JP7581867B2

JP7581867B2 - Computer program, authenticity determination method, authenticity determination device, and counterfeit prevention medium

Info

Publication number: JP7581867B2
Application number: JP2020217580A
Authority: JP
Inventors: 隆青野
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2024-11-13
Anticipated expiration: 2040-12-25
Also published as: JP2022102699A

Description

本発明は、コンピュータプログラム、真贋判定方法、真贋判定装置及び偽造防止媒体に関する。 The present invention relates to a computer program, an authenticity determination method, an authenticity determination device, and a counterfeit prevention medium.

キャッシュカード、クレジットカード、小切手カード等のカード類、金券類、身分証明書、重要書類、ブランド品等のような偽造防止を必要とする物品に対して、ホログラムを用いた偽造防止手段が図られている。偽造防止手段は税関における知的財産侵害物品の判定にも使用されている。 Holograms are used as an anti-counterfeiting measure for items that require protection against counterfeiting, such as cash cards, credit cards, check cards, vouchers, identification cards, important documents, and brand-name goods. Anti-counterfeiting measures are also used by customs to determine whether an item infringes intellectual property.

特許文献１には、真贋判定の対象物に設けられた偽造防止媒体によって再生されるホログラムを撮像し、撮像されたホログラムと、真の偽造防止媒体によって再生されるべきホログラムとを並べて表示させる真贋判定支援装置が開示されている。 Patent document 1 discloses an authenticity determination support device that captures an image of a hologram reproduced by an anti-counterfeiting medium attached to an object to be authenticated, and displays the captured hologram side by side with a hologram that should be reproduced by a genuine anti-counterfeiting medium.

国際公開第２０１６／１９０１０７号International Publication No. 2016/190107

しかし、特許文献１のような装置にあっては、真の偽造防止媒体によって再生するホログラムの特徴を充分に理解した上で、表示される２つのホログラムの相違を目視で判定する必要があり、特別な技能がなければ区別がつけられない。特に、真贋のホログラムパターンの相違が微小な場合に、誤認識をしてしまう虞がある。 However, with a device like that described in Patent Document 1, it is necessary to fully understand the characteristics of the hologram reproduced by the genuine anti-counterfeiting medium and then visually judge the difference between the two displayed holograms, which is difficult to distinguish without special skill. In particular, when the difference between the genuine and counterfeit hologram patterns is minute, there is a risk of misrecognition.

本開示の目的は、特別な技能を必要とせずに真贋判定を容易に行うことができるコンピュータプログラム、真贋判定方法、真贋判定装置及び偽造防止媒体を提供することにある。 The objective of the present disclosure is to provide a computer program, an authenticity determination method, an authenticity determination device, and a counterfeit prevention medium that can easily perform authenticity determination without requiring special skills.

本開示に係るコンピュータプログラムは、入射光を回折する光回折構造体を含む偽造防止媒体が設けられた対象物の真贋を判定する処理をコンピュータに実行させるためのコンピュータプログラムであって、前記偽造防止媒体からの回折光を受光する２次元受光素子から該回折光の空間強度分布を取得し、取得した前記空間強度分布を空間周波数分布に変換し、変換された前記空間周波数分布に基づいて、前記対象物の真贋を判定し、判定した結果を出力する処理を前記コンピュータに実行させる。 The computer program according to the present disclosure is a computer program for causing a computer to execute a process for determining the authenticity of an object provided with an anti-counterfeiting medium that includes an optical diffraction structure that diffracts incident light, and causes the computer to execute a process for acquiring a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the anti-counterfeiting medium, converting the acquired spatial intensity distribution into a spatial frequency distribution, determining the authenticity of the object based on the converted spatial frequency distribution, and outputting the determination result.

本開示に係る真贋判定方法は、入射光を回折する光回折構造体を含む偽造防止媒体が設けられた対象物の真贋を判定する真贋判定方法であって、前記偽造防止媒体からの回折光を受光する２次元受光素子から該回折光の空間強度分布を取得し、取得した前記空間強度分布を空間周波数分布に変換し、変換された前記空間周波数分布に基づいて、前記対象物の真贋を判定する。 The authenticity determination method according to the present disclosure is a method for determining the authenticity of an object provided with an anti-counterfeiting medium that includes an optical diffraction structure that diffracts incident light, and involves obtaining a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the anti-counterfeiting medium, converting the obtained spatial intensity distribution into a spatial frequency distribution, and determining the authenticity of the object based on the converted spatial frequency distribution.

本開示に係る真贋判定装置は、入射光を回折する光回折構造体を含む偽造防止媒体が設けられた対象物の真贋を判定する真贋判定装置であって、前記偽造防止媒体からの回折光を受光する２次元受光素子から該回折光の空間強度分布を取得する取得部と、取得した前記空間強度分布を空間周波数分布に変換する変換処理部と、変換された前記空間周波数分布に基づいて、前記対象物の真贋を判定する判定部と、判定した結果を出力する出力部とを備える。 The authenticity determination device according to the present disclosure is an authenticity determination device that determines the authenticity of an object provided with an anti-counterfeiting medium that includes an optical diffraction structure that diffracts incident light, and includes an acquisition unit that acquires a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the anti-counterfeiting medium, a conversion processing unit that converts the acquired spatial intensity distribution into a spatial frequency distribution, a determination unit that determines the authenticity of the object based on the converted spatial frequency distribution, and an output unit that outputs the determination result.

本開示に係る偽造防止媒体は、対象物の真贋を判定するための偽造防止媒体であって、図柄を有する基材と、前記図柄の所定部分に設けられており、入射光を回折する光回折構造体とを備え、前記光回折構造体は、前記基材の形状又は前記図柄によって定まる所定方向に周期的な構造パターンを有する。 The anti-counterfeiting medium according to the present disclosure is an anti-counterfeiting medium for determining the authenticity of an object, and comprises a substrate having a pattern, and an optical diffraction structure that is provided at a predetermined portion of the pattern and diffracts incident light, and the optical diffraction structure has a periodic structural pattern in a predetermined direction determined by the shape of the substrate or the pattern.

本開示によれば、特別な技能を必要とせずに真贋判定を容易に行うことができる。 According to this disclosure, authenticity can be easily determined without requiring special skills.

実施形態１に係る真贋判定装置の構成例を示すブロック図である。1 is a block diagram showing an example of the configuration of an authenticity determining device according to a first embodiment; 実施形態１に係る偽造防止媒体の一例を模式的に示す断面図である。1 is a cross-sectional view showing a schematic example of a counterfeit prevention medium according to a first embodiment. 実施形態１に係る真贋判定の処理手順を示すフローチャートである。4 is a flowchart showing a process for authenticity determination according to the first embodiment. 実施形態１に係る真贋判定処理を示す概念図である。FIG. 2 is a conceptual diagram showing an authenticity determination process according to the first embodiment. 実施形態２に係る偽造防止媒体の一例を模式的に示す断面図である。FIG. 11 is a cross-sectional view showing a schematic example of a counterfeit prevention medium according to a second embodiment. 実施形態２に係る偽造防止媒体の撮像及び周波数変換により得られる空間周波数分布を示す概念図である。11 is a conceptual diagram showing a spatial frequency distribution obtained by imaging and frequency conversion of a counterfeit prevention medium according to a second embodiment. FIG. 実施形態３に係る真贋判定の処理手順を示すフローチャートである。13 is a flowchart showing a processing procedure for authenticity determination according to the third embodiment. 実施形態３に係る偽造防止媒体の撮像及び周波数変換により得られる空間周波数分布を示す概念図である。13 is a conceptual diagram showing a spatial frequency distribution obtained by imaging and frequency conversion of a counterfeit prevention medium according to the third embodiment. FIG.

本開示の実施形態に係るコンピュータプログラム、真贋判定方法、真贋判定装置及び偽造防止媒体を、以下に図面を参照しつつ説明する。なお、本開示はこれらの例示に限定されるものではなく、特許請求の範囲によって示され、特許請求の範囲と均等の意味及び範囲内でのすべての変更が含まれることが意図される。また、以下に記載する実施形態の少なくとも一部を任意に組み合わせてもよい。 A computer program, an authenticity determination method, an authenticity determination device, and a counterfeit prevention medium according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is intended to include all modifications that are set forth in the claims and are equivalent in meaning and scope to the claims. In addition, at least some of the embodiments described below may be combined in any desired manner.

