JPH1196430A - Magnetic detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain uniformly stabilized magnetization, and to attain magnetic pattern detection with high sensitivity and satisfactory reproducibility only by providing a magnetizing means on a magnetizing face side for a medium by setting the magnetic field direction of magnetization by a magnetizing means as the width direction of a carrying direction. SOLUTION: A magnet 11 constituted of a permanent magnet as a magnetizing means magnetized on the magnetizing face of a medium 10 is attached to the upper face side of a carrying path 12 so as to be faced to each other, and the direction of the magnetic pole of the magnet 11 is set as a width direction vertically crossing the carrying direction. A magnetic sensor 13 as a magnetic detecting means is arranged at the upper part in the post stage of the carrying direction of the magnet 11, and a touch roller 15 energized by a spring 14 is brought into contact with that so as to be faced to each other. This, the direction of the magnetic field of the magnetization by the magnet 11 of the magnetizing means is set as the width direction so that the direction of the residual magnetic field of the magnetized medium 10 can be lined up in a direction horizontal to the magnetizing face and in the width direction vertical to the magnetizing direction (carrying direction), and stable magnetization can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for identifying a medium by magnetizing a medium containing a magnetic material such as a bill or a check, detecting the residual magnetic field and reading the magnetic characteristics and magnetic pattern of the medium. The present invention relates to a magnetic detection device capable of performing the following.

[0002]

2. Description of the Related Art As described above, when a medium is magnetized and its residual magnetic field is detected, since the residual magnetic field can be directly taken out as an output of a magnetic sensor, the absolute amount of the residual magnetic field can be evaluated. Has features.

As shown in FIG. 1, the magnet 11 is arranged so that the N and S poles of the magnet 11 are perpendicular to the magnetized surface of the medium 10 to be conveyed. The magnet 11 is magnetized by applying a constant magnetic field.

In this case, the magnetic flux emitted from the N pole is directed to the S pole and generates a magnetic field as shown in the figure. Since the direction of the residual magnetic field formed on the magnetized surface of the medium 10 magnetized by this configuration changes depending on the positional relationship with the medium 10, there is a problem in that the magnetization varies greatly.

FIG. 2 shows a configuration for solving the above-mentioned problem, in which two magnets 11 a and 11
b with the different magnetic poles facing each other, and the upper magnet 1
The magnetic flux generated from the N pole of 1a is formed so as to penetrate the medium 10 and travel toward the S pole of the lower magnet 11b, and a magnetic field is always generated in the direction perpendicular to the medium 10 on the magnetized surface of the medium 10. It is configured to be.

According to this structure, since the magnetic flux penetrates the medium 10, stable magnetization is possible. However, two magnets are required, the number of parts increases, and the assembling work also increases. Having.

[0007]

According to the present invention, uniform and stable magnetization can be obtained only by forming the magnetizing means only on the magnetized surface side with respect to the medium, and high sensitivity and good reproducibility are obtained. An object of the present invention is to provide a magnetic detection device capable of detecting a magnetic pattern.

[0008]

According to a first aspect of the present invention, there is provided a conveying means for conveying a medium, a magnetizing means for magnetizing the medium conveyed by the conveying means, and a magnetizing means for magnetizing the medium conveyed by the conveying means. A magnetism detecting means for detecting a residual magnetic field of the magnetized medium, wherein the direction of the magnetic field of the magnetization by the magnetizing means is set to the width direction in the transport direction.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a means having directivity in sensitivity is used as the magnetic detecting means, and the direction of the sensitivity of the magnetic detecting means is changed. Is set in the same direction as the direction of the magnetic field magnetized by the magnetizing means.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, the magnetizing means is formed in a roller shape by a magnet which generates a magnetic field in the axial direction, and the conveying means is provided. The magnetic detection device also serves as

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the magnetizing means is controlled to perform magnetizing and non-magnetizing at set time intervals. When the magnetizing means is non-magnetized, the magnetism detecting means is a magnetic detecting device which controls to detect a magnetic field.

