JP2004212927A - Display body including concealed pattern by optical diffraction structure and its discrimination tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display body that includes a concealed pattern in which visual discrimination of the pattern is made extremely difficult, forgery preventing effect is made superior, and an optical diffraction structure is utilized and to provide its discrimination tool. <P>SOLUTION: The display surface 2 of the display body including an optical diffraction structure is constituted of a double structure having stripe pairs 6 of first and second linear stripes 6<SB>1</SB>and 6<SB>2</SB>which are adjacent to each other and parallel with each other and have different diffraction characteristics and a linear diffraction grating which constitutes the stripes 6<SB>1</SB>and 6<SB>2</SB>. The configuration of the linear diffraction grating is the same in a region 11<SB>2</SB>which constitutes a secret pattern "H" and a region 11<SB>1</SB>which is other than the region 11<SB>2</SB>and the configuration of the stripe pairs 6 is made different. Thus, normal display pattern is visually observed by the difference in configuration for every region of the linear diffraction grating and the concealed pattern is difficult to be visually observed. When the discrimination tool which generates moire phenomenon with the stripe pairs 6 is superimposed onto the display body, the normal display pattern is not observed, but the concealed pattern can be discriminated this time. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４６】
この表から明らかなように、この形態の表示面２においては、Ｘのパターンの領域２１_１１、２１_１２、２１_１３、２１_１４では、何れの縞対６の幅程度以上の微小部分において、第１回折格子７_１ （β_１ ＝０°）と第２回折格子７_２ （β_１ ＝４５°）とが同じ割合で含むものであり、通常の目視状態では同じ明るさで同じ色の一様領域に見える。同様に、Ｙのパターンの領域２１_２１、２１_２２、２１_２３、２１_２４、２１_２５でも、第１回折格子７_１ （β_１ ＝９０°）と第２回折格子７_２ （β_１ ＝１３５°）とが同じ割合で含むものであり、Ｘのパターンの領域とは異なるが、同じ明るさで同じ色の一様領域に見える。同様に、Ｚのパターンの領域２１_３１、２１_３２、２１_３３、２１_３４でも、第１回折格子７_１ （β_１ ＝２２．５°）と第２回折格子７_２ （β_１ ＝６７．５°）とが同じ割合で含むものであり、Ｘのパターンの領域、Ｙのパターンの領域とは異なるが、同じ明るさで同じ色の一様領域に見える。
【００４７】
これに対して、文字パターンＡを構成する領域２１_１２、２１_１３、２１_１４それぞれは、縞対６の傾き角αが隣接する領域２１_１１、とは異なり、領域２１_２２は、縞対６の傾き角αが隣接する領域２１_２１、２１_２３、２１_２４とは異なり、領域２１_３２は、縞対６の傾き角αが隣接する領域２１_３１、２１_３３、２１_３４とは異なるものの、縞対６の繰り返しピッチｄはｄ≦１／５ｍｍを満たすように設定されるので、判別具を用いない通常の目視状態では、図８（ａ）に示すように、中央部の上下に２分割された円パターン（上半円パターンＺと下半円パターンＹの組み合わせ）が背景の長方形から中央部円領域を除いたパターンＸ中に存在する表示パターンのみが観察され、隠し文字“Ａ”は判別不可能である。
【００４８】
そして、図７に平面図を示すような、平行な直線透明部９_１ と直線不透明部９_２ との繰り返しパターンであって、その繰り返しピッチが表示面２の縞対６の繰り返しピッチと同じｄを有し、直線透明部９_１ 、直線透明部９_２ の基準線Ｓに対する傾き角が、隠し文字パターンＡを構成する領域２１_１２、２１_１３、２１_１４、２１_２２、２１_３２の縞対６の傾き角と同じ４５°の判別具８を、図６の部分表示面２に近接あるいは密着して重ね合わせると、領域２１_１２、２１_１３、２１_１４、２１_２２、２１_３２ではモアレ現象により、第１縞６_１ 又は第２縞６_２ の何れか一方が直線透明部９_１ に略対応し、他方が直線不透明部９_２ に略対応することになる結果、略一方の回折格子７_１ 又は７_２ による回折光がその回折格子の回折方向に回折される。これに対して、それ以外の領域２１_１１、２１_２１、２１_２３、２１_２４、２１_２５、２１_３１、２１_３３、２１_３４では、直線透明部９_１ 、直線透明部９_２ の基傾き角がそれらの領域での縞対６の傾き角（１３５°）と大きく異なるので、何らモアレ現象が起きず、図３の場合と同様に、それぞれの領域では、領域２１_１２、２１_１３、２１_１４、２１_２２、２１_３２からの回折光の略半分の強度で回折光を回折することになる。その結果、図８（ｂ）に示すように、領域２１_１２、２１_１３、２１_１４、２１_２２、２１_３２がそれ以外の領域に比較して相対的により明るく観察され、この例では隠し文字“Ａ”が判別可能となる。
【００４９】
なお、この場合、文字パターンＡを構成する領域２１_１２、２１_１３、２１_１４と領域２１_２２と領域２１_３２間では、照明光源の位置により、若干明るさや色が相互に異なって見えるが、通常の目視環境では多くの光源や面光源が存在するので、この文字パターンＡ内での明るさや色の違いは、隠し文字“Ａ”を判別するのに邪魔となるものではない。
【００５０】
ところで、判別具を用いない通常の目視状態で判別可能なパターン（図６のＸ、Ｙ、Ｚのパターン）、隠しパターン（図３の文字“Ｈ”、図６の文字“Ａ”）共に、それぞれのパターンＰの周辺に、図９に示すように、そのパターンＰを構成する縞対６の周期に対して半周期ずれた周期の縞対で縁取りＰ’を形成することもできる。このような縁取りＰ’を施すことによって、判別困難な隠しパターンを判別具８を用いて判別する際に、判別しやすくし、判別可能なパターンに対してもその境界をより鮮明化する効果がある。
【００５１】
以上の説明では、隠しパターンの領域の縞対６の傾き角と、それ以外の領域６の縞対の傾き角との差は、９０°（直交）になるように設定していたが、隠し効果が変らない許容角度を含めた場合、９０°±１０°の範囲内に設定すればよい。
【００５２】
また、縞対６を構成する第１回折格子７_１ と第２回折格子７_２ は、傾き角が異なる（β_１ ≠β_２ ）か、その回折格子の格子ピッチが異なるかの少なくとも一方を満たすように選ぶものとしたが、その傾き角と格子ピッチの２つの要素を共に異ならせて構成することにより、隠しパターンの効果をより高めることができる。
【００５３】
また、以上において、判別具８は、平行な直線透明部９_１ と直線不透明部９_２ との繰り返しパターンであって、その繰り返しピッチが表示面２の縞対６の繰り返しピッチと同じｄを有し、直線透明部９_１ 、直線透明部９_２ の基準線Ｓに対する傾き角が、隠しパターンの領域の縞対６の傾き角と同じであればよいと説明したが、このような判別具８は、印刷物１０に対して決められた角度で近づけると、隠しパターンがモアレ現象により、判別具８を介して表示される。判別具８を介して表示された隠しパターンが所定のパターンであった場合に、その印刷物は正しい供給者から供給された正当な製品（真正品）であると判定される。
【００５４】
判別具８は、判別具８を透過して印刷物の隠しパターンに照射された光を観察者が目視できなければならないために、透明なベース基材に判別パターンが形成されているものを用いる。ベース基材は透明度が高い方が好ましい。また、判別具８は、頻繁に使用されるために、ベース基材を強固な枠材で固定したものが多く使用される。この枠材には取っ手等を付けることも可能で、そのことによって判別具８の透明なベース基材が指紋や油で汚れることを防止する。
【００５５】
隠しパターンの判別に際し、判別具８を、表示体１が形成された印刷物１０に密着させる程度に近づけて判別する。その密着の状態から一定の距離までは隠しパターンの判別が可能であるが、モアレ現象を利用しているために、表示体１と判別具８の距離が空きすぎると、判別が困難になる。
【００５６】
図１０を参照して、判別具８に付与する判別パターンの各種の他の形態について説明する。
【００５７】
透明基材の表面に形成された図１０（ａ）、（ｂ）、（ｃ），（ｄ）の判別パターンを表示体１の隠しパターンの表面に接近させ、隠しパターンによる判別画像を発生させる。
