JP4057746B2

JP4057746B2 - Substrate for three-dimensional optical recording medium and method for manufacturing three-dimensional optical recording medium

Info

Publication number: JP4057746B2
Application number: JP17335699A
Authority: JP
Inventors: 俊文滝澤
Original assignee: Mitsubishi Chemical Corp
Current assignee: Mitsubishi Chemical Corp
Priority date: 1999-06-18
Filing date: 1999-06-18
Publication date: 2008-03-05
Anticipated expiration: 2019-06-18
Also published as: JP2001005368A

Description

【０００１】
【発明の属する技術分野】
本発明は、多層光メモリ，ホログラムメモリ等の大容量，高密度の光記録媒体の製造に用いて好適の、三次元光記録媒体用基板及び三次元光記録媒体の製造方法に関する。
【０００２】
【従来の技術】
従来、ＣＤ−Ｒ等のディスク状の光記録媒体の製造方法として、スピンコート法が知られている。この方法は、ディスク状基板のプリピット及びプリグルーブが形成されている情報面に、記録材料である有機色素を適当な有機溶媒に溶解して成る塗布液を滴下した後、基板を回転させ、遠心力によって余剰の塗布液を情報面から除去し、記録層を形成するものである。
【０００３】
【発明が解決しようとする課題】
ところで、近年、来るべきマルチメディア情報化時代への対応として、光記録媒体のさらなる大容量化，高密度化に向けた研究開発が行なわれている。例えば、図２０に示すように、透明基板１０３上に積層した記録層１０１を集光レーザビーム１０２の焦点深度以上に厚くし、焦点位置をずらすことにより媒体内の深さ方向に三次元的な記録を行なう多層記録方式の光記録媒体（多層光メモリ）１００や、図２１に示すように、一対の透明基板１０９，１１０間で挟持された記録層１０８に、物体からの反射光や信号等の情報を表す信号ビーム１０６と、記録層１０８中で信号ビーム１０６と干渉を起こすための参照ビーム１０７とを照射し、参照ビーム１０７の入射角を少しずつ変えていくことにより、記録層１０８内の同一箇所に複数個のホログラムを多重記録するホログラム方式の光記録媒体（ホログラムメモリ）１０５のように、記録層の平面内のみならず厚み方向にも三次元的に記録することにより記録容量を向上させた三次元光記録媒体が開発されている。
【０００４】
これらの多層光メモリ１００，ホログラムメモリ１０５はいずれも、記録層に合成樹脂を多く含み（９０重量％以上）、樹脂の熱または光による構造変化と、これに伴う光学的性質の変化を利用した光記録媒体であり、記録層の厚みが数十〜数百μｍと従来の光記録媒体に比べて非常に厚いのが特徴である。また、これらの光記録媒体では、記録層の厚み方向にも三次元的に記録する必要から、従来の平面的に記録する光記録媒体に比較して記録層の厚みの均一性はより厳しく要求される。即ち、三次元光記録媒体は、二次元のものに比べて記録層をより厚く、しかも厚みをより均一性のあるものにしなくてはならない。
【０００５】
合成樹脂を多く含む材料により均一厚みの層を形成する方法としては、上述したスピンコート法を用いるのが一般的であるが、ＣＤ−Ｒ等のように１０μｍ未満の比較的薄い層であれば均一に形成できるものの、遠心力の作用により塗布液が広がってしまうため、より厚い、特に１００μｍ以上の層を形成するのは困難である。また、層を厚く形成させるために基板を低速で回転させると、ディスクのエッジ部の膜厚が特に厚くなってしまい、厚みの均一性を確保できなくなってしまう。さらに、塗布液の粘度を高くする方法も考えられるが、粘度コントロールのために塗布液の組成を変えることは、媒体の記録特性への影響を考えると難しい場合が多い。
【０００６】