以下、図面に基づいて実施形態を具体的に説明する。
（実施形態１）
図１は、真贋判定装置１の構成例を示すブロック図である。真贋判定装置１は、制御部１０、記憶部１１、光源部１２、撮像部１３、表示部１４及び操作部１５を備える。真贋判定装置１は、例えばスマートフォン、携帯電話、タブレット端末、ＰＤＡ（Personal Digital Assistant）、スマートグラス等の可搬型のコンピュータである。真贋判定装置１は、真贋判定の対象物３に設けられた光回折構造体２２ａを有する偽造防止媒体２を撮像し、周波数変換することによって、対象物３の真贋を判定するものである（図２～４参照）。 Hereinafter, the embodiment will be described in detail with reference to the drawings.
(Embodiment 1)
Fig. 1 is a block diagram showing an example of the configuration of an authenticity determination device 1. The authenticity determination device 1 includes a control unit 10, a storage unit 11, a light source unit 12, an imaging unit 13, a display unit 14, and an operation unit 15. The authenticity determination device 1 is a portable computer such as a smartphone, a mobile phone, a tablet terminal, a PDA (Personal Digital Assistant), or smart glasses. The authenticity determination device 1 determines the authenticity of an object 3 by capturing an image of an anti-counterfeiting medium 2 having an optical diffraction structure 22a provided on the object 3 to be subjected to authenticity determination and performing frequency conversion (see Figs. 2 to 4).

制御部１０は、ＣＰＵ（Central Processing Unit）又はＭＰＵ（Micro-Processing Unit）、ＲＯＭ（Read Only Memory）、ＲＡＭ（Random Access Memory）、入出力インタフェース等を有するマイクロコンピュータである。制御部１０の入出力インタフェースには、光源部１２、及び撮像部１３、表示部１４及び操作部１５が接続されている。ＲＯＭはコンピュータの初期動作に必要なプログラムを記憶している。ＲＡＭは、ＤＲＡＭ（Dynamic RAM）、ＳＲＡＭ（Static RAM）等のメモリであり、制御部１０の演算処理を実行する際に記憶部１１から読み出された後述のコンピュータプログラムＰ、又は制御部１０の演算処理によって生ずる各種データを一時記憶する。ＣＰＵはコンピュータプログラムＰを実行することにより、各構成部の動作を制御し、対象物３の真贋を判定する処理を実行する。つまり、制御部１０を備えたコンピュータは、コンピュータプログラムＰを実行することにより、本実施形態１に係る真贋判定装置１として動作し、本実施形態１に係る真贋判定方法を実施する。 The control unit 10 is a microcomputer having a CPU (Central Processing Unit) or MPU (Micro-Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an input/output interface, etc. The light source unit 12, the imaging unit 13, the display unit 14, and the operation unit 15 are connected to the input/output interface of the control unit 10. The ROM stores programs necessary for the initial operation of the computer. The RAM is a memory such as a DRAM (Dynamic RAM) or an SRAM (Static RAM), and temporarily stores a computer program P (described later) read from the storage unit 11 when the control unit 10 executes the arithmetic processing, or various data generated by the arithmetic processing of the control unit 10. The CPU executes the computer program P to control the operation of each component and execute the process of determining the authenticity of the object 3. In other words, the computer equipped with the control unit 10 executes the computer program P to operate as the authenticity determination device 1 according to the present embodiment 1, and to implement the authenticity determination method according to the present embodiment 1.

記憶部１１は、ＥＥＰＲＯＭ（Electrically Erasable Programmable ROM）、フラッシュメモリ等の不揮発性メモリであり、本実施形態１に係る真贋判定方法の実施に必要なコンピュータプログラムＰを記憶している。なお、実施形態１に係る記憶部１１は、真贋判定装置１の内蔵メモリであるが、外付けのフラッシュメモリ、ハードディスク、ＳＳＤ（Solid State Drive）等であってもよい。 The storage unit 11 is a non-volatile memory such as an EEPROM (Electrically Erasable Programmable ROM) or a flash memory, and stores a computer program P required for implementing the authenticity determination method according to the first embodiment. Note that the storage unit 11 according to the first embodiment is a built-in memory of the authenticity determination device 1, but may be an external flash memory, a hard disk, an SSD (Solid State Drive), etc.

本実施形態１に係るコンピュータプログラムＰは、記録媒体Ｍにコンピュータ読み取り可能に記録されている態様でもよい。記憶部１１は、図示しない読出装置によって記録媒体Ｍから読み出されたコンピュータプログラムＰを記憶する。記録媒体ＭはＳＤ（Secure Digital）カード、マイクロＳＤカード、コンパクトフラッシュ（登録商標）などの可搬型の半導体メモリである。また、記録媒体ＭはＣＤ（Compact Disc）－ＲＯＭ、ＤＶＤ（Digital Versatile Disc）－ＲＯＭ、ＢＤ（Blu-ray(登録商標)Disc）等の光ディスクでもよい。更に、記録媒体Ｍは、フレキシブルディスク、ハードディスク等の磁気ディスク、磁気光ディスク等であってもよい。更にまた、本実施形態１に係るコンピュータプログラムＰは、図示しない通信網に接続されている図示しない外部サーバが提供する態様であってもよい。真贋判定装置１は、通信網を介して提供された本実施形態１に係るコンピュータプログラムＰをダウンロードし、記憶部１１に記憶させる。 The computer program P according to the first embodiment may be recorded in a computer-readable manner on a recording medium M. The storage unit 11 stores the computer program P read from the recording medium M by a reading device (not shown). The recording medium M is a portable semiconductor memory such as a Secure Digital (SD) card, a micro SD card, or a Compact Flash (registered trademark). The recording medium M may also be an optical disk such as a Compact Disc (CD)-ROM, a Digital Versatile Disc (DVD)-ROM, or a Blu-ray (registered trademark) Disc (BD). The recording medium M may also be a flexible disk, a magnetic disk such as a hard disk, or a magnetic optical disk. The computer program P according to the first embodiment may also be provided by an external server (not shown) connected to a communication network (not shown). The authenticity determination device 1 downloads the computer program P according to the first embodiment provided via the communication network and stores it in the storage unit 11.

光源部１２は偽造防止媒体２を照明するＬＥＤライトである。ＬＥＤライトは、偽造防止媒体２に対して光を照射し、回折光を生じさせるための光源の一例である。光源部１２が発する光の波長は特に限定されるものでは無く赤色、青色、緑色等の単色光であってもよいし、白色光であってもよい。 The light source unit 12 is an LED light that illuminates the anti-counterfeiting medium 2. The LED light is an example of a light source that irradiates the anti-counterfeiting medium 2 with light and generates diffracted light. The wavelength of the light emitted by the light source unit 12 is not particularly limited, and may be monochromatic light such as red, blue, or green, or may be white light.

撮像部１３は、レンズと、該レンズにて結像した像を電気信号に変換するＣＭＯＳ、ＣＣＤ等の撮像素子１３ａと、撮像素子１３ａにて変換された電気信号をデジタルの画像データにＡＤ変換し、ＡＤ変換された画像データに各種画像処理を施す画像処理部とを備える。撮像素子１３ａは格子状に配列した受光素子を有する２次元受光素子である。撮像部１３は、撮像して得た画像データを制御部１０に与える。本実施形態１では、撮像部１３は偽造防止媒体２を撮像するために用いられる。以下、当該画像データを撮像画像５（図４参照）と呼ぶ。撮像画像５は、縦横に配列した複数の画素を有し、一部の複数の画素値は偽造防止媒体２からの回折光の強度を示している。つまり、撮像画像５は回折光の空間高度分布を示すデータを含む。撮像部１３によって撮像して得た撮像画像５は記憶部１１が記憶する。なお、撮像部１３は、動画及び静止画のいずれも撮像することができる。 The imaging unit 13 includes a lens, an imaging element 13a such as a CMOS or CCD that converts an image formed by the lens into an electrical signal, and an image processing unit that AD converts the electrical signal converted by the imaging element 13a into digital image data and performs various image processing on the AD-converted image data. The imaging element 13a is a two-dimensional light receiving element having light receiving elements arranged in a lattice pattern. The imaging unit 13 provides the image data obtained by imaging to the control unit 10. In this embodiment 1, the imaging unit 13 is used to image the counterfeit prevention medium 2. Hereinafter, the image data is referred to as the captured image 5 (see FIG. 4). The captured image 5 has multiple pixels arranged vertically and horizontally, and some of the multiple pixel values indicate the intensity of diffracted light from the counterfeit prevention medium 2. In other words, the captured image 5 includes data indicating the spatial altitude distribution of the diffracted light. The captured image 5 obtained by imaging the imaging unit 13 is stored in the storage unit 11. The imaging unit 13 can capture both moving images and still images.