【００５８】
図１０（ａ）の場合は、水平線（基準線）に対して、直線透明部９_１ と直線着色部９_２ ’の傾き角が４５°の万線による判別パターンである。万線は、直線透明部９_１ と着色された直線部９_２ ’が対となった繰り返しパターンであり、透明な直線部９_１ の幅と、着色された直線部９_２ ’の幅は、同一でも、異なっていてもよい。ただし、その繰り返しピッチは表示面２の縞対６（特に、隠しパターンの縞対６）の繰り返しピッチと同じにする。
【００５９】
図１０（ｂ）は、水平線（基準線）に対して、直線透明部９_１ と直線着色部９_２ ’の傾き角が１３５°の万線による判別パターンである。その他は、図１０（ａ）の場合と同様。
【００６０】
図１０（ｃ）、水平線（基準線）に対して、格子１９の角度が４５°の回折格子を用いた判別パターンである。モアレ現象をある程度生起させるには、判別具８の判別パターンとして、方向性のあるものを用いればよい。この場合は、回折格子をそのような方向性のあるものとして用いてモアレ現象を起こさせる。
【００６１】
図１０（ｄ）、水平線（基準線）に対して、網点２９の整列方向の角度が１３５°の網点を用いた判別パターンである。この場合も、方向性のある網点を判別パターンに用いている。網点２９は、透明な部分と着色された部分が独立した点、又は、２箇所が鎖状に繋がった点で構成されており、透明な部分を繋ぐ（鎖状の）線と、着色された部分を繋ぐ（鎖状の）線が対になって形成されている。この対になった部分が１３５°の角度に形成されている。
【００６２】
ところで、判別具８として、図４や図７のように、平行な直線透明部９_１ と直線不透明部９_２ との繰り返しパターンからなる判別パターンを用いる場合に、図１１にその繰り返しパターンの一部を拡大して示すように、直線透明部９_１ の幅をａ、直線不透明部９_２ の幅をｂとするとき、ａ／ｂ≒１、すなわち、直線透明部９_１ と直線不透明部９_２ を略同じ幅としてもよいが、ａ／ｂは２／３〜１／４の範囲、すなわち、直線透明部９_１ の幅を直線不透明部９_２ の幅より小さく設定することが望ましい。その理由は、２／３≧ａ／ｂ≧１／４の範囲においては、判別具８を表示面２に近接あるいは密着して重ね合わせると、隠しパターン“Ｈ”、“Ａ”がコントラスト良く観察される。これに対して、ａ／ｂが２／３を越えると、判別具８を通して見える光量が多すぎて明るくなりすぎてコントラストが低下し、隠しパターンが見え難くなり、逆に、ａ／ｂが１／４を下回ると、その光量が少なすぎて暗くなって隠しパターンが見え難くなるためにである。
【００６３】
ところで、以上の説明において、表示体１の表示面２の光回折構造を構成する回折格子７_１ 、７_２ については、詳しく説明しなかった。通常、印刷物等に貼着して用いる表示面２に用いる回折格子としては、凹凸のレリーフ構造の回折格子のレリーフ面あるいは平面に蒸着等で金属反射膜を設けて反射型とした回折格子が用いられるが、それ以外に、振幅が周期的に変化する振幅型回折格子を構成するもの又は屈折率が周期的に変化して位相型回折格子を構成するものの裏面に金属反射膜を設けて反射型とした回折格子、体積型感光材料中に干渉縞で回折格子を構成した体積型回折格子等を用いてもよい。
【００６４】
もちろん、表示面２を反射型でなく透過型のもので構成し、回折格子も透過型の回折格子で構成してもよい。
【００６５】
さて、本発明による以上のような隠しパターンを含む部分表示面２を有する表示体１（又は、表示面２のみ）は、転写箔、ラベル、フィルム等種々の形態に構成することができる。転写箔形態の場合には、例えば商品券、クレジットカード、パッケージ等に適用でき、ラベル形態の場合には、例えばソフトウエア、カートリッジ、医薬品等のパッケージ等に適用でき、フィルム形態の場合には、例えばそのフィルムを１〜２ｍｍ程度の幅にマイクロスリットし、用紙の抄造時に紙中に共に抄き込んで偽造防止を図ることができる。また、ラベル形態の場合には、脆質層を層構成中に介在させて、偽造のためにラベルを剥離しようとしたときにその脆質層から剥がれるようにして偽造のために表示体を剥がすことを困難にすることができる（脆質ラベル）。以下、本発明の光回折構造による隠しパターンを内包する表示体を、転写箔、ラベル、脆質ラベル、フィルムの各形態に構成する場合の、層構成とその作製工程の例を説明する。
【００６６】
図１２は、本発明の光回折構造による隠しパターンを内包する表示体を転写箔３１として構成する場合の層構成を示す断面図であり、その作製方法に従ってその構成を説明すると、ＰＥＴ等の透明樹脂フィルムからなる基材４４上に剥離層４５を塗布し、その剥離層４５上に回折格子形成層４１を塗布し、回折格子形成層４１に凹凸レリーフ構造の回折格子原版をエンボスしてその凹凸レリーフ構造の回折格子を複製し、その複製されたレリーフ回折格子面上に反射層４２を蒸着することにより反射型の回折格子４３を形成し、その回折格子４３の反射層４２側にヒートシール層４６を塗布して、図１２のような層構成の転写箔３１を完成する。
【００６７】
ここで、基材４４を構成する樹脂フィルムとしては、ポリプロピレン樹脂フィルム、ポリカーボネート樹脂フィルム、若しくは、ポリエチレンテレフタレート樹脂フィルム等が好ましく、中でも、これらに加え、機械的強度の優れた２軸延伸ポリエチレンテレフタレート樹脂フィルムが適している。
【００６８】
また、剥離層４５を構成する樹脂は、基材４４の素材や、剥離層４５と接着する回折格子形成層４１の材質にもよるが、ポリエステル樹脂、アクリル骨格樹脂、塩化ビニル−酢酸ビニル共重合樹脂、酢酸セルロースと熱硬化型アクリル樹脂との２成分のブレンド樹脂、メラミン樹脂、若しくは、ニトロセルロース樹脂を使用することができる。例えば、基材４４がポリエチレンテレフタレート樹脂（ＰＥＴ）フィルムであるときは、剥離層４５と基材４４との密着力の点で、ポリエステル樹脂が好ましい。これらの樹脂には、さらにポリエチレンワックス等のワックス、若しくは、シリコーン樹脂を添加して剥離性を向上させてもよい。剥離層４５は、上記の樹脂を適宜な溶剤若しくは分散剤を用いて溶解若しくは分散させて、塗布若しくは印刷に適した組成物を調製したものを、公知の塗布方法若しくは印刷方法により、基材４４に積層形成することができる。
【００６９】
また、回折格子形成層４１を構成する合成樹脂としては、ポリ塩化ビニル、アクリル樹脂（例、ＰＭＭＡ）、ポリスチレン、ポリカーボネート等の熱可塑性樹脂、不飽和ポリエステル、メラミン、エポキシ、ポリエステル（メタ）アクリレート、ウレタン（メタ）アクリレート、エポキシ（メタ）アクリレート、ポリエーテル（メタ）アクリレート、ポリオール（メタ）アクリレート、メラミン（メタ）アクリレート、トリアジン系アクリレート等の熱硬化性樹脂をそれぞれ単独、あるいは、上記熱可塑性樹脂と熱硬化性樹脂とを混合して使用することができ、さらには、ラジカル重合性不飽和基を有する熱成形性物質、あるいは、これらにラジカル重合性不飽和単量体を加え電離放射線硬化性としたもの等を使用することができる。この他、銀塩、重クロム酸ゼラチン、サーモプラスチック、ジアゾ系感光材料、フォトレジスト、強誘電体、フォトクロミックス材料、サーモクロミックス材料、カルコゲンガラスなどの感光材料なども使用できる。
【００７０】
上記の合成樹脂からなる層への凹凸レリーフ構造の回折格子の形成は、上記の材料を用いて、従来既知の方法によって形成することができる。例えば、回折格子が凹凸の形で記録された原版をプレス型として用い、上記樹脂層上にその原版を重ねて加熱ロール等の適宜手段により、両者を加熱圧着することにより、原版の凹凸模様を複製することができる。あるいは、紫外線硬化性とした樹脂層上にその原版を重ねて、紫外線を照射してその樹脂層を硬化させて原版の凹凸模様を複製することができる。
【００７１】
反射層４２を構成する材質としては、Ｍｇ、Ａｌ、Ｔｉ、Ｃｒ、Ｃｕ、Ｚｎ、Ｇａ、Ｇｅ、Ｓｅ、Ｒｂ、Ｐｄ、Ａｇ、Ｃｄ、Ｉｎ、Ｓｎ、Ｓｂ、Ｔｅ、Ａｕ、Ｐｂ、若しくは、Ｂｉ等の金属、又は、それらの酸化物、若しくは、それらの窒化物を単独で、若しくは、組み合わせ、薄膜として形成する。金属薄膜層を反射層４２として用いるときには、これらの中でも、Ａｌ、Ｃｒ、Ｎｉ、Ａｇ、若しくは、Ａｕ等が特に好ましい。
【００７２】
反射層４２を形成するには、真空蒸着法、スパッタリング法、若しくは、イオンプレーティング法等の公知の薄膜形成法によって行う。
【００７３】
ヒートシール層４６を構成する材質としては、例えば、エチレン−酢酸ビニル共重合体樹脂、ポリアミド樹脂、ポリエステル樹脂、ポリエチレン樹脂、エチレン−イソブチルアクリレート共重合体樹脂、ブチラール樹脂、ポリ酢酸ビニル及びその共重合体樹脂、セルロース誘導体、ポリメチルメタクリレート樹脂、ポリビニルエーテル樹脂、ポリウレタン樹脂、ポリカーボネート樹脂、ポリプロピレン樹脂、エポキシ樹脂、又は、フェノール樹脂が使用できる。あるいは、ＳＢＳ（スチレン−ブタジエン−スチレンブロックコポリマー）、ＳＩＳ（スチレン−イソプレン−スチレンブロックコポリマー）、ＳＥＢＳ（スチレン−エチレン−ブチレン−スチレンブロックコポリマー）等の熱可塑性エラストマー、又は、反応ホットメルト性樹脂等を使用してもよい。
【００７４】
図１３は、本発明の光回折構造による隠しパターンを内包する表示体をラベル３２として構成する場合の層構成を示す断面図であり、その作製方法に従ってその構成を説明すると、ＰＥＴ等の透明樹脂フィルムからなる基材４４上に回折格子形成層４１を塗布し、回折格子形成層４１に凹凸レリーフ構造の回折格子原版をエンボスしてその凹凸レリーフ構造の回折格子を複製し、その複製されたレリーフ回折格子面上に反射層４２を蒸着することにより反射型の回折格子４３を形成し、その回折格子４３の反射層４２側に粘着層４７を塗布し、その粘着層４７上にその保護用としてセパレータ（剥離紙）４８をラミネートして、図１２のような層構成のラベル３２を完成する。
【００７５】
ここで、基材４４、回折格子形成層４１、反射層４２を構成する材質としては、図１２の場合と同様である。
【００７６】