本発明は上述の課題に鑑み創案されたもので、合成樹脂を多く含み比較的厚みのある記録層を有する三次元光記録媒体を容易に製造できるようにした、三次元光記録媒体用基体及び三次元光記録媒体の製造方法を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、本発明の三次元光記録媒体用基体は、合成樹脂を多く含有してなる記録層内に三次元的に情報を記録する三次元光記録媒体用の基体であって、該記録層を形成する記録層用空間の両面を区画形成する一対の透明基板と、該一対の透明基板の相互間に介装され、該一対の透明基板を所定の距離をもって結合するとともに該記録層用空間の縁部を区画形成するスペーサとから構成され、さらに、該スペーサが、光硬化性又は熱硬化性フィルムからなり、該フィルムを該一対の透明基板間に介装し、光硬化又は熱硬化させることにより、該一対の透明基板と該フィルムによる該スペーサとが一体化されていることを特徴としている（請求項１）。
【０００８】
ここで、該スペーサに該記録層用空間を外部に開にする開口部が設けられていることが好ましく、該一対の透明基板はディスク状であって、該記録層用空間は円環状に形成され、該スペーサは円環状の該記録層用空間の外周縁部と内周縁部とにそれぞれ設けられていることがより好ましい。
【０００９】
また、該スペーサが、該一対の透明基板のうちの少なくとも一方に予め一体に形成されていることが好ましい。
また、別の本発明の三次元光記録媒体用基体は、合成樹脂を多く含有してなる記録層内に三次元的に情報を記録する三次元光記録媒体用の基体であって、該記録層を形成する記録層用空間の両面を区画形成する一対の透明基板と、該一対の透明基板の相互間に介装され、該一対の透明基板を所定の距離をもって結合するとともに該記録層用空間の縁部を区画形成するスペーサとから構成され、該スペーサの縁部外周に、該一対の透明基板の縁部外周よりも窪んだ窪み部が形成されていることを特徴とする（請求項２）。
ここで、該スペーサの縁部外面全体を、該一対の透明基板の縁部外面よりも該記録層を形成する空間内に変位した位置に設定することにより、該窪み部が形成されていることがより好ましい（請求項３）。若しくは、該窪み部が、該スペーサの縁部の外面を面取りされ形成された面取り部によって構成されていることがより好ましい（請求項４）。
【００１０】
また、本発明の三次元光記録媒体の製造方法は、上記の三次元光記録媒体用基体（請求項１）であって、該スペーサに該記録用空間を外部に開にする開口部が設けられた三次元光記録媒体用基体を用いて三次元光記録媒体を製造する方法であって、該一対の透明基板と該スペーサとを結合して、該三次元光記録媒体用基体を組み立てる基体組立工程と、該開口部から該記録層空間内に、該記録層を形成する光硬化性又は熱硬化性の液状の樹脂を注入する樹脂注入工程と、該記録媒体用空間内に注入された液状の樹脂を光硬化又は熱硬化させる樹脂硬化工程とをそなえたことを特徴としている（請求項５）。
【００１１】
さらに、別の本発明の三次元光記録媒体の製造方法は、合成樹脂を多く含有してなる記録層内に三次元的に情報を記録する三次元光記録媒体用の基体であって、該記録層を形成する記録層用空間の両面を区画形成する一対の透明基板と、該一対の透明基板の相互間に介装され、該一対の透明基板を所定の距離をもって結合するとともに該記録層用空間の縁部を区画形成するスペーサとから構成された三次元光記録媒体用基体を用いて三次元光記録媒体を製造する方法であって、該一対の透明基板のうち、該スペーサの一部又は全部を装着された一方の透明基板上の該記録層用空間に、記録層を形成する光硬化性又は熱硬化性の液状の樹脂を充填する第一の工程と、液状の樹脂を充填した該一方の透明基板に他方の基板を重ね合わせる第二の工程と、該スペーサ間に充填された液状の樹脂を光硬化又は熱硬化させる第三の工程とをそなえるとともに、該第二の工程に先立ち該三次元光記録媒体用基体の周囲を真空雰囲気とする工程をそなえたことを特徴としている（請求項６）。
ここで、該スペーサが光硬化性又は熱硬化性フィルムからなり、該第三の工程において該液状の樹脂とともに該スペーサをも硬化させ、該透明基板と該スペーサとを貼り合わせることが好ましい。
【００１３】
【発明の実施の形態】
以下、図面を参照して本発明の実施の形態を説明する。
