JPH11101690A - Authenticity judging method for information recording medium and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to judge the authenticity of an information recording medium at a high level, by comparing the spectra of the reflected light or transmitted light of an inspection object and a genuine item against the same light source. SOLUTION: When an inspection object 1 is set on a sample port 12, the flash power circuit 5 of a light source 4 is operated, and the radiation of pulse light or continuous light from the light source 4 is started. The light guided into an optical integrating sphere 2 via an optical filter 3 is radiated to the surface of a sample after sufficiently repeated reflections in the spherical surface, and its reflected light is guided to a spectral reflection diffraction grating 6 from a measured light outlet window 13. The measured light is spectrally diffracted by the diffraction grating 6, photoelectric transfer is applied to each spectrum by light receiving elements 7, and a digital signal is extracted by an A/D converting circuit 8. An authenticity judgment signal is outputted through data processing by a microcomputer 9, an output display device 10 is operated via an I/O interface, and the control system 11 of a peripheral apparatus is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for judging the authenticity of various information recording media, in particular, media for recording credit information, such as ID cards, credit cards, and prepaid cards. is there.

[0002]

2. Description of the Related Art Various information recording media, in particular, information such as ID cards, credit cards, prepaid cards, etc., which include information indicating personal guarantees or monetary value guarantees, and credit information records to be created only by specific persons The social reputation and economic value of the medium are significantly impaired by the appearance of counterfeit goods.

[0003] Forgery of such an information recording medium is prevented,
As a technology for determining the authenticity, a technology for forming an information recording medium with an encrypted material has been proposed. For example, Japanese Patent Application No. 6-191761 discloses a technique using an anthraquinone-based compound having an absorption band for a laser beam of a specific wavelength dispersed in an acrylic resin or a polycarbonate resin as a password member of an information recording medium. Proposed. In addition, the Bank of Japan uses a special light-emitting ink that emits orange when irradiated with ultraviolet light on a seal on a banknote table as a means of determining authenticity. However, the authenticity determination method using these special rays is a digital determination of 1 or 0, and if a compound absorbing the above specific wavelength or a special ink equivalent is found, forgery can be performed relatively easily. There is.

[0004]

An object of the present invention is to provide a method for judging the authenticity of an information recording medium, which makes the judgment of the authenticity of the information recording medium at a high level, and makes it extremely difficult to manufacture a counterfeit product, and an apparatus used for implementing the method. The purpose is to provide.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, have found that the metamerism (conditional equality) phenomenon used in the toning technique, that is, under the condition that two different objects are incidentally illuminated and received. It has been found that this problem can be solved by applying the phenomenon that a different color is exhibited if the illumination light receiving condition is changed, even if they look the same color, and complete the present invention having the following contents. Was. (1) In determining the authenticity of the inspection target of the information recording medium, comparing the spectral spectrum of the reflected light or transmitted light of the inspection target with respect to the light source with the spectral spectrum of the reflected light or transmitted light of the genuine product with respect to the same light source. A method for determining the authenticity of an information recording medium by using (2) In determining whether the information recording medium is authentic, the authenticity of the information recording medium is compared by comparing the spectral reflectance or spectral transmittance of the inspection object with the spectral reflectance or spectral transmittance of the genuine product. How to determine. (3) In determining whether the information recording medium is true or false, the color of the inspection object is measured under illumination and light receiving conditions different from those in which the information recording medium is normally used,
A method of judging the authenticity of an information recording medium by comparing the color of a genuine product under the same illumination and light receiving conditions. (4) In determining the authenticity of the inspection target of the information recording medium, the information is measured by measuring the color of the inspection target under a plurality of illumination light receiving conditions and comparing the color with a genuine product under the same illumination light receiving condition. A method for determining the authenticity of a recording medium. (5) When determining the authenticity of the inspection target of the information recording medium, the color of the inspection target is measured under a plurality of types of light sources, respectively, and compared with the genuine color under the same light source. A method to determine the authenticity of. (6) The difference between the color of the object to be inspected and the genuine product is evaluated by the value of ΔE ^* ab of the following formula representing the color difference based on the L ^* a ^* b ^* color system recommended by the International Commission on Illumination in 1976. (3) The method for judging the authenticity of an information recording medium according to any one of (3) to (5).

