JP2843743B2 - Method and apparatus for determining authenticity of an object to be detected - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to important documents and securities,
The present invention relates to a method and an apparatus for determining the authenticity of an object requiring authenticity, such as a voucher, a card, a work of art, or the like.

[0002]

2. Description of the Related Art As means for checking the authenticity of documents and the like, Japanese Patent Application Laid-Open No. 3-27489 and Patent Application Publication
Checking means using microwaves are known, as can be seen in -501250. In this prior art, microwaves are incident on a large number of particles randomly distributed in a document,
A unique digital mark corresponding to the response microwave packet
They are recorded at appropriate places in the documents according to certain rules. And when judging the authenticity of the document, the microwave is incident on the document, and the response microwave flux is compared with the digital mark, so that when the two coincide,
I try to judge it as genuine.

[0003]

The checking means using a microwave as in the prior art described above is susceptible to external noise when measuring a response microwave packet, so that the SN ratio deteriorates. In addition, since the above-described prior art device oscillates a microwave, it may be a noise source. In addition, microwave transmitters and receivers are becoming smaller.
Difficult and expensive. Incidentally, JP-A-3-4838
As in the case of the magnetic card described in
For magnetizing (permanent magnetization) the tripe magnetic powder,
Simple means such as sprinkling fine iron powder on the ki stripe
Therefore, since the recorded contents can be understood, security is improved.
There's a problem. Also described in JP-A-63-157082
The magnetic layer on the surface of a banknote is magnetically
What is detected is that the magnetic characteristics of the magnetic layer
Easy to operate, and when an external magnetic field acts,
Lack of stability, for example, the characteristics may change
Met.

Accordingly, an object of the present invention is to enable a compact and low-cost apparatus to determine the authenticity of an object to be detected without having a high SN ratio and being a source of noise.

[0005]

SUMMARY OF THE INVENTION The method of the present invention, which has been developed to achieve the above-mentioned object, is to magnetically scan a scanning area of an object to which a large number of magnetically sensitive elements are randomly mixed. A method of discriminating the authenticity of an object, wherein a biased magnetic field is applied to a core having a gap, a scanning area of the object is passed at a predetermined speed near the gap, and the scanning area is passed. In this case, the high-permeability material randomly distributed in this scanning area
A change in the induced voltage generated in the core due to a change in the magnetic permeability of the gap portion with time according to the number of the magnetically sensitive elements is captured , and the induced voltage detection signal is encoded and the encoded code is encoded. Recorded in the code display section of the detected object, when determining the authenticity of the detected object, passing the scanning area through the gap portion of the core at a predetermined speed while applying a bias magnetic field to the core, An induced voltage detection signal is obtained by detecting an induced voltage corresponding to the change in the magnetic permeability generated in the core, and an encryption code recorded in the code display section is read and decrypted to decode the code. The code is reproduced, and the collation code is collated with the induced voltage detection signal. When both correspond, it is determined that the detected object is genuine. And butterflies.

The apparatus according to the present invention comprises a core having a gap, means for applying a bias magnetic field to the core, a transport mechanism for passing a scanning area of the object to be detected near the gap of the core at a predetermined speed, and above the scanning area is included in the scanning area when passing through the gap portion
A detector for detecting a change in the magnetic permeability of the scanning region by detecting an induced voltage generated in the core in accordance with the large number of magnetically sensitive elements, and a code for the induced voltage detection signal detected by the detector. Code writing means for converting and recording the code on the code display section of the object to be detected, code reading means for reading the code recorded on the code display section, and scanning the scanning area when determining the authenticity of the object to be detected that is obtained by
Means for comparing an induction voltage detection signal corresponding to the change in magnetic permeability with a code recorded in the code display unit and determining that the detected object is genuine when both correspond. I have.

