JPH0836627A - Magnetic pattern and its forming method - Google Patents

Abstract

PURPOSE:To obtain a magnetic pattern in which the intensity of a magnetic output signal is uniform independently of a lateral width of a magnetic bar by using two kinds of magnetic bars or over whose lateral width being a width in the arrangement direction differs and forming any magnetic bar with sets of one unit bar or over and providing a very small gap between unit bars. CONSTITUTION:A magnetic pattern 1 consists of plural kinds of magnetic bars 2 whose lateral width is d1 and magnetic bars 3 whose lateral width d2 arranged as a pattern and each magnetic bar is a set of one common unit bar A or over. The magnetic bar 2 is made up of sets of two unit bars A at an interval of d3 and the magnetic bar 3 is made up of one unit bar. Thus, the lateral width of the magnetic bars is decided by number of sets of the unit bars A and two kinds or over of the magnetic bars whose lateral width differs are used. The cross section of the magnetic pattern 1 depends on the arrangement of the unit bars A whose thickness is (h) and the layer thickness of the magnetic bars 2, 3 is uniform (=h) independently of the lateral width of the magnetic bars.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic pattern, and more particularly to a magnetic pattern in which the intensity of a magnetic output signal obtained when scanning a magnetic head is uniform and a method for forming the magnetic pattern.

[0002]

2. Description of the Related Art For example, in order to prevent counterfeiting of a card such as a prepaid card, a magnetic pattern is formed on the card. This is to determine the authenticity of a card by reading a magnetic pattern formed in advance during use and determining whether or not a predetermined magnetic output signal can be obtained.

A magnetic head wound with two coils is used to read the magnetic pattern as described above. When a constant current is passed through one coil of the magnetic head and the magnetic head scans the magnetic pattern. The induced current or voltage induced is detected by the other coil. The induced current is generated according to the change in the magnetic flux of the magnetic head.

On the other hand, a ferromagnetic material is used as a material for forming the magnetic pattern, and various shapes of the magnetic pattern are considered, but a so-called bar code pattern is generally used. The magnetic pattern, which is a barcode-like pattern, is formed by arranging a plurality of magnetic bars that are pattern elements in the lateral width direction, and the magnetic bars that form the magnetic pattern have two or more lateral widths.

The bar code-like magnetic pattern is
A magnetic output signal can be obtained by closely contacting the above magnetic head and scanning at a constant speed.

As a method of forming the magnetic pattern as described above, a screen printing method, an offset printing method, a gravure printing method or the like can be used. These printing methods are advantageous in terms of manufacturing cost.

[0007]

However, the pattern formation by the printing method has the following problems due to the characteristics of the printing method.

For example, in the screen printing method, there is a correlation between the printed line width, that is, the lateral width and the printed film thickness, and even when a screen plate having the same emulsion thickness is used, the printed film thickness increases as the lateral width increases. Is common.

FIG. 4 shows a conventional magnetic pattern formed by the screen printing method. As shown in FIG. 4 (a),
The magnetic pattern 51 is composed of a plurality of magnetic bars 52 having a printed line width, that is, a horizontal width d1, and a plurality of magnetic bars 53 having a horizontal width d2 arranged in the horizontal width direction. Figure 4 (b)
Is a diagram showing a cross-sectional state of the magnetic pattern 51,
Compared with the film thickness h of the magnetic bar 53 having a narrow lateral width d2,
The film thickness H of the magnetic bar 52 having a wide lateral width d1 is large. A magnetic output signal waveform generated when the magnetic head scans such a magnetic pattern from left to right in the figure at a constant velocity is as shown in FIG. As shown in FIG. 4C, the magnetic output signal waveform corresponds to the rising edge 52 a of the magnetic bar 52 and corresponds to the rising edge 5 a.
2a and a positive pulse 54a different from the magnetic bar 52
Corresponding to the trailing edge 52b of the negative pulse 54b, which differentiates the trailing edge 52b, and the leading edge 53a of the next magnetic bar 53, which differentiates the trailing edge 53a. Such a positive pulse 55a,
A negative pulse 55b corresponding to the trailing edge 53b of the magnetic bar 53, which is obtained by differentiating the trailing edge 53b.
Composed of and. Then, the amplitudes of the positive pulse 54a and the negative pulse 54b are larger than the amplitudes of the positive pulse 55a and the negative pulse 55b, reflecting the difference in the film thickness of the magnetic bar.