Regarding the object to be inspected L ^* (1) = 25 (100 Y / YO) ^1/3 −16 a ^* (1) = 500 (X / XO) ^1/3 − (Y / YO)
^1/3 b ^* (1) = 200 (Y / YO) ¹ /3-(Z / ZO)
About ^1/3 genuine product L ^* (0) = 25 (100Y / YO) ^1/3 -16 a ^* (0) = 500 (X / XO) ¹ / 3- (Y / YO)
^1/3 b ^* (0) = 200 (Y / YO) ¹ /3-(Z / ZO)
^1/3 Regarding the difference between the two ΔL ^* = L ^* (1) −L ^* (0) Δa ^* = a ^* (1) −a ^* (0) Δb ^* = b ^* (1) −b ^* (0) ΔE ^* ab = ｛(ΔL ^* ) ² + (Δa ^* ) ² + (Δ
b ^* ) ² } [X, Y, and Z are tristimulus values of reflected light or transmitted light, and XO, YO, and ZO are tristimulus values of a light source. (7) The method according to (6) above, wherein when the value of ΔE ^* ab is 0.5 or more, the inspection target is determined to be a fake. (8) Select a certain reference product, determine the difference in color between the test object and the reference product, and the difference in color between the genuine product and the reference product, and compare the two differences to compare the colors of the test object and the genuine product. The authenticity determination method for an information recording medium according to any one of the above (3) to (7). (9) The method according to any one of the above (1) to (8), wherein the comparison between the inspection object and the authentic product is performed using a photograph or a color copy of each. (10) At least a part of the surface of the information recording medium is toned by mixing a plurality of colorants.
(9) The method for judging the authenticity of an information recording medium according to any one of (9). (11) The method according to any one of the above (1) to (10), wherein the information recording medium is a credit information recording medium. (12) The information recording according to (11) above, wherein the credit information recording medium is an ID card, a passport, a license, an identification card, a credit card, a cash card, a prepaid card, a bill, a cash voucher, a securities, or a gift certificate. A method for determining the authenticity of a medium. (13) The information recording medium according to any one of (1) to (10), wherein the information recording medium is a compact disk, a digital video disk, a mini disk, a magneto-optical disk, a phase change disk, a laser disk, or a write-once disk for a database. Method for determining the authenticity of information recording media. (14) Inspection object supporting means, illumination means for the inspection object, spectroscopic means of reflected light or transmitted light from the inspection object, reading means of the split light, and means for comparing the spectral spectrum of the inspection object with the spectrum spectrum of a genuine product And a means for displaying a comparison result and, if necessary, a means for transmitting the comparison result to a recording information reading device. (15) support means for the test object, illumination means for the test object, a sensor for measuring tristimulus values of reflected light or transmitted light from the test object,
A device for judging the authenticity of an information recording medium, comprising: means for comparing a test object with a genuine product based on tristimulus values; means for displaying a comparison result;

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Inspection object] The information recording medium for which the authenticity is to be determined according to the present invention is a medium on which useful information is recorded or should be recorded, and whose economic value or social credibility is impaired by forgery. If there is, it is not limited by the nature and content of the information, the principle of the recording method, the form and material of the medium, and the like.

For example, the information recording medium to which the present invention is applied includes the following. (1) A magnetic recording medium in which a magnetic substance fine powder is applied to a non-magnetic medium, for example, an iron oxide powder applied to a polyester film or the like. Specifically, cards such as cash cards, credit cards, prepaid cards, ID cards, etc. , Floppy disk, cassette tape, video tape and the like. (2) An information recording medium that irradiates a semiconductor laser beam, photoelectrically converts the difference between the reflectance of the flat surface and the recessed hole that has been cut into the medium in advance, and extracts it as a digital electric signal. For example, a thin disk molded of polycarbonate resin A digital disc is formed by engraving a digitized signal on a disc, specifically, a laser disc, a compact disc, a digital video disc, or the like. (3) The semiconductor laser light is irradiated, and the difference between the magnetic portion that has been reversely magnetized in advance on the perpendicular magnetic film applied to the surface of the medium and the magnetic portion in the initial state is determined by the degree of reflection of the reflected light via the deflection filter. It is an information recording medium that converts and extracts it as a digital electric signal. For example, a metal film having the property of being magnetized in the vertical direction, such as beryllium metal, is applied to one surface of a thin disk-shaped formed of a polycarbonate resin, a magnetic field is applied to the entire surface, and initialization is performed. Information is engraved and recorded on the recording film by a method of inverting magnetization. At the time of reading, the semiconductor laser light for reading is searched, and the reflected light of the laser deflected by the direction of magnetization is extracted through a deflection filter. Specifically, a magneto-optical disk, a magneto-optical card, or the like having a large-capacity recording portion, such as a dictionary disk, a patent information disk, and a game software disk. (4) An information recording medium incorporating a storage element made of a static type semiconductor integrated circuit having a flip-flop circuit, and a read-only memory (ROM) used in a specification that can be mounted on a so-called personal computer or word processor.
There is a case where a storage element made into an IC, called a C card, is made into a card and used for personal use. (5) Information recording media such as gift certificates, cash vouchers, securities, identification cards, or cash or premium exchange media may be used. These are mainly printed on paper or plastic products. Further, it may be an information recording medium such as music software, video software, paintings, books, and computer software related to copyright.

