JPS6369018A - Magnetic recording medium and its manufacture, and detection method for magnetic information - Google Patents

Abstract

PURPOSE:To make it difficult to the illegal use of a magnetic recording medium and to manufacture it easily at a moderate cost by installing a magnetically changing part that can be visually checked directly or indirectly on a magnetic layer in the magnetic recording medium obtained in such a way that a magnetic paint is coated on the base of a nonmagnetic body to form the magnetic layer. CONSTITUTION:The nonmagnetic base 1 sent from a reel 1a is suited to a coating head 3 to constitute the magnetic layer 4 thereon. Then a magnetic field orientation device 5 is passed by to orient. A magnet 16, with specific characters, figures, patterns and so on given to its end surface while they are wet, gives a magnetic field from the side of the base 2 to provide the magnetically changing part that can be visually checked on some of the magnetic layer 4. A magnetic card 15 equipped with a hiding layer on the magnetic layer 4 cannot be visually checked. However, through the use of a magnetic viewer 16, said part can be visually checked. Namely a card 16 with identification information that a user, etc., cannot see, is attainable.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a method for preventing counterfeiting by inserting judgment information into a magnetic recording medium, which cannot be added or erased later, at the time of applying magnetic paint. The present invention relates to a magnetic recording medium with excellent properties, a method of manufacturing the same, and a method of detecting the same.

(Prior Art) (Problems to be Solved by the Invention) In recent years, magnetic recording media, particularly in the form of magnetic cards, have increasingly been used as money bills in place of small-denomination coins. The biggest problem here is how to prevent unauthorized use due to falsification of magnetic information or duplication of cards.

Therefore, various measures are used to prevent unauthorized use.

The simplest method is to use software to encrypt magnetically recorded information and enter a password, but this method is not very effective in preventing unauthorized use.

Therefore, a method has been proposed in which the magnetic card itself has a function to prevent unauthorized use, which is more effective in preventing unauthorized use. These can be roughly divided into two types: one is a method that makes it difficult to tamper with or copy magnetic information by concealing the recorded magnetic information and making it unreadable, and the other is a method that makes it difficult to tamper with or copy magnetic information. This method prevents counterfeiting by including an identification function in the card to determine whether it is genuine or not.

For example, the first type of anti-fraud measure is known by making the recording section multi-layered.

There are some that block legitimate information, making it unreadable, or overlay dummy information, making it difficult to analyze legitimate information. Also, as a second type of fraud prevention measure.

Some are equipped with optical barcodes or magnetic barcodes.

However, each of these methods has drawbacks and is still not satisfactory. In other words, the first method has drawbacks such as complicated manufacturing processes and complicated recording/reading devices.Also, once the details of the concealment method are known, anyone familiar with magnetic recording can read out the information. It is possible to analyze the card, and therefore it is also possible to copy it.The second type of anti-fraud card is a card that has correct identification information, even if the magnetic information can be forged. However, this method also has the drawbacks of complicating the manufacturing process and complicating the reading device for the 1-judgment information.

(Means for Solving the Problems) The magnetic recording medium according to the present invention belongs to the second type, and it overcomes the drawbacks of the conventional methods, provides a magnetic recording medium that is very difficult to use illegally, and The present invention provides a simple and inexpensive manufacturing method for a recording medium, and further provides a method for reading a signal for preventing unauthorized use from the magnetic recording medium.

That is, the outline of the present invention is to provide a magnetic recording medium having a magnetic layer formed by coating a magnetic paint on a base made of a non-magnetic material, in which a visually visible magnetic change part is directly or indirectly formed on the magnetic layer. The first invention is a magnetic recording medium that has a magnetic recording medium that has a magnetic layer that is coated with magnetic paint on a base made of a non-magnetic material.

By applying a magnetic field from the base side using a magnet with a figure or pattern shaped part provided at least on the end face.

A second invention provides a method for manufacturing a magnetic recording medium, characterized in that a magnetically changing part having a shape corresponding to the character 2 figure or pattern is generated in a part of the magnetic layer, and then the magnetic layer is dried, The third invention is a detection method for detecting magnetic information from the shape of a magnetically changed object in a magnetic recording medium as described above.