表示部１４は、液晶パネル、有機ＥＬディスプレイ、電子ペーパ、プラズマディスプレイ等である。表示部１４は、制御部１０から与えられた撮像画像５、その他の画像データに応じた各種情報を表示する。 The display unit 14 is a liquid crystal panel, an organic EL display, electronic paper, a plasma display, etc. The display unit 14 displays the captured image 5 provided by the control unit 10 and various information corresponding to other image data.

操作部１５は、ユーザによる操作を受け付け、操作内容に対応した制御信号を制御部１０へ出力するインタフェースである。操作部１５は、例えば表示部１４の表面又は内部に設けられたタッチセンサ、機械式操作ボタン等である。タッチセンサは、ユーザの指が表示部１４に触れたこと、指が触れた位置等を検出することにより、ユーザの操作を受け付け、受け付けた操作情報を制御部１０に与える。つまり、制御部１０は操作部１５にてユーザの操作を受け付けることができる。また、操作部１５はユーザの音声指令を収集するマイクであってもよい。 The operation unit 15 is an interface that accepts operations by the user and outputs a control signal corresponding to the operation content to the control unit 10. The operation unit 15 is, for example, a touch sensor or a mechanical operation button provided on the surface or inside the display unit 14. The touch sensor accepts the user's operation by detecting that the user's finger has touched the display unit 14 and the position where the finger has touched, and provides the accepted operation information to the control unit 10. In other words, the control unit 10 can accept the user's operation at the operation unit 15. The operation unit 15 may also be a microphone that collects voice commands from the user.

図２は偽造防止媒体２の一例を模式的に示す断面図である。本実施形態１に係る偽造防止媒体２は、シート状の基材２０を備える。基材２０は、ポリエチレンテレフタレート等の樹脂で形成されている。基材２０の外形は矩形状であり、所定の図柄２１を有する。例えば、図２に示すように車両の図柄２１を有する。基材２０の外形及び図柄２１の内容は特に限定されるものでは無いが、撮像画像５における偽造防止媒体２の画像の向きを特定するための基準となる線分を含む構成が望ましい。
偽造防止媒体２は、光源部１２からの光を回折する反射型の一又は複数の光回折構造体２２ａを図柄２１の所定部分２１ａに有する。光回折構造体２２ａは、所定方向に周期的な凹凸構造パターンを有し、光源部１２からの光を回折する。図２に示す例では、偽造防止媒体２は、所定の単一方向、すなわちその外形の長辺方向に周期的な凹凸構造パターンを有する。また、偽造防止媒体２は、図柄２１の車両の進行方向に周期的な凹凸構造パターンを有するともいえる。このように構成された光回折構造体２２ａを要素として、所定部分２１ａに複数の光回折構造体２２ａが配列している。
なお、図２には、光源部１２からの光を回折する周期的な凹凸構造パターンを例示したが、屈折率が異なる部位を周期的に設けた構造パターンによって光回折構造体２２ａを構成してもよい。また、本実施形態１では反射型の光回折構造体２２ａを説明するが透過型の光回折構造体２２ａであってもよい。 2 is a cross-sectional view showing a schematic example of the counterfeit prevention medium 2. The counterfeit prevention medium 2 according to the first embodiment includes a sheet-shaped substrate 20. The substrate 20 is formed of a resin such as polyethylene terephthalate. The substrate 20 has a rectangular outer shape and has a predetermined design 21. For example, as shown in FIG. 2, the substrate 20 has a vehicle design 21. The outer shape of the substrate 20 and the content of the design 21 are not particularly limited, but a configuration including a line segment that serves as a reference for identifying the orientation of the image of the counterfeit prevention medium 2 in the captured image 5 is desirable.
The counterfeit prevention medium 2 has one or more reflective optical diffraction structures 22a that diffract light from the light source unit 12 in a predetermined portion 21a of the design 21. The optical diffraction structure 22a has a periodic uneven structure pattern in a predetermined direction, and diffracts light from the light source unit 12. In the example shown in FIG. 2, the counterfeit prevention medium 2 has a periodic uneven structure pattern in a predetermined single direction, i.e., in the long side direction of its outer shape. It can also be said that the counterfeit prevention medium 2 has a periodic uneven structure pattern in the traveling direction of the vehicle of the design 21. A plurality of optical diffraction structures 22a are arranged in the predetermined portion 21a, using the optical diffraction structures 22a configured in this way as elements.
2 illustrates an example of a periodic uneven structure pattern that diffracts light from the light source unit 12, but the optical diffraction structure 22a may be configured by a structure pattern in which portions having different refractive indexes are provided periodically. In addition, although the optical diffraction structure 22a of the reflective type is described in the first embodiment, the optical diffraction structure 22a of the transmissive type may be used.

光回折構造体２２ａが設けられる所定部分２１ａは、図柄２１の一箇所に設けてもよいし、複数箇所に分散して設けてもよい。偽造防止媒体２は、観察者が光回折構造体２２ａを視認しにくい箇所に所定部分２１ａを有する構成が好ましい。また、図柄２１は、光回折構造体２２ａに類似の反射面を当該所定部分２１ａ以外の部位に有する構成が好ましい。更に、図柄２１の所定部分２１ａ以外の部位に、ダミー光回折構造体を設けてもよい。つまり、後述するように制御部１０の解析対象とならない部位に、上記所定方向と異なる方向に周期的な凹凸構造パターンを有するダミー光回折構造体を設けるとよい。偽造防止媒体２の偽造がより困難になる。 The predetermined portion 21a where the optical diffraction structure 22a is provided may be provided in one place of the pattern 21, or may be provided in multiple dispersed places. The anti-counterfeiting medium 2 is preferably configured to have the predetermined portion 21a in a place where the observer has difficulty in visually recognizing the optical diffraction structure 22a. The pattern 21 is preferably configured to have a reflective surface similar to the optical diffraction structure 22a in a portion other than the predetermined portion 21a. Furthermore, a dummy optical diffraction structure may be provided in a portion of the pattern 21 other than the predetermined portion 21a. In other words, as described later, a dummy optical diffraction structure having a periodic uneven structure pattern in a direction different from the above-mentioned predetermined direction may be provided in a portion that is not the subject of analysis by the control unit 10. This makes it more difficult to counterfeit the anti-counterfeiting medium 2.

図３は、実施形態１に係る真贋判定の処理手順を示すフローチャート、図４は、実施形態１に係る真贋判定処理を示す概念図である。制御部１０は、光源部１２を点灯させ（ステップＳ１１１）、撮像部１３にて偽造防止媒体２を撮像する（ステップＳ１１２）。記憶部１１は偽造防止媒体２の形状又は図柄２１の特徴量を記憶しており、制御部１０は撮像して得た撮像画像５の特徴量を算出することにより、偽造防止媒体２を認識することができる。また、制御部１０は撮像画像５における偽造防止媒体２の向きを認識することができる。
なお、ステップＳ１１２を実行する制御部１０は、偽造防止媒体２からの回折光を受光する撮像素子（２次元受光素子）１３ａから当該回折光の空間強度分布を取得する取得部として機能する。 Fig. 3 is a flow chart showing the process of authenticity determination according to the first embodiment, and Fig. 4 is a conceptual diagram showing the authenticity determination process according to the first embodiment. The control unit 10 turns on the light source unit 12 (step S111), and captures an image of the counterfeit prevention medium 2 with the imaging unit 13 (step S112). The memory unit 11 stores the feature amounts of the shape or design 21 of the counterfeit prevention medium 2, and the control unit 10 can recognize the counterfeit prevention medium 2 by calculating the feature amounts of the captured image 5 obtained by capturing the image. The control unit 10 can also recognize the orientation of the counterfeit prevention medium 2 in the captured image 5.
The control unit 10 that executes step S112 functions as an acquisition unit that acquires the spatial intensity distribution of the diffracted light from the counterfeit prevention medium 2 from the imaging element (two-dimensional light receiving element) 13a that receives the diffracted light.