[0009] The objects where the advantages of the present invention are particularly exhibited are recording of credit information such as ID cards, passports, licenses, identification cards, credit cards, cash cards, prepaid cards, bills, cash vouchers, securities, and gift certificates. A medium, that is, an information recording medium that includes information indicating a guarantee for an individual or a guarantee of a monetary value and should be created only by a specific person. This credit information recording medium
This is because the appearance of counterfeit goods essentially impairs their social credibility and economic value.

Further, the advantages of the present invention are also effectively exerted for judging the authenticity of various media on which information relating to copyright and confidential information are to be recorded. Examples of such an information recording medium include a CD-ROM (read only), a CD-R (write-once type), a CD (compact disc) including a CD-RAM (rewritable), and a DVD-RO.
M (read only), DVD-R (write-once type), DVD-
DVD (digital video disk) including RAM (rewritable), MD (mini disk), MO (magneto-optical disk), PD (phase change disk), LD (laser disk), WO (write-once disk for database) Can be mentioned.

[Principles and Techniques Underlying the Present Invention] Generally, an object has a specific reflectance (spectral reflectance) for light of each wavelength, and emits light from a light source containing various wavelengths. When it is received, it emits reflected light with a distribution corresponding to it. this,
The expression is as follows. (Spectral distribution of light source) x (Spectral reflectance of object) = (Spectral distribution of reflected light) Humans perceive the color of the object by the reflected light, but humans can perceive the colors of red, green, It is said that human eyes have a sensation (sensor) corresponding to the light of the three primary colors of blue. Each of these three sensors has a large sensitivity in a specific wavelength range. This can be expressed by the following equation. (Spectral distribution of reflected light) × (Spectral sensitivity of human eyes) = (Color perceived by human eyes) Therefore, even if two objects have different spectral reflectances,
It may look the same color under certain light sources. this,
It is called metamerism. The metameric color is likely to occur when the types of colorants (pigments, dyes) are different.

There are two methods for objectively measuring the color of an object. The first method is a direct reading method of stimulus value, which irradiates an object with a specific light source and measures its reflected light with three sensors having spectral sensitivities almost corresponding to human eyes, and calculates "3. In this method, three values of X, Y, and Z called "stimulus values" are directly obtained, and colors are displayed in each color system based on the values. In addition, for simplification, any of X, Y, and Z may be used alone or in combination of two.

A second method is a spectral colorimetric method, which irradiates an object with a light source, disperses the reflected light, and measures the reflectance for each wavelength with a plurality of (for example, 40) sensors. I do. The tristimulus value X,
The values of Y and Z are determined, and based on the values, numerical display of colors in various color systems is performed. After measuring the spectral reflectance of an object, the spectral colorimeter uses the spectral distribution data of various light sources stored in the main unit and the spectral sensitivity data corresponding to the human eye to measure the color values under various light sources. Can be calculated and displayed. This can be expressed by the following equation. (Spectral distribution of light source) × (spectral reflectance of object) × (spectral sensitivity corresponding to human eyes) → tristimulus value (XYZ) → color values of various color systems The present invention uses the above principle and method. This is applied to the determination of the authenticity of an information recording medium. That is, the present invention, even if two objects that look the same color to the human eye under certain illumination and light receiving conditions, the difference becomes clear if the spectral spectrum or spectral reflectance of the reflected light is analyzed, or The fact that the color difference can be observed by changing the light receiving condition of the light source or the like is applied to the determination of the authenticity of the information recording medium.
In the above, only the reflected light of the object has been described, but the same application is also possible for the transmitted light of the object, and the present invention includes the same.

According to the present invention, the information recording medium
The following methods can be cited as basic methods for determining the authenticity of an inspection target. Method A: By comparing the spectral spectrum of the reflected light or transmitted light of the inspection object with respect to the light source with the spectrum spectrum of the genuine product, or by comparing the spectral reflectance or spectral transmittance of the inspection object with the spectral reflectance or spectral transmission of the genuine product A method of judging the truth by comparing it with a rate. Method B: Authenticity by measuring the color of the test object under illumination and light receiving conditions different from the state where the information recording medium is usually used, for example, under a special light source, and comparing with a genuine product under the illumination and light receiving conditions. How to determine. Method C: A method of determining the authenticity by measuring the color of an inspection object under a plurality of illumination light receiving conditions, for example, under a plurality of types of light sources, and comparing the color with an authentic product.