(Function) The magnetic recording medium according to the present invention records specific characters when the magnetic layer is in an undried state at the time of coating.

Since a magnetic field is applied from the base side using a magnet having a figure or pattern shaped part on at least the end face, a magnetically variable part corresponding to the shape of the shaped part can be imparted to the magnetic layer.

Note that the magnetically variable portion referred to herein refers to a portion where the orientation state of the magnetic layer is different from other portions and the thickness of the magnetic layer is different from other portions.

In the previous stage, the magnetic layer was placed inside the magnetic field orientation device at 1l13IA.
The magnetic field orientation may be performed by causing the magnetic field to be aligned, or the magnetic field orientation may not be performed.

Since the magnetically changing portion corresponding to the display of the character 9 figures, patterns, etc. has a different orientation of the magnetic hydrophilic material from other portions, it is directly visible in the magnetic recording medium that has this as an exposed surface. , 9 If the surface is covered with a protective coating or the like, it can be visually observed indirectly using a magnetic viewer.

Note that in the magnetic recording medium according to the present invention, as described above, the character 9
In a magnetically variable part that corresponds to the display of figures, patterns, etc., the orientation of the magnetic material in that part is naturally different from that in other general parts, and the thickness of the magnetic layer is also different, so the magnetic head can be used to move over this part. When reading, it is possible to obtain an output that is thought to be caused by discontinuities in the orientation and thickness of the magnetic layer at the boundaries of the transition regions.

Also, the specific recording density on the magnetic layer including this part,
When a recording pattern is written and read using a magnetic head, the magnetic output decreases at the changing portion.Next, the present invention will be explained with reference to side A.

FIG. 1 shows the manufacturing process of the magnetic recording medium of the present invention.

A non-magnetic base 2 such as polyethylene terephthalate sent from the tar 1a is coated with a coating head 3 of a coating machine to form a magnetic layer 4, and then passed through a magnetic field orientation device 5 for orientation treatment. While the magnetic layer 4 is not dry, a magnetic field is applied from the base side using a magnet 6 whose end face has at least the shape of a specific character 1, pattern, etc.

A magneto-magnetic change portion corresponding to the shape of the magnetic layer is provided in a portion of the magnetic layer.

The magnet 6 used in the present invention is 1, for example, as shown in FIG.
A permanent magnet 8a is embedded in a roll 8 made of a non-magnetic material, and shapes such as letters, numbers, figures, patterns, etc. are displayed on the end surface of the permanent magnet 8a.

As for the structure of the magnet itself, as shown in FIG. 3-(1), a permanent magnet 9 having a specific shape, for example, a cross-sectional shape like the number 1, may be used, or as shown in FIG. 3-(2). Yen A
A high magnetic permeability metal body 11 having a specific shape and representing the number 1, for example, is placed on top of the shaped permanent magnet 10.
(For example, sendust) may be bonded. or,
As shown in Figure 3-(3), a specific shape such as the number 1
An electromagnet 1 formed by bonding a high magnetic permeability metal body 11 representing
2 may be used. In FIG. 1, after applying a magnetic change portion to a part of the magnetic layer using the means shown in FIG. reel lb,
Wind it up. FIG. 4 shows an example of a magnetic recording medium manufactured in this manner. Kanji characters 13 and numerals 14 are magnetically variable portions that have been added in this manner and are visible as they are.

Note that the magnetically changing portion may be any other number, single letter, pattern, or the like. At the stage of creating such a magnetically changing part,
If the magnetic field of the magnet as shown in FIG. 3 is too weak, the shape cannot be left sufficiently. Therefore, it is necessary to select and process an appropriate magnetic field strength.

This achieves the formation of the changed portion, which is essential in the present invention.

In the embodiments of the present invention, a magnetic field equal to or more than half the strength of the coercive force of the magnetic powder was applied, but it is possible to leave a magnetically variable portion sufficient to meet the purpose of the present invention. The shape of this magnetically changing part is 1, for example, the lot number of the card,
If you use background patterns etc.