次いで、制御部１０は、図４に示すように、偽造防止媒体２を撮像して得た撮像画像５から所定の画像部分５０を抽出する（ステップＳ１１３）。記憶部１１は、偽造防止媒体２の画像における所定部分２１ａに相当する画像部分５０の位置及び範囲を記憶している。制御部１０は、記憶している当該位置及び範囲の情報に基づいて、撮像画像５から上記画像部分５０を抽出する。 Then, as shown in FIG. 4, the control unit 10 extracts a predetermined image portion 50 from the captured image 5 obtained by capturing an image of the counterfeit prevention medium 2 (step S113). The storage unit 11 stores the position and range of the image portion 50 that corresponds to the predetermined portion 21a in the image of the counterfeit prevention medium 2. The control unit 10 extracts the image portion 50 from the captured image 5 based on the stored information on the position and range.

一方、制御部１０は、撮像画像５における偽造防止媒体２の形状又は図柄２１によって定まる所定方向を特定する（ステップＳ１１４）。所定方向は、光回折構造体２２ａの周期的な凹凸構造パターンが表れる方向である。図４に示す例では、撮像画像５は正立した偽造防止媒体２の画像を含み、撮像画像５の水平方向（Ｘ軸方向）が所定方向として特定される。図２及び図４に示す例では、偽造防止媒体２の外形の長辺方向が水平方向になる状態が正立した状態とする。なお、偽造防止媒体２の画像は必ずしも正立している必要は無い。
撮像画像５が傾いた偽造防止媒体２の画像を含む場合、所定方向が偽造防止媒体２横方向である場合、水平方向に対する当該画像の傾き方向が所定方向として特定される。 On the other hand, the control unit 10 specifies a predetermined direction determined by the shape or design 21 of the counterfeit prevention medium 2 in the captured image 5 (step S114). The predetermined direction is a direction in which the periodic uneven structure pattern of the optical diffraction structure 22a appears. In the example shown in Fig. 4, the captured image 5 includes an upright image of the counterfeit prevention medium 2, and the horizontal direction (X-axis direction) of the captured image 5 is specified as the predetermined direction. In the examples shown in Figs. 2 and 4, the upright state is a state in which the long side direction of the outer shape of the counterfeit prevention medium 2 is horizontal. Note that the image of the counterfeit prevention medium 2 does not necessarily have to be upright.
When the captured image 5 includes an inclined image of the counterfeit prevention medium 2, if the predetermined direction is the lateral direction of the counterfeit prevention medium 2, the inclination direction of the image with respect to the horizontal direction is identified as the predetermined direction.

次いで、制御部１０は、図４に示すようにステップＳ１１３で抽出された画像部分５０、すなわち回折光の空間強度分布を、空間周波数分布に変換する（ステップＳ１１５）。図４に示す周波数空間のｘ軸は、撮像画像５又は画像部分の水平方向（Ｘ軸）に対応し、周波数空間のｙ軸は、撮像画像５又は画像部分の垂直方向（Ｙ軸）に対応する。
なお、ステップＳ１１５を実行する制御部１０は、取得した空間強度分布を空間周波数分布に変換する変換処理部として機能する。 Next, the control unit 10 converts the image portion 50 extracted in step S113, i.e., the spatial intensity distribution of the diffracted light, into a spatial frequency distribution (step S115) as shown in Fig. 4. The x-axis of the frequency space shown in Fig. 4 corresponds to the horizontal direction (X-axis) of the captured image 5 or the image portion, and the y-axis of the frequency space corresponds to the vertical direction (Y-axis) of the captured image 5 or the image portion.
The control unit 10 that executes step S115 functions as a conversion processing unit that converts the acquired spatial intensity distribution into a spatial frequency distribution.

そして、制御部１０は、周波数空間における空間周波数成分のピークが、ステップＳ１１４で特定した所定方向に対応する線上に配列しているか否かを判定する（ステップＳ１１６）。空間周波数成分のピークは、例えば周波数空間における空間周波数成分の平均値よりも、所定値以上大きな極大値を有する空間周波数成分である。所定値は、周波数空間における空間周波数成分の分散に基づく値でもよいし、所定値でもよい。なお、真性の偽造防止媒体２から得られる上記空間周波数分布を解析すると、通常、複数のピークが特定される。当該ピークは、必ずしも空間周波数成分の最大値ではない。また、上記したピークの特定方法は一例であり、光回折構造体２２ａにおける周期的な凹凸構造パターンの方向を特定することが可能であれば、当該ピークの特定方法は特に限定されるものではない。
なお、ステップＳ１１６を実行する制御部１０は、変換された空間周波数分布に基づいて、対象物の真贋を判定する判定部として機能する。 Then, the control unit 10 judges whether the peaks of the spatial frequency components in the frequency space are arranged on a line corresponding to the predetermined direction specified in step S114 (step S116). The peaks of the spatial frequency components are, for example, spatial frequency components having a maximum value greater than the average value of the spatial frequency components in the frequency space by a predetermined value or more. The predetermined value may be a value based on the variance of the spatial frequency components in the frequency space, or may be a predetermined value. When the spatial frequency distribution obtained from the genuine anti-counterfeiting medium 2 is analyzed, a plurality of peaks are usually identified. The peaks are not necessarily the maximum values of the spatial frequency components. The above-mentioned method of identifying the peaks is an example, and the method of identifying the peaks is not particularly limited as long as it is possible to identify the direction of the periodic uneven structure pattern in the optical diffraction structure 22a.
The control unit 10 that executes step S116 functions as a determination unit that determines the authenticity of the object based on the converted spatial frequency distribution.

画像部分５０における所定方向が水平方向（Ｘ軸方向）である場合、画像部分５０は当該水平方向に周期的な強度分布を有するため、所定方向に対応する線上は周波数空間におけるｘ軸上となる。
なお、画像部分５０における所定方向が垂直方向（Ｙ軸方向）である場合、画像部分５０は当該垂直方向に周期的な強度分布を有するため、所定方向に対応する線上は周波数空間におけるｙ軸上となる。また、画像部分５０における所定方向が水平方向（Ｘ軸方向）に対して角度θをなす場合、画像部分５０は当該水平方向に対して角度θをなす方向に周期的な強度分布を有するため、所定方向に対応する線上は周波数空間のｘ軸に対して角度θをなす線分上となる。 When the predetermined direction in the image portion 50 is the horizontal direction (X-axis direction), the image portion 50 has a periodic intensity distribution in the horizontal direction, so that the line corresponding to the predetermined direction is on the x-axis in frequency space.
When the predetermined direction in the image portion 50 is the vertical direction (Y-axis direction), the image portion 50 has a periodic intensity distribution in the vertical direction, so that the line corresponding to the predetermined direction is on the y-axis in frequency space. When the predetermined direction in the image portion 50 forms an angle θ with the horizontal direction (X-axis direction), the image portion 50 has a periodic intensity distribution in the direction that forms an angle θ with the horizontal direction, so that the line corresponding to the predetermined direction is on a line segment that forms an angle θ with the x-axis in frequency space.

当該ピークが配列方向に対応する線上に配列していると判定した場合（ステップＳ１１６：ＹＥＳ）、制御部１０は、対象物３が真正であることを示す情報を出力し（ステップＳ１１７）、処理を終える。例えば、制御部１０は、対象物３が真正なものであることを示す文字情報を表示部１４に表示する。なお、ステップＳ１１７を実行する制御部１０は、判定した結果を出力する出力部として機能する。 If it is determined that the peaks are arranged on a line corresponding to the arrangement direction (step S116: YES), the control unit 10 outputs information indicating that the object 3 is genuine (step S117) and ends the process. For example, the control unit 10 displays text information indicating that the object 3 is genuine on the display unit 14. The control unit 10 that executes step S117 functions as an output unit that outputs the determination result.