The magnetic element used in the present invention is a Co-F
e-Si-B amorphous alloys, Fe-Ni alloys,
A linear member, foil, powder, or a mixture thereof made of a high magnetic permeability alloy material such as permalloy or soft ferrite is suitable. As a means for applying a bias magnetic field to the core, a DC current may be supplied to an exciting coil provided in the core, or a permanent magnet provided in the core may be used. The material of the core is suitably a high permeability alloy material.

[0008]

According to the present invention, when the magnetic element is a linear member or foil, a large number of magnetic elements are randomly mixed in the scanning area of the object to be detected. When the magnetic sensing element is a powder, a random shading (change in density) of the powder is applied to the scanning area of the detection object, a random pattern is drawn by keeping the powder density constant, or Combine both. Then, the output pattern of the induced voltage generated according to the magnetic sensitive element when passing through the scanning region through the gap portion of the core is used for checking the authenticity of the object. That is, by moving the object to be detected at a predetermined speed by the transport mechanism, the scanning region is passed through the gap portion of the core to which the bias magnetic field has been applied. At this time, the magnetic permeability of the gap changes as the magnetic element included in the scanning area passes through the gap, and the number of magnetic fluxes passing through the core changes. This change in magnetic flux induces an induced voltage in a detector such as a detection coil.

The induced voltage generated in this manner changes for each minute portion of the scanning region depending on the mixing density of the magnetic sensing element mixed in the scanning region, the size or the arrangement direction of the magnetic sensing device, and so on. An induced voltage detection signal having a unique output pattern is obtained. The detection signal is encrypted according to a specific rule when the object is created, and is recorded on the code display unit of the object.

[0010] When collating whether or not the detected object is genuine, the scanning area is scanned again to obtain the induced voltage detection signal, and the code recorded on the code display section of the detected object is obtained. The code is decoded to reproduce the collation code, and when the collation code corresponds to the induced voltage detection signal, it is determined that the object to be detected is authentic.

The present invention can be used for securities, cash vouchers,
Starting with papers such as important documents, plastic cards such as ID cards, CD cards, and credit cards,
It is used to prevent counterfeiting of works of art, etc. or to determine whether they are genuine or imitation.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, a large number of magnetically sensitive elements 12 are randomly mixed in the base material 11 of the detection object 10. The substrate 11 is made of a non-magnetic material such as paper or plastic. One example of the magnetic sensitive element 12 is
Wire made of high permeability alloy material with wire diameter of φ7μm to 50μm and length of about 5mm to 30mm, or thickness of 7μm to 50μ
m, a foil made of a high magnetic permeability alloy material having a length of about 5 mm to 30 mm, or a powder made of a high magnetic permeability alloy material having a diameter of about 0.1 μm to 10 μm. At least a specific scanning area 13 is mixed so that the magnetic sensitive element 12 is contained at a certain density.

When the magnetic sensitive element 12 is a linear member or foil, a large number of magnetic sensitive elements 1
2 are randomly mixed so as to be scattered. When the magnetic sensitive element 12 is a powder, the scanning area 13 of the detection target 10 is
The density of the powder is changed randomly (change in density), a random pattern is drawn with the density of the powder kept constant, or both are combined.

As will be described later, information corresponding to the distribution state of the magnetic sensitive elements 12 in the scanning area 13 is encrypted and displayed on the code display unit 15 on the detection object 10. The scanning region 13 of the detection target 10 is magnetically scanned by the processing device 20 having the induced voltage detecting function for authenticity determination illustrated in FIG.

The processing apparatus 20 includes a housing 25 and a transport mechanism 26 for moving the object 10 at a constant speed. The transport mechanism 26 moves the object 10 in the direction of arrow F in the figure at a constant speed by a transport member 27 using a belt, a roller, or the like.