A fifth aspect of the present invention is characterized in that a banknote is magnetized by the magnetic detecting device according to the first, second, third or fourth aspect and the residual magnetic field is detected.

According to a sixth aspect of the present invention, a printed matter printed with magnetic ink is magnetized by the magnetic detection device according to the first, second, third or fourth aspect, and the residual magnetic field is detected. Features.

[0014]

According to the present invention, the direction of the magnetic field of the magnetization by the magnetizing means is set to the width direction in the transport direction, so that the direction of the residual magnetic field of the magnetized medium is shifted to the magnetization surface. On the other hand, it is horizontal and aligned in the width direction perpendicular to the magnetizing direction (transport direction), so that the magnetized state can be obtained. Furthermore, since the residual magnetic field has a width in the transport direction, even if the positional relationship with the magnetic detecting means is slightly displaced, it is permissible, and a stable and reproducible detection waveform can be obtained, and the magnetic pattern of the medium can be obtained. Can be obtained with an output corresponding to the coercive force of the magnetic material. As a result, it is possible to reduce the cost, reduce the size, and improve the discrimination performance of the device by magnetizing only the magnetized surface side.

Further, according to the present invention, by setting the direction of the sensitivity of the magnetism detecting means to the same direction as the direction of the magnetic field (transport width direction) magnetized by the magnetizing means, the magnetic characteristics on the medium ( (Corresponding to the intensity of the residual magnetic field) and an output corresponding to the magnetic pattern, and accurate identification can be obtained.

Further, according to the present invention, since the magnetizing means is formed in the shape of a roller with a magnet and also serves as a transporting means, it is not necessary to secure a space for the magnet exclusively for magnetizing, and the size of the detecting unit can be reduced. Become. In addition, since the transport roller is also used, the medium and the roller-shaped magnetizing means are in direct contact with each other, and can be reliably magnetized even with a weak magnetic field.

Further, according to the present invention, the magnetizing means and the magnetic detecting means are arranged close to each other by alternately performing the magnetizing of the magnetizing means and the magnetic field detection of the magnetic detecting means at a set time interval. However, no countermeasures such as a shield are required between the two, and a compact configuration can be achieved. If the time interval described above is sufficiently small, stable detection by the magnetic detecting means can be performed without being affected by the magnetic field generated by the magnetizing means.

Further, when the magnetic detection device of the present invention is used to identify a printed matter printed with magnetic ink such as a bill or a check, the function can be effectively exerted.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The drawings show the magnetic detection device. In FIGS. 3 and 4, the medium 10 is a medium using a magnetic material that generates a residual magnetic field by being magnetized, such as a banknote or a check printed with magnetic ink. The transport path 12 is transported in the X direction by an appropriate transport unit such as a transport roller or a transport belt.

A magnet 11 composed of a permanent magnet as a magnetizing means for magnetizing the magnetized surface of the medium 10 is provided on the upper surface side of the transport 12.
The magnets 11 have their magnetic poles set in the width direction perpendicular to the transport direction.

A magnetic sensor 13 is disposed above the magnetizing means in the direction of conveyance of the magnets 11 as a magnetic detecting means.
Is facing.

The above-mentioned magnetic sensor 13 is constituted by an MI element (magnetic impedance element) having directivity in sensitivity, and the direction of the sensitivity is set in the width direction perpendicular to the transport direction.

FIG. 5 shows the medium 1 by the magnet 11 of the magnetizing means.
0 indicates a magnetized state, and the magnetic flux acts on the medium 10 in the width direction because the polarity of the magnet 11 is in the width direction in the transport direction. Since the residual magnetic field H of the medium 10 depends on the strength of the magnetic field at the time of magnetization, it is necessary to apply a high magnetic field equal to or higher than the saturation magnetic field of the medium 10, so that the magnetic force of the magnet 11 can cover the magnetic field. Is set to

FIG. 6 shows a state in which the magnetic sensor 13 as the magnetic detecting means detects the residual magnetic field of the medium 10. The residual magnetic field H of the magnetized medium 10 generates a magnetic flux in the width direction. H is detected by the magnetic sensor 13 whose sensitivity directivity is set in the same width direction.