粘着層４７を構成する接着剤としては、ポリ酢酸ビニル樹脂、ポリビニルアルコール、ポリビニルアセタール（ポリビニルホルマール、ポリビニルブチラール等）、シアノアクリレート、ポリビニルアルキルエーテル、ポリ塩化ビニル、ポリアミド、ポリメタクリル酸メチル、ニトロセルロース、酢酸セルロース、熱可塑性エポキシ、ポリスチレン、エチレン−酢酸ビニルコポリマー、エチレン−アクリル酸エチルコポリマー等、ユリア樹脂、メラミン樹脂、フェノール樹脂、レゾルシノール樹脂、フラン樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、ポリウレタン樹脂、ポリイミド、ポリアミドイミド、ポリベンツイミダゾール、ポリベンゾチアゾール等、あるいは、ゴム系の天然ゴム、再生ゴム、スチレン−ブタジエンゴム、アクリロニトリル−ブタジエンゴム、クロロプレンゴム、ブチルゴム、ポリスルフィドゴム、シリコーンゴム、ポリウレタンゴム、ステレオゴム（合成天然ゴム）、エチレンプロピレンゴム、ブロックコポリマーゴム（ＳＢＳ，ＳＩＳ，ＳＥＢＳ等）が使用できる。
【００７７】
また、セパレータ（剥離紙）４８としては、従来公知の紙やフィルム基材に剥離処理を施したものが使用できる。
【００７８】
図１４は、本発明の光回折構造による隠しパターンを内包する表示体を脆質ラベル３３として構成する場合の層構成を示す断面図であり、その作製方法に従ってその構成を説明すると、ＰＥＴ等の透明樹脂フィルムからなる基材４４上に脆質層４９を塗布し、その脆質層４９上に回折格子形成層４１を塗布し、回折格子形成層４１に凹凸レリーフ構造の回折格子原版をエンボスしてその凹凸レリーフ構造の回折格子を複製し、その複製されたレリーフ回折格子面上に反射層４２を蒸着することにより反射型の回折格子４３を形成し、その回折格子４３の反射層４２側に粘着層４７を塗布し、その粘着層４７上にセパレータ（剥離紙）４８をラミネートして、図１２のような層構成の脆質ラベル３３を完成する。
【００７９】
ここで、基材４４、回折格子形成層４１、反射層４２、粘着層４７、セパレータ（剥離紙）４８を構成する材質としては、図１３の場合と同様である。
【００８０】
脆質層４９を構成する材料としては、図１２の場合の剥離層４５を構成する樹脂と同じ系列のものが用いられる。
【００８１】
図１５は、本発明の光回折構造による隠しパターンを内包する表示体をフィルム３４として構成する場合の層構成を示す断面図であり、その作製方法に従ってその構成を説明すると、ＰＥＴ等の透明樹脂フィルムからなる基材４４上に回折格子形成層４１を塗布し、回折格子形成層４１に凹凸レリーフ構造の回折格子原版をエンボスしてその凹凸レリーフ構造の回折格子を複製し、その複製されたレリーフ回折格子面上に反射層４２を蒸着することにより反射型の回折格子４３を形成して、図１４のような層構成のフィルム３４が完成する。
【００８２】
ここで、基材４４、回折格子形成層４１、反射層４２を構成する材質としては、図１２〜図１４の場合と同様である。
【００８３】
ここで、図１２〜図１５において、回折格子形成層４１に凹凸レリーフ構造の回折格子をエンボスするための回折格子原版の作製方法の例を簡単に説明しておく。そのためには、Ｃｒメッキされたガラス板を用意し、その上に電子線レジストを塗布し、電子線描画により、回折格子パターンを描画し、その後に電子線レジストを現像することにより、断面矩形波状の凹凸レリーフ構造が得られる。
【００８４】
そのような電子線レジストの凹凸レリーフ構造の回折格子パターン上に紫外線硬化性樹脂あるいは熱硬化性樹脂を塗布して紫外線照射あるいは加熱により、その凹凸レリーフ構造を紫外線硬化性樹脂あるいは熱硬化性樹脂に複製することにより、電子線描画の回折格子パターンのネガ版が得られる。そのネガ版から同様に複製してポジ版を得るか、あるいは、このような複製を偶数回繰り返すことにより得られたポジ版を、上記の回折格子形成層４１に凹凸レリーフ構造の回折格子をエンボスするための回折格子原版として用いることができる。
【００８５】
以上、本発明の光回折構造による隠しパターンを内包する表示体及びそのための判別具をいくつかの実施例に基づいて説明してきたが、本発明はこれら実施例に限定されず種々の変形が可能である。
【００８６】
【発明の効果】
以上の説明から明らかなように、本発明の光回折構造による隠しパターンを内包する表示体及びそのための判別具によると、光回折構造を含む表示体の表示面を、相互に隣接していて平行で、回折特性の異なる第１直線縞と第２直線縞の縞対と、それら直線縞を構成する直線回折格子との二重構造で構成し、隠しパターンを構成する領域とそれ以外の領域では直線回折格子の構成は同じで、縞対の構成を異なるものとすることにより、目視状態では直線回折格子の領域毎の構成の違いによって通常の表示パターンが観察でき、隠しパターンは判別困難であるが、上記の縞対とモアレ現象を生じる本発明による判別具を重ね合わせることで、今度は通常の表示パターンではなく隠しパターンが判別可能となる。そのため、目視による判別が極めて困難な隠しパターンを含み、偽造防止効果が大きく、デザイン性の高い表示体を得ることができる。
【図面の簡単な説明】
【図１】本発明による隠しパターンを有する光回折構造を転写した印刷物の一例について説明するための図である。
【図２】本発明において部分表示面中の均一な特性及び構成を有する表示単位領域の基本構成を説明するための図である。
【図３】本発明による第１形態の光回折構造による隠しパターンを含む部分表示面の拡大図である。
【図４】図３の部分表示面の隠しパターンを判別するための判別具の一例の平面図である。
【図５】図３の部分表示面から判別される隠しパターンを示す図である。
【図６】本発明による第２形態の光回折構造による隠しパターンを含む部分表示面の拡大図である。
【図７】図６の部分表示面の隠しパターンを判別するための判別具の一例の平面図である。
【図８】図３の部分表示面の目視状態で観察される表示パターンと、図７の判別具を用いて判別される隠しパターンとを示す図である。
【図９】本発明に基づいて各パターンの周辺に設ける縁取りを説明するための図である。
【図１０】判別具に付与する判別パターンの各種の他の形態について説明するための図である。
【図１１】平行な直線透明部と直線不透明部との繰り返しパターンからなる判別パターンの幅関係を説明するための図である。
【図１２】本発明の光回折構造による隠しパターンを内包する表示体を転写箔として構成する場合の層構成を示す断面図である。
【図１３】本発明の光回折構造による隠しパターンを内包する表示体をラベルとして構成する場合の層構成を示す断面図である。
【図１４】本発明の光回折構造による隠しパターンを内包する表示体を脆質ラベルとして構成する場合の層構成を示す断面図である。
【図１５】本発明の光回折構造による隠しパターンを内包する表示体をフィルムとして構成する場合の層構成を示す断面図である。
【符号の説明】
Ｓ…基準線
Ｘ、Ｙ、Ｚ…パターン
Ｐ…パターン
Ｐ’…縁取り
１…隠しパターンを内包する表示体
２…隠しパターンを含む部分表示面
３…その他の部分表示面
５…表示単位領域
６…縞対
６_１ …第１直線縞
６_２ …第２直線縞
７_１ …第１直線回折格子
７_２ …第２直線回折格子
８…判別具
９_１ …直線透明部
９_２ …直線透明部
９_２ ’…直線着色部
１０…印刷物
１１_１ 、１１_２ …領域
１９…格子
２１_１１、２１_１２、２１_１３、２１_１４…パターンＸを構成する領域
２１_２１、２１_２２、２１_２３、２１_２４、２１_２５…パターンＹを構成する領域
２１_３１、２１_３２、２１_３３、２１_３４…パターンＺを構成する領域
２９…網点
３１…転写箔
３２…ラベル
３３…脆質ラベル
３４…フィルム
４１…回折格子形成層
４２…反射層
４３…反射型の回折格子
４４…基材
４５…剥離層
４６…ヒートシール層
４７…粘着層
４８…セパレータ（剥離紙）
４９…脆質層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hidden pattern by a light diffraction structure and a discriminating tool therefor, and more particularly, to a hidden pattern by a light diffraction structure that is difficult to discriminate in a normal visual recognition state and a discriminating tool therefor.
[0002]
[Prior art]
2. Description of the Related Art In recent years, cases of counterfeiting of high-value bills and gift certificates with a color copier have frequently occurred. For this reason, high-value bills and gift certificates incorporate small dots and fine lines, which cannot be read by a sensor of a color copier, in a pattern designed with the same reflection density in a part of the design. As a result, when trying to copy these high-value banknotes and gift certificates with a color copier, the scanner of the copier reads small dots and thin lines, and the portions are white and discriminated as copy products. .
[0003]
In addition, a method of discriminating a copy product by providing a shining metal portion in a part of the design of a printed material has been implemented.
