JPH04274021A - Magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to magnetic cards, magnetic tickets,
The present invention relates to magnetic recording media such as magnetic commuter passes, magnetic coupon tickets, magnetic sheets, etc., and particularly relates to magnetic recording media that can significantly enhance the anti-counterfeiting effect.

0002

[Prior Art] Conventionally, in magnetic recording media such as magnetic cards, magnetic tickets, magnetic commuter passes, magnetic coupon tickets, and magnetic sheets, card-like base materials (hereinafter simply referred to as base materials) such as PET and paper have been used. Coat magnetic paint directly on top of the
Alternatively, a magnetic recording layer having a constant width in a predetermined direction is provided by transferring a magnetic transfer foil. In this case, in addition to the required magnetostatic properties and electromagnetic conversion properties, the magnetic recording layer has
Physical and chemical properties such as durability, abrasion resistance, heat resistance, chemical resistance, and solvent resistance are required. Generally, a protective layer is provided on top of this magnetic recording layer.

[0003] On the other hand, as a recent trend, there has been an increasing demand for designs to hide the hue of the magnetic recording layer so that it appears as if it were not a magnetic recording medium. In this case, methods for hiding the magnetic recording layer of the magnetic recording medium include providing a metal vapor deposition layer on the entire surface to hide the magnetic recording layer, or coating the magnetic recording layer with silver ink. methods have been adopted.

Furthermore, in recent years, for the purpose of preventing counterfeiting of magnetic recording media, desired patterns (for example, barcodes, etc.) are printed on the magnetic recording layer using magnetic ink.
It has been proposed that a pattern layer is provided to form a pattern. In this type of magnetic card, when a magnetic field is applied to the barcode part, the magnetic field is returned to the barcode formed with magnetic ink, so only the barcode formed with this magnetic ink can be read with a magnetic head. Can be done. In this case, the pattern of the magnetic ink records the amount of money and the pattern of each issuing institution.

[0005] Below, some examples of this type of magnetic recording medium that have been conventionally used will be explained. As shown in the cross-sectional view and plan view (viewed from the magnetic surface) in FIGS. 9 and 10, the first magnetic recording medium includes a magnetic recording layer 2 provided on a card base material 1, and a magnetic recording layer 2 provided on the card base material 1. A silver layer 3, which is a hidden layer, is provided on the layer 2, and only one type of magnetic data is recorded thereon.

Further, the second magnetic recording medium has a magnetic recording layer 2 provided on a card base material 1, as shown in cross-sectional views and plan views in FIGS. 11 and 12.
A magnetic bar 4 is provided on top in the illustrated pattern, and a silver layer 3 is further provided on this magnetic recording layer 2 and magnetic bar 4, making it possible to record two types of data: magnetic recording and magnetic bar. It is.

Further, the third magnetic recording medium has a first magnetic recording layer 21 provided on the card base material 1, as shown in cross-sectional views and plan views in FIGS. 13 and 14. A second magnetic recording layer 21 having a lower coercive force is placed on the magnetic recording layer 21 of
A magnetic recording layer 22 is provided, and this second magnetic recording layer 2
2, a magnetic bar 4 is provided in the illustrated pattern, and a silver layer 3 is further provided on the second magnetic recording layer 22 and the magnetic bar 4, thereby making it possible to record three types of data. .

On the other hand, the fourth magnetic recording medium has a magnetic recording layer 2 provided on a card base material 1, as shown in cross-sectional views and plan views in FIGS. 15 and 16.
A first magnetic bar 41 and a second magnetic bar 42 having different magnetic properties are provided thereon in the illustrated pattern, and a silver layer 3 is further provided on this magnetic recording layer 2 and each magnetic bar 41, 42, Two types of magnetic bars with different magnetic properties 4
1 and 42, the recorded data is made unintelligible.

Further, the fifth magnetic recording medium has a magnetic recording layer 2 provided on a card base material 1, as shown in cross-sectional views and plan views in FIGS. 17 and 18.
A first magnetic bar 41 and a second magnetic bar 42 having different magnetic properties are provided thereon in the illustrated pattern, and a silver layer 3 is further provided on this magnetic recording layer 2 and each magnetic bar 41, 42, and furthermore, An optical bar 5 having data formed as an optically readable pattern is provided on the silver layer 3, thereby making it possible to record four types of data.