This is identification information that cannot be erased or added to to prevent forgery or unauthorized use.

FIG. 5 shows a magnetic card 15 with a magnetic change part as described above and a concealing layer provided on the magnetic layer. Magnetic changes such as these become invisible to the naked eye. However, Magnetic Fukuviewer 16 (for example, 3M Company B-10)
22) enables visual inspection. That is, this example is an example of a card that has identification information that is invisible to the card user. Note that FIG. 6 is a cross-sectional view of the magnetic card shown in FIG. 5, in which a magnetic layer 18 is provided on a base film 19, and its surface is covered with a masking material such as by printing ink containing aluminum pigment. A layer 17 is provided.

FIG. 7 to FIG. 13 show the relationship between the magnetically changing portion and the output voltage.

As shown in Figure 7, magnetically changing part 2 in the shape of the number "1"
When 0 is added and the magnetic head reads out the top of the strip 21 including the center of that number, a magnetic change will occur as shown in Figure 8 Output Synchroscope Display State Diagram even without any magnetic recording in advance. At the border between one part and another part (both side edges of the ``1'' character).

Due to discontinuities in magnetic field orientation and magnetic layer thickness, a seemingly Lerhals-like output is obtained. This pulse-like output changes the interval between pulses depending on the shape of the magnetic change part,
Moreover, the output value of the pulse also changes.

For example, if a magnetic change part is provided in the shape of a number (1234567890) as shown in Figure 11, and the 24 part is read out with a magnetic head, pulse output will be obtained at a specific interval for each number as shown in Figure 12. This makes it possible to identify numbers.

Furthermore, if writing and reading are performed in the 24 part with a specific recording density and recording pattern, the output pattern will be used as identification information because the output will decrease at intervals specific to each number.

If a magnetically changing portion is provided without performing magnetic field orientation when coating the magnetic layer, the output decrease 22 as shown in FIG. 9 will not occur even if similar writing and reading are performed, but on the contrary, as shown in FIG. 10. A very small output increase 23 occurs. However, in this case as well, a pulse-like output as shown in FIG. 8 can be obtained and can be used as identification information.

Example Examples of the present invention will be described below.

Example 1: A magnetic paint having the following formulation was prepared.

Magnetic powder (barium ferrite) Ba0.6 (F @z O,s ) ・・・・・・
・・・・・・・・・・・・・・・・・・100 parts by weight (coercive force 2750 6e surface area BET7m”) Carbon black (Cabot product name VULCAN XC-72)
・・・・・・・・・・・・3 parts by weight lecithin...
・・・・・・・・・・・・1 part by weight Salt-vinyl acetate/vinyl alcohol copolymer resin (Sekisui Chemical Co., Ltd., trade name Kosuretsuku A)
20 parts by weight Polyurethane resin 20 parts by weight (Japan Polyurethane Industry Co., Ltd. trade name N-2304) Polyisocyanate・・・・・・・・・5 parts by weight (Japan Polyurethane Industries Co., Ltd. trade name Coronate L) Toluene・・・・・・・・・
...6031 parts methyl ethyl ketone...6
0 parts by weight Methyl isobutyl ketone: 60 parts by weight Coating was carried out using the method shown in FIG. 1.

A permanent magnet as shown in FIG. 3 was used as the magnet for attaching the magnetically changing portion. The strength of the magnetic field is 1.
5 and 5e. This magnet was assembled into an aluminum roll and used as shown in FIG.

A magnetic card as shown in FIG. 4 was obtained from the magnetic material produced in this manner. The number 140 part of this card is visible, and when enlarged it looks like Figure 11.
When the portion 24 in the figure was read using a magnetic head, an output as shown in FIG. 12 was obtained. In addition, a magnetic head for high coercive force is used in the section 24 to achieve a recording density of 200FC.
When all 1 outputs F (up to 16) were written and read using a magnetic head, outputs as shown in FIG. 13 were obtained.

Example 2: A magnetic paint similar to Example 1 was prepared.