[0004]
Such a metal portion reflects 100% of the incident light, so that the copy machine reproduces the portion in black. As an embodiment, for example, a gold thread is sewn on a surface layer of paper to perform a copy check.
[0005]
In addition, a metal deposition process is performed on the uneven surface of the optical diffraction structure duplicated with a transparent resin, and heat transfer is performed to a part of a printing area, thereby preventing copying by a copying machine. The light diffractive structure is used as a means for preventing counterfeiting of a thermally transferred printed matter or the product itself, while trying to suppress improper copying by the reflection effect of the metal surface. The light diffraction structure is often used as a means for preventing forgery of cash vouchers and the like because of the need for advanced manufacturing technology.
[0006]
However, with the improvement of the manufacturing technology, it has become possible to manufacture an optical diffraction structure that is close to the real thing at first glance.
[0007]
In order to check for such counterfeit products, there has been proposed a technique of incorporating a difficult-to-discriminate hidden pattern in an optical diffraction structure and using it as a means of authenticity discrimination. There is a problem of being discriminated, and since other patterns are not formed in the portion where the hidden pattern is formed, it is assumed that a hidden pattern may be present, resulting in a problem of reducing the forgery prevention effect. there were.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of such a problem of the related art, and an object of the present invention is to provide a display body including a hidden pattern formed by a light diffraction structure that is extremely difficult to visually discriminate and has a large anti-counterfeit effect, and Is provided.
[0009]
[Means for Solving the Problems]
The display body including the hidden pattern by the light diffraction structure of the present invention to achieve the above object is a display body including the light diffraction structure, and its display surface has a different diffraction characteristic and an arbitrary outer shape according to the display pattern. And a plurality of pattern regions having an inner shape are arranged in parallel, and each pattern region is adjacent to each other and parallel, and is filled by repeating a pair of first and second linear fringes having different diffraction characteristics. The first linear stripes are formed by a first linear diffraction grating, and the second linear stripes are formed by a second linear diffraction grating. On the other hand, the inclination angle of the first linear fringe and the second linear fringe is the inclination angle α of the fringe pair, and the inclination angle of the first linear diffraction grating is the inclination angle β of the first linear diffraction grating. ₁ , The inclination angle of the second linear diffraction grating to the inclination angle β of the second linear diffraction grating. ₂ In this case, the inclination angle α of the stripe pair of the pattern region forming at least one hidden pattern in the plurality of pattern regions is set to be different from the inclination angle α of the stripe pair of the other pattern regions. And the inclination angle β of the first linear diffraction grating in the pattern area constituting the hidden pattern ₁ And the inclination angle β of the second linear diffraction grating ₂ Is the inclination angle β of the first linear diffraction grating in the pattern area other than the pattern area constituting the hidden pattern adjacent to the pattern area. ₁ And the inclination angle β of the second linear diffraction grating ₂ Are set to be equal to each other.
[0010]
In this case, the pattern area constituting the hidden pattern is composed of one or more isolated pattern areas, and the inclination angle β of the first linear diffraction grating of the pattern area constituting the hidden pattern ₁ And the inclination angle β of the second linear diffraction grating ₂ Is the inclination angle β of the first linear diffraction grating in the other pattern area. ₁ And the inclination angle β of the second linear diffraction grating ₂ , Respectively.
[0011]
Alternatively, the pattern region constituting the hidden pattern includes a plurality of pattern regions adjacent to each other, the inclination angle α of the stripe pair of the plurality of mutually adjacent pattern regions constituting the hidden pattern is set to be the same, It is set to be different from the inclination angle α of the stripe pairs of the other pattern regions adjacent to the plurality of mutually adjacent pattern regions constituting the hidden pattern, and adjacent to each other constituting the hidden pattern. Angle β of the first linear diffraction grating of each of the plurality of pattern regions ₁ And the inclination angle β of the second linear diffraction grating ₂ Means the inclination angle β of the first linear diffraction grating in a pattern area other than a plurality of mutually adjacent pattern areas constituting the hidden pattern adjacent to the pattern area. ₁ And the inclination angle β of the second linear diffraction grating ₂ , Respectively.
[0012]
Further, the first linear diffraction grating and the second linear diffraction grating in each of the plurality of pattern regions arranged adjacent to each other in parallel may be configured to satisfy at least one of a different inclination angle or a different grating pitch. It is desirable that it is set.
[0013]
In addition, when the repetition pitch of the stripe pairs in each of the plurality of pattern regions arranged adjacent to each other in parallel is d, it is preferable that d ≦ １ ／ mm.
[0014]
In addition, it is desirable that the difference between the inclination angle α of the stripe pairs in the pattern area constituting the hidden pattern and the inclination angle α of the stripe pairs in the other pattern areas be set within a range of 90 ° ± 10 °. .
[0015]
In addition, it is preferable that the pattern region forming the at least one hidden pattern is bordered by a stripe pair having a period shifted by a half period with respect to the period of the stripe pair forming the pattern region.
[0016]
In addition, it is preferable that the first linear diffraction grating and the second linear diffraction grating are reflection type diffraction gratings.
[0017]
Further, the display body including the hidden pattern by the light diffraction structure of the present invention can be configured in a transfer foil form, a label form, or a film form.
[0018]
The present invention is a discriminating tool for a display body including a hidden pattern by any of the above light diffraction structures, and is a repetitive pattern of a parallel linear transparent portion and a linear opaque portion, A discriminator having a pattern having the same inclination angle and the same repetition pitch as a stripe pair of a pattern area constituting at least one hidden pattern in the plurality of pattern areas;
[0019]
In this case, it is desirable that the width of the straight transparent portion is set smaller than the width of the straight opaque portion.
[0020]
In the present invention, the display surfaces of the display body including the light diffraction structure are formed of a pair of first and second linear fringes that are adjacent to each other and parallel to each other and have different diffraction characteristics, and constitute the linear fringes. It is composed of a double structure with a linear diffraction grating, and the configuration of the linear diffraction grating is the same in the region forming the hidden pattern and the other region. The normal display pattern can be observed due to the difference in the configuration of each lattice area, and the hidden pattern is difficult to discriminate.However, by superimposing the above-mentioned stripe pair and the discriminator that causes the moire phenomenon, this time the normal display pattern And a hidden pattern can be determined. Therefore, it is possible to obtain a display body that includes a hidden pattern that is extremely difficult to visually discriminate, has a large forgery prevention effect, and has high designability.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a hidden pattern by the light diffraction structure of the present invention and a discriminating tool therefor will be described with reference to the drawings.
[0022]
FIG. 1 is a view for explaining an example of a printed material on which a light diffraction structure having a hidden pattern according to the present invention is transferred, as one embodiment of the present invention. A display body 1 containing a hidden pattern for preventing forgery or copying is formed at a predetermined position on a printed material 10. In this case, the display body 1 is formed such that an extremely thin resin having projections and depressions is blown to a predetermined size by heat, and is formed on a printed material 10 such as paper as a label by a heat-reactive adhesive.
[0023]
Alternatively, it is punched into a predetermined size in a state where the light diffraction structure is formed on the base film, and is formed on the printed material 10 with an adhesive or an adhesive together with the base film.
[0024]
In many cases, printed matter on which such a display body 1 is formed is difficult to be forged or copied, and includes, for example, bills, gift certificates, entrance tickets, gift certificates, bills, checks, and the like. In addition, the printing itself includes a technique that cannot be duplicated without a special technique, and is double-protected against counterfeiting and misuse by copying.
[0025]
The display surface 1 is composed of a partial display surface 2 including a hidden pattern and another partial display surface 3. Even if both the partial display surface 2 and the partial display surface 3 are a display surface formed by an optical diffraction structure, the display surface 1 has a hidden pattern. May be a display surface based on the light diffraction structure, and the other partial display surfaces 3 may be display surfaces not based on the light diffraction structure such as printing. Of course, the display surface 3 may consist of only the partial display surface 2 including the hidden pattern by the light diffraction structure.
[0026]
Here, in the present invention, a basic configuration of a display unit region having uniform characteristics and configuration in the partial display surface 2 will be described with reference to FIG. Such display unit areas are arranged in parallel to form the partial display surface 2.
[0027]
In FIG. 2, a display unit area 5 constitutes an arbitrary external and internal pattern area corresponding to a display pattern, and the pattern areas are adjacent to each other, are parallel, and have first linear stripes having different diffraction characteristics. 6 ₁ And the second straight stripe 6 ₂ Of the first straight stripe 6 ₁ Is the first linear diffraction grating 7 ₁ And the second linear stripe 6 ₂ Is the second linear diffraction grating 7 ₂ It is constituted by. And the first straight stripe 6 ₁ , The second straight stripe 6 ₂ Is the angle of inclination of the first linear diffraction grating 7 with respect to the reference line S. ₁ Is the angle of inclination of the ₁ The second linear diffraction grating 7 ₂ Is the angle of inclination of the ₂ And Here, as the reference line S, for example, a direction recognized as being horizontal with respect to the display pattern on the display surface 2, for example, a straight line parallel to the long side direction of the display surface 2 is used. The diffraction grating 7 ₁ , 7 ₂ Is the angle of the grid line with respect to the reference line S.
[0028]
Here, when the repetition pitch of the stripe pairs 6 is d, d ≦ ｄ mm is set, and the first linear diffraction grating 7 ₁ And the second linear diffraction grating 7 ₂ Is different from the inclination angle (β ₁ ≠ β ₂ ) Or the grating pitch of the diffraction gratings is different. The first linear diffraction grating 7 ₁ The second linear diffraction grating 7 ₂ Is naturally set to be sufficiently smaller than the repetition pitch d of the stripe pairs 6. Usually, diffraction grating 7 ₁ , 7 ₂ Is used in the range of 0.5 μm to 2 μm. Also, the first linear diffraction grating 7 ₁ And the second linear diffraction grating 7 ₂ Difference of inclination angle with ₁ −β ₂ | Is preferably, but not limited to, set in the range of 30 ° to 90 °.