Furthermore, the sixth magnetic recording medium has a magnetic recording layer 2 provided on the card base material 1, as shown in cross-sectional views and plan views in FIGS. A thermal or evaporated layer 6 is provided on top, and two types of data are recorded.

[0011]

However, in the first and sixth magnetic recording media, data can be easily read and tampered with, which is undesirable from the standpoint of preventing forgery. Also, the second, third, fourth, fifth
In each magnetic recording medium, the magnetic bar 4 is hidden by a silver layer 3, and although it is possible to make the recorded data indiscernible, the concealment is not complete, so the bar cannot be seen with the naked eye or with a mag viewer, etc. However, there is a problem in that it does not completely prevent counterfeiting. especially,
In each of the fourth and fifth magnetic recording media, if the pattern of the magnetic bar is known, the recorded data is immediately known, which is undesirable from the standpoint of preventing forgery. moreover,
In each of these second, third, fourth, and fifth magnetic recording media, a step of printing the magnetic bar 4 or the optical bar 5 is required, which increases the production time and costs of the magnetic recording medium. There is also the problem that the cost is also high.

The present invention has been made to solve the above-mentioned problems, and provides a magnetic recording device that can significantly improve the anti-counterfeiting effect, reduce production time, and reduce costs. The purpose is to provide a medium.

[0013]

[Means for Solving the Problems] In order to achieve the above object, the magnetic recording medium of the present invention includes at least two types of magnetic recording layers having mutually different coercive forces on a card base material such that they partially overlap. It is made up of layers.

In particular, a second magnetic recording layer having a coercive force larger or smaller than the coercive force of the first magnetic recording layer is provided on the first magnetic recording layer, a part of which is attached to the first magnetic recording layer. or a second magnetic recording layer having a coercive force larger or smaller than that of the first magnetic recording layer, and a second magnetic recording layer having a coercive force larger or smaller than that of the first magnetic recording layer. A magnetic shield layer is partially provided so that the first magnetic recording layer and the second magnetic recording layer do not come into direct contact with each other.

[0015]

[Operation] Therefore, in the magnetic recording medium of the present invention, at least two types of magnetic recording layers having different coercive forces are used.
By laminating them on a card base material so that some of them overlap, at least three types of magnetic properties can be utilized.
That is, since at least three different reproduction output voltage levels can be obtained, the anti-counterfeiting effect can be significantly enhanced. In addition, as mentioned above, there is no need to print magnetic bars or optical bars, so
The time required to create a magnetic recording medium can be shortened, and the cost can also be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the magnetic recording medium of the present invention, at least two types of magnetic recording layers having different coercive forces are laminated on a card base material so that the layers partially overlap.

An embodiment of the present invention based on the above concept will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing an example of the structure of a magnetic recording medium according to the present invention, and FIG. 2 is a plan view of FIG. As shown in the figure, the magnetic recording medium of this embodiment includes a base material 11,
A first magnetic recording layer 12 with high coercive force is provided on the base 11, and a portion of the first magnetic recording layer 12 is provided on the first magnetic recording layer 12 so as to be in direct contact with the first magnetic recording layer 12. a second magnetic recording layer 13 with low coercive force; a concealing layer 14 provided on the first magnetic recording layer 12 and the second magnetic recording layer 13 to conceal them; A protective layer 15 is provided. The first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13 (the part where each magnetic recording layer is in contact) are each filled with predetermined information. It is possible to record.

Here, the base material 11 is formed in the shape of a card or a sheet, and its material is, for example, a resin material (PET (polyester), PVC, etc.) or paper (coated paper, high-quality paper, etc.). . In addition, the first magnetic recording layer 1
2 and the second magnetic recording layer 13 are formed, for example, by directly printing magnetic ink. In this case, the composition of the magnetic paint takes into consideration adhesiveness to the base material 11, flexibility when formed into a coating film, abrasion resistance, chemical resistance, etc. The first magnetic recording layer 12 is formed by screen printing a magnetic ink (for example, one whose main components are a magnetic material such as barium ferrite and an adhesive) as shown in FIG. . The second magnetic recording layer 13 is made of a magnetic ink (e.g., γ-Fe2O3 or Co
: The main components are a magnetic material such as γ-Fe2O3 and an adhesive), and are formed by screen printing.