まず、本発明の第１実施形態としての三次元光記録媒体用基体について説明する。なお、本実施形態にかかる三次元光記録媒体はディスク状のものであり、記録層は円環状（ドーナツ状）に形成されるものである。
【００１４】
本三次元光記録媒体用基体１は、多層光メモリ，ホログラムメモリ等の大容量，高密度の三次元光記録媒体の製造に用いて好適の三次元光記録媒体用基体であり、図１に示すように、一対の透明基板２，３と、大小一組の円環状のスペーサ４，５とから構成されている。
透明基板２，３は、円盤状に形成されており、その中央には外周円と同心の円形の穴を有している。透明基板２，３の材質としては、ガラスや透明樹脂（例えばポリカーボネイト樹脂，アクリル樹脂，メタクリル樹脂，ポリスチレン樹脂，塩化ビニル樹脂，エポキシ樹脂，ポリエステル樹脂，アモルファスポリオレフィン等）を用いることができる。
【００１５】
スペーサ４，５は、透明基板２，３間の距離を所定の大きさに均一に保つための部材であり、多層光メモリ，ホログラムメモリ等の本三次元光記録媒体用基体１の用途に応じた厚さ（好ましくは、３０μｍ以上５００μｍ以下の厚さ）に形成されている。スペーサ４は透明基板２，３の外周部２ａ，３ａの相互間に介装されるもので、スペーサ４の外径は透明基板２，３の外径と略同径に設定されている。スペーサ５は透明基板２，３の内周部２ｂ，３ｂの相互間に介装されるもので、スペーサ５の内径は透明基板２，３の内径と略同径に設定されている。また、スペーサ４には、一部に切れ目４ａが設けられており、この切れ目４ａにおいてスペーサ４の開口部が形成されている。
【００１６】
スペーサ４，５の材質としては、光硬化性又は熱硬化性の樹脂、例えばアクリル系樹脂，エポキシ系樹脂，イソシアネート系樹脂等を用いることができるが、好ましくは、記録層を形成する樹脂の屈折率に近いものを選択するようにする。なお、本発明の第１実施形態にかかるスペーサとしては、図１に示すように予め独立して形成しておいたスペーサ４，５を使用することが好ましいが、未硬化の樹脂組成物を一方の基板上に塗布し、他方の基板を貼り合わせたのち硬化することによって、スペーサとしてもかまわない。
【００１７】
予め独立してスペーサを形成しておく場合、例えば、光硬化性又は熱硬化性の樹脂を、ダイキャスト法，ディップコート法，ロールコート法等の公知方法を用いて用途に応じた所定の厚さのフィルムにし、光又は熱にて部分硬化させた後、適宜の形状に打ち抜くことにより、円環状の樹脂フィルムとしてスペーサ４，５を得ることができる。若しくは、スペーサ４，５の形状に応じた型枠に光硬化性又は熱硬化性の樹脂を注入し、光又は熱にて部分硬化させた後、型枠から取り出すことによっても、円環状の樹脂フィルムとしてスペーサ４，５を得ることができる。
【００１８】
そして、本三次元光記録媒体用基体１は、透明基板２，３の外周部２ａ，３ａ間及び内周部２ｂ，３ｂ間に、それぞれスペーサ４，５を挟装することにより一体に形成されるものであり、一方の透明基板２の外周部３ａ又は２ａ上，内周部３ｂ又は２ｂ上にそれぞれスペーサ４，５を積層した後、さらに、他方の透明基板３を積層し、光硬化性又は熱硬化性の樹脂フィルムであるスペーサ４，５に光又は熱を当てて更に硬化させることにより形成される。
【００１９】
本発明の第１実施形態としての三次元光記録媒体用基体１は上述のように構成されているので、三次元光記録媒体の製造にあたっては、まず、上述のようにして透明基板２，３及びスペーサ４，５を結合して、三次元光記録媒体用基体１を形成する（基体組立工程）。この結果、三次元光記録媒体用基体１の内部には、図２（ａ），図２（ｂ）に示すように、透明基板２，３とスペーサ４，５とにより囲まれる内部空間（記録層用空間）６が形成される。この内部空間６は、記録層を形成する樹脂を充填するための空間であり、外側のスペーサ４に形成された切れ目（開口部）４ａによって外部と連通している。
【００２０】
したがって、本三次元光記録媒体用基体１を用いて光記録媒体を製造する場合には、例えば次のような方法を用いることが可能になる。図３を参照しながら本三次元光記録媒体の製造方法について説明すると、まず、図３（ａ）に示すように、予め基体組立工程で組み立てられた三次元光記録媒体用基体１の周囲を真空雰囲気にする。そして、図３（ｂ）に示すように、真空雰囲気下でスペーサ４に形成された切れ目４ａを記録層を形成する液状の樹脂８が満たされた容器７内に浸ける。