[0029]
As described above, the display unit region 5 configured by parallel-assembling the partial display surfaces 2 including the hidden pattern by the light diffraction structure according to the present invention includes the linear diffraction grating 7. ₁ , 7 ₂ And first linear fringes 6 constituted by the linear diffraction gratings. ₁ , The second straight stripe 6 ₂ Has a double structure with the stripe pair 6 of FIG.
[0030]
In the following description, the first linear stripe 6 ₁ , The second straight stripe 6 ₂ , First linear diffraction grating 7 ₁ The second linear diffraction grating 7 ₂ The first fringe 6 is omitted when it is not necessary. ₁ , Second stripe 6 ₂ , First diffraction grating 7 ₁ The second diffraction grating 7 ₂ Call.
[0031]
FIG. 3 is an enlarged view of the partial display surface 2 including a hidden pattern formed by the first embodiment of the light diffraction structure according to the present invention. ₁ And the second stripe 6 ₂ First diffraction grating 7 constituting ₁ And second diffraction grating 7 ₂ Is also drawn out and shown sideways.
[0032]
On the display surface 2, the display pattern is a region “11” of the character “H” ₂ And a region 11 excluding the character "H" in the center of the background ₁ Consists of Here, the character "H" is configured as a hidden pattern.
[0033]
Here, the area 11 ₁ The first stripe 6 constituting ₁ , Second stripe 6 ₂ The inclination angle α of (striped pair 6) is selected to be, for example, 45 °, and ₂ The first stripe 6 constituting ₁ , Second stripe 6 ₂ The inclination angle α of (stripes 6) is selected to be, for example, 135 °. In the repetition pitch d of the stripe pairs 6, the region 11 ₁ , Area 11 ₂ Both are set the same.
[0034]
However, it is important to note that region 11 ₁ , Area 11 ₂ In each case, the first stripe 6 ₁ First diffraction grating 7 constituting ₁ (FIG. 2) inclination angle β ₁ Is selected to be, for example, 0 ° as shown in FIG. ₂ The second diffraction grating 7 constituting ₂ Angle of inclination β ₂ Is selected, for example, at 45 °.
[0035]
That is, in the display surface 2 of this embodiment, the tilt angle β in any area of the display surface 2 in a minute portion that is equal to or more than the width of the stripe pair 6. ₁ = 0 ° first diffraction grating 7 ₁ And the inclination angle β ₂ = 45 ° second diffraction grating 7 ₂ Are included in the same ratio, and the area 11 ₁ And area 11 ₂ However, although the inclination angle α of the stripe pairs 6 is different, since the repetition pitch d of the stripe pairs 6 is set so as to satisfy d ≦ 、 mm, they cannot be distinguished from each other in a normal visual state. Therefore, in a normal visual state not using a discriminator described later, the entire display surface 2 is observed without any display pattern of uniform brightness, and the hidden character “H” cannot be discriminated.
[0036]
Here, as shown in the plan view of FIG. ₁ And straight opaque part 9 ₂ And the repetition pitch thereof has the same d as the repetition pitch of the stripe pairs 6 on the display surface 2. ₁ , Straight transparent part 9 ₂ Of the hidden pattern with respect to the reference line S ₂ When the discriminator 8 having the same angle of 135 ° as the inclination angle of the stripe pair 6 is placed close to or in close contact with the partial display surface 2 in FIG. ₂ Then, due to the moire phenomenon, the first stripe 6 ₁ Or the second stripe 6 ₂ Either of them is a linear transparent part 9 ₁ And the other is a straight opaque portion 9 ₂ Substantially corresponds to the diffraction grating 7 ₁ Or 7 ₂ Is diffracted in the diffraction direction of the diffraction grating. In contrast, area 11 ₁ In this case, since the inclination angle (45 °) of the stripe pair 6 is greatly different, no moire phenomenon occurs and the region 11 ₂ Straight opaque part 9 ₂ Diffraction grating 7 having the same inclination angle as diffraction grating not hidden by ₁ Or 7 ₂ Is a straight transparent part 9 ₁ , And is diffracted in the same direction with substantially half the diffraction intensity. As a result, as shown in FIG. ₂ Are relatively brighter, and area 11 ₁ Are observed relatively darker, and in this example, the hidden character “H” can be distinguished.
[0037]
Next, FIG. 6 is an enlarged view of the partial display surface 2 including a hidden pattern by the light diffraction structure of the second embodiment according to the present invention. In FIG. 6, the first stripe 6 in each region is shown. ₁ And the second stripe 6 ₂ First diffraction grating 7 constituting ₁ And second diffraction grating 7 ₂ Is also drawn out and shown sideways.
[0038]
On the display surface 2, the display pattern includes a circular pattern (an upper semicircular pattern and a lower semicircular pattern) which is divided into upper and lower portions of a central portion, and a pattern obtained by removing a central circular region from a rectangle of the background. , And the letter “A” superimposed on them. Here, the character "A" is configured as a hidden pattern.
[0039]
The regions arranged in parallel on the display surface 2 are as follows.
○ Pattern (X) excluding the central circle area from the rectangle:
Area 21 ₁₁ : A region excluding the central circle region, the top of the letter “A”, and the two toe tips from the rectangle
Area 21 ₁₂ : Area outside the central circle area at the top of the letter “A”
Area 21 _Thirteen , 21 ₁₄ : Area outside the center circle area at the tip of the two feet of the letter “A”
○ Lower half circle pattern (Y) at the center:
Area 21 ₂₁ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ : An area that does not overlap with the letter “A” in the lower semicircular pattern area at the center
Area 21 ₂₂ : Area of character "A" in the lower half-circle pattern area at the center
○ Central upper semicircular pattern area (Z):
Area 21 ₃₁ , 21 ₃₃ , 21 ₃₄ : Area that does not overlap with the letter “A” in the upper semicircular pattern area in the center
Area 21 ₃₂ : The area of the character "A" in the upper half circle pattern area at the center
It is.
[0040]
That is, the three patterns of X, Y, and Z are arranged in parallel to form the display surface 2, and the X pattern corresponds to the region 21. ₁₁ , 21 ₁₂ , 21 _Thirteen , 21 ₁₄ Are arranged in parallel, and the pattern of Y is ₂₁ , 21 ₂₂ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ Are formed in parallel, and the pattern of Z is ₃₁ , 21 ₃₂ , 21 ₃₃ , 21 ₃₄ Are configured in parallel.
[0041]
On the other hand, the hidden pattern character “A” (character pattern A) ₁₁ ~ 21 ₃₄ Area 21 in ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ Are configured in parallel. Region 21 in these regions ₁₂ , 21 _Thirteen , 21 ₁₄ Is also a region of the X pattern, and is a region 21 ₂₂ Is also the area of the Y pattern, and the area 21 ₃₂ Also serves as the area of the Z pattern.
[0042]
Then, the area 21 constituting the character pattern A ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ Has the first stripe 6 ₁ , Second stripe 6 ₂ For example, 45 ° is selected as the inclination angle α of the (striped pair 6), and the other region 21 is selected. ₁₁ , 21 ₂₁ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ , 21 ₃₁ , 21 ₃₃ , 21 ₃₄ Has the first stripe 6 ₁ , Second stripe 6 ₂ As the inclination angle α of (striped pair 6), for example, 135 ° is selected. Note that the same pitch is set in all regions at the repetition pitch d of the stripe pairs 6.
[0043]
Diffraction grating 7 ₁ , 7 ₂ Angle of inclination β ₁ , Β ₂ As for FIG. 2, as shown in FIG. 6, for example, as shown in FIG. ₁₁ , 21 ₁₂ , 21 _Thirteen , 21 ₁₄ Now, the region 21 of the 0 °, 45 °, and Y patterns ₂₁ , 21 ₂₂ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ Then, 90 ° and 135 °, Z pattern area 21 ₃₁ , 21 ₃₂ , 21 ₃₃ , 21 ₃₄ In this case, 22.5 ° and 67.5 ° are selected.
[0044]
The inclination angle α of the stripe pair 6 corresponding to each of the above regions and the diffraction grating 7 ₁ , 7 ₂ Angle of inclination β ₁ , Β ₂ Is shown in the following table.
[0045]

[0046]
As is clear from this table, on the display surface 2 in this mode, the area 21 of the X pattern ₁₁ , 21 ₁₂ , 21 _Thirteen , 21 ₁₄ Then, the first diffraction grating 7 is formed in a minute portion having a width of about ₁ (Β ₁ = 0 °) and the second diffraction grating 7 ₂ (Β ₁ = 45 °) in the same ratio, and in a normal visual state, they appear as a uniform area of the same color with the same brightness. Similarly, the area 21 of the Y pattern ₂₁ , 21 ₂₂ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ However, the first diffraction grating 7 ₁ (Β ₁ = 90 °) and the second diffraction grating 7 ₂ (Β ₁ = 135 °) at the same ratio, and is different from the X pattern area, but looks like a uniform area of the same color with the same brightness. Similarly, the area 21 of the Z pattern ₃₁ , 21 ₃₂ , 21 ₃₃ , 21 ₃₄ However, the first diffraction grating 7 ₁ (Β ₁ = 22.5 °) and the second diffraction grating 7 ₂ (Β ₁ = 67.5 °) in the same ratio, and are different from the X pattern area and the Y pattern area, but appear as uniform areas of the same brightness and the same color.