On the other hand, the hiding layer 14 is
2 and the second magnetic recording layer 13 are hidden so that they cannot be visually distinguished, and are formed by depositing a metal such as Al, or by depositing a metal such as Ag, Cr, Al, Zn, or Sn.
, Pb, Cu, Bi, Ge, In, and other non-magnetic metal powders are shaped into flakes with a thickness of 10 μm or less and a diameter of 100 μm or less to give them a hiding power, such as hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, It is dispersed in a binder solution of starch, polymethacrylic acid resin, ABS resin, vinyl acetate chloride, etc., and a coating liquid is formed with a film thickness of 1 to 4 μm. Moreover, the protective layer 15 is
For example, the main component is transparent vinyl resin, etc., and the concealing layer 1
4, and its material is, for example, a polymer binder such as polymethacrylic acid resin or nitrocellulose.

In the magnetic recording medium configured as described above, reading of information recorded in the first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13 is performed. is carried out by the following method.

First, the magnetic properties of the first magnetic recording layer 12 are shown in FIG. 3a, and the magnetic properties of the second magnetic recording layer 13 are shown in FIG. 3b.
The magnetic properties of the first magnetic recording layer 12+second magnetic recording layer 13 are as shown in FIG. 3c. For such a magnetic recording medium, the first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13 are read together at the bias current value BA of the magnetic head. . Then, the reproduction output voltage waveform of the first magnetic recording layer 12, the reproduction output voltage waveform of the second magnetic recording layer 13, and the reproduction output voltage waveform of the first magnetic recording layer 12+second magnetic recording layer 13 are as follows. As shown in FIG. 4, different reproduction output voltages are obtained. Also, at the bias current value BA of the magnetic head, only one pattern can be read using the difference in the output voltage level of the magnetic ink forming the first magnetic recording layer 12 and the second magnetic recording layer 13. Do this. That is, when a difference occurs in the output voltage level, by setting a reading method and a recognition method corresponding to the pattern in advance, for example, as shown in FIG. 4, it is possible to know the validity of the magnetic recording medium. Therefore, if a difference in output voltage level does not occur in accordance with the pattern, it means that the magnetic recording medium is not the appropriate magnetic recording medium.

As described above, the two magnetic recording layers 12, 1
3, three magnetic properties a, b, c, that is, the original magnetic property a of the first magnetic recording layer 12, the original magnetic property b of the second magnetic recording layer 13, and the first magnetic recording By being able to have a magnetic property c that is a combination of the magnetic property a of the layer 12 and the magnetic property b of the second magnetic recording layer 13,
Since the reproduction output voltages of the first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13 are different, it is possible to obtain information from the output waveform when reading recorded information. It is possible to recognize both the bit pattern and the magnitude of the voltage difference.

As described above, the magnetic recording medium of this embodiment has a first magnetic recording layer 12 having a high coercive force on the substrate 11, and a first magnetic recording layer 12 on the first magnetic recording layer 12. A second magnetic recording layer 13 with a low coercive force is provided so that the portion thereof is in direct contact with the first magnetic recording layer 12, and these are further provided on the first magnetic recording layer 12 and the second magnetic recording layer 13. A concealing layer 14 for concealment is provided, and a protective layer 15 is further provided on this concealing layer 14.

Therefore, conventionally it was possible to provide only one or two types of magnetic properties, but the magnetic recording medium of this embodiment has two types of magnetic properties without using a magnetic bar.
The two magnetic recording layers 12 and 13 can have three types of magnetic properties, the first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13.
Since the respective reproduction output voltages are different, it is possible to recognize both the bit pattern obtained from the output waveform and the magnitude of the voltage difference when reading recorded information. That is, the first
Pattern data of only the magnetic recording layer 12, pattern data of only the second magnetic recording layer 13, first magnetic recording layer 12
+ Pattern data of the second magnetic recording layer 13 can be provided. This makes it possible to significantly enhance the anti-counterfeiting effect. In other words, by patterning the hidden magnetic recording layer, data for one or two magnetic recording methods can be read and recognized by using a readout method and recognition method that utilizes the reproduction output voltage level corresponding to the pattern. It has an extremely high anti-counterfeiting effect against falsification and alteration. Furthermore, since the conventional process of printing magnetic bars or optical bars is not necessary, the time required to create a magnetic recording medium can be shortened and costs can be reduced. Furthermore, a hiding layer 1 is provided on the first magnetic recording layer 12 and the second magnetic recording layer 13.
4, the first magnetic recording layer 12 and the second
The magnetic recording layer 13 can be completely hidden.

