JP2000242920A - Magnetic card and its truth discrimination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high discriminative precision without a precise MR sensor and to perform double protection for fabrication/alteration by providing a hard magnetic body layer on a soft magnetic body layer constituting a security pattern and having a security track making the hard magnetic body layer surface answering to the arranged place of the soft magnetic body layer a projection part. SOLUTION: The soft magnetic body layer 4 is provided partially on the place answering to the security track 1 of a magnetic card surface side, and the security pattern is formed, and the hard magnetic body layer is provided on the whole magnetic card surface, and the hard magnetic body layer surface answering to the arranged place of the soft magnetic body layer 4 is made the projection part. This security pattern is read by a magnetic head, and by comparing it with the prescribed collation data, the truth is judged, and the truth is discriminated even by whether or not a difference between read outputs in the case of a forward direction and an opposite direction is a prescribed difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card widely used, for example, as a prepaid card, an ID card, a credit card, a cash card, a commuter pass, a ticket, and the like, and a method of determining the authenticity thereof.

[0002]

2. Description of the Related Art Conventionally, a coercive force, such as a mixture of a soft magnetic material and a semi-hard magnetic material, and a mixture of a soft magnetic material and a hard magnetic material, are provided below a hard magnetic layer serving as a magnetic recording layer. 2. Description of the Related Art A magnetic card having a magnetic pattern layer formed as a coating film made of an ink in which two or more different magnetic materials are mixed is known (Japanese Patent Application Laid-Open No. 8-221532). To determine the authenticity of the magnetic card, the magnetic recording of the magnetic recording layer is temporarily erased at the time of reading, and the weak magnetic pattern of the magnetic pattern layer is read twice by switching the DC bias applied to the magnetic head between strong and weak. Since two or more magnetic materials having different coercive forces are mixed in the magnetic pattern layer, this is performed by comparing two types of magnetic patterns detected by two readings with the collation data.

[0003]

The above-described conventional magnetic card and its authenticity discrimination method involve mixing a magnetic pattern based on an attached pattern of a magnetic pattern layer and two or more magnetic materials having different coercive forces. There is an advantage that it is possible to determine the authenticity from both sides of the fluctuation of the magnetic pattern based on the fact that there is a double defense against forgery and alteration.

However, in the above-described conventional magnetic card and its authenticity discrimination method, if there is uneven mixing of two or more kinds of magnetic materials different from each other or uneven application thereof, there is a possibility that the authentic card is regarded as a forged or altered card. is there. Also, depending on the difference in coercive force of the magnetic materials to be mixed, the difference in the magnetic pattern based on this difference becomes subtle, and there is a problem that a high-accuracy MR sensor is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to obtain high discrimination accuracy without using a high-precision MR sensor, and to provide double protection against forgery and alteration. The purpose is to be able to.

[0006]

For this purpose, the present invention provides a hard magnetic layer provided on a soft magnetic layer which is partially provided to form a security pattern, and wherein the soft magnetic layer is provided. It is an object of the present invention to provide a magnetic card having a security track in which a surface of a hard magnetic material layer corresponding to a portion has a convex portion.

Further, according to the present invention, in the above-mentioned magnetic card in which the magnetization direction of the hard magnetic layer is aligned in one direction, the security pattern of the magnetic card is determined by comparing the direction of the leakage magnetic field of the magnetic head to which a DC bias current is applied with the hard magnetic layer. The magnetic head to which the DC bias current is applied is read in two directions, a forward direction in which the magnetization directions of the magnetic material layers match and a reverse direction in which both directions are opposite to each other, and the magnetic heads in the forward and reverse directions. The present invention provides a method for determining the authenticity of a magnetic card, comprising comparing read outputs from a magnetic card and determining whether there is a difference between read outputs in forward and reverse directions.

[0008]

FIG. 1 is a perspective view showing an example of a magnetic card according to the present invention, and FIG. 2 is an enlarged sectional view of a security track 1 in FIG.

In the magnetic card shown in the figure, a hard magnetic layer 3 serving as a magnetic recording layer is formed on the entire front surface side, and security tracks 1 and data tracks 2 are set at predetermined positions. The security track 1 in the magnetic card of the present invention is provided with a hard magnetic layer 3 on a soft magnetic layer 4 which is partially attached to form a security pattern.
Has a convex portion on the surface corresponding to the location where the soft magnetic layer 4 is provided.