Originally, the magnetic pattern provided on a card such as a prepaid card for which forgery prevention is desired should have the same pulse amplitude even if the width of the magnetic bar is different. Since the film thickness varies depending on the width of the magnetic bar, the magnetic output signal waveform generated when scanning with the magnetic head depends on the width of the magnetic bar, and the authenticity of the card cannot be accurately determined. was there.

The present invention has been made in view of the above situation, and a magnetic pattern in which the intensity of a magnetic output signal generated when scanning with a magnetic head is uniform without depending on the lateral width of the magnetic bar, and the magnetic pattern. It is an object of the present invention to provide a method for forming such a magnetic pattern.

[0012]

In order to achieve the above-mentioned object, the magnetic pattern of the present invention is a magnetic pattern composed of magnetic bars arranged in a pattern, and the magnetic pattern has a predetermined speed in the arrangement direction of each magnetic bar. In a magnetic pattern for obtaining information by amplifying a signal generated at the time when the magnetic head scanned by the scanner scans the rising end and the falling end of each magnetic bar to obtain information, There are two or more types having different widths in the arrangement direction, and each magnetic bar is a set of one or more unit bars, and each magnetic bar is a unit of two or more unit bars. The structure is such that a minute gap is provided between the bars.

Further, the magnetic pattern forming method of the present invention is a magnetic pattern composed of magnetic bars arranged in a pattern, wherein the magnetic heads scanned at a predetermined speed in the arrangement direction of the magnetic bars respectively generate magnetic fields. In a method of forming a magnetic pattern for obtaining information by amplifying a signal generated when scanning a rising edge and a falling edge of a bar with an amplifier having a predetermined response speed, one or more unit bars are collected to form a magnetic bar. In addition, by providing a minute gap between each unit bar in a magnetic bar that is a set of two or more unit bars,
Two or more types of magnetic bars having different widths in the arrangement direction are formed.

[0014]

Each magnetic bar is composed of a common set of unit bars, the width of the magnetic bar is determined by the number of set of unit bars, and the magnetic bar which is a set of two or more unit bars is between the unit bars. Since there is a minute gap in the magnetic bar, scanning a magnetic pattern in which such magnetic bars are arranged in the arrangement direction of each magnetic bar by a magnetic head causes a magnetic bar that is a set of two or more unit bars to A signal is generated when the magnetic head scans the rising edge and the falling edge of the unit bar, but the signals at the rising edge and the falling edge of the unit bar facing each other with a small gap are amplified to obtain a signal. As a result, a magnetic output signal as one magnetic bar is generated from the magnetic bar, which is a set of two or more unit bars. KazuSatoshi for each magnetic bar thickness is the same, the amplitude of the magnetic output signal is made uniform without depending on the width of the magnetic bar.

[0015]

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

FIG. 1 is a diagram for explaining one embodiment of the present invention, and FIG. 1 (a) is a plan view showing a magnetic pattern of the present invention. In FIG. 1A, a magnetic pattern 1 is formed by arranging a plurality of magnetic bars 2 having a lateral width = d1 and magnetic bars 3 having a lateral width = d2 in a pattern. Each magnetic bar is a collection of one or more common unit bars A. That is, the magnetic bar 2 having a lateral width = d1 is configured by collecting two unit bars A having a lateral width = d2 with a gap = d3, and the magnetic bar 3 having a lateral width = d2 is one unit having a lateral width = d2. Composed of bar A. Therefore, in the present invention, the lateral width of the magnetic bar is determined by the number of sets of unit bars A, and there are two or more types of magnetic bars having different lateral widths.

Such a magnetic pattern 1 can be formed, for example, by preparing a screen printing plate with a pattern as shown in FIG. 1A and printing with a magnetic ink. As shown in FIG. 1B, the cross-sectional shape of the magnetic pattern 1 formed in this manner is such that the unit bars A having a width = d2 are arranged with a film thickness h, and are composed of the unit bars A. The film thickness of the magnetic bar 2 having a lateral width = d1 and the film thickness of the magnetic bar 3 having a lateral width = d2 are both the film thickness h and uniform regardless of the lateral width of the magnetic bar.