Coating was performed by the method shown in FIG. However, the orientation device 4 was not used and no orientation treatment was performed. The same magnet as in Example 1 was used to provide the magnetically variable portion.

An ink containing an aluminum pigment was printed on the magnetic material produced in this way using a gravure printing method to hide the magnetic layer. A magnetic card 15 was manufactured from the magnetic original fabric thus obtained.

The magnetically variable portions added during coating cannot be seen directly, but can be made visible as shown at 16 in FIG. 5 by using a magnetic viewer.

When the magnetically variable portion of this card was read using a magnetic head, pulses as shown in FIG. 12 were obtained.

(Effects of the Invention) As described above, the magnetic card of the present invention is provided with a magnetic change part that is directly visible or indirectly visible by magnetic means, and by visually observing this, b'l Lm can be determined. Alternatively, genuine cards and counterfeit cards can be easily distinguished by magnetic detection. Also, this magnetic change part will be added later.

Since it cannot be erased, it has a special effect in that it is difficult to counterfeit, although the manufacturing method is relatively simple. In addition, since a concealing layer can be provided on the magnetic recording layer by coating, printing, etc.
The chemical change part, that is, the anti-counterfeiting part, can be made invisible under normal conditions and made visible only when a magnetic viewer is used, so there is no functionally relevant design on the magnetic recording surface.

Patterns can be added to enhance the product's appeal, advertisements can be added, etc. Furthermore, there is no need to limit the magnetic powder used to form the magnetic layer, so high coercive force magnetic powder, which has been in high demand in recent years, is used. can do.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the manufacturing process of the magnetic recording medium of the present invention, Fig. 2 is a perspective view showing an example of the magnetization device used in the invention, and Fig. 3 (1) to 3) is an explanatory diagram showing the manufacturing process of the magnetic recording medium of the present invention. FIG. 4 is a front view showing an example of the magnetic recording medium according to the present invention, and FIG. 6 is a sectional view showing the structure of the magnetic recording medium in FIG. 5, FIG. 7 is an explanatory diagram showing the relationship between the magnetic change part and the magnetic head, and FIG. 8 is a diagram showing the structure of the magnetic recording medium in FIG. A graph showing the pulse state when a voltage is applied. Figure 9 is a state diagram showing the output voltage using a synchroscope (when the magnetic layer is oriented in a magnetic field during coating). Figure 10 is a state diagram using the same synchroscope. The following is a phase diagram (when the magnetic layer is not oriented by a magnetic field during coating). Fig. 11 is a diagram showing the relationship between the magnetic change part with numbers 1-0 and the magnetic head, Fig. 12 is a graph showing the state of its output pulse, and Fig. 13 is a state diagram showing its output voltage using a synchroscope. be. 1. Reel 2. Non-magnetic base 3, coating head 4. Magnetic layer 5, magnet 6. Dryer 7, reel 8. Roll 3a, permanent magnet 9. Permanent magnet 10, permanent magnet 11, high magnetic permeability metal body 12 representing the number 1, electromagnet
13. 14 kanji, 15 numbers. Magnetic card 16, magnetic viewer 17, concealing layer 1, magnetic layer 19, base film 20, TJf1 pneumatic ratio changing part band 22. Output Down 23, Output Up Agent Patent Attorney Mamoru Takeuchi 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) A magnetic recording medium comprising a base made of a non-magnetic material coated with a magnetic paint, characterized in that the magnetic layer has a visually visible magnetically changing part. magnetic recording media (2) When applying magnetic paint to form a magnetic layer on a base made of non-magnetic material, before the coated surface of the magnetic paint dries, shapes of characters, figures, or patterns are applied at least to the end surface. By applying a magnetic field from the base side using a magnet, a magnetically changing area corresponding to the character, figure or pattern is generated in a part of the magnetic layer, and then the magnetic layer is dried. A method for manufacturing a magnetic recording medium. (3) A magnetic recording medium comprising a base made of a non-magnetic material coated with a magnetic coating material, in which the magnetic layer has a visually visible magnetically variable portion directly or indirectly; Method of detecting magnetic information according to the shape of the changing part