An induced voltage detecting coil pair 33 composed of an exciting coil 31 and a detecting coil 32 is provided in the course of the movement of the object 10. The excitation coil 31 and the detection coil 32 are provided on a core 41 of the detection head 40. The core 41 is made of a high-permeability alloy material.
A gap 42 is provided on the side facing 3. The scanning region 13 of the detection object 10 passes near the gap 42 (gap portion 42a). A DC power supply circuit 45 is connected to the excitation coil 31 as an example of a means for applying a bias magnetic field to the core 41.

It is also possible to use both the excitation coil 31 and the detection coil 32. In this case, the number of coils is one, so that the cost can be further reduced. In the above-described embodiment, the detection coil 32 is employed as an example of the magnetic detector. However, a magnetic detection element such as a Hall element may be used instead of the detection coil 32.

The processing device 20 includes a controller 50 using a microcomputer or the like, a code writing unit 51 for recording the following encryption code on the code display unit 15 of the object 10, and a code recording unit 51 recorded on the code display unit 15. A code reader 52 for reading the encrypted code. The code writing unit 51 and the code reading unit 52 are connected to a read / write circuit 53. The controller 50 includes a digital converter 60, a comparator 61, an encryption code converter 62, and the like. Controller 5
0 is connected to the display 65.

Next, the operation of the embodiment apparatus 20 will be described. A DC current is supplied to the exciting coil 31 by the DC power supply circuit 45 to apply a bias magnetic field to the core 41. If the magnetic sensitive element 12 is not present in the gap portion 42a of the core 41, the number of magnetic fluxes passing through the core 41 is constant, and the voltage output to the controller 50 is substantially zero.

When the object 10 is moved in the direction of arrow F at a predetermined speed by the transport mechanism 26 and the scanning region 13 is passed through the gap portion 42a of the core 41, a plurality of minute portions of the scanning region 13 sequentially pass through the gap portion 42a. By passing through the gap portion 4 depending on the mixing state of the magnetically sensitive element 12,
Since the magnetic permeability of 2a changes over time, the number of magnetic fluxes passing through the core 41 changes. As a result, an induced voltage is generated in the detection coil 32.

Since the magnitude of the induced voltage changes according to the mixing density, thickness (diameter), length, direction, and the like of the magnetic sensitive element 12, an output voltage pattern as illustrated in FIG. Measured. This output voltage is detected at every minute time, and the output voltage at each minute time is ranked and digitized in a plurality of stages, whereby a coded induced voltage detection signal unique to the scanning region 13 is obtained. .

When the object 10 is prepared, the induced voltage detection signal is converted into an encryption code by the encryption code converter 62 according to a specific rule, and the encryption code is displayed by a code writing unit 51 such as a magnetic head. Recorded in the unit 15. When the processing device 20 is linked to a host computer, the encryption code may be recorded in the host computer. Although the code display section 15 of this embodiment is a magnetic band, the code may be recorded on the code display section 15 as a bar code using a print head, for example. FIG. 4 shows an outline of the above-described series of steps (processing for creating the detection object 10).

The collation as to whether or not the detected object 10 is genuine is also performed using the processing device 20. That is, as in the case where the detection target 10 is created, the scanning region 13 is scanned at a predetermined speed by the processing device 20 to obtain an induced voltage detection signal corresponding to the magnetic sensitive element 12 included in the scanning region 13. Further, the code reading unit 5 reads the encryption code recorded on the code display unit 15 of the detected object 10.
2 and decryption of the encryption code by the encryption code converter 62, thereby reproducing the verification code.

Then, the collation code and the induced voltage detection signal are compared by the comparator 61. Only when the two coincide with each other, the object 10 is determined to be genuine, and the collation result is displayed on the display 65. Is displayed. FIG. 5 shows an outline of the above series of steps (collation processing).

According to the processor 20, even a weak magnetic field can be detected, and even if the encryption code or other information is magnetically recorded on the code display section 15 or other places, the magnetic field can be detected. There is no destruction of information. Since the induced voltage detection signal is obtained by the core 41 having the gap 42, it is hardly affected by external noise.