Method A is a method directly utilizing the fact that an object has a unique spectral reflectance and the spectral spectrum of reflected light or transmitted light to a certain light source is also unique. is there. The method B and the method C utilize the fact that if the spectral reflectances of the two objects are different, they can be expressed as a color difference by changing the light receiving condition of the light source or the like. It is.

As a specific analysis method by the method A, for example, the following method can be adopted. A method in which the spectral spectrum of reflected light or transmitted light to be inspected is superimposed on the spectral spectrum of a genuine product, and a determination is made based on differences in the overall waveform. A method that focuses on the spectral intensity at a specific wavelength, compares the test object with a genuine product, and determines the difference based on the intensity difference. A method that focuses on the spectral intensity in a specific wavelength range, integrates the spectral intensity in that wavelength range, and compares and determines the respective integrated values of the inspection target and the genuine product. A method that focuses on spectral intensities in a plurality of wavelength ranges, and compares the inspection target with a genuine product based on a sum of integrated values of spectral intensities in respective wavelength ranges. The same method as described above can be applied to the spectral reflectance or the spectral transmittance.

In the method B and the method C, a method of expressing a color difference is based on each value of L ^* , a ^* , and b ^* represented by the CIE color difference display formula proposed by the International Commission on Illumination in 1976. It is appropriate to adopt the ΔE ^* ab value obtained by the above. According to this, for a light source, for an inspection object: L ^* (1) = 25 (100Y / YO) ^1/3 −16 a ^* (1) = 500 (X / XO) ^1/3 − (Y / YO)
^1/3 b ^* (1) = 200 (Y / YO) ¹ /3-(Z / ZO)
About ^1/3 genuine product: L ^* (0) = 25 (100Y / YO) ^1/3 -16 a ^* (0) = 500 (X / XO) ¹ / 3- (Y / YO)
^1/3 b ^* (0) = 200 (Y / YO) ¹ /3-(Z / ZO)
The difference between the two when ^1/3 is set: ΔL ^* = L ^* (1) −L ^* (0) Δa ^* = a ^* (1) −a ^* (0) Δb ^* = b ^* (1) −b ^* (0) ΔE ^* ab = ｛(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* )
^The color difference is expressed as ² ｝ ^1/2 . Here, X, Y, and Z are tristimulus values of reflected light or transmitted light, and XO, YO, and ZO are tristimulus values of each light source.

The above data relating to the standard information recording medium can be used by setting data derived from previously measured values in the computer memory of the determination device. Thus, ΔE obtained by a certain light source
^{* In} the case of authenticity determination based on the magnitude of the ab value, the security manager may arbitrarily determine the specific criteria for management. ΔE ^* ab ₁ to ΔE ^* obtained using n light sources of arbitrary natural numbers from the viewpoint of high safety and simple judgment ^.
the average value of ab _n, if a ΣΔE ^* abn / n <R was true, the method determines that the false is not satisfied it is preferable. Alternatively, Δ
If the E ^* ab value exceeds R, a method of determining a fake can be adopted. This R is an arbitrary constant and is a numerical value managed for security. Specifically, for example, if R is set to 0.5, the determination has sufficient accuracy and can be applied in many cases. That is, it is almost difficult to create a fake that passes this determination.

[Details of Truth Judgment Method] In the present invention, the information recording medium to be inspected is irradiated with light, and its reflected light or transmitted light is measured. The measurement location, that is, the light irradiation location may be the entire area or the specific area of the information recording medium surface. In the latter case, the information recording portion or another portion may be used. If a part irrelevant to the information recording part is used as a measurement part and this part is encrypted, in addition to the inherent secret of the recording part according to the conventional method, multiple secrets are applied and security can be enhanced.

The state of the measurement point may be any state as long as it is colored, and may be a single color, a mixed color system, a chromatic color, or an achromatic color.
It is also possible to select a part of the pattern as a measurement point,
Irrespective of the presence or absence of surface irregularities and through holes. In order to make the manufacture of an imitation product more difficult, it is preferable that the measurement location is toned using various types of coloring agents (pigments, paints, etc.) having high chroma and lightness. Further, since the metamerism of a seal or an image having a holographic function greatly changes depending on the wavelength of the light source, it is easy to determine whether the seal is true or false, and it is difficult to forge.
Further, if the comparison between the inspection object and the genuine product is made by photographing or color copying both of them, the difference may become clearer. Also, select certain reference products,
In some cases, it is more effective to determine the difference between the color of the test object and the reference product and the difference between the color of the genuine product and the reference product, and compare the two differences to compare the colors of the test object and the genuine product.