当該ピークが配列方向に対応する線上に配列していないと判定した場合（ステップＳ１１６：ＮＯ）、制御部１０は、対象物３が贋物であることを示す情報を出力し（ステップＳ１１８）、処理を終える。例えば、制御部１０は、対象物３が贋物であることを示す文字情報を表示部１４に表示する。なお、ステップＳ１１８を実行する制御部１０は、判定した結果を出力する出力部として機能する。 If it is determined that the peaks are not aligned on a line corresponding to the alignment direction (step S116: NO), the control unit 10 outputs information indicating that the object 3 is a counterfeit (step S118) and ends the process. For example, the control unit 10 displays text information indicating that the object 3 is a counterfeit on the display unit 14. The control unit 10 that executes step S118 functions as an output unit that outputs the determination result.

以上の通り、本実施形態１に係る真贋判定装置１、真贋判定方法、コンピュータプログラムＰ及び偽造防止媒体２によれば、ユーザは特別な技能を必要とせずに真贋判定を容易に行うことができる。具体的には、ユーザは、偽造防止媒体２を撮像するのみで対象物３の真贋を判定することができる。 As described above, the authenticity determination device 1, the authenticity determination method, the computer program P, and the counterfeit prevention medium 2 according to the first embodiment allow a user to easily determine authenticity without requiring special skills. Specifically, the user can determine the authenticity of the object 3 simply by capturing an image of the counterfeit prevention medium 2.

より詳細には、真贋判定装置１の制御部１０は、偽造防止媒体２を撮像し、撮像画像５に含まれる所定の画像部分５０を抽出して周波数変換し、空間周波数成分のピークが所定の単一方向に対応する線上に配列しているか否かを判定することにより、当該偽造防止媒体２が設けられた対象物３の真贋を判定する。このように、撮像画像５に含まれる所定の画像部分５０における空間周波数成分を解析することによって対象物３の真贋を判定する構成であるため、ユーザは偽造防止媒体２を視認して特徴を判別する必要はなく、偽造防止媒体２を撮像するのみで対象物３の真贋を知ることができる。 More specifically, the control unit 10 of the authenticity determination device 1 images the anti-counterfeiting medium 2, extracts a predetermined image portion 50 included in the captured image 5, performs frequency conversion, and determines whether the peaks of the spatial frequency components are arranged on a line corresponding to a predetermined single direction, thereby determining the authenticity of the object 3 on which the anti-counterfeiting medium 2 is provided. In this way, since the authenticity of the object 3 is determined by analyzing the spatial frequency components in the predetermined image portion 50 included in the captured image 5, the user does not need to visually recognize the anti-counterfeiting medium 2 to distinguish its features, and can know the authenticity of the object 3 simply by imaging the anti-counterfeiting medium 2.

また、本実施形態１に係る偽造防止媒体２は図柄２１を含み、当該図柄２１の所定部分２１ａに光回折構造２２ａを設けているため、偽造防止媒体２の偽造を困難にすることができる。 In addition, the counterfeit prevention medium 2 according to this embodiment 1 includes a pattern 21, and an optical diffraction structure 22a is provided in a specific portion 21a of the pattern 21, making it difficult to counterfeit the counterfeit prevention medium 2.

更に、制御部１０は、撮像画像５における偽造防止媒体２の外形又は図柄２１を認識し、当該外形又は図柄２１によって、光回折構造２２ａの回折パターンの方向（所定方向）を特定する構成であるため、ユーザは撮像姿勢を厳密に調整する必要は無く、容易に偽造防止媒体２を撮像し、対象物３の真贋判定を行うことができる。 Furthermore, the control unit 10 is configured to recognize the external shape or pattern 21 of the anti-counterfeiting medium 2 in the captured image 5 and to identify the direction (predetermined direction) of the diffraction pattern of the optical diffraction structure 22a based on the external shape or pattern 21, so the user does not need to precisely adjust the imaging posture, and can easily image the anti-counterfeiting medium 2 and determine the authenticity of the target object 3.

（実施形態２）
実施形態２に係る真贋判定装置１、真贋判定方法、コンピュータプログラムＰ及び偽造防止媒体２は、偽造防止媒体２の光回折構造体２２ａの構成と、真贋判定処理の内容が実施形態１と異なる。真贋判定装置１のハードウェア、その他の構成は、実施形態１に係る真贋判定装置１等と同様であるため、同様の箇所には同じ符号を付し、詳細な説明を省略する。 (Embodiment 2)
The authenticity determination device 1, authenticity determination method, computer program P, and anti-counterfeiting medium 2 according to the second embodiment differ from those of the first embodiment in the configuration of the optical diffraction structure 22a of the anti-counterfeiting medium 2 and the contents of the authenticity determination process. Since the hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination device 1 according to the first embodiment, the same reference numerals are used for similar parts and detailed descriptions are omitted.

図５は、実施形態２に係る偽造防止媒体２の一例を模式的に示す断面図である。実施形態２に係る偽造防止媒体２は、第１方向（第１の所定方向）に周期的な凹凸構造パターンを有する第１光回折構造体２２ａと、第１方向に直交する第２方向（第２の所定方向）に周期的な凹凸構造パターンを有する第２光回折構造体２２ｂとを所定部分２１ａに有する。図５に示す例では、複数の第１光回折構造体２２ａと、複数の第２光回折構造体２２ｂとが交互に隣り合うように格子状に配されている。 Figure 5 is a cross-sectional view showing a schematic example of an anti-counterfeiting medium 2 according to embodiment 2. The anti-counterfeiting medium 2 according to embodiment 2 has, in a specified portion 21a, a first optical diffraction structure 22a having a periodic uneven structure pattern in a first direction (first specified direction) and a second optical diffraction structure 22b having a periodic uneven structure pattern in a second direction (second specified direction) perpendicular to the first direction. In the example shown in Figure 5, a plurality of first optical diffraction structures 22a and a plurality of second optical diffraction structures 22b are arranged in a lattice pattern so as to be alternately adjacent to each other.

図６は、実施形態２に係る偽造防止媒体２の撮像及び周波数変換により得られる空間周波数分布を示す概念図である。このように構成された偽造防止媒体２を撮像して得た撮像画像５は、実施形態一同様、正立した偽造防止媒体２の画像を含み、所定部分２１ａに対応する画像部分５０は、水平方向及び垂直方向に周期的な強度分布を有するものとする。かかる画像部分５０が有する回折光の空間強度分布を周波数変換すると、図６に示すような空間周波数分布が得られる。第１方向及び第２方向に対応するｘ軸及びｙ軸上に空間周波数成分のピークが配列した空間周波数分布が得られる。 Figure 6 is a conceptual diagram showing the spatial frequency distribution obtained by imaging and frequency conversion of the counterfeit prevention medium 2 according to the second embodiment. The captured image 5 obtained by imaging the counterfeit prevention medium 2 configured in this manner includes an image of the upright counterfeit prevention medium 2, as in the first embodiment, and the image portion 50 corresponding to the specified portion 21a has a periodic intensity distribution in the horizontal and vertical directions. When the spatial intensity distribution of the diffracted light possessed by such image portion 50 is frequency converted, a spatial frequency distribution as shown in Figure 6 is obtained. A spatial frequency distribution is obtained in which the peaks of the spatial frequency components are arranged on the x-axis and y-axis corresponding to the first and second directions.

真贋判定装置１の制御部１０は、実施形態１と同様の真贋判定処理（ステップＳ１１１～Ｓ１１８）を実行することによって、実施形態２に係る偽造防止媒体２が設けられた対象物３の真贋を判定することができる。ただし、ステップＳ１１６において、制御部１０は、周波数空間における空間周波数成分のピークが第１方向及び第２方向に対応するｘ軸及びｙ軸上に配列しているか否かを判定する。この点が実施形態１と異なる。 The control unit 10 of the authenticity determination device 1 can determine the authenticity of the object 3 provided with the counterfeit prevention medium 2 according to the second embodiment by executing the same authenticity determination process (steps S111 to S118) as in the first embodiment. However, in step S116, the control unit 10 determines whether the peaks of the spatial frequency components in the frequency space are aligned on the x-axis and y-axis corresponding to the first direction and the second direction. This is different from the first embodiment.