[0047]
On the other hand, the area 21 forming the character pattern A ₁₂ , 21 _Thirteen , 21 ₁₄ In each of the regions 21 where the inclination angle α of the stripe pair 6 is adjacent. ₁₁ , Unlike area 21 ₂₂ Is a region 21 where the inclination angle α of the stripe pair 6 is adjacent. ₂₁ , 21 ₂₃ , 21 ₂₄ Unlike region 21 ₃₂ Is a region 21 where the inclination angle α of the stripe pair 6 is adjacent. ₃₁ , 21 ₃₃ , 21 ₃₄ However, since the repetition pitch d of the stripe pairs 6 is set so as to satisfy d ≦ １ ／ mm, in a normal visual state without using a discriminator, as shown in FIG. A display pattern in which a circular pattern (combination of an upper semicircular pattern Z and a lower semicircular pattern Y) divided into two parts above and below is present only in a pattern X that is obtained by removing a central circular area from a background rectangle is observed and hidden. The letter "A" is indistinguishable.
[0048]
Then, a parallel linear transparent portion 9 as shown in a plan view in FIG. ₁ And straight opaque part 9 ₂ And the repetition pitch thereof has the same d as the repetition pitch of the stripe pairs 6 on the display surface 2. ₁ , Straight transparent part 9 ₂ The angle of inclination of the region 21 with respect to the reference line S constitutes the hidden character pattern A. ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ When the discriminator 8 having the same inclination angle of 45 ° as the stripe angle of the stripe pair 6 is superimposed close to or in close contact with the partial display surface 2 in FIG. ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ Then, due to the moire phenomenon, the first stripe 6 ₁ Or the second stripe 6 ₂ Either of them is a linear transparent part 9 ₁ And the other is a straight opaque portion 9 ₂ Substantially corresponds to the diffraction grating 7 ₁ Or 7 ₂ Is diffracted in the diffraction direction of the diffraction grating. On the other hand, the other area 21 ₁₁ , 21 ₂₁ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ , 21 ₃₁ , 21 ₃₃ , 21 ₃₄ Then, the straight transparent part 9 ₁ , Straight transparent part 9 ₂ Is significantly different from the inclination angle (135 °) of the stripe pair 6 in those regions, no moiré phenomenon occurs, and as in the case of FIG. ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ Will be diffracted at approximately half the intensity of the diffracted light from. As a result, as shown in FIG. ₁₂ , 21 _Thirteen , 21 ₁₄ , 21 ₂₂ , 21 ₃₂ Are observed to be relatively brighter than the other areas, and in this example, the hidden character “A” can be distinguished.
[0049]
In this case, the area 21 forming the character pattern A ₁₂ , 21 _Thirteen , 21 ₁₄ And area 21 ₂₂ And area 21 ₃₂ Although the brightness and the color look slightly different depending on the position of the illumination light source, there are many light sources and surface light sources in a normal visual environment, so the difference in the brightness and color in the character pattern A is It does not hinder the determination of the hidden character "A".
[0050]
By the way, both the pattern (X, Y, and Z patterns in FIG. 6) and the hidden pattern (character “H” in FIG. 3 and character “A” in FIG. 6) that can be discriminated in a normal visual state without using a discriminator, As shown in FIG. 9, a border P ′ can be formed around each pattern P with a stripe pair having a period shifted by a half period with respect to the period of the stripe pair 6 constituting the pattern P. By applying such a border P ′, it is possible to easily distinguish a hidden pattern that is difficult to distinguish using the distinguishing tool 8 and to make the boundary of a distinguishable pattern clearer. is there.
[0051]
In the above description, the difference between the inclination angle of the stripe pair 6 in the region of the hidden pattern and the inclination angle of the stripe pair in the other region 6 is set to be 90 ° (orthogonal). When the allowable angle at which the effect does not change is included, the angle may be set within a range of 90 ° ± 10 °.
[0052]
Also, the first diffraction grating 7 forming the stripe pair 6 ₁ And second diffraction grating 7 ₂ Have different inclination angles (β ₁ ≠ β ₂ ) Or the grating pitch of the diffraction grating is different. However, the effect of the hidden pattern can be reduced by configuring the two elements of the inclination angle and the grating pitch to be different from each other. Can be more enhanced.
[0053]
Further, in the above, the discriminating tool 8 includes the parallel linear transparent portion 9. ₁ And straight opaque part 9 ₂ And the repetition pitch thereof has the same d as the repetition pitch of the stripe pairs 6 on the display surface 2. ₁ , Straight transparent part 9 ₂ Has been described as long as the angle of inclination with respect to the reference line S is the same as the angle of inclination of the stripe pair 6 in the area of the hidden pattern, but such a discriminator 8 approaches the printed matter 10 at a predetermined angle. Then, the hidden pattern is displayed via the discriminator 8 by the moire phenomenon. When the hidden pattern displayed via the determination tool 8 is a predetermined pattern, the printed matter is determined to be a legitimate product (genuine product) supplied from a correct supplier.
[0054]
The discriminating tool 8 uses a discriminating pattern formed on a transparent base material because the observer must be able to see the light transmitted through the discriminating tool 8 and applied to the hidden pattern of the printed matter. The base substrate preferably has a high degree of transparency. Further, since the discriminating tool 8 is frequently used, the discriminating tool 8 in which a base material is fixed with a strong frame material is often used. A handle or the like can be attached to this frame material, thereby preventing the transparent base material of the discrimination tool 8 from being stained with fingerprints or oil.
[0055]
When the hidden pattern is determined, the determination tool 8 is determined by bringing the determination tool 8 close to the printed matter 10 on which the display 1 is formed. The hidden pattern can be discriminated up to a certain distance from the state of close contact. However, if the distance between the display 1 and the discriminator 8 is too large, the discrimination becomes difficult because the moiré phenomenon is used.
[0056]
With reference to FIG. 10, various other forms of the discrimination pattern provided to the discrimination tool 8 will be described.
[0057]
The discrimination patterns of FIGS. 10A, 10B, 10C, and 10D formed on the surface of the transparent base material are brought close to the surface of the hidden pattern of the display 1 to generate a discriminated image based on the hidden pattern. .
[0058]
In the case of FIG. 10A, the straight transparent portion 9 is set with respect to the horizontal line (reference line). ₁ And linear coloring section 9 ₂ This is a discrimination pattern based on a line having an inclination angle of 45 °. The line is a straight transparent part 9 ₁ And colored straight section 9 ₂ 'Is a paired repetition pattern, and the transparent linear portion 9 ₁ Width and the colored linear portion 9 ₂ 'May be the same or different. However, the repetition pitch is the same as the repetition pitch of the stripe pair 6 on the display surface 2 (particularly, the stripe pair 6 of the hidden pattern).
[0059]
FIG. 10 (b) shows a straight line transparent portion 9 with respect to a horizontal line (reference line). ₁ And linear coloring section 9 ₂ Is a discrimination pattern based on a line having an inclination angle of 135 °. Others are the same as in the case of FIG.
[0060]
FIG. 10C shows a discrimination pattern using a diffraction grating in which the angle of the grating 19 is 45 ° with respect to the horizontal line (reference line). In order to cause the moiré phenomenon to some extent, a discriminating pattern of the discriminating tool 8 may be one having directivity. In this case, a moire phenomenon is caused by using a diffraction grating as such a directional material.
[0061]
FIG. 10D shows a discrimination pattern using a halftone dot having an angle of 135 ° in the alignment direction of the halftone dot 29 with respect to the horizontal line (reference line). Also in this case, halftone dots having directionality are used for the discrimination pattern. The halftone dot 29 is composed of a point where the transparent part and the colored part are independent or a point where two parts are connected in a chain, and a line (chain) connecting the transparent parts and a colored part. (Chain-shaped) lines connecting the portions are formed in pairs. This paired portion is formed at an angle of 135 °.
[0062]
By the way, as shown in FIG. 4 and FIG. ₁ And straight opaque part 9 ₂ In the case of using a discrimination pattern composed of a repetition pattern of a straight transparent portion 9 as shown in FIG. ₁ Width of a, straight opaque part 9 ₂ A / b ≒ 1, that is, the linear transparent portion 9 ₁ And straight opaque part 9 ₂ May be approximately the same width, but a / b is in the range of ／ to ４, that is, the linear transparent portion 9. ₁ The width of the straight opaque part 9 ₂ It is desirable to set the width smaller than the width. The reason is that in the range of 2/3 ≧ a / b ≧ １ ／, when the discriminator 8 is superimposed close to or in close contact with the display surface 2, the hidden patterns “H” and “A” are observed with good contrast. Is done. On the other hand, when a / b exceeds 2/3, the amount of light that can be seen through the discriminator 8 becomes too large and becomes too bright to lower the contrast, making the hidden pattern difficult to see, and conversely, a / b becomes 1 If it is less than / 4, the amount of light is so small that it becomes dark and the hidden pattern becomes difficult to see.
[0063]
By the way, in the above description, the diffraction grating 7 constituting the light diffraction structure of the display surface 2 of the display 1 is described. ₁ , 7 ₂ Was not explained in detail. Usually, as the diffraction grating used for the display surface 2 used by being attached to a printed matter or the like, a reflection type diffraction grating in which a metal reflection film is provided by vapor deposition or the like on a relief surface or a flat surface of a diffraction grating having an uneven relief structure is used. However, in addition to the above, a metal reflective film is provided on the back surface of an amplitude type diffraction grating whose amplitude changes periodically or a phase type diffraction grating whose refractive index changes periodically to form a reflection type. Or a volume type diffraction grating having a diffraction grating composed of interference fringes in a volume type photosensitive material.