The magnetic output signal waveforms produced when the magnetic head scans such a magnetic pattern 1 from left to right in the figure at a constant speed are as shown in FIGS. 1 (c) and 1 (d). FIG. 1 (c) shows only the positive pulse of the magnetic output signal waveform, and FIG. 1 (d) shows only the negative pulse of the magnetic output signal waveform. That is, the magnetic output signal waveform corresponds to the rising ends 2a and 2c of each unit bar A forming the magnetic bar 2, and the positive pulses 4a and 4c which are obtained by differentiating the rising ends and the magnetic bar 2 are generated. Negative pulse 4 corresponding to the falling edges 2b and 2d of each unit bar A that constitutes the negative pulse 4 is obtained by differentiating the falling edges.
b, 4d, and the rising edge 3a of the unit bar A constituting the magnetic bar 3, the positive pulse 5a obtained by differentiating the rising edge, and the rising of the unit bar A constituting the magnetic bar 3. Corresponding to the falling edge 3b, the negative pulse 5b is formed by differentiating the falling edge. At this stage, since the thickness of each magnetic bar forming the magnetic pattern 1 is the same as described above, the positive pulse 4
a, 4c and negative pulses 4b, 4d have positive pulse 5a
And the amplitude of the negative pulse 5b.

Next, the signal pulse is amplified by an amplifier having a predetermined response speed to be used as information. Here, with the miniaturization of the magnetic pattern and the increase of the card transport speed,
The response speed of the amplifier for amplifying the magnetic output signal waveform is not always sufficient, and the leakage of a certain amount of magnetic flux generated in the magnetic head cannot be ignored in the above miniaturization.
There is a problem that a magnetic output signal is delayed due to the influence of the inductance of the coil in the magnetic head. For example, as shown in FIG. 2B, the magnetic output waveform generated when the magnetic head scans the magnetic bar 11 as shown in FIG. A positive pulse 12a that is obtained by differentiating the rising end portion of the magnetic bar 11 and a falling edge portion 11b of the magnetic bar 11 that is obtained by differentiating the falling edge portion of the magnetic bar 11. And negative pulse 12b. And FIG.2 (c) shows the magnetic output signal which amplified the magnetic output signal waveform shown by FIG.2 (b) with the amplifier. The times t1 and t3 in the magnetic output signal increase in proportion to the leakage of the magnetic flux from the magnetic head. Also, at times t2 and t4
Is influenced by the inductance of the coil in the magnetic head and the response speed of the amplifier in addition to the leakage of magnetic flux from the magnetic head. Therefore, in reality, there is a time t5 + t6 for discriminating the magnetic bar 11, which is determined by the magnetic head and the amplifier regardless of the magnetic pattern. In such a case, even if a plurality of signals can be detected by the magnetic head within a certain period of time, it is difficult to amplify and take out the signals. That is, even if there are a plurality of signals detected by the magnetic head passing through the magnetic bar within the response time of the amplifier or a plurality of signals detected by a sufficiently fine magnetic bar, these signals are not the amplified magnetic output signals. It cannot be.

From this, by setting the gap d3 of the unit bar A constituting the magnetic bar 2 as described later, the positive pulses 4a, 4c of the magnetic output signal waveform shown in FIG. 1C, and Of the negative pulses 4b and 4d of the magnetic output signal waveform shown in FIG. 1D, the negative pulse 4b and the positive pulse 4b at the falling end 2b and the rising end 2c of the unit bar A facing each other with a gap d3 therebetween. Pulse 4c
At the time of amplification, it is not output due to the delay due to the response speed of the amplifier. Therefore, as shown in FIG. 1E, magnetic output signal amplification waveforms 4a 'and 4d' corresponding to the positive pulse 4a and the negative pulse 4d are obtained from the magnetic bar 2 which is a set of two unit bars A. Thus, the magnetic bar 2 exhibits the function as one magnetic bar.

Here, the width d3 of the gap of the unit bar A described above.
Is preferably small in consideration of the response speed of the amplifier and the leakage magnetic flux from the magnetic head. However, for example, the screen printing plate is made by photolithography in which a screen mesh coated with a photocurable emulsion is masked with a positive film, and the minimum value of the gap of the unit bar A is the number of screen meshes, the emulsion thickness, It is necessary to determine the exposure time and the accuracy of the positive film. Further, since a high pressure is applied to the emulsion by a squeegee during printing, the gap width d3 of the unit bar A is set on the assumption that the emulsion is made of a material that is not easily broken even in such a pressurized state. As an example, the emulsion thickness is 3 to 20 μm and the gap d3 is 10 to 50 μm.
m.