実施形態２に係る真贋判定装置１等によれば、実施形態１同様、ユーザは特別な技能を必要とせずに真贋判定を容易に行うことができる。実施形態２では、入射光を回折する周期的な凹凸構造パターンの配列方向が異なる第１光回折構造体２２ａ及び第２光回折構造体２２ｂを備えるため、より精度よく対象物３の真贋を判定することができ、より効果的に対象物３の偽造を防止することができる。 According to the authenticity determination device 1 etc. of embodiment 2, as in embodiment 1, a user can easily determine authenticity without requiring special skills. In embodiment 2, the device is provided with a first optical diffraction structure 22a and a second optical diffraction structure 22b in which the arrangement directions of the periodic uneven structure patterns that diffract incident light are different, so that the authenticity of the object 3 can be determined with higher accuracy, and counterfeiting of the object 3 can be more effectively prevented.

なお、実施形態２では、図５に示すように直交する第１方向及び第２方向に周期的な凹凸構造パターンを有する第１光回折構造体２２ａ及び第２光回折構造体２２ｂを例示したが、凹凸構造パターンの配列方向は特に限定されるものでは無く、また３つ以上の方向に凹凸構造パターンを配列した複数種類の光回折構造体２２ａを偽造防止媒体２に設けてもよい。 In the second embodiment, as shown in FIG. 5, the first optical diffraction structure 22a and the second optical diffraction structure 22b are illustrated as having periodic concave-convex structure patterns in the first and second directions that are orthogonal to each other. However, the arrangement direction of the concave-convex structure patterns is not particularly limited, and multiple types of optical diffraction structures 22a having concave-convex structure patterns arranged in three or more directions may be provided on the counterfeit prevention medium 2.

（実施形態３）
実施形態３に係る真贋判定装置１、真贋判定方法、コンピュータプログラムＰ及び偽造防止媒体２は、偽造防止媒体２の光回折構造体２２ａの構成と、真贋判定処理の内容が実施形態１及び２と異なる。真贋判定装置１のハードウェア、その他の構成は、実施形態１及び２に係る真贋判定装置１等と同様であるため、同様の箇所には同じ符号を付し、詳細な説明を省略する。 (Embodiment 3)
The authenticity determination device 1, authenticity determination method, computer program P, and anti-counterfeiting medium 2 according to the third embodiment differ from those of the first and second embodiments in the configuration of the optical diffraction structure 22a of the anti-counterfeiting medium 2 and the contents of the authenticity determination process. Since the hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination device 1 according to the first and second embodiments, the same reference numerals are used for similar parts and detailed descriptions are omitted.

実施形態３に係る偽造防止媒体２は、第１方向（第１の所定方向）に周期的な凹凸構造パターンを有する第１光回折構造体２２ａと、第１方向に対して所定角度をなす第２方向（第２の所定方向）に周期的な凹凸構造パターンを有する第２光回折構造体２２ｂとを所定部分２１ａに有する。第１方向は、例えば偽造防止媒体２の外形の長辺方向である。所定角度は例えば４５°である。
なお、言うまでも無く、第１方向及び第２方向の向き、所定角度の大きさは特に限定されるものでは無い。また、実施形態２と同様、複数の第１光回折構造体２２ａと、複数の第２光回折構造体２２ｂとが交互に隣り合うように格子状に配するとよい。 The counterfeit prevention medium 2 according to the third embodiment has, in a predetermined portion 21a, a first optical diffraction structure 22a having a periodic concave-convex structure pattern in a first direction (first predetermined direction) and a second optical diffraction structure 22b having a periodic concave-convex structure pattern in a second direction (second predetermined direction) that forms a predetermined angle with the first direction. The first direction is, for example, the direction of the long side of the outer shape of the counterfeit prevention medium 2. The predetermined angle is, for example, 45°.
Needless to say, the orientation of the first direction and the second direction and the size of the predetermined angle are not particularly limited. Also, similar to the second embodiment, it is preferable to arrange the first optical diffraction structures 22a and the second optical diffraction structures 22b alternately adjacent to each other in a lattice pattern.

図７は、実施形態３に係る真贋判定の処理手順を示すフローチャート、図８は、実施形態３に係る偽造防止媒体２の撮像及び周波数変換により得られる空間周波数分布を示す概念図である。実施形態３に係る真贋判定装置１の制御部１０は、実施形態１と同様、光源部１２を点灯させ（ステップＳ３１１）、撮像部１３にて偽造防止媒体２を撮像し（ステップＳ３１２）、偽造防止媒体２を撮像して得た撮像画像５から所定の画像部分５０を抽出し（ステップＳ３１３）、抽出した画像部分５０、すなわち回折光の空間強度分布を、空間周波数分布に変換する（ステップＳ３１４）。 Fig. 7 is a flow chart showing the processing procedure for authenticity determination according to the third embodiment, and Fig. 8 is a conceptual diagram showing the spatial frequency distribution obtained by imaging and frequency conversion of the anti-counterfeiting medium 2 according to the third embodiment. As in the first embodiment, the control unit 10 of the authenticity determination device 1 according to the third embodiment turns on the light source unit 12 (step S311), images the anti-counterfeiting medium 2 with the imaging unit 13 (step S312), extracts a predetermined image portion 50 from the captured image 5 obtained by imaging the anti-counterfeiting medium 2 (step S313), and converts the extracted image portion 50, i.e., the spatial intensity distribution of the diffracted light, into a spatial frequency distribution (step S314).

そして、制御部１０は、周波数空間における空間周波数成分のピークが配列する方向を特定し（ステップＳ３１５）、空間周波数成分のピークが配列する２つの方向が所定角度を有するか否かを判定する（ステップＳ３１６）。なお、ここでは、真正の偽造防止媒体２の撮像画像５を周波数変換した場合、空間周波数成分のピークが配列する２つの方向が特定されることを前提にしている。空間周波数成分のピークが配列する方向が単一方向であったり、３つ以上の複数方向であったり、配列方向が特定できない場合、制御部１０はステップＳ３１６において、所定角度を有しないと判定するものとする。 Then, the control unit 10 identifies the direction in which the peaks of the spatial frequency components are arranged in the frequency space (step S315), and determines whether the two directions in which the peaks of the spatial frequency components are arranged have a predetermined angle (step S316). Note that, here, it is assumed that when the captured image 5 of the genuine anti-counterfeiting medium 2 is frequency converted, the two directions in which the peaks of the spatial frequency components are arranged are identified. If the direction in which the peaks of the spatial frequency components are arranged is a single direction, or three or more directions, or the arrangement direction cannot be identified, the control unit 10 determines in step S316 that it does not have a predetermined angle.

所定角度を有すると判定した場合（ステップＳ３１６：ＹＥＳ）、制御部１０は、対象物３が真正であることを示す情報を出力し（ステップＳ３１７）、処理を終える。所定角度を有しないと判定した場合（ステップＳ３１６：ＮＯ）、制御部１０は、対象物３が贋物であることを示す情報を出力し（ステップＳ３１８）、処理を終える。 If it is determined that the object 3 has the predetermined angle (step S316: YES), the control unit 10 outputs information indicating that the object 3 is genuine (step S317) and ends the process. If it is determined that the object 3 does not have the predetermined angle (step S316: NO), the control unit 10 outputs information indicating that the object 3 is a counterfeit (step S318) and ends the process.

実施形態３に係る真贋判定装置１等によれば偽造防止媒体２の撮像方向を特定することなく、周波数空間における空間周波数成分のピークが配列する方向を特定し、特定された配列方向がなす角度を特定するのみで、偽造防止媒体２が設けられた対象物３の真贋を判定することができる。 The authenticity determination device 1 according to the third embodiment can determine the authenticity of the object 3 on which the anti-counterfeiting medium 2 is provided, without specifying the imaging direction of the anti-counterfeiting medium 2, by simply specifying the direction in which the peaks of the spatial frequency components in the frequency space are arranged and specifying the angle formed by the specified arrangement direction.

なお、実施形態３では偽造防止媒体２は、凹凸構造パターンの配列方向が２方向である例を説明したが、３方向以上の複数方向に周期的な凹凸構造パターンを有する構成でもよい。この場合、制御部１０は、間周波数分布における空間周波数成分のピークが配列する複数の方向が互いに所定角度を有するか否かを判定すればよい。また、言うまでも無く、複数の配列方向がなす角度は同一である必要はなく、異なる角度をなすものであってもよい。 In the third embodiment, the anti-counterfeiting medium 2 has been described as an example in which the uneven structure pattern is arranged in two directions, but it may also be configured to have a periodic uneven structure pattern in three or more directions. In this case, the control unit 10 only needs to determine whether the multiple directions in which the peaks of the spatial frequency components in the frequency distribution are arranged have a predetermined angle with each other. Needless to say, the angles formed by the multiple arrangement directions do not need to be the same, and they may form different angles.