[0064]
Of course, the display surface 2 may be constituted by a transmission type, not a reflection type, and the diffraction grating may be constituted by a transmission type diffraction grating.
[0065]
Now, the display 1 (or only the display surface 2) having the partial display surface 2 including the above-described hidden pattern according to the present invention can be configured in various forms such as a transfer foil, a label, and a film. In the case of the transfer foil form, for example, it can be applied to gift certificates, credit cards, packages, etc., in the case of the label form, for example, it can be applied to packages of software, cartridges, pharmaceuticals, etc., and in the case of the film form, For example, the film can be micro-slit to a width of about 1 to 2 mm, and can be made into the paper at the time of paper making to prevent forgery. In the case of the label form, a brittle layer is interposed in the layer structure so that when the label is peeled for forgery, the label is peeled off from the brittle layer so that the display body is peeled for forgery. Can be difficult (brittle labels). Hereinafter, an example of a layer configuration and an example of a manufacturing process thereof when a display body including a hidden pattern by the light diffraction structure of the present invention is configured in each form of a transfer foil, a label, a brittle label, and a film will be described.
[0066]
FIG. 12 is a cross-sectional view showing a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is formed as a transfer foil 31. The structure will be described according to a manufacturing method thereof. A release layer 45 is applied on a base material 44 made of a resin film, a diffraction grating forming layer 41 is applied on the release layer 45, and a diffraction grating master having an uneven relief structure is embossed on the diffraction grating forming layer 41 to obtain the unevenness. A diffraction grating having a relief structure is duplicated, and a reflection layer is formed on the duplicated relief diffraction grating surface to form a reflection type diffraction grating 43. A heat seal layer is formed on the reflection grating 42 side of the diffraction grating 43. 46 is applied to complete the transfer foil 31 having a layer configuration as shown in FIG.
[0067]
Here, as the resin film constituting the base material 44, a polypropylene resin film, a polycarbonate resin film, a polyethylene terephthalate resin film or the like is preferable, and among them, a biaxially stretched polyethylene terephthalate resin having excellent mechanical strength is preferable. Film is suitable.
[0068]
The resin constituting the release layer 45 depends on the material of the base material 44 and the material of the diffraction grating forming layer 41 adhered to the release layer 45. However, polyester resin, acrylic skeleton resin, vinyl chloride-vinyl acetate copolymer Resin, a two-component blend resin of cellulose acetate and a thermosetting acrylic resin, a melamine resin, or a nitrocellulose resin can be used. For example, when the substrate 44 is a polyethylene terephthalate resin (PET) film, a polyester resin is preferable in terms of the adhesion between the release layer 45 and the substrate 44. A wax such as polyethylene wax or a silicone resin may be added to these resins to improve the releasability. The release layer 45 is prepared by dissolving or dispersing the above resin using an appropriate solvent or dispersant to prepare a composition suitable for coating or printing, and forming the base material 44 by a known coating method or printing method. Can be laminated.
[0069]
Examples of the synthetic resin constituting the diffraction grating forming layer 41 include thermoplastic resins such as polyvinyl chloride, acrylic resin (eg, PMMA), polystyrene, and polycarbonate, unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, Thermosetting resins such as urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and triazine acrylate, respectively, or the above thermoplastic resins And a thermosetting resin can be used as a mixture, and further, a thermoformable substance having a radically polymerizable unsaturated group, or a radically polymerizable unsaturated monomer added thereto and ionizing radiation curable Can be used. In addition, photosensitive materials such as silver salts, dichromated gelatin, thermoplastics, diazo photosensitive materials, photoresists, ferroelectrics, photochromic materials, thermochromic materials, and chalcogen glass can also be used.
[0070]
The formation of the diffraction grating of the relief structure on the layer made of the above synthetic resin can be performed by a conventionally known method using the above materials. For example, using a master in which a diffraction grating is recorded in the form of concavities and convexities as a press mold, superimposing the master on the resin layer, and heating and pressing both with appropriate means such as a heating roll, thereby forming the concavo-convex pattern of the master. Can be duplicated. Alternatively, the original can be overlaid on a resin layer that has been cured with ultraviolet light, and the resin layer can be cured by irradiating ultraviolet rays to replicate the concavo-convex pattern of the original.
[0071]
As a material forming the reflective layer 42, Mg, Al, Ti, Cr, Cu, Zn, Ga, Ge, Se, Rb, Pd, Ag, Cd, In, Sn, Sb, Te, Au, Pb, or A metal such as Bi, an oxide thereof, or a nitride thereof is used alone or in combination to form a thin film. When a metal thin film layer is used as the reflection layer 42, among these, Al, Cr, Ni, Ag, Au, or the like is particularly preferable.
[0072]
The reflective layer 42 is formed by a known thin film forming method such as a vacuum evaporation method, a sputtering method, or an ion plating method.
[0073]
Examples of the material constituting the heat seal layer 46 include, for example, ethylene-vinyl acetate copolymer resin, polyamide resin, polyester resin, polyethylene resin, ethylene-isobutyl acrylate copolymer resin, butyral resin, polyvinyl acetate and copolymers thereof. A coalescing resin, a cellulose derivative, a polymethyl methacrylate resin, a polyvinyl ether resin, a polyurethane resin, a polycarbonate resin, a polypropylene resin, an epoxy resin, or a phenol resin can be used. Alternatively, a thermoplastic elastomer such as SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), or a reactive hot melt resin, etc. May be used.
[0074]
FIG. 13 is a cross-sectional view showing a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is formed as a label 32. The structure will be described according to a manufacturing method thereof. A diffraction grating forming layer 41 is applied on a substrate 44 made of a film, a diffraction grating original having an uneven relief structure is embossed on the diffraction grating forming layer 41, and the diffraction grating having the uneven relief structure is duplicated. The reflection type diffraction grating 43 is formed by vapor-depositing the reflection layer 42 on the diffraction grating surface, the adhesive layer 47 is applied to the reflection layer 42 side of the diffraction grating 43, and the adhesive layer 47 is provided on the adhesive layer 47 for protection. A separator (release paper) 48 is laminated to complete the label 32 having a layer configuration as shown in FIG.
[0075]
Here, the materials constituting the base material 44, the diffraction grating forming layer 41, and the reflective layer 42 are the same as those in FIG.
[0076]
Examples of the adhesive constituting the adhesive layer 47 include polyvinyl acetate resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, polyvinyl chloride, polyamide, polymethyl methacrylate, and nitrocellulose. , Cellulose acetate, thermoplastic epoxy, polystyrene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, etc., urea resin, melamine resin, phenol resin, resorcinol resin, furan resin, epoxy resin, unsaturated polyester resin, polyurethane resin, Polyimide, polyamide imide, polybenzimidazole, polybenzothiazole, etc., or rubber-based natural rubber, recycled rubber, styrene-butadiene rubber, acrylo Tolyl - butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene-propylene rubber, block copolymer rubbers (SBS, SIS, SEBS, etc.) can be used.
[0077]
Further, as the separator (release paper) 48, a conventionally known paper or film base material subjected to a release treatment can be used.
[0078]
FIG. 14 is a cross-sectional view showing a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is configured as a brittle label 33. The structure will be described according to a manufacturing method thereof. A brittle layer 49 is applied on a base material 44 made of a transparent resin film, a diffraction grating forming layer 41 is applied on the brittle layer 49, and a diffraction grating master having an uneven relief structure is embossed on the diffraction grating forming layer 41. Then, the diffraction grating having the concave-convex relief structure is duplicated, and a reflection type diffraction grating 43 is formed by depositing a reflection layer 42 on the duplicated relief diffraction grating surface. An adhesive layer 47 is applied, and a separator (release paper) 48 is laminated on the adhesive layer 47 to complete the brittle label 33 having a layer configuration as shown in FIG.
[0079]
Here, the materials constituting the base material 44, the diffraction grating forming layer 41, the reflection layer 42, the adhesive layer 47, and the separator (release paper) 48 are the same as those in FIG.
[0080]
As the material forming the brittle layer 49, the same series of resin as the resin forming the release layer 45 in the case of FIG. 12 is used.
[0081]
FIG. 15 is a cross-sectional view showing a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is formed as a film 34. The structure will be described in accordance with a manufacturing method thereof. A diffraction grating forming layer 41 is applied on a substrate 44 made of a film, a diffraction grating original having an uneven relief structure is embossed on the diffraction grating forming layer 41, and the diffraction grating having the uneven relief structure is duplicated. The reflection type diffraction grating 43 is formed by depositing the reflection layer 42 on the diffraction grating surface, and the film 34 having the layer configuration as shown in FIG. 14 is completed.
[0082]
Here, the materials constituting the base material 44, the diffraction grating forming layer 41, and the reflecting layer 42 are the same as those in FIGS.
[0083]
Here, an example of a method of manufacturing a diffraction grating master for embossing a diffraction grating having a relief structure on the diffraction grating forming layer 41 will be briefly described with reference to FIGS. To do so, prepare a Cr-plated glass plate, apply an electron beam resist on it, draw a diffraction grating pattern by electron beam drawing, and then develop the electron beam resist to obtain a rectangular wave cross section. Is obtained.
[0084]
An ultraviolet-curable resin or a thermosetting resin is applied on the diffraction grating pattern of the concave-convex relief structure of such an electron beam resist, and the concave-convex relief structure is converted to an ultraviolet-curable resin or a thermosetting resin by irradiating ultraviolet rays or heating. By duplication, a negative plate of the diffraction grating pattern for electron beam drawing is obtained. The negative plate is similarly duplicated to obtain a positive plate, or the positive plate obtained by repeating such duplication an even number of times is embossed with a diffraction grating having an uneven relief structure on the diffraction grating forming layer 41. Can be used as a diffraction grating master.