If the measurement site of the information recording medium is opaque, reflected light is measured, and if it is transparent, transmitted light is measured. Light for irradiating the inspection target requires one or more types of light sources, and it is preferable to use a plurality of different light sources in order to improve determination accuracy. Commonly used light sources include D ₇₅ light source, D ₆₅ light source, D ₅₅ light source, D ₅₀ light source,
A light source, a C light source, a white light source, a fluorescent lamp (F1 to F12), and the like, and may be a light source in a wavelength region including an ultraviolet region or an infrared region in addition to a visible light region.

As a method for obtaining a different light source, a different light source may be obtained from a white light source or a specific light source by an optical filter having a specific wavelength. Further, based on the spectral spectrum data obtained by using a certain light source, the spectral spectrum data which would be obtained by another light source can be converted and obtained on a computer. The geometric condition of illumination and light reception such as the angle of light to be irradiated on the inspection object and the reflection angle of light to be measured may be arbitrary.

The apparatus for determining the authenticity of an information recording medium according to the present invention includes a spectroscopic method and a direct-reading method. The former has an advantage that a large amount of spectral data is collected and its use is large, and the latter is advantageous. Has the advantage of being simple. Hereinafter, the structure and operation principle of both will be described.

[Spectral Truth Judgment Apparatus and Its Operation] (a) Structure of Spectral Truth Apparatus The spectral true / false judgment apparatus of the present invention comprises an inspection object support means, an illumination means for an inspection object, and a reflection from the inspection object. Light or transmitted light spectroscopy means, spectroscopy light reading means, inspection object spectrum spectrum and genuine spectrum spectrum comparison means,
It comprises means for displaying the result of comparison, and means for transmitting the result of comparison to the recorded information reading device as required.
One embodiment is shown in FIG. This device measures a sample port (12) that sets an arbitrary part of the inspection object (1) on a part of the spherical surface of the optical integrating sphere (2) and the opposite side of the center of the optical integrating sphere (2). It has a light exit window (13), and the light source introduction window (14) of the optical integrating sphere (2) and the optical filter (approximately perpendicular to the line connecting the sample port (12) and the measurement light exit window (13)). 3) It further has a light source (4) and its flash power supply / circuit (5), a transmitted light measurement sample port (15) outside the measurement light exit window (13), and a reflection type diffraction grating for spectroscopy ( 6) is arranged and connected to an A / D conversion circuit (8) and a microcomputer (9) via a light receiving element (7) that receives the reflected light of the reflection type diffraction grating for spectrum (6), and the output of the microcomputer One of the terminals is connected to the output display device (10) The other is made of and connected to the control system of the other device (the recording information reading device) (11).

When the measurement is performed only with the reflected light, the transmitted light measurement sample port (15) is not required.
When the measurement is performed using only the transmitted light, the sample port (12) becomes unnecessary, so that the sample port (12) is replaced with a standard white tile. In this spectroscopic device, a sample piece is irradiated with light modulated using an optical integrating sphere, spectrally separated by a diffraction grating, and intensity data of the spectrally separated light is measured.

The authenticity determination device of the present invention may be installed in a magnetic card reader, a floppy disk device, a CD reader, a bar code reader, etc. in any of a spectroscopic device and a direct reading device. It is used for card payment machines, cash dispensers, ticketing systems, reservation systems, automatic ticket gates, various security systems, consultation ticket card systems, etc.

(B) Operation of the spectroscopic device The device of FIG. 1 operates as follows. Inspection object (1)
Is set to the sample port (12), the flash power supply / circuit (5) of the light source operates in conjunction with this, and irradiation of pulse light or continuous light from the light source (4) starts. If necessary, the light guided into the optical integrating sphere (2) through an optical filter repeats sufficient reflection within the spherical surface and irradiates the surface of the sample, and the reflected light is transmitted to the measurement exit window (1).
The light exits from 3) and is guided to the reflection type diffraction grating for spectroscopy (6).
The measurement light is split by the spectroscopic reflection diffraction grating (6), photoelectric conversion is performed for each spectrum by the light receiving element (7), and is further extracted as a digital signal by A / D conversion. After this, data processing by microcomputer,
A true / false determination signal is output, the output display device (10) is operated via the I / O interface, and the control system (11) of the attached device is operated.