（実施形態４）
実施形態４に係る真贋判定装置１、真贋判定方法、コンピュータプログラムＰ及び偽造防止媒体２は、光源部１２が所定波長域の光を発する点、所定波長域の回折光の空間強度分布を空間周波数分布に変換して解析する点が実施形態１～３と異なる。真贋判定装置１のその他のハードウェア、その他の構成は、実施形態１に係る真贋判定装置１等と同様であるため、同様の箇所には同じ符号を付し、詳細な説明を省略する。 (Embodiment 4)
The authenticity determination device 1, authenticity determination method, computer program P, and counterfeit prevention medium 2 according to the fourth embodiment differ from those according to the first to third embodiments in that the light source unit 12 emits light in a predetermined wavelength range, and that the spatial intensity distribution of diffracted light in the predetermined wavelength range is converted into a spatial frequency distribution for analysis. The other hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination device 1 according to the first embodiment, and therefore similar parts are denoted by the same reference numerals and detailed description will be omitted.

実施形態４に係る真贋判定装置１の光源部１２は、赤色ＬＥＤ、緑色ＬＥＤ及び青色ＬＥＤを有する。また、光源部１２は色温度可変のＬＥＤを有する構成であってもよい。 The light source unit 12 of the authenticity determination device 1 according to the fourth embodiment has a red LED, a green LED, and a blue LED. The light source unit 12 may also have an LED with a variable color temperature.

実施形態４に係る制御部１０は、実施形態１と同様の真贋判定処理（ステップＳ１１１～Ｓ１１８）を実行することによって、実施形態４に係る偽造防止媒体２が設けられた対象物３の真贋を判定する。ただし、実施形態４に係る制御部１０は、ステップＳ１１１において光源部１２が所定波長域の光を発するように当該光源部１２を点灯させる。例えば、光源部１２は青色の光を偽造防止媒体２に照射する。このように、実施形態４においては、制御部１０は、所定波長域の回折光の空間強度分布を周波数変換し、周波数変換された空間周波数分布における周波数ピークの配列が所定方向に対応する線上にあるか否かを判定することによって、対象物３の真贋判定を行う。 The control unit 10 according to the fourth embodiment executes the same authenticity determination process (steps S111 to S118) as in the first embodiment to determine the authenticity of the object 3 provided with the counterfeit prevention medium 2 according to the fourth embodiment. However, in step S111, the control unit 10 according to the fourth embodiment turns on the light source unit 12 so that the light source unit 12 emits light in a predetermined wavelength range. For example, the light source unit 12 irradiates the counterfeit prevention medium 2 with blue light. Thus, in the fourth embodiment, the control unit 10 frequency-converts the spatial intensity distribution of the diffracted light in the predetermined wavelength range, and determines whether the arrangement of frequency peaks in the frequency-converted spatial frequency distribution is on a line corresponding to a predetermined direction, thereby determining the authenticity of the object 3.

実施形態４に係る真贋判定装置１等によれば、所定波長域の光を照射することによって、実施形態１同様、ユーザは特別な技能を必要とせずに真贋判定を容易に行うことができる。 According to the authenticity determination device 1 etc. of embodiment 4, by irradiating light in a predetermined wavelength range, the user can easily perform authenticity determination without requiring special skills, as in embodiment 1.

なお、偽造防止媒体２は、撮像画像５において偽造防止媒体２の画像が所定サイズ範囲の大きさとなるような位置から偽造防止媒体２を撮像する場合、少なくとも所定波長域の光（例えば青色光）の１次回折光が撮像部１３の撮像範囲に入り、所定波長域外の光（例えば、赤色光）の１次回折光が撮像部１３の撮像範囲に入らないように構成してもよい。
この場合、所定波長域の光を照射しないと、真贋判定を行うことができない構成である。従って、より効果的に対象物３の偽造を防止することができる。 In addition, when the anti-counterfeiting medium 2 is imaged from a position where the image of the anti-counterfeiting medium 2 in the captured image 5 is within a predetermined size range, the anti-counterfeiting medium 2 may be configured so that at least first-order diffracted light of light in a predetermined wavelength range (e.g., blue light) enters the imaging range of the imaging unit 13, and first-order diffracted light of light outside the predetermined wavelength range (e.g., red light) does not enter the imaging range of the imaging unit 13.
In this case, unless light in a predetermined wavelength range is irradiated, authenticity cannot be determined, so counterfeiting of the object 3 can be more effectively prevented.

また、偽造防止媒体２は、撮像画像５において偽造防止媒体２の画像が所定サイズ範囲の大きさとなるような位置から偽造防止媒体２を撮像する場合、所定波長域の光の１次回折光が撮像範囲に入るように構成された光回折構造体２２ａを所定部分２１ａに含み、所定波長域外の光の１次回折光が撮像範囲に入らないように構成された光回折構造体２２ａを当該所定分部外に含むように構成してもよい。制御部１０は、所定部分２１ａの画像部分５０であって、所定波長域の撮像画像５を解析対象として選択する。このように構成することにより、偽造防止媒体２の偽造がより困難になる。
なお、制御部１０は、真贋判定装置１に設けられた撮像部１３の画角情報を記憶部１１から読み出し、所定波長域の光の１次回折光が撮像範囲に入り、所定波長域外の光の１次回折光が撮像範囲に入らない撮像距離を算出し、偽造防止媒体２の撮像方法をユーザに指示するように構成してもよい。 Furthermore, when the counterfeit prevention medium 2 is imaged from a position where the image of the counterfeit prevention medium 2 in the captured image 5 is within a predetermined size range, the counterfeit prevention medium 2 may be configured to include, in the predetermined portion 21a, an optical diffraction structure 22a configured so that first-order diffracted light of light in a predetermined wavelength range falls within the imaging range, and to include, outside the predetermined portion, an optical diffraction structure 22a configured so that first-order diffracted light of light outside the predetermined wavelength range does not fall within the imaging range. The control unit 10 selects, as the analysis target, the image portion 50 of the predetermined portion 21a, which is the captured image 5 in the predetermined wavelength range. By configuring in this manner, counterfeiting of the counterfeit prevention medium 2 becomes more difficult.
In addition, the control unit 10 may be configured to read out the angle of view information of the imaging unit 13 provided in the authenticity determination device 1 from the memory unit 11, calculate the imaging distance at which the first-order diffracted light of light in a specified wavelength range falls within the imaging range and the first-order diffracted light of light outside the specified wavelength range does not fall within the imaging range, and instruct the user on the imaging method for the anti-counterfeiting medium 2.

更に上記説明では、光源部１２が所定波長域の光を照射する例を説明したが、光源部１２は白色光を照射するように構成し、制御部１０が、ＲＧＢ成分（赤色成分、緑色成分、青色成分）を有する撮像画像５から所定波長域の撮像画像５、つまり所定波長域の回折光の空間強度分布を選択し、当該空間強度分布を周波数変換し、真贋判定を行うように構成してもよい。このように構成することにより、偽造防止媒体２の偽造がより困難になる。
更にまた、真贋判定処理において光源部１２は所定波長域の光（青色光）と、所定波長域外の光（赤色光）とを交互に照射し、制御部１０は、所定波長域の光を照射して撮像したときに撮像画像５を真贋判定の解析対象として選択するように構成してもよい。 Furthermore, in the above description, an example has been described in which the light source unit 12 irradiates light in a predetermined wavelength range, but the light source unit 12 may be configured to irradiate white light, and the control unit 10 may select an image 5 in a predetermined wavelength range from an image 5 having RGB components (red component, green component, blue component), that is, a spatial intensity distribution of diffracted light in a predetermined wavelength range, and frequency-convert the spatial intensity distribution to determine authenticity. By configuring in this way, counterfeiting of the counterfeit prevention medium 2 becomes more difficult.
Furthermore, in the authenticity determination process, the light source unit 12 may alternately irradiate light in a predetermined wavelength range (blue light) and light outside the predetermined wavelength range (red light), and the control unit 10 may be configured to select the captured image 5 as the target for analysis in authenticity determination when it is imaged by irradiating it with light in the predetermined wavelength range.