FIG. 7 shows a detection circuit based on the magnetic sensor 13, wherein Vac is a high-frequency power supply, R is a resistor, Iac is a small high-frequency current, Vout is an output voltage at an output terminal, and Hex is a residual magnetic field of the medium 10.

FIG. 8 shows a state in which a print pattern 16 (16a, 16b, 16c) is formed on the medium 10 with magnetic ink.
Through the magnetic detection device disclosed in FIGS.
When magnetized at 1 and the magnetic pattern due to the residual magnetic field is read by the magnetic sensor 13 and the magnetism is detected by the detection circuit of FIG. 7, the detection output can obtain the detection waveform shown in FIG.

According to this embodiment, the magnet 11 of the magnetizing means
Is set in the width direction of the transport direction, the direction of the residual magnetic field H of the magnetized medium 10 is
Aligned with the width direction that is horizontal to the magnetization surface and perpendicular to the magnetization direction (transport direction), and stable magnetization is obtained.

Further, since the residual magnetic field H has a width in the transport direction, even if the positional relationship with the magnetic sensor 13 of the magnetic detecting means is slightly displaced, a reproducible and stable waveform can be obtained. As a result, the magnetic pattern of the medium can be obtained with an output corresponding to the coercive force of the magnetic material, and as a result, the cost of the apparatus can be reduced, the size can be reduced, and the identification performance can be improved by magnetizing only the magnetized surface side. .

FIGS. 10 and 11 show a second embodiment.
This example shows an example in which the magnetizing means is constituted by the magnetic head 11c. Since the magnetism detecting means is constituted by the magnetic sensor 13 of the first embodiment, a detailed description thereof will be omitted.

The magnetizing means according to this embodiment is provided such that the gap of the magnetic head 11c is set in the width direction perpendicular to the transport direction so that a magnetic flux of a magnetic field is generated in the width direction. Note that the magnetic head 11c is brought into contact with a transfer roller 17 having a transfer force to apply a transfer force to the medium 10.

According to this embodiment, since the intensity of the magnetic field generated in the gap of the magnetic head 11c is proportional to the current flowing through the magnetic head 11c, the intensity of the magnetization can be freely changed by controlling the current. Can be.

FIGS. 12 and 13 show a third embodiment.
This example shows an example in which the magnetizing means is formed in a roller shape by using a permanent magnet. Since the magnetism detecting means is constituted by the magnetic sensor 13 of the first embodiment, a detailed description thereof will be omitted.

The polarity of the magnetized roller 11d formed in a roller shape by the above-mentioned permanent magnet is set in the direction of the axis, so that the magnetic flux of the magnetic field is generated in the direction of the conveyance width, and the conveyance roller 17 is set to this. The contact also serves as a transport means.

With this configuration, it is not necessary to secure a space for the magnet exclusively for the magnetization, and the size of the detection unit can be reduced. In addition, because it is configured to also serve as a transport means,
The magnet comes into direct contact with the medium 10 and can be reliably magnetized even with a weak magnetic field.

FIGS. 14 and 15 show a fourth embodiment.
This example shows an example in which the magnetizing means is constituted by the magnetic head 11c, and the current control circuit 18 controls the current to be turned off / on (corresponding to the non-magnetized / magnetized control). Since the magnetic detection means is constituted by the magnetic sensor 13 of the first embodiment,
Detailed description is omitted.

The magnetizing means according to this embodiment is provided such that the gap of the magnetic head 11c is set in the width direction perpendicular to the transport direction so that the magnetic flux of the magnetic field is generated in the width direction. This is the same as the second embodiment shown in FIGS.