More specifically, in the illustrated magnetic card, a security pattern is formed by partially providing a soft magnetic material layer 4 at a position corresponding to the security track 1 on the surface side of the base material 5 and then forming the base material. 5, a hard magnetic layer 3 is provided on the entire front surface side, and a concealing layer 6 and a protective layer 7 are sequentially provided on the hard magnetic layer 3.

The substrate 5, the hard magnetic layer 3, the concealing layer 6, and the protective layer 7 are the same as those used in a general magnetic card.

As the substrate 5, for example, a sheet of synthetic resin such as polyester, vinyl chloride, polyethylene and polypropylene, as well as paper and the like can be used.

The hard magnetic material layer 3 is formed as a coating film of a hard magnetic material, and is formed by printing or coating with ink or paint in which hard magnetic powder is dispersed in a binder solution. The hard magnetic material in the present invention has a coercive force of 200 (Oe) or more, and examples thereof include barium ferrite, strontium ferrite, chromium dioxide, magnetite, γ-iron oxide, and chromium dioxide.

The concealing layer 6 covers the hard magnetic material layer 3 and is formed by printing or coating with ink or paint having a high concealing power. This concealing layer 6
The hard magnetic layer 3 is preferably provided so as to have a flat surface so as to cover the projections on the surface.

The protective layer 7 protects the inner layers from being scratched by the magnetic head 8 (see FIG. 3 et seq.), And is formed by printing or coating with a hard resin ink or paint such as acrylic resin. You. Also,
The concealing layer 6 and the protective layer 7 can be formed as one layer having both functions by using a hard resin-based ink or paint having a high concealing power.

In the magnetic card of the present invention, in particular, the soft magnetic layer 4 constituting the security pattern is partially formed under the hard magnetic layer 3 in the security track 1. The feature is that the surface of the hard magnetic material layer 3 corresponding to the attachment location is a convex portion.

The soft magnetic material layer 4 is formed as a coating film of a soft magnetic material, and is formed by printing or coating with an ink or paint in which a soft magnetic material powder is dispersed in a binder solution. The soft magnetic material in the present invention has a coercive force of 30 (Oe) or less, for example, a metal or alloy such as iron and nickel, a metal ferrite such as Mn-Zn ferrite, Mn ferrite, and magnetite, and a sendust (Fe-Al). -Si), permalloy (N
i-Fe-Mo), permender (Co-Fe), an amorphous magnetic material, or the like can be used. As a security pattern formed by the soft magnetic layer 4, for example, a bar code pattern can be given.

The projections on the surface of the hard magnetic layer 3 corresponding to the locations where the soft magnetic layer 4 is provided can be easily formed by reflecting the irregularities of the security pattern on the surface of the hard magnetic layer 4. it can. In other words, when the soft magnetic layer 4 is provided as the above-mentioned coating film and then the hard magnetic layer 3 is provided as the above-mentioned coating film, the thickness of the soft magnetic layer 4 partially provided is When the hard magnetic layer 4 is provided so that the unevenness of the security pattern due to the above is reflected on the surface of the hard magnetic layer 4 without flattening, the hard magnetic material corresponding to the location where the soft magnetic layer 4 is provided The surface of the layer 4 becomes a convex portion, and the surface of the hard magnetic layer 4 corresponding to a portion where the soft magnetic layer 4 is not provided becomes a concave portion.

As described above, security track 1
In the case of a magnetic card having a soft magnetic layer 4 constituting a security pattern below the hard magnetic layer 3 in the above, and in which irregularities corresponding to the security pattern are formed on the surface of the hard magnetic layer 3 in the security track 1 The hard magnetic layer 3 in the security track 1 is demagnetized by direct current, and the magnetic head 8 (see FIG. 3 et seq.) To which a direct current bias current is applied while the magnetization of the hard magnetic layer 3 is aligned in one direction. When the pattern is read, there are two cases: a forward direction in which the direction of the leakage magnetic field of the magnetic head 8 matches the magnetization direction of the hard magnetic layer 3 of the magnetic card, and a reverse case in which both directions are opposite to each other. A difference occurs in the read output. Therefore, by comparing the read security pattern with the collation data set in advance, the authenticity can be determined, and at the same time, the difference between the read output from the magnetic head in the forward direction and the read output from the magnetic head in the reverse direction is obtained. Whether it is true or not and whether this difference is a predetermined difference can be determined as true or false.