なお、実施形態１～４では、真贋判定装置１の一例として、スマートフォン等の可搬型コンピュータを例示したが、複数のコンピュータを含んで構成されるマルチコンピュータであってよい。また、真贋判定装置１は、サーバクライアントシステムや、クラウドサーバ、ソフトウェアによって仮想的に構築された仮想マシンであってもよい。本実施形態１に係るコンピュータプログラムＰは、複数のコンピュータ又はサイトで分散して実行される構成であってもよい。 In the first to fourth embodiments, a portable computer such as a smartphone is given as an example of the authenticity determination device 1, but the authenticity determination device 1 may be a multi-computer including multiple computers. The authenticity determination device 1 may also be a server-client system, a cloud server, or a virtual machine virtually constructed by software. The computer program P according to the first embodiment may be configured to be executed in a distributed manner on multiple computers or sites.

また、本実施形態１～４では、真贋判定装置１の一例として、光源部１２及び撮像部１３を備える可搬型コンピュータを説明したが、光源部１２又は撮像部１３はコンピュータでる真贋判定装置１と別体の構成であってもよい。 In addition, in the first to fourth embodiments, a portable computer equipped with a light source unit 12 and an image capturing unit 13 has been described as an example of the authenticity determination device 1, but the light source unit 12 or the image capturing unit 13 may be configured separately from the authenticity determination device 1, which is a computer.

更に、本実施形態１～４では平らな対象物３にシート状の偽造防止媒体２を貼付する例を説明したが、対象物３及び偽造防止媒体２は平面状である必要は無く、湾曲したものであってもよい。 Furthermore, in the first to fourth embodiments, an example has been described in which a sheet-shaped anti-counterfeiting medium 2 is affixed to a flat object 3, but the object 3 and the anti-counterfeiting medium 2 do not have to be flat and may be curved.

更にまた、本実施形態１～４では真贋判定をコンピュータが実行する例を説明したが、真贋判定方法の一部又は全部を人が実行するように構成してもよい。 Furthermore, in the first to fourth embodiments, examples have been described in which the authenticity determination is performed by a computer, but the authenticity determination method may be configured to be partially or entirely performed by a person.

今回開示された実施形態はすべての点で例示であって、制限的なものではないと考えられるべきである。本発明の範囲は、上記した意味ではなく、特許請求の範囲によって示され、特許請求の範囲と均等の意味及び範囲内でのすべての変更が含まれることが意図される。 The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is indicated by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims.

１真贋判定装置
２偽造防止媒体
３対象物
５撮像画像
１０制御部
１１記憶部
１２光源部
１３撮像部
１４表示部
１５操作部
５０画像部分
２１図柄
２１ａ所定部分
２２ａ光回折構造体（第１光回折構造体）
２２ｂ第２光回折構造体
Ｍ記録媒体
Ｐコンピュータプログラム REFERENCE SIGNS LIST 1 Authenticity determination device 2 Counterfeit prevention medium 3 Object 5 Captured image 10 Control unit 11 Memory unit 12 Light source unit 13 Capture unit 14 Display unit 15 Operation unit 50 Image portion 21 Design 21a Predetermined portion 22a Optical diffraction structure (first optical diffraction structure)
22b Second optical diffraction structure M Recording medium P Computer program

Claims

A computer program for causing a computer to execute a process for determining the authenticity of an object provided with a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a predetermined direction that diffracts incident light, the computer program comprising:
acquiring a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the counterfeit prevention medium;
Converting the acquired spatial intensity distribution into a spatial frequency distribution;
determining whether or not peaks of spatial frequency components in a frequency space are arranged on a line corresponding to the predetermined direction based on the transformed spatial frequency distribution, thereby determining the authenticity of the object;
A computer program for causing the computer to execute a process of outputting a result of the determination.

the predetermined direction is a predetermined single direction,
The process of determining authenticity is as follows:
The authenticity of the object is determined by determining whether or not the peaks of spatial frequency components in the frequency space are arranged on a line corresponding to the predetermined single direction.
2. The computer program product of claim 1 .

the predetermined direction is a plurality of predetermined directions,
The process of determining authenticity is as follows:
The authenticity of the object is determined by determining whether or not the peaks of spatial frequency components in the frequency space are arranged on lines corresponding to the predetermined multiple directions.
2. The computer program product of claim 1 .

the two-dimensional light receiving element is an image sensor, and an image of the counterfeit prevention medium is obtained from the image sensor;
The process of determining authenticity is as follows:
The computer program according to any one of claims 1 to 3, which determines the authenticity of the object by determining whether or not peaks of spatial frequency components in frequency space are arranged on a predetermined line determined by the shape or pattern of the anti-counterfeiting medium and on a line corresponding to the predetermined direction .

A computer program for causing a computer to execute a process for determining the authenticity of an object provided with a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a plurality of predetermined directions that diffracts incident light, the computer program comprising:
acquiring a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the counterfeit prevention medium;
Converting the acquired spatial intensity distribution into a spatial frequency distribution;
determining whether an angle formed by a plurality of directions in which peaks of spatial frequency components are arranged in a frequency space is a predetermined angle based on the transformed spatial frequency distribution, thereby determining the authenticity of the object;
Output the judged result
A computer program for causing the computer to execute a process.

The counterfeit prevention medium has a pattern, and includes the optical diffraction structure in a predetermined portion of the pattern;
the two-dimensional light receiving element is an image sensor, and an image of the counterfeit prevention medium is obtained from the image sensor;
Extracting an image portion corresponding to the predetermined portion from the acquired image;
The computer program according to any one of claims 1 to 5 , for causing the computer to execute a process of converting the spatial intensity distribution of the diffracted light in the extracted image portion into a spatial frequency distribution.

The computer program according to any one of claims 1 to 6 , which converts a spatial intensity distribution of diffracted light in a predetermined wavelength range into a spatial frequency distribution.

A method for determining authenticity of an object having a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a predetermined direction that diffracts incident light, the method comprising the steps of:
The computer includes:
acquiring a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the counterfeit prevention medium;
Converting the acquired spatial intensity distribution into a spatial frequency distribution;
Based on the transformed spatial frequency distribution, it is determined whether or not peaks of spatial frequency components in a frequency space are arranged on a line corresponding to the predetermined direction, thereby determining the authenticity of the object.
The authentication method to perform the process.

A method for determining authenticity of an object having a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a plurality of predetermined directions and diffracting incident light, the method comprising the steps of:
The computer includes:
acquiring a spatial intensity distribution of the diffracted light from a two-dimensional light receiving element that receives the diffracted light from the counterfeit prevention medium;
Converting the acquired spatial intensity distribution into a spatial frequency distribution;
Based on the transformed spatial frequency distribution, it is determined whether an angle formed by a plurality of directions in which the peaks of the spatial frequency components are arranged in the frequency space is a predetermined angle, thereby determining the authenticity of the object.
The authentication method to perform the process .

An authenticity determination device for determining the authenticity of an object provided with a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a predetermined direction that diffracts incident light,
an acquisition unit that acquires a spatial intensity distribution of diffracted light from a two-dimensional light receiving element that receives diffracted light from the counterfeit prevention medium;
a conversion processing unit that converts the acquired spatial intensity distribution into a spatial frequency distribution;
a determination unit that determines whether or not peaks of spatial frequency components in a frequency space are arranged on a line corresponding to the predetermined direction based on the transformed spatial frequency distribution, thereby determining the authenticity of the object;
and an output unit that outputs the determination result.

An authenticity determination device for determining the authenticity of an object provided with a counterfeit prevention medium including an optical diffraction structure having a periodic structure pattern in a plurality of predetermined directions that diffracts incident light, comprising:
an acquisition unit that acquires a spatial intensity distribution of diffracted light from a two-dimensional light receiving element that receives diffracted light from the counterfeit prevention medium;
a conversion processing unit that converts the acquired spatial intensity distribution into a spatial frequency distribution;
a determination unit that determines whether an angle formed by a plurality of directions in which peaks of spatial frequency components are arranged in a frequency space is a predetermined angle based on the transformed spatial frequency distribution, thereby determining the authenticity of the object;
An output unit that outputs the judgment result;
An authenticity determination device comprising: