JP5369675B2 - True / false judgment system - Google Patents

Description

The present invention makes authenticity determinations such as identification cards, membership cards such as personal identification cards, packing materials used for packing goods or goods, or tags or stickers given for identification of goods. The present invention relates to an apparatus for determining authenticity of a required article.

There are not a few situations in which authenticity of an object is required in the field of identification card, card for identity authentication such as membership card, or industrial goods management. For such authenticity determination, a method of applying an optical identification code such as a bar code or a two-dimensional code or an electromagnetic identification element such as an IC chip is often used.
However, when using an optical identification code, the identification code is individually printed on the object. When using an IC chip, the IC chip is embedded in the object or an IC tag is attached to the object. Some processing must be performed individually, resulting in increased costs and design constraints, which has been an obstacle to introduction.

In recent years, a technique for newly detecting the surface state of an object and using it for authenticity determination has been disclosed.
For example, the technique disclosed in Japanese Patent No. 3927326 (Patent Document 1) is a technique that irradiates an object with laser light, detects a speckle pattern generated as reflected light at that time, and uses it for authentication.
A speckle pattern is a speckled pattern created by random interference caused by unevenness on the surface of an object when it is irradiated with coherent light such as laser light. However, the object is the same material. However, a different pattern is shown for each object. Therefore, it is possible to determine authenticity by measuring a pattern for each object in advance under the same conditions, and comparing and comparing the pattern of the test object with the pattern measured in advance.
The technique described in Patent Document 1 is characterized in that it is not necessary to individually add printing or an IC chip to an object, and because the determination is made on the surface of the object itself, the load at the time of introduction is small.
Japanese Patent No. 3927326

However, since the technique described in Patent Document 1 uses reflected light when irradiated with laser light, there is a drawback that it cannot be applied when the object is transparent. Transparent materials are widely used as exterior materials for articles, and transparent materials are sometimes used to enhance the design of ID cards, so articles made of such transparent materials (transparent materials) On the other hand, it is extremely useful to be able to determine authenticity without deteriorating the surface design and without adding an element for identification.

Therefore, an object of the present invention is to provide a system capable of determining authenticity even for a transparent object without requiring a process such as individually assigning an identification code to the object. .

The authenticity determination system of the present invention for solving the above problems is
A true / false determination system using a speckle pattern that appears when an object is irradiated with laser light,
The surface of the authenticity judgment body comprising a transparent base material and a light selective reflection layer having a characteristic of reflecting either the left circularly polarized light or the right circularly polarized light in the predetermined central wavelength region of the incident light and transmitting the remaining light. First speckle pattern detection means comprising: a laser beam irradiation unit that irradiates a predetermined irradiation region with laser light; and an imaging unit that images a specific speckle pattern obtained by irradiating the irradiation region with laser light A registration unit that registers the speckle pattern information obtained from the first speckle pattern detection unit in association with an identification code that identifies the authenticity determination object, a second unit that includes a laser beam irradiation unit and an imaging unit. Collation means for collating speckle pattern information obtained from the speckle pattern detection means and speckle pattern information registered in the registration means ;
Equipped with a,
The laser light irradiation unit includes a circularly polarized light conversion filter, and irradiates the surface of the authenticity determination body with laser light converted to a predetermined polarization .

Et al is, the imaging unit includes a circular polarization selective filter, characterized in that so as to image the laser beam of the predetermined polarization component.
Further, the irradiation area is a surface area of the light selective reflection layer.

In the authenticity determination system of the present invention, the laser light irradiation unit and the authenticity determination object are relatively moved by the scanning unit, so that the scanning area is irradiated with the laser light, and the speckle pattern from the irradiation area is obtained. Speckle pattern information is obtained by detecting with a photo sensor.

The authenticity determination system of the present invention is characterized in that the first speckle pattern detection means, the second speckle pattern detection means, and the registration means are connected via a network.

According to the authenticity determination system of the present invention, comparison for authenticity determination is performed without adding an element for determining an identification code, an IC chip, or the like to an object to be determined individually. Verification is possible. In particular, it is possible to determine the authenticity of a transparent object that is difficult to detect by ordinary means without impairing transparency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a true / false determination system according to the present invention.
The authenticity determination system according to the present invention includes a true / false determination object 10 having a light selective reflection layer, and a speckle pattern detection that irradiates a laser light to the authenticity determination object 10 and images a speckle pattern formed by the reflected laser light. Means 1 (first speckle pattern detection means), 1 ′ (second speckle pattern detection means), and a true / false determination server 50 for registering and collating speckle patterns. The speckle pattern detection means 1, 1 ′ and the authenticity determination server 50 are connected via the network 5.

The speckle pattern detection means 1 and 1 ′ have a laser irradiation unit 21 and an imaging unit 22, respectively, irradiate the authenticity determination body 10 on the inspection object (subject) with laser light and reflect it from the light selective reflection layer. A pattern (speckle pattern) created by the laser beam to be captured is imaged. The speckle pattern detection means 1, 1 ′ will be described in detail later by taking a speckle pattern detection device 20 as shown in FIG. 3 as an example.