Further, the above-described method of determining the authenticity will be described with reference to FIGS. In the magnetic cards shown in FIGS. 3 to 5, the concealing layer 6 and the protective layer 7 shown in FIG. 2 are omitted.

FIG. 3 shows an output waveform (a) from the hard magnetic layer 3 together with a state in which the security pattern is read by the magnetic head 8 from the forward-oriented magnetic card.
3 shows an output waveform (b) from the soft magnetic layer 4 and an output waveform (c) from the magnetic head 8. FIG.
Are the front and rear of the magnetic card in FIG. 3 (left and right in the figure)
FIG. 11 is a similar view of a magnetic card in which is reversed to be reversed.

When the authenticity of a magnetic card is determined by the method of the present invention, first, the magnetization direction of the hard magnetic layer 3 in the security track 1 (see FIG. 1) is set in a state of being aligned in one direction. In FIG. 3, the hard magnetic layer 3 of the magnetic card has already been magnetized in the same direction, and is magnetized in the direction of S → N from left to right in the figure. The magnetic head 8 is applied with a DC bias current from the bias terminal 9, and the direction of the leakage magnetic field of the magnetic head 8 in FIG. 3 is S → N from left to right in the figure. That is, the magnetic card in FIG. 3 is placed in the forward direction in which the direction of the leakage magnetic field of the magnetic head 8 and the magnetization direction of the hard magnetic layer 3 match.

By the way, as described above, the surface of the hard magnetic layer 3 is formed with irregularities corresponding to the security pattern by the soft magnetic layer 4. Further, as described above, the hard magnetic layer 3 in FIG.
Since → N, magnetic poles along the magnetization direction of the hard magnetic layer 3 are generated on the left and right of each convex portion of the hard magnetic layer 3. That is, the left side in the figure of each projection is the S pole, and the right side is the N pole. In addition, since the leakage magnetic field of the magnetic head 8 is S → N from left to right in the figure, when the soft magnetic layer 4 immediately below the magnetic head 8 is magnetized by the leakage magnetic field, the left side in the figure has an S pole, The right side is an N pole, and magnetic poles coincident with the left and right sides of each projection are generated. That is, as shown in FIGS. 3A and 3B, the polarity of the output by the convex portion of the hard magnetic layer 3 and the soft magnetic layer 4
3C, the read output waveform obtained from the output terminal 10 of the magnetic head 8 greatly fluctuates as shown in FIG. 3C.

On the other hand, as shown in FIG. 4, when the magnetic card is reversed, the magnetization direction of the hard magnetic layer 3 is
From right to left becomes S → N, which is opposite to the case of FIG.
The left and right sides of the convex portion of the hard magnetic layer 3 and the left and right sides of the soft magnetic layer 4 show opposite polarities. Therefore, as shown in FIGS. 4A and 4B, the polarity of the output by the convex portion of the hard magnetic material layer 3 and the polarity of the output by the soft magnetic material layer 4 are reversed, and the two cancel each other. Therefore, as shown in FIG. 4C, the waveform of the read output obtained from the output terminal 10 of the magnetic head 8 has a small amplitude.

As is clear from the comparison between the waveform of FIG. 3C and the waveform of FIG. 4C, the waveform is obtained corresponding to the position of the soft magnetic layer 4 when reading a forward magnetic card. The read output waveform is larger than the read output waveform obtained corresponding to the position of the soft magnetic layer 4 when reading the magnetic card in the reverse direction (the absolute value becomes larger). In other words, when the magnetic card is turned forward,
There will be a difference in the read output obtained when the magnetic card is turned upside down.

For example, when the soft magnetic material layer 4 is formed on the flat hard magnetic material layer 3, the output from the soft magnetic material layer 4 is directly output without amplifying and canceling action by the hard magnetic material layer 3. Since the reading is performed, the difference between the reading outputs as described above does not occur. When the soft magnetic layer 4 is formed of a hard magnetic layer or a non-magnetic layer, the thickness of the hard magnetic layer 3 is substantially changed. Such a difference in read output does not occur. Therefore, by inspecting whether or not there is a difference in read output between the case where the magnetic card is turned forward and the case where the magnetic card is turned upside down, the soft magnetic layer 4 is attached to the surface of the magnetic card later. For example, a forged card reproducing a security pattern can be eliminated. Also,
The difference in read output between the case where the magnetic card is turned forward and the case where the magnetic card is turned reversely changes depending on the type (coercive force) of the soft magnetic material constituting the soft magnetic material layer 4. By comparing with a predetermined value based on the above, it is possible to inspect whether or not the soft magnetic material layer 4 is made of a proper material, thereby making it possible to determine whether the soft magnetic layer 4 is authentic.