Next, another embodiment of the present invention will be described.

FIG. 5 is a sectional view showing another example of the structure of the magnetic recording medium according to the present invention, and FIG. 6 is a plan view of FIG. In the figures, the same elements as in FIGS. 1 and 2 are designated by the same reference numerals. That is, as shown in the figure, the magnetic recording medium of this embodiment includes a base material 11 and this base material 11.
A high coercivity first magnetic recording layer 12 provided above, and a low coercivity magnetic recording layer 12 provided on this first magnetic recording layer 12 so that a portion thereof is in direct contact with the first magnetic recording layer 12. second force
between the first magnetic recording layer 12 and the second magnetic recording layer 13, the first magnetic recording layer 1
2 and the second magnetic recording layer 13 so that they do not come into direct contact with each other, and a magnetic shield layer 16 provided on the first magnetic recording layer 12 and the second magnetic recording layer 13, It is composed of a concealing layer 14 that conceals the information, and a protective layer 15 provided on the concealing layer 14. The first magnetic recording layer 12, the second magnetic recording layer 13, and the first magnetic recording layer 12+second magnetic recording layer 13 (the part where each magnetic recording layer is in contact) are each filled with predetermined information. It is possible to record.

Here, the magnetic shield layer 16 is for providing magnetic shielding between the first magnetic recording layer 12 and the second magnetic recording layer 13, and is made of, for example, Ni, Fe, permalloy (Ni:Fe). = 78:22), soft magnetic metal powder such as sendust is shaped into flakes with a thickness of 20 μm or less and a diameter of 200 μm or less, and dispersed in a binder solution such as polyvinyl alcohol, polymethacrylic acid resin, polystyrene, vinyl acetate chloride, etc. The coating liquid is formed to have a film thickness of 1 to 4 μm.

In the magnetic recording medium constructed as above, the first magnetic recording layer 12, the second magnetic recording layer 13,
The reading of the recorded information on the first magnetic recording layer 12 and the second magnetic recording layer 13 is carried out in the same manner as described above, and the two magnetic recording layers 12 and 13 are used to determine the three magnetic properties a. , b, c, that is, the first magnetic recording layer 12
the original magnetic property a of the second magnetic recording layer 13, the original magnetic property b of the second magnetic recording layer 13, the combined magnetic property of the magnetic property a of the first magnetic recording layer 12 and the magnetic property b of the second magnetic recording layer 13. By being able to have c, the first magnetic recording layer 1
2. Since the reproduction output voltages of the second magnetic recording layer 13 and the first magnetic recording layer 12 + second magnetic recording layer 13 are different, both the output waveform and the voltage difference are recognized when reading recorded information. be able to.

Next, FIG. 7 is a sectional view showing an example of the structure of a magnetic recording medium according to the present invention, and FIG. 8 is a plan view of FIG. In the figures, the same elements as in FIGS. 1 and 2 are designated by the same reference numerals. That is, as shown in the figure, the magnetic recording medium of this embodiment includes a base material 11 and this base material 1.
a first magnetic recording layer 12 with high coercive force provided on 1;
A second magnetic recording layer 13 with medium coercive force is provided on the first magnetic recording layer 12 so that a portion thereof is in direct contact with the first magnetic recording layer 12; 13, a third magnetic recording layer 17 with low coercive force provided so that a part thereof is in direct contact with the second magnetic recording layer 13, and these first magnetic recording layer 12 and second magnetic recording layer 13. A concealing layer 14 provided on the layer 13 and the third magnetic recording layer 17 to conceal them, and a protective layer 15 provided on the concealing layer 14.
It consists of. and a first magnetic recording layer 12,
Second magnetic recording layer 13, first magnetic recording layer 12+second magnetic recording layer 13 (portion where each magnetic recording layer is in contact) second
Predetermined information can be recorded on each of the magnetic recording layer 13 and the third magnetic recording layer 17 (the portion where the magnetic recording layers are in contact with each other).