However, the current supplied to the magnetic head 11c is turned off / on at predetermined time intervals by the current control circuit 18.
A pulse current for turning ON is supplied, and the magnetic sensor 13 detects a residual magnetic field of the medium 10 in synchronization with the OFF pulse current.

That is, when the current is ON (H, high), a magnetic field is generated in the gap of the magnetic head 11c, and the medium 1
0 is set. When the current is OFF (L, low),
Since no magnetic field is generated in the gap, the medium 10 is not magnetized. Therefore, the interval of OFF / ON (non-magnetization / magnetization) in the current control is set sufficiently small with respect to the detection pattern, and the residual magnetic field is detected by the magnetic sensor 13 when the current is L.

With such a configuration, the influence of the magnetic field created by the magnetic head 11c, which is a magnetizing means, is measured by the magnetic sensor 1.
Thus, stable detection can be performed without receiving the signal 3, so that it is not necessary to take measures such as sealing for the magnetizing means and the magnetic sensor 13.

In correspondence between the structure of the present invention and the above-described embodiment, the conveying means of the present invention may be any appropriate conveying / conveying means including the conveying rollers and the conveying belt of the embodiment,
In the same manner, the magnetizing means corresponds to the magnet 11, the magnetic head 11c, and the magnetizing roller 11d, and the magnetic detecting means corresponds to the magnetic sensor 13 composed of the MI element. The present invention is not limited to the above-described embodiment, and can be used for authenticity determination of banknotes, denominations and discrimination of printed matter using magnetic ink, and the technical idea described in the claims. It can be applied based on

[Brief description of the drawings]

FIG. 1 is a side view showing a prior art of a magnetizing method.

FIG. 2 is a side view showing another prior art of the magnetizing method.

FIG. 3 is a side view of the magnetic detection device according to the first embodiment.

FIG. 4 is a plan view of the magnetic detection device.

FIG. 5 is a front view showing a magnetized state.

FIG. 6 is a front view showing a state in which a residual magnetic field is detected.

FIG. 7 is a magnetic field detection circuit diagram.

FIG. 8 is a plan view showing a print pattern of a medium.

FIG. 9 is a detection waveform diagram of a residual magnetic field.

FIG. 10 is a front view of a magnetic detection device according to a second embodiment.

FIG. 11 is a side view of the magnetic detection device.

FIG. 12 is a front view of a magnetic detection device according to a third embodiment.

FIG. 13 is a side view of the magnetic detection device.

FIG. 14 is a front view of a magnetic detection device according to a fourth embodiment.

FIG. 15 is a waveform diagram of a magnetizing current.

[Explanation of symbols]

 Reference Signs List 10 medium 11 magnet 11b magnetic head 11c magnetizing roller 13 magnetic sensor 17 transport roller

Claims (6)

[Claims] 1. A conveying means for conveying a medium, a magnetizing means for magnetizing the medium conveyed by the conveying means, and a magnetic detecting means for detecting a residual magnetic field of the medium magnetized by the magnetizing means. A magnetism detecting device, wherein the direction of the magnetic field of the magnetization by the magnetizing means is set to the width direction in the transport direction. 2. The apparatus according to claim 1, wherein said magnetic detecting means comprises means having directivity in sensitivity, and the direction of sensitivity of said magnetic detecting means is set to the same direction as the direction of a magnetic field magnetized by said magnetizing means. 2. The magnetic detection device according to 1. 3. The transfer means according to claim 1, wherein said magnetizing means is formed in a roller shape by a magnet which generates a magnetic field in the axial direction.
The magnetic detection device according to claim 1. 4. The apparatus according to claim 1, wherein said magnetizing means is controlled to perform magnetizing and non-magnetizing at a set time interval.
2. The magnetic detection device according to claim 1, wherein the magnetic detection unit controls to detect a magnetic field. 5. The method according to claim 1, wherein said medium is set in a bill.
5. The magnetic detection device according to 3 or 4. 6. The magnetic detection device according to claim 1, wherein the medium is set to a printed material printed with magnetic ink.