The registration means 51 of the authenticity determination server 50 is for registering an identification code such as an ID code and a speckle pattern in advance, and the pattern data from the speckle pattern detection means 1 The data is stored in the data storage unit 53 in association with the ID of the subject. The ID and speckle pattern of the subject are stored in advance through the same procedure for all the subjects.

The collating means 52 is for collating the speckle pattern of an unknown subject with the registered speckle pattern at the time of authenticity determination. That is, an unknown subject is measured by the speckle pattern detecting means 1 ′, and the speckle pattern obtained is compared and collated with the pattern in the pattern DB 55 by the collating means 52. If there is a match, “true”, otherwise Is determined to be “false”.
Note that the speckle pattern detecting means 1 and 1 'may be the same device or different devices.

FIG. 2 shows the structure of the authenticity determination body in the authenticity determination system of the present invention.
The authenticity determination body 10 includes a base material 11 made of a transparent member and a light selective reflection layer 12. The light selective reflection layer 12 is either left circularly polarized light or right circularly polarized light in a predetermined central wavelength region of incident light. A layer made of a material having a characteristic of reflecting one side and transmitting the rest. Since the light selective reflection layer 12 transmits light outside the above-described central wavelength region, the light selective reflection layer 12 looks almost transparent to the naked eye, but when irradiated with laser light that matches the characteristics (direction of circularly polarized light, wavelength) of the light selective reflection layer 12 The laser light is reflected by the light selective reflection layer 12. At this time, since a speckle pattern corresponding to the unique state of the light selective reflection layer 12 is generated, the authenticity determination can be performed by detecting this pattern and using it for collation.

From such characteristics of the light selective reflection layer 12, the authenticity determination body 10 composed of the base material 11 made of a transparent member and the light selective reflection layer 12 has transparency, but the authenticity determination as described above. It selectively reflects light that is effective. That is, the authenticity determination for the transparent body can be realized. In addition, as a authenticity determination body, the light selective reflection layer 12 should just be formed in at least one part on a base material. Further, the base material 11 does not need to be a transparent member and may be an opaque member, but it is effective to use a transparent member for the base material for the authenticity determination of the transparent body, which is a feature of the present invention. Is.

Examples of the light selective reflection layer 12 include a cholesteric liquid crystal layer. The cholesteric liquid crystal has light selective reflectivity that reflects either left circularly polarized light or right circularly polarized light around a predetermined selected wavelength range.
The generation of circularly polarized light by cholesteric liquid crystal and its application to authenticity determination are described in detail in Japanese Patent Laid-Open No. 2000-25373 (Patent Document 2), which is the same applicant as the present invention.
Moreover, the authenticity determination body used by this invention can be obtained by laminating | stacking a cholesteric liquid crystal on a transparent base material by methods, such as application | coating and sticking, on a transparent base material. A method for forming a cholesteric liquid crystal is described in detail in Japanese Patent Application Laid-Open No. 2005-297499 (Patent Document 3) by the same applicant as well as Patent Document 2.
Japanese Patent No. 2000-25373 Japanese Patent No. 2005-297499

The transparent member is not limited because it depends on the purpose of use. For example, polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose ( TAC), diacetylcellulose, polyethylene / vinyl alcohol, and other various plastic materials.

FIG. 3 shows the configuration of the speckle pattern detection apparatus.
The speckle pattern detection apparatus 20 includes a laser light source 21 for irradiating the authenticity determination body 10 with laser light and an imaging unit 22 for detecting a speckle pattern generated by reflected light. The wavelength of the laser light source is preferably closer to the center wavelength of the selective reflection region of the light selective reflection layer 12.
If the same circularly polarized light component selected by the light selective reflection layer 12 is included in the laser light from the laser light source, the authenticity determination body may be irradiated as it is, but it is irradiated through the circular polarization conversion filter 32. Thus, the circularly polarized light component can be increased. For example, light emitted from a laser light source mainly composed of linearly polarized light is converted into circularly polarized light by inserting a circularly polarizing conversion filter 32 using a linearly polarizing plate and a λ / 4 plate (phase plate) as shown in FIG. Can be converted.

The phase plate 31 is an optical plate that generates a “phase difference” from a phase difference caused by a speed difference between a fast axis and a slow axis when light passes through a substance exhibiting birefringence. The λ / 4 plate 42 indicates that a phase difference of ¼ wavelength (90 degrees) is generated in the light transmitted through the plate, and converts the linearly polarized light component into circularly polarized light and the circularly polarized light component into linearly polarized light. Has characteristics.

The imaging unit 22 for detecting reflected light may receive the reflected light from the authenticity determination body as it is, but circularly polarized light that transmits the same circularly polarized component as the circularly polarized component that is selectively reflected by the light selective reflection layer 12. It is preferable to receive via the selection filter 33. By passing through the circularly polarized light selection filter 33, light composed of other polarization components is shielded, so that the reflected light from the authenticity determination body can be detected efficiently.