The present invention provides a proof that the painting is genuine by embedding the magneto-sensitive element 12 on the back of the canvas of the painting and recording the same encryption code in the code display section as in the above embodiment. You can also. In addition, the present invention is useful for discriminating imitation from a real object by embedding the magnetic sensitive element 12 in a three-dimensional object such as a work of art.

[0027]

According to the present invention, since the contents of the scanning area are magnetically detected, the apparatus can be made smaller in size and can be implemented at low cost as compared with the checking means using microwaves. Since the distribution state of the magnetically sensitive element can be detected even with a weak magnetic field, generation of noise from the device is avoided. Further, the SN ratio is high and the reproducibility is good. Also
Because it does not magnetize the scanning area, sprinkle fine iron powder.
I do not understand the recorded content at all even if I put it on
High security and low cost, such as no change
The reproducibility can be maintained.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a processing apparatus according to an embodiment of the present invention in a partial cross section.

FIG. 2 is a plan view conceptually showing an example of an object to be detected.

FIG. 3 is a diagram showing an example of an output voltage pattern generated when an object to be detected is scanned by the processing apparatus shown in FIG. 1;

FIG. 4 is a flowchart showing steps of a process when creating an object to be detected.

FIG. 5 is a flowchart showing steps of a process when matching an object to be detected;

[Explanation of symbols]

10: detected object, 12: magnetic sensitive element, 13: scanning area,
Reference numeral 15: code display unit, 20: processing device, 26: transport mechanism, 31: excitation coil (means for generating a bias magnetic field), 32: detection coil (detector), 41: core, 42
... gap, 50 ... controller, 51 ... code writing section, 52 ... code reading section.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-27489 (JP, A) JP-A-3-48389 (JP, A) JP-A-63-157082 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G07D 7/00 G06K 17/00

Claims (2)

(57) [Claims] 1. A method for magnetically scanning a scanning area of an object in which a large number of magnetically sensitive elements are randomly mixed to determine the authenticity of the object. In a state where a bias magnetic field is applied, the scanning area of the object to be detected is passed near the gap at a predetermined speed, and is made of a high magnetic permeability material which is randomly distributed in the scanning area when the scanning area passes. Many
The magnetic permeability of the gap portion through in response to the sense of the magnetic element
Of the induced voltage generated in the core by varying synchronic
The change is captured , the induced voltage detection signal is encoded into an encryption code, and this encryption code is recorded in the code display section of the object to be detected. When the authenticity of the object is determined, a bias magnetic field is applied to the core. In this state, the scanning area is passed through the gap portion of the core at a predetermined speed, and the transparency generated in the core at that time.
An induced voltage detection signal is obtained by detecting an induced voltage corresponding to a change in magnetic susceptibility, and a collation code is reproduced by reading an encrypted code recorded on the code display unit and decoding the encrypted code. A method for judging the authenticity of an object to be detected, wherein the verification code is compared with the induced voltage detection signal, and when both correspond, the object is determined to be authentic. 2. An apparatus for judging the authenticity of an object by magnetically scanning a scanning area of the object in which a number of magnetically sensitive elements made of a high magnetic permeability material are randomly mixed. A core having a gap, a means for applying a bias magnetic field to the core, a transport mechanism for passing a scanning area of the object to be detected near the gap of the core at a predetermined speed, and the scanning area passing through the gap. The magnetic permeability of the scanning area is detected by detecting an induced voltage generated in the core according to the large number of magnetic sensitive elements included in the scanning area.
A detector for detecting a change; code writing means for coding an induced voltage detection signal detected by the detector and recording the code on a code display section of the object; and code reading for reading a code recorded on the code display section comparison means and the code recorded in the induced voltage detection signal and the code display portion corresponding to the magnetic permeability index change that is obtained by scanning the scanning area in determining the authenticity of the object to be detected Means for judging that the detected object is genuine when the two correspond to each other.