic recording medium on a card base material in which the coercive forces of the magnetic layer and the high coercive force magnetic layer are different by three times or more, and the magnetic card of the second invention has a high coercive force. Since the card-specific information is magnetically recorded in the card-specific information recording area of the magnetic layer, the card-specific information is checked in addition to the conventional user information during magnetic reading. The upper layer appears to have one magnetic layer, which is useful in preventing card forgery. Moreover, since the coercive force between the low coercive force magnetic layer and the high coercive force magnetic layer is more than three times different, it is impossible for a card counterfeiter to erase the card-specific information recorded in the high coercive force magnetic layer, and Since it is impossible to change the card specific information, counterfeiting can be reliably prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view showing a magnetic card, and FIG. 2 is a plan view showing a magnetic card.
3 to 6 are vertical sectional views of main parts showing the magnetic card, FIG. 7 is an explanatory diagram of manufacturing the card of the present invention, and FIG. 8 is a diagram showing the process of magnetic recording. FIG. 9 is an explanatory diagram showing a magnetic card on which user information and card-specific information are recorded, and FIGS. 10 and 11 are explanatory diagrams showing the process of card forgery. 1a, 1...Magnetic card, 2...Low coercive force magnetic layer,
3... High coercive force magnetic layer, 4... Multilayer magnetic recording medium, 5
...Card base material, 6...Card specific information recording area,
8...User information recording area, a...Card specific information, b...User information.

Claims (1)

[Scope of Claims] 1. A low coercive force magnetic layer and a high coercive force magnetic layer each having a card specific information recording area and a user information recording area are laminated, and the low coercive force magnetic layer and the high coercive force magnetic layer are laminated. 1. A magnetic card comprising a card base material formed with a multilayer magnetic recording medium whose coercive force differs by three times or more. 2 A low coercive force magnetic layer and a high coercive force magnetic layer each having a card specific information recording area and a user information recording area are laminated, and the coercive force of the low coercive force magnetic layer and the high coercive force magnetic layer is tripled. A magnetic card formed by forming a multilayer magnetic recording medium as described above on a card base material, characterized in that card-specific information is magnetically recorded in a card-specific information recording area of a high coercive force magnetic layer. card.