In each of the above-described embodiments, two types of magnetic bars are pattern-arranged: a magnetic bar 2 having a width of d1 consisting of two unit bars A and a magnetic bar 3 having a width of d2 consisting of one unit bar A1. However, the combination of the unit bars A is not limited to this. For example, from the relationship between the width of the magnetic bar having the smallest width and the widths of other magnetic bars, the magnetic bars having the smallest width may be a set of two or more unit bars A.
FIG. 3 is a diagram for explaining the magnetic pattern of the present invention in such a mode. In FIG. 3, the magnetic pattern 21 includes a magnetic bar 22 having a width = d1 and a magnetic bar 23 having a width = d2.
Are arranged in the width direction. Each magnetic bar is a collection of two or more common unit bars A. That is, the magnetic bar 22 having a width = d1 has a width = d
5 unit bars A are formed by collecting three unit bars A with a gap = d4, and a magnetic bar 23 having a width = d2 is formed by collecting two unit bars A having a width = d5 with a gap = d4. ing.

The magnetic ink that can be used in the present invention is not particularly limited, and known magnetic ink can be used.

Although the width of the magnetic bar forming the magnetic pattern is two kinds in the above-mentioned embodiment, the present invention is not limited to this. Even if the width of the magnetic bar is three or more kinds. Good.

Next, the present invention will be described in more detail by showing concrete examples. (Example 1) As a printing plate, a screen printing plate 1 provided with an ink adhering portion in a pattern as shown in FIG.
It was created.

(Structure of screen printing plate 1) Screen mesh: 325 lines / inch. Emulsion: Photo-curable emulsion mask. Emulsion thickness: 10 μm. Size of ink adhering part: d1 = 210 μm d2 = 100 μm d3 = 10 μm. A magnetic ink (viscosity (B-type viscometer, 25 ° C., 60 rpm): 10,000 cps) having the following composition was prepared.

(Composition of magnetic ink) Soft magnetic powder 70 parts by weight Vinyl chloride-vinyl acetate copolymer resin 4 parts by weight Polyurethane resin 4 parts by weight Organic bentonite 0.6 parts by weight Organic solvent (Isophorone / butyl carbitol acetate = 2/1) ... 21.4 parts by weight Next, a polyethylene terephthalate card (thickness 188 μm) was prepared as a material to be printed, and screen printing was performed on this card under the following conditions. Then, the magnetic ink was dried under the condition of 80 ° C. to form a magnetic pattern.

(Screen printing conditions) -Squeegee speed: 45 cm / sec-Squeegee material: Urethane rubber The film thickness and unit bar gap of each unit bar constituting each magnetic bar of the magnetic pattern thus formed on the card are The measurement results are shown in Table 1 below.

Further, a magnetic output signal of a magnetic pattern is detected by an inspection machine (manufactured by San-Etec Co., Ltd. magnetic card evaluation machine EMMC-3), and a magnetic bar having a small width (Fig. 1) is detected.
The average value of the amplified signal strength in the magnetic bar 3 in (a) is set to 100, and the magnetic bar having a wide width (see FIG. 1).
The average value of the amplified signal intensity in (a) (corresponding to the magnetic bar 2) is shown in Table 1 below. The measurement conditions in the above inspection machine are as follows.

(Measurement conditions) -Card transport speed: 220 cm / sec-Magnetic head gap: 5 μm-Bias current: 40 mA (Example 2) As a printing plate, the ink adhering portion dimension d1 = 2
A magnetic field was formed on the card in the same manner as in Example 1 except that the screen printing plate 2 was prepared in the same manner as the screen printing plate 1 in Example 1 except that 40 μm and d3 = 40 μm. A pattern was formed.

Table 1 below shows the results of measuring the film thickness of the unit bar and the unit bar gap constituting each magnetic bar of the magnetic pattern thus formed on the card.

Further, as in the first embodiment, the magnetic output signal of the magnetic pattern is detected, and the average value of the amplified signal strength in the magnetic bar having a small width is set to 100, and the average value of the amplified signal strength in the magnetic bar having a wide width is calculated. The results are shown in Table 1 below. (Comparative Example 1) As a printing plate, the size d1 of the ink adhering portion is 2
A screen printing plate 3 was prepared in the same manner as the screen printing plate 1 of Example 1 except that 05 μm and d3 = 5 μm.
A magnetic pattern was formed on the card in the same manner as in Example 1 except that this screen printing plate 3 was used.

Table 1 below shows the results of measuring the film thickness and unit bar gap of each magnetic bar constituting each magnetic bar of the magnetic pattern thus formed on the card.