When the object to be inspected is transparent, a sample is set in the transmitted light measurement sample port (15),
The light emitted from the measurement light exit window (13) is applied to the sample in the same manner as described above, and the transmitted light is guided to the reflection type diffraction grating for spectroscopy (6).

[Direct-reading type authenticity determination apparatus and its operation] (a) Structure of direct-reading type apparatus The spectral type authenticity determination apparatus of the present invention comprises an inspection object supporting means, an illumination means for the inspection object, and a reflection from the inspection object. Light or transmitted light tristimulus value measurement sensor, means for comparing the test object based on the tristimulus value with a genuine product, means for displaying the result of comparison, and means for transmitting the result of comparison to the recording information reading device as necessary It is. One embodiment is shown in FIG. This device consists of a light source (24) and its flash power supply / circuit (25)
And a light guiding fiber (2) connected to the light source (24).
6) Through the light source light measurement sensor (30, 31, 32)
To measure the tristimulus value of the light source light, while directly connecting the sample piece (21) via the connected light guide fiber (22).
Is illuminated, and the reflected light is used as a sample light measurement fiber (2
3) to guide the sample light measurement sensors (27, 28, 2).
9), the sample light is directly read and measured by a sensor corresponding to the spectral sensitivity of the human eye, and connected to an A / D conversion circuit (33) and a microcomputer (34) to obtain tristimulus values X, Y, Z
And one of the output terminals of the microcomputer is connected to the output display device (35), and the other is connected to the control system (11) of another device (such as a recorded information reading device). Things. In this direct-reading type apparatus, the sensitivity of the color matching function can be increased without using the optical integrated light, irradiating the sample piece with light at an incident angle of, for example, 45 degrees, and dispersing the reflected light in the vertical direction. And tristimulus values X, Y, and Z are obtained.

(B) Operation of Direct Reading Device The device of FIG. 2 operates as follows. The sample piece (21) is directly illuminated via a light guide fiber (22) connected to a light source (24), and the reflected light is guided by a sample light measuring fiber (23) to provide color sensation to human eyes. Are measured by three sensors (27, 28, 29) corresponding to the three primary colors (red, green, and blue) of light having a performance similar to the following. After measuring the light source light in the same manner, these electric signals were converted to A / A
The signal is converted into a digital signal by a D conversion circuit (33), and further connected to a microcomputer (34) to connect the tristimulus values X,
After determining Y and Z, the microcomputer outputs a true / false judgment signal by data processing, activates the output display device (10) via the I / O interface, and controls the control system of the accompanying equipment. Activate.

[0031]

The present invention will be described in more detail with reference to the following examples. [Production Examples 1-4] Polycarbonate resin (Teflon FN1500A manufactured by Idemitsu Petrochemical Co., Ltd. (Mv: 1450)
0)) were mixed with the pigments shown in Table 1 in the proportions shown in Table 2, and 2)
Extruded at 60 ° C. to pelletize. Note that tris (2,4-di-tert-butylphenyl) phosphite (Irgafos 168) was used as an antioxidant.

[0032]

[Table 1]

[0033]

[Table 2]

[Production Examples 5 and 6] The same pigments and antioxidants as in Production Examples 1 and 2 were mixed and dispersed in commercially available clear lacquer in the same proportions to obtain paints shown in Table 3.

[0035]

[Table 3]

Example 1 The compositions described in Production Examples 1 and 2 were used for a card substrate and injection molded to produce a credit card-shaped molded article. The color difference ΔE ^* ab (based on the CIE color difference display formula shown by the International Commission on Illumination in 1976) of the two types of card base materials obtained was measured using a spectrophotometer (Ma
The measurement was carried out under various light sources using MS20 Plus manufactured by cbeth. In addition, the visual field at the time of measurement was 20 mm, the visual field angle was 10 °, and the measurement was performed by a reflection method. Table 4 shows the obtained results.

[0037]

[Table 4]

As can be understood from Table 4, when the card base material of Production Example 1 was used as a reference (genuine product), the color difference ΔE ^* ab of the card base material of Production Example 2 (the object to be inspected) in comparison with this was ,
It varies greatly depending on the type of light source. For example, although the color difference between the two under the D light source is small (it is difficult to determine the authenticity),
Under the A light source, a large color difference is observed, and it turns out that it is a fake. In addition, it is possible to determine a fake from the average value under various light sources.