As described above, the authenticity of the magnetic card is determined based on the security pattern to be read and the change in the read output in the forward and reverse readings. Will be tolerated.

The security pattern can be read by moving one of the magnetic card and the magnetic head 8 relative to the other. Regardless of which direction is moved from left to right in the figure or from right to left, the relationship between the direction of the magnetic pole generated in the convex portion on the surface of the hard magnetic material layer 3 and the direction of the leakage magnetic field is the same. The polarity of the read output is reversed, but in absolute value, the read output is large in the forward direction and the read output is small in the reverse direction.

The switching between the forward direction and the reverse direction is shown in FIGS.
Can be performed by reversing the front and back of the magnetic card, but the magnetic head 8
Can be performed by reversing the direction of the leakage magnetic field. That is, from the state of FIG. 3, the direction of the DC bias current to the magnetic head 8 was reversed and the direction of the leakage magnetic field was reversed in the state of FIG. 5, and forward reading was performed in the state of FIG. Next, as shown in FIG. 5, if the direction of the leakage magnetic field is reversed and reading is performed in the opposite direction, the same true / false determination as described above can be performed. In this case, the switching between the forward direction and the reverse direction can be performed only by reversing the direction of the DC bias current. The structure of the device can be simplified.

In particular, when two magnetic heads 8 whose leakage magnetic field directions are reversed are arranged back and forth, and one of the two magnetic heads 8 and the magnetic card is moved with respect to the other, and reading is performed, Reading in the forward direction and in the reverse direction can be performed without switching the direction of the bias current, and the trouble of setting the timing of switching the direction of the DC bias current can be omitted.

Although the hard magnetic layer 3 is provided directly on the soft magnetic layer 4 in the magnetic card described with reference to FIGS. A non-magnetic layer) may be interposed. However, in order to easily read the difference between the security pattern and the read output, it is preferable that the hard magnetic layer 3 directly covers the soft magnetic layer 4.

[0032]

Example 1 An ink having the following composition was prepared as an ink for forming a soft magnetic layer constituting a security pattern.

Vinyl chloride-vinyl acetate copolymer resin 10 parts by weight Polyurethane resin 10 parts by weight Soft magnetic powder 40 parts by weight Cyclohexanone 40 parts by weight

Using a white polyester sheet as a base material,
A barcode-shaped security pattern was formed thereon by printing with the above ink, and a hard magnetic layer, a concealing layer, and a protective layer were sequentially coated thereon. The hard magnetic layer was coated so that the surface of the hard magnetic layer reflected the irregularities of the security pattern.

The hard magnetic layer of the obtained magnetic card was subjected to direct current demagnetization, and the magnetization of the hard magnetic layer was aligned in one direction. next,
Forward and reverse readings were performed by applying a DC bias to the magnetic head.

As a result, the amplitude of the read output obtained by forward reading was large, and the amplitude of the read output obtained by reverse reading was small, and a clear difference was observed between the two.

Comparative Example 1 Forward and reverse readings were performed in the same manner as in Example 1 except that the surface of the hard magnetic layer was made flat.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between the two. Further, the magnitude of the amplitude of the read output was smaller than that in the case of the forward reading in the first embodiment.

COMPARATIVE EXAMPLE 2 A hard magnetic layer was formed as a flat layer, and a soft magnetic layer (security pattern), a concealing layer, and a protective layer were laminated thereon in this order. And read in the opposite direction.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between the two. Further, the magnitude of the amplitude of the read output was smaller than that in the case of the forward reading in the first embodiment.

Comparative Example 3 An ink having the following composition was prepared as an ink for forming a security pattern.

Vinyl chloride-vinyl acetate copolymer resin 10 parts by weight Polyurethane resin 10 parts by weight Hard magnetic powder 40 parts by weight Cyclohexanone 40 parts by weight

Reading was performed in the forward and reverse directions in the same manner as in Example 1 except that a security pattern was formed using the above ink.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between the two. Further, the magnitude of the amplitude of the read output was smaller than that in the first embodiment when reading in the opposite direction.

Comparative Example 4 Forward and reverse readings were performed in the same manner as in Comparative Example 2 except that a security pattern was formed using the ink prepared in Comparative Example 3.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between the two. Further, the magnitude of the amplitude of the read output was the same as in Comparative Example 3.