Further, as in the first embodiment, the magnetic output signal of the magnetic pattern is detected, and the average value of the amplified signal strength in the magnetic bar having a small width is set to 100, and the average value of the amplified signal strength in the magnetic bar having a wide width is calculated. The results are shown in Table 1 below. (Comparative Example 2) As a printing plate, the dimension d1 of the ink adhering portion is 2
A screen printing plate 4 was prepared in the same manner as the screen printing plate 1 of Example 1 except that 60 μm and d3 = 60 μm, and the same procedure as in Example 1 was carried out except that this screen printing plate 4 was used. A pattern was formed.

Table 1 below shows the results of measuring the film thickness and unit bar gap of each magnetic bar constituting each magnetic bar of the magnetic pattern thus formed on the card.

Further, as in the first embodiment, the magnetic output signal of the magnetic pattern is detected, and the average value of the amplified signal strength in the magnetic bar having a small width is set to 100, and the average value of the amplified signal strength in the magnetic bar having a wide width is set. The results are shown in Table 1 below. (Comparative Example 3) The following screen printing plate 5 was used to form a conventional magnetic pattern, which is not a set of unit bars, as a magnetic bar constituting a magnetic pattern on the card as shown in FIG.

(Structure of screen printing plate 5) -Screen mesh: 325 lines / inch-Emulsion: Photo-curable emulsion mask-Emulsion thickness: 10 μm-Ink adhering part dimension: d1 = 100 μm d2 = 210 μm The results of measuring the film thickness of the magnetic pattern formed above are shown in Table 1 below.

Further, as in the first embodiment, the magnetic output signal of the magnetic pattern is detected, and the average value of the amplified signal strength in the magnetic bar having a small width is set to 100, and the average value of the amplified signal strength in the magnetic bar having a wide width is calculated. The results are shown in Table 1 below.

[0039]

[Table 1]

[0040]

As described above in detail, according to the present invention, two or more kinds of magnetic bars having different widths are constituted by a common set of unit bars, and the magnetic bar is a set of two or more unit bars. Has a small gap between each unit bar, and the width of the magnetic bar is determined by the number of sets of unit bars.The film thickness of each magnetic bar is determined by the film thickness of the unit bar that constitutes it. Therefore, a magnetic pattern with a uniform film thickness can be obtained without depending on the width of the magnetic bar. Therefore, the intensity of the magnetic output signal generated when the magnetic head scans the magnetic pattern in the array direction of each magnetic bar. Does not depend on the width of the magnetic bar, and in a magnetic bar composed of two or more unit bars, the signals at the rising edge and the falling edge of the unit bars facing each other with a minute gap are A magnetic bar, which is a set of two or more unit bars, can not be taken out as a width signal, and functions as one magnetic bar. Therefore, the accuracy of the obtained information is improved, and the authenticity of the card is improved. The false judgment can be made accurately.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an example of a magnetic pattern of the present invention.

FIG. 2 is a diagram for explaining amplification of a magnetic output signal.

FIG. 3 is a diagram for explaining another embodiment of the magnetic pattern of the present invention.

FIG. 4 is a diagram showing a conventional magnetic pattern.

[Explanation of symbols]

 1, 21 ... Magnetic pattern 2, 3, 11, 22, 23 ... Magnetic bar A ... Unit bar

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G06K 19/10 G11B 5/02 Z 8841-5D

Claims (2)

[Claims] 1. A magnetic pattern comprising magnetic bars arranged in a pattern, wherein a magnetic head scanned at a predetermined speed in the arrangement direction of each magnetic bar has a rising end and a falling end of each magnetic bar. In a magnetic pattern for obtaining information by amplifying a signal generated at the time of scanning with an amplifier having a predetermined response speed, there are two or more kinds of the magnetic bars having different widths in the arrangement direction. The magnetic bar is a set of one or more unit bars, and the magnetic bar, which is a set of two or more unit bars, has a minute gap between the unit bars. 2. A magnetic pattern comprising magnetic bars arranged in a pattern, wherein a magnetic head scanned at a predetermined speed in the arrangement direction of each magnetic bar has a rising end and a falling end of each magnetic bar. In a method of forming a magnetic pattern for obtaining information by amplifying a signal generated at the time of scanning with an amplifier having a predetermined response speed, one or more unit bars are assembled into a magnetic bar, and 2
A magnetic bar, which is a set of a plurality of unit bars, is provided with a minute gap between the unit bars to form two or more types of magnetic bars having different widths in the arrangement direction. Pattern formation method.