[0031] Also in the magnetic recording medium configured as above, the first magnetic recording layer 12, the second magnetic recording layer 13,
Reading of recorded information on the third magnetic recording layer 17, the first magnetic recording layer 12+second magnetic recording layer 13, and the second magnetic recording layer 13+third magnetic recording layer 17 is performed in the same manner as described above. Three magnetic recording layers 12, 13
, 17, four magnetic properties, namely, the original magnetic properties of the first magnetic recording layer 12 and the second magnetic recording layer 13
original magnetic properties of the third magnetic recording layer 17, magnetic properties that are a combination of the magnetic properties of the first magnetic recording layer 12 and the second magnetic recording layer 13, and the magnetic properties of the second magnetic recording layer 17. The first magnetic recording layer 12, the second magnetic recording layer 13,
Since the reproduction output voltages of the first magnetic recording layer 12 + second magnetic recording layer 13 and the second magnetic recording layer 13 + third magnetic recording layer 17 are different, when reading recorded information, there is a difference between the output waveform and the voltage. can recognize both.

It should be noted that the present invention is not limited to the above-described embodiments, but can also be implemented in the following manner.

In each of the above embodiments, two types of magnetic recording layers are used to provide three types of magnetic properties, but the present invention is not limited to this, and three or more types of magnetic recording layers may be used. It may be made to have four or more types of magnetic properties.

Furthermore, in each of the above embodiments, the protective layer 15
may be omitted.

[0035]

As explained above, according to the present invention, at least two types of magnetic recording layers having different coercive forces can be used.
Magnetic recording is constructed by laminating it on the card base material so that some parts overlap, so it can significantly improve the anti-counterfeiting effect, as well as shorten the production time and reduce costs. Media can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a magnetic recording medium according to the present invention.

FIG. 2 is a plan view of the magnetic recording medium in the same example.

FIG. 3 is a diagram showing an example of the magnetic characteristics of the magnetic recording medium in the same example.

FIG. 4 is a diagram showing an example of an output voltage waveform of the magnetic recording medium in the same example.

FIG. 5 is a sectional view showing another embodiment of the magnetic recording medium according to the present invention.

FIG. 6 is a plan view of a magnetic recording medium in another embodiment.

FIG. 7 is a sectional view showing another embodiment of the magnetic recording medium according to the present invention.

FIG. 8 is a plan view of a magnetic recording medium in another embodiment.

FIG. 9 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 10 is a plan view of the magnetic recording medium in FIG. 9;

FIG. 11 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 12 is a plan view of the magnetic recording medium in FIG. 11.

FIG. 13 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 14 is a plan view of the magnetic recording medium in FIG. 13.

FIG. 15 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 16 is a plan view of the magnetic recording medium in FIG. 15.

FIG. 17 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 18 is a plan view of the magnetic recording medium in FIG. 17.

FIG. 19 is a cross-sectional view showing a configuration example of a conventional magnetic recording medium.

FIG. 20 is a plan view of the magnetic recording medium in FIG. 19.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11... Substrate, 12... First magnetic recording layer, 13... Second magnetic recording layer, 14... Hiding layer, 15... Protective layer, 16... Magnetic shielding layer.

Claims (3)

[Claims] 1. A magnetic recording medium comprising at least two types of magnetic recording layers having different coercive forces, which are laminated on a card base material so that the layers partially overlap. 2. A second magnetic recording layer having a coercive force larger or smaller than the coercive force of the first magnetic recording layer, a part of which is disposed on the first magnetic recording layer. 2. The magnetic recording medium according to claim 1, wherein the magnetic recording medium is formed by laminating layers so as to be in direct contact with each other. 3. A second magnetic recording layer having a coercive force larger or smaller than the coercive force of the first magnetic recording layer is laminated on the first magnetic recording layer, and a second magnetic recording layer is laminated on the first magnetic recording layer. 2. The magnetic recording medium according to claim 1, further comprising a magnetic shield layer partially provided so that the magnetic shield layer and the second magnetic recording layer do not come into direct contact with each other.