Comparative Example 5 An ink having the following composition was prepared as an ink for forming a security pattern.

Vinyl chloride-vinyl acetate copolymer resin 10 parts by weight Polyurethane resin 10 parts by weight Nonmagnetic pigment 40 parts by weight Cyclohexanone 40 parts by weight

Reading was performed in the forward and reverse directions in the same manner as in Example 1 except that a security pattern was formed using the above ink.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between them. The magnitude of the read output amplitude was smaller than Comparative Examples 3 and 4.

Comparative Example 6 Forward and reverse readings were performed in the same manner as in Comparative Example 2 except that the ink prepared in Comparative Example 5 was used.

As a result, the obtained read output showed almost the same amplitude in both the forward and reverse directions, and no difference was observed between the two. The magnitude of the read output amplitude was smaller than Comparative Examples 3 and 4.

[0053]

The present invention is as described above. In addition to the security pattern read from the soft magnetic layer 4, the present invention can be applied to the case where the magnetic card is turned forward and the case where the magnetic card is turned reversely. True / false determination can be made based on the output difference, and double security can be achieved. Further, since this read output difference can be easily detected by a general MR sensor, it is possible to use a high-precision MR sensor without using it. It is possible to determine the authenticity with high accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a magnetic card according to the present invention.

FIG. 2 is an enlarged sectional view of a security track portion in FIG.

FIG. 3 is an explanatory diagram at the time of reading when the magnetic card according to the present invention is directed forward.

FIG. 4 is an explanatory diagram at the time of reading in a state where the front and back of the magnetic card of FIG. 3 are turned upside down.

5 is an explanatory diagram of a state in which the direction of the leakage magnetic field of the magnetic head of FIG. 3 is reversed so that the magnetic card is turned in the opposite direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Security track 2 Data track 3 Hard magnetic layer 4 Soft magnetic layer 5 Base material 6 Concealment layer 7 Protective layer 8 Magnetic head 9 Bias terminal 10 Output terminal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Maki Nakanishi 4- 14-12 Koishikawa, Bunkyo-ku, Tokyo Joint printing Co., Ltd. (72) Inventor Kenji Sugaya 4- 14-12 Koishikawa, Bunkyo-ku, Tokyo Joint printing (72) Inventor Masahiro Honda 4-14-12 Koishikawa, Bunkyo-ku, Tokyo Kyodo Printing Co., Ltd. F-term (reference) 5B058 CA31 KA32 YA06 5D006 BA08 BA19 BA20 DA01 EA01 FA00 5D091 AA12 BB06 CC05 DD04 GG06 HH01 JJ21

Claims (7)

[Claims] 1. A hard magnetic layer is provided on a soft magnetic layer which is partially provided to form a security pattern, and the surface of the hard magnetic layer corresponding to the location where the soft magnetic layer is provided is convex. A magnetic card having a security track as a part. 2. The projection on the surface of the hard magnetic layer is formed by reflecting the unevenness of the security pattern due to the thickness of the soft magnetic layer provided partially on the surface of the hard magnetic layer. The magnetic card according to claim 1, wherein: 3. The magnetic card according to claim 1, wherein the magnetization direction of the hard magnetic material layer is aligned in one direction, and the security pattern of the magnetic card is determined by adjusting the direction of the leakage magnetic field of the magnetic head to which a DC bias current is applied. The magnetic head to which the DC bias current is applied is read in two directions, a forward direction in which the magnetization direction of the hard magnetic material layer matches and a reverse direction in which the two directions are opposite to each other. A method for determining the authenticity of a magnetic card, comprising comparing read output from a head and determining whether there is a difference between read outputs in forward and reverse directions. 4. The method according to claim 3, wherein a difference between the read output in the forward direction and the read output in the reverse direction is compared with a predetermined value. 5. The reading for the forward direction and the reverse direction,
5. The method according to claim 3, wherein one of the magnetic head and the magnetic card is moved with respect to the other, and the magnetic card is turned upside down. 6. The reading in the forward direction and in the reverse direction,
5. The method according to claim 3, wherein one of the magnetic head and the magnetic card is moved with respect to the other and the direction of the leakage magnetic field of the magnetic head is reversed. 7. The reading in the forward direction and in the reverse direction,
5. The method according to claim 3, wherein one of the two magnetic heads and the magnetic card in which the directions of the DC bias currents are opposite to each other is moved with respect to the other.