Example 2 Using the compositions described in Production Examples 3 and 4, a CD substrate was molded by injection molding (molding temperature: 310 ° C., mold temperature: 120 ° C.). Obtained C
When the color of the D substrate was measured by the transmission method, the results shown in Table 5 were obtained.

[0040]

[Table 5]

As can be seen from Table 5, C in Production Example 3
When the D substrate is used as a reference (genuine product), the color difference ΔE ^* ab of the CD substrate (inspection object) of Production Example 4 that is compared with the D substrate also changes depending on the type of light source. For example, the color difference between the two under the D light source is subtle and it is difficult to determine the authenticity, but a large color difference is observed under the FD light source, and it is determined that the image is a fake.
In addition, it is possible to determine a fake from the average value under various light sources.

Example 3 Two types of commercially available hologram pattern films (original figures 1 and 2) having the designs shown in FIGS. 3 and 4 were photographed using a color copying machine (AC935, manufactured by Fuji Xerox Co., Ltd.). Copy image (copy Figure 1,
2) was obtained. Color difference between actual hologram pattern films (original figures 1 and 2) and color copy image (copy figure 1,
The color difference between 2) was measured in the same manner as in Example 1, and the results in Table 6 were obtained.

[0043]

[Table 6]

As can be seen from Table 6, the actual hologram
For the ram pattern film, refer to the original drawing 1
Product) and the original drawing 2 (inspection object)
Color difference ΔE ^*ab is delicate and true / false judgment using various light sources
Is difficult. However, the copy Figure 1 (genuine color copy
Figure 2 (color copy image to be inspected)
Color difference ΔE^*ab shows a large value under various light sources. sand
In other words, rather than measuring the color difference in real
One example where it is more effective to use a shot image
You.

Example 4 A circle (30 mm) in a circle on a color image of a petal as shown in the photograph in FIG.
The color of three places C was measured in the same manner as in Example 1, and the results in Table 7 were obtained.

[0046]

[Table 7]

As can be seen from Table 7, the difference between the part B and the part C was evaluated based on the difference in color difference between each part and the part A. The difference between the portions B and C changes depending on the type of light source. For example, the difference between the two is difficult to determine under the C light source,
A large color difference is observed under the FD light source, and the difference is found. This is done by selecting an appropriate reference product (part A), determining the color difference between the inspection target (part C) and the reference product, and determining the color difference between the authentic product (part B) and the reference product, and comparing the two. It is an example showing that it is effective to determine a difference between a target and a genuine product.

Example 5 Each of the paints of Production Examples 5 and 6 was applied to a cartridge of two commercially available magneto-optical disks having different owners to a thickness of 20 μm, and the coating area was 2 μm.
0 mm ² . The color of the painted portion of this magneto-optical disk was measured under the same conditions as in Example 1. The results shown in Table 8 were obtained.

[0049]

[Table 8]

As understood from Table 8, the color difference ΔE ^* ab of the magneto-optical disk coated with the paint of Production Example 6 in comparison with the magneto-optical disk coated with the paint of Production Example 5 also changes depending on the type of light source. . For example, the color difference between the two under the D light source is subtle and it is difficult to determine the difference, but under the A light source, a large color difference is observed, and the difference is found. Further, the difference can be determined from the average value under various light sources.

[0051]

According to the present invention, an objective and highly accurate method for judging the authenticity of an information recording medium and an apparatus used for implementing the method are provided, and the production of a counterfeit product becomes extremely difficult. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a spectral authenticity determination device of the present invention.

FIG. 2 is a schematic diagram of a direct-reading authenticity determination device of the present invention.

FIG. 3 is a diagram of a hologram pattern film used in an embodiment of the present invention (1).

FIG. 4 is a diagram (2) of a hologram pattern film used in an embodiment of the present invention.

FIG. 5 is an image of a petal used in an example of the present invention. Zones A, B, and C indicate measurement points.

[Explanation of symbols]

 1: Inspection object 2: Optical integrating sphere 3: Optical filter 4: Light source 5: Flash power supply / circuit 6: Reflection diffraction grating for spectrum 7: Light receiving element 8: A / D conversion circuit 9: Microcomputer 10: Output display device 11: Control system of other equipment 12: Sample port 13: Measurement light exit window 14: Light source introduction window 15: Transmitted light measurement sample port 21: Sample piece 22: Light guide fiber 23: Fiber for sample light measurement 24: Light source 25: Flash power supply / circuit 26: Light guide fiber 27: Sample light measurement sensor 28: Sample light measurement sensor 29: Sample light measurement sensor 30: Light source light measurement sensor 31: Light source light measurement sensor 32: Light source light measurement sensor 33: A / D conversion circuit 34: microcomputer 35: output display device 36: control system of other equipment