[0085]
As described above, the display body including the hidden pattern by the light diffraction structure of the present invention and the discriminating tool therefor have been described based on some embodiments, but the present invention is not limited to these embodiments and various modifications are possible. It is.
[0086]
【The invention's effect】
As is clear from the above description, according to the display body including the hidden pattern by the light diffraction structure of the present invention and the discriminating tool therefor, the display surfaces of the display body including the light diffraction structure are adjacent to each other and parallel to each other. In a double structure of a first linear fringe pair and a second linear fringe pair having different diffraction characteristics, and a linear diffraction grating forming the straight fringes, a region forming a hidden pattern and other regions have The configuration of the linear diffraction grating is the same, and by making the configuration of the stripe pairs different, a normal display pattern can be observed due to the difference in the configuration of each region of the linear diffraction grating in a visual state, and the hidden pattern is difficult to distinguish. However, by superimposing the above-mentioned stripe pair and the discriminator according to the present invention which causes the moiré phenomenon, it becomes possible to discriminate a hidden pattern instead of a normal display pattern. Therefore, it is possible to obtain a display body that includes a hidden pattern that is extremely difficult to visually discriminate, has a large forgery prevention effect, and has high designability.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an example of a printed material to which a light diffraction structure having a hidden pattern according to the present invention is transferred.
FIG. 2 is a diagram for explaining a basic configuration of a display unit area having uniform characteristics and a configuration on a partial display surface in the present invention.
FIG. 3 is an enlarged view of a partial display surface including a hidden pattern by the light diffraction structure of the first embodiment according to the present invention.
FIG. 4 is a plan view of an example of a discriminator for discriminating a hidden pattern on the partial display surface of FIG. 3;
FIG. 5 is a diagram showing a hidden pattern determined from the partial display surface of FIG. 3;
FIG. 6 is an enlarged view of a partial display surface including a hidden pattern by a light diffraction structure according to a second embodiment of the present invention.
7 is a plan view of an example of a discriminator for discriminating a hidden pattern on the partial display surface in FIG. 6;
8 is a diagram showing a display pattern observed in a visual state of the partial display surface of FIG. 3 and a hidden pattern determined using the determination tool of FIG. 7;
FIG. 9 is a diagram for explaining a border provided around each pattern according to the present invention.
FIG. 10 is a diagram for explaining various other forms of a discrimination pattern provided to the discrimination tool.
FIG. 11 is a diagram for explaining a width relationship of a discrimination pattern including a repeating pattern of a parallel linear transparent portion and a linear opaque portion.
FIG. 12 is a cross-sectional view illustrating a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is configured as a transfer foil.
FIG. 13 is a cross-sectional view illustrating a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is configured as a label.
FIG. 14 is a cross-sectional view showing a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is configured as a brittle label.
FIG. 15 is a cross-sectional view illustrating a layer structure when a display body including a hidden pattern by the light diffraction structure of the present invention is configured as a film.
[Explanation of symbols]
S: Reference line
X, Y, Z ... pattern
P… Pattern
P '... border
1 ... Display body containing hidden pattern
2. Partial display surface including hidden pattern
3. Other display surface
5. Display unit area
6… Stripes
6 ₁ ... First straight stripe
6 ₂ ... Second straight stripes
7 ₁ ... First linear diffraction grating
7 ₂ ... Second linear diffraction grating
8 ... Determination tool
9 ₁ … Straight transparent part
9 ₂ … Straight transparent part
9 ₂ '… Straight colored part
10. Printed matter
11 ₁ , 11 ₂ …region
19 ... Lattice
21 ₁₁ , 21 ₁₂ , 21 _Thirteen , 21 ₁₄ ... Area constituting pattern X
21 ₂₁ , 21 ₂₂ , 21 ₂₃ , 21 ₂₄ , 21 ₂₅ ... Area constituting pattern Y
21 ₃₁ , 21 ₃₂ , 21 ₃₃ , 21 ₃₄ ... Areas constituting pattern Z
29 ... dot
31 ... Transfer foil
32 ... Label
33 ... brittle label
34 ... Film
41 ... Diffraction grating forming layer
42 ... Reflection layer
43 ... Reflection type diffraction grating
44 ... Base material
45 ... release layer
46 ... Heat seal layer
47 ... Adhesive layer
48 ... Separator (release paper)
49 ... brittle layer

Claims (13)

A display body including an optical diffraction structure, the display surface of which has different diffraction characteristics, a plurality of pattern regions having an arbitrary outer shape and inner shape according to the display pattern are arranged in parallel, each pattern region, Adjacent to each other and parallel to each other, the first linear fringes are filled by repetition of a fringe pair of first linear fringes and second linear fringes having different diffraction characteristics, and the first linear fringes are formed by a first linear diffraction grating. The second linear fringes are respectively constituted by second linear diffraction gratings, and the inclination angles of the first linear fringes and the second linear fringes with respect to a reference line set with respect to the display surface are represented by a gradient of a fringe pair. When the angle α is the inclination angle β _{1 of} the first linear diffraction grating, the inclination angle of the first linear diffraction grating is the inclination angle β ₁ of the first linear diffraction grating, and the inclination angle β 2 of the second linear diffraction grating is the inclination angle β ₂ of the second linear diffraction grating. At least one hidden pattern in the pattern area of The inclination angle α of the stripe pairs in the pattern area to be formed is set to be different from the inclination angle α of the stripe pairs in the other pattern areas, and the first linear diffraction grating of the pattern area constituting the hidden pattern the inclination angle beta ₁ and the inclination angle beta ₂ of the second linear diffraction grating, the inclination angle beta ₁ of the first linear diffraction grating pattern region other than the pattern region constituting the hidden pattern adjacent to the pattern region second A display body including a hidden pattern formed by a light diffraction structure, wherein the display body is set to be equal to the inclination angle β ₂ of the linear diffraction grating. The pattern area constituting the hidden pattern is composed of one or more isolated pattern areas, and the inclination angle β ₁ of the first linear diffraction grating and the inclination angle β ₂ of the second linear diffraction grating in the pattern area constituting the hidden pattern are _2. The light diffraction structure according to claim ₁ , wherein the inclination angle .beta.1 of the first linear diffraction grating and the inclination angle .beta.2 of the second linear diffraction grating in other pattern areas are set to be equal to each other. Display body that contains a hidden pattern. The pattern area forming the hidden pattern includes a plurality of pattern areas adjacent to each other, and the inclination angle α of the stripe pair of the plurality of adjacent pattern areas forming the hidden pattern is set to be the same, and The inclination angle α of the stripe pairs of the other pattern areas adjacent to the plurality of mutually adjacent pattern areas constituting the pattern is set to be different from each other, and the mutually adjacent plurality of the plurality of adjacent pattern areas constituting the hidden pattern are formed. The inclination angle β ₁ of the first linear diffraction grating and the inclination angle β ₂ of the second linear diffraction grating in each of the pattern regions of the pattern region are a plurality of adjacent ones constituting the hidden pattern adjacent to the pattern region. JP that inclination angle beta ₁ of the first linear diffraction grating pattern region other than the pattern region of the the inclination angle beta ₂ of the second linear diffraction grating are respectively set equal A display body including a hidden pattern formed by the light diffraction structure according to claim 1. The first linear diffraction grating and the second linear diffraction grating in each of a plurality of pattern regions arranged adjacent to each other in parallel are set so as to satisfy at least one of a different inclination angle and a different grating pitch. A display body including a hidden pattern formed by the light diffraction structure according to any one of claims 1 to 3. 5. When the repetition pitch of the stripe pairs in each of a plurality of pattern regions arranged adjacent to each other in parallel is d, d ≦ １ ／ mm is set. 5. A display body including a hidden pattern by the light diffraction structure according to claim 1. The difference between the inclination angle α of the stripe pairs in the pattern area forming the hidden pattern and the inclination angle α of the stripe pairs in the other pattern areas is set within a range of 90 ° ± 10 °. A display body including a hidden pattern formed by the light diffraction structure according to claim 1. 7. The pattern region forming the at least one hidden pattern is bordered by a stripe pair having a period shifted by a half period with respect to a period of the stripe pair forming the pattern region. A display body including a hidden pattern formed by the light diffraction structure according to any one of the above. The display body including a hidden pattern by the light diffraction structure according to any one of claims 1 to 7, wherein the first linear diffraction grating and the second linear diffraction grating are formed of a reflection type diffraction grating. . The display body including a hidden pattern by the light diffraction structure according to any one of claims 1 to 8, wherein the display body is configured in a transfer foil form. The display body including a hidden pattern by the light diffraction structure according to any one of claims 1 to 8, wherein the display body is configured in a label form. The display body including a hidden pattern by the light diffraction structure according to any one of claims 1 to 8, wherein the display body is configured in a film form. A discriminator for a display body including a hidden pattern by the light diffraction structure according to claim 1, wherein the discriminator is a repetitive pattern of a parallel linear transparent portion and a linear opaque portion, A hidden pattern formed by a light diffraction structure including a pattern having the same inclination angle and the same repetition pitch as a stripe pair of a pattern area forming at least one hidden pattern in the plurality of pattern areas of the display body. Discriminator for display objects to be displayed. 13. The discriminator according to claim 12, wherein the width of the linear transparent portion is set smaller than the width of the linear opaque portion.

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