FIG. 4B shows the configuration of the circularly polarized light selection filter 33. By appropriately combining the λ / 4 plate 42 and the linearly polarizing plate 41, only light having right circularly polarized light or left circularly polarized light component can be transmitted. The linearly polarizing plate 41 is for removing unnecessary polarization components.
FIG. 4 shows a circularly polarizing filter in which a λ / 4 plate 42 and a linearly polarizing plate 41 are combined. FIG. 4A shows linearly polarized light as circularly polarized light, and FIG. 4B shows circularly polarized light. The state of conversion to linearly polarized light is shown.

The imaging unit 22 uses an imaging device such as a two-dimensional CCD, for example, and can capture a speckle pattern from a predetermined area of the authenticity determination body with the test object fixed.
In the above example, a speckle pattern by laser spot irradiation is imaged. In addition, a one-dimensional or two-dimensional scanning image can be obtained by moving an authenticity determination body using an element such as a photosensor as an image sensor. It is also possible to make a determination using this pattern. In this case, since the irradiation position of the laser beam is moved with the movement of the authenticity determination body, the speckle pattern is continuously changed, and therefore the light input to the photosensor is continuously changed. The profile of this change may be used for authenticity determination, and the scanned image may be one-dimensional or two-dimensional.

FIG. 5 is an operation flowchart of the authenticity determination system. FIG. 5A shows a flow up to registration of a pattern for authenticity determination, and FIG. 5B shows a flow of unknown pattern matching determination.
In registering the pattern of FIG. 5A, the speckle pattern detection means 1 is used, and first, an object is set so that a predetermined inspection area determined as an inspection location is irradiated with laser light (S51). Subsequently, a speckle pattern generated by the laser beam irradiated by the laser beam irradiation unit 21 is captured by the imaging unit 22 (S52). The fetched speckle pattern is sent to the authenticity determination server 50 together with the identification code unique to the object (S53). The identification code may be any code that can identify individual objects, such as a production number.
The speckle pattern and the identification code are recorded in the data storage unit 53 in association with each other.
By repeating the above procedure for all objects (S55), a database such as the pattern data DB 55 is obtained.

In the determination of the unknown object, the speckle pattern detection means 1 ′ is used to set the object, irradiate the laser beam (S61), and capture the speckle pattern (S62) as in the registration. . The fetched speckle pattern is sent to the true / false determination server 50 (S63), and the collating means 52 compares the speckle pattern with the pattern stored in the pattern data DB 55 (S64), and matches them. If there is, “true” is determined, otherwise “false” is determined (S65). For example, if the result is “true”, the result may be notified to the operator or the like together with the corresponding identification code.

As described above, according to the authenticity determination system of the present invention using circularly polarized light and a speckle pattern, an identification code can be individually printed or an IC chip can be determined for an object to be determined. Of course, comparison and verification for authenticity determination can be performed without adding an element or the like, especially for transparent objects that are difficult to detect by ordinary means. It is possible to provide a mechanism that enables authenticity determination without impairing design properties.

Configuration diagram of authenticity determination system Authenticator configuration diagram Configuration diagram of speckle pattern detection device Diagram showing the operation of the circular polarizing filter Operation flow diagram of authenticity determination system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Speckle pattern detection means 5 Network 10 Authenticity determination body 11 Base material 12 Light selective reflection layer 20 Speckle pattern detection apparatus 21 Laser beam irradiation part 22 Imaging part 32 Circular polarization conversion filter 33 Circular polarization selection filter 41 Linear Polarizing plate 42 λ / 4 plate 50 Authenticity determination server 51 Registration unit 52 Verification unit 53 Data storage unit

Claims (5)

An authenticity determination system using speckle patterns,
The surface of the authenticity judgment body comprising a transparent base material and a light selective reflection layer having a characteristic of reflecting either the left circularly polarized light or the right circularly polarized light in the predetermined central wavelength region of the incident light and transmitting the remaining light. A laser beam irradiation unit for irradiating a predetermined irradiation region with laser beam;
A first speckle pattern detection means comprising an imaging unit that images a specific speckle pattern obtained by irradiating the irradiation area with laser light;
Registration means for registering the speckle pattern information obtained from the first speckle pattern detection means in association with an identification code that identifies the authenticity determination body;
Collating means for collating speckle pattern information obtained from the second speckle pattern detecting means comprising a laser beam irradiation part and an imaging part and speckle pattern information registered in the registering means ;
Equipped with a,
The laser beam irradiation unit includes a circularly polarized light conversion filter, and irradiates the authenticity determination body surface with a laser beam converted into a predetermined polarized light . The imaging unit according to claim 1 Symbol placement authenticity determination system characterized in that it comprises a circular polarization selective filter, and adapted to image a laser beam of a predetermined polarization component. The authenticity determination system according to claim 1 or 2 , wherein the irradiation area is an area of the surface of the light selective reflection layer. The laser light irradiation unit and the authenticity determination body are relatively moved by a scanning unit, so that the scanning area is irradiated with laser light, and a speckle pattern from the irradiation area is detected by a photosensor, and speckles are detected. authenticity determination system according to any one of claims 1-3, characterized in that to obtain the pattern information. Authenticity determination system according to claim 1-4 wherein the first Suppe cycle pattern detecting means second Suppe cycle pattern detecting means and the registration means, characterized in that it is connected via a network .

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