Claims (15)

[Claims] When determining the authenticity of an object to be inspected for an information recording medium, a spectrum of reflected light or transmitted light of the object to be inspected with respect to the light source is compared with a spectrum of reflected light or transmitted light of a genuine product with respect to the same light source. To determine whether the information recording medium is true or false. 2. A method for determining the authenticity of an information recording medium, comprising: comparing a spectral reflectance or a spectral transmittance of the inspection object with a spectral reflectance or a spectral transmittance of a genuine product; A method to determine the authenticity. 3. A method for determining the authenticity of an object to be inspected for an information recording medium, measuring the color of the object to be inspected under illumination and light receiving conditions different from a state in which the information recording medium is normally used, and detecting the same illumination and receiving light. A method for judging the authenticity of an information recording medium by comparing the color of the genuine product under the conditions. 4. When determining the authenticity of an object to be inspected for an information recording medium, the color of the object to be inspected is measured under a plurality of light receiving conditions and compared with the color of a genuine product under the same light receiving condition. A method for determining the authenticity of an information recording medium by using 5. A method for determining the authenticity of an object to be inspected for an information recording medium by measuring the color of the object to be inspected under a plurality of types of light sources and comparing it with the color of a genuine product under the same light source. A method for determining the authenticity of a recording medium. 6. The difference between the color of an object to be inspected and that of a genuine product is evaluated by the value of ΔE ^* ab of the following expression representing a color difference based on the L ^* a ^* b ^* color system recommended by the International Commission on Illumination in 1976. 6. The method according to claim 3, wherein the authenticity of the information recording medium is determined. Regarding the inspection target L ^* (1) = 25 (100 Y / YO) ^1/3 −16 a ^* (1) = 500 (X / XO) ^1/3 − (Y / YO)
^1/3 b ^* (1) = 200 (Y / YO) ¹ /3-(Z / ZO)
About ^1/3 genuine product L ^* (0) = 25 (100Y / YO) ^1/3 -16 a ^* (0) = 500 (X / XO) ¹ / 3- (Y / YO)
^1/3 b ^* (0) = 200 (Y / YO) ¹ /3-(Z / ZO)
^1/3 Regarding the difference between the two ΔL ^* = L ^* (1) −L ^* (0) Δa ^* = a ^* (1) −a ^* (0) Δb ^* = b ^* (1) −b ^* (0) ΔE ^* ab = ｛(ΔL ^* ) ² + (Δa ^* ) ² + (Δ
b ^* ) ² } [X, Y, and Z are tristimulus values of reflected light or transmitted light, and XO, YO, and ZO are tristimulus values of a light source. ] 7. The method according to claim 6, wherein when the value of ΔE ^* ab is 0.5 or more, the inspection object is determined to be a fake. 8. A fixed reference product is selected, and a difference in color between the inspection object and the reference product and a difference in color between the genuine product and the reference product are determined. By comparing these two differences, the colors of the inspection object and the genuine product are determined. 8. The method according to claim 3, wherein the comparison is performed. 9. The method according to claim 1, wherein the comparison between the object to be inspected and a genuine product is performed using a photograph or a color copy. 10. The method according to claim 1, wherein at least a part of the surface of the information recording medium is toned by mixing a plurality of coloring agents. 11. The method according to claim 1, wherein the information recording medium is a credit information recording medium. 12. The information according to claim 11, wherein the credit information recording medium is an ID card, a passport, a license, an identification card, a credit card, a cash card, a prepaid card, a bill, a cash voucher, a securities or a gift certificate. A method for determining the authenticity of a recording medium. 13. The information recording medium is a compact disc,
11. The method according to claim 1, wherein the information recording medium is a digital video disk, a mini disk, a magneto-optical disk, a phase change disk, a laser disk, or a write-once disk for a database. 14. An inspection object support means, an illumination means for an inspection object, a spectroscopic means for reflected light or transmitted light from the inspection object, a reading means for spectroscopic light, and a method for converting a spectral spectrum of an inspection object and a spectrum spectrum of a genuine product. An authenticity determination apparatus for an information recording medium, comprising: a comparison unit, a comparison result display unit, and a unit for transmitting the comparison result to a recording information reading device as necessary. 15. A test object supporting means, an illuminating means for the test object, a tristimulus value measuring sensor for reflected light or transmitted light from the test object, a means for comparing the test object with a genuine product based on the tristimulus value,
An apparatus for judging the authenticity of an information recording medium, comprising: means for displaying a comparison result;