【００２１】
記録層を形成する樹脂８としては、光硬化性又は熱硬化性の樹脂、例えば、アクリル系やメタクリル系のようにエチレン性不飽和二重結合含有化合物のラジカル反応で重合するものや、エポキシ系のように光でカチオン反応するもの等の光硬化可能なモノマーと、必要に応じ光硬化又は熱硬化可能なバインダー樹脂を含む材料、ポリ（ｐ−ヒドロキシスチレン）とヘキサメトシキメチルメラミンの組み合わせのようなものが考えられるが、具体的には、記録方式に応じて適宜選択する。
【００２２】
次に、図３（ｃ）に示すように、真空雰囲気を解除して三次元光記録媒体用基体１の周囲雰囲気を大気圧に戻す。これにより、容器７内の液状樹脂８は、大気圧により押されて切れ目４ａから真空状態になっている内部空間６内に充填されていく（以上、樹脂注入工程）。
そして、三次元光記録媒体用基体１に光又は熱を加えることにより、切れ目４ａから内部空間６内に吸引された液状樹脂８を光硬化又は熱硬化させ、図３（ｄ）に示すように、記録層９を形成する（樹脂硬化工程）。以上の工程により、光記録媒体が製造される。
【００２３】
このように本三次元光記録媒体用基体１によれば、透明基板２，３間の隙間がスペーサ４，５により予め所定の間隔に設定されるとともに、記録層９が形成される空間がスペーサ４の切れ目４ａのみにより外部と連通する閉空間になっているので、閉空間（内部空間）６内を真空雰囲気にして記録層を形成する樹脂を引き込むだけで、均一な厚みの記録層９を容易に形成することができ、多層光メモリ，ホログラムメモリ等の厚みのある記録層９を有する三次元光記録媒体の製造が容易になるという利点がある。
【００２４】
また、スペーサ４，５として光硬化性又は熱硬化性フィルムを用いることにより、透明基板２，３との接合が容易になり、また、従来の透明基板をそのまま用いることができるという利点がある。
なお、上述の実施形態では、外周側のスペーサ４に切れ目４ａを設けて、この切れ目４ａを内部空間６内に記録層を形成する液状樹脂を充填するための通路にしているが、図４に示すように、内周側のスペーサ５に切れ目（開口部）５ａを設けて、この切れ目５ａを内部空間６内に記録層を形成する液状樹脂を充填するための通路としてもよい。
【００２５】
また、上述の実施形態では、光硬化性又は熱硬化性の樹脂フィルムによりスペーサ４，５を成形し、光硬化又は熱硬化を用いて透明基板２，３に接合しているが、図５に示すように、はりあわせ樹脂１０を用いてスペーサ４，５を透明基板２，３に接合するようにしてもよい。この場合、スペーサ４，５の材料は光硬化性又は熱硬化性の樹脂で無くても良く、例えば先に基板材料として挙げたものやポリアミド系樹脂等を使用することができる。ただし、この場合も、はりあわせ樹脂１０及びスペーサ４，５の屈折率は記録層を形成する樹脂の屈折率に近いほうが好ましい。
【００２６】
また、外周側のスペーサ４の外径は、はりあわせ樹脂１０のはみ出しによる外観の悪化を防止するため、透明基板２，３の外径よりもわずかに小径に設定して、透明基板２，３の外周の表面よりも窪んだ窪み部を形成することが好ましい。さらに、内周側のスペーサ５の内径についても、透明基板２，３の内径よりもわずかに大径に設定して、透明基板２，３の内周の表面よりも窪んだ窪み部を形成することが好ましい。
【００２７】
次に、本発明の第２実施形態としての三次元光記録媒体用基体について説明すると、本三次元光記録媒体用基体１１は、図６に示すように、一対の透明基板１２，１３から構成されている。
透明基板１２，１３は、円盤状に形成されており、その中央には外周円と同心の円形の穴を有している。また、一方の透明基板１２の外周部及び内周部には、それぞれ円環状の側壁１４，１５が一体に形成されている。これらの側壁１４，１５は、透明基板１２，１３を重ね合わせた時に、内部の隙間高さを均一に保つスペーサとして機能するものであり、多層光メモリ，ホログラムメモリ等の本三次元光記録媒体用基体１の用途に応じた高さ（好ましくは、３０μｍ以上５００μｍ以下の高さ）に形成されている。また、外周側の側壁１４には、一部に切り欠き１４ａが設けられており、この切り欠き１４ａにおいて開口部が形成されている。
【００２８】
本三次元光記録媒体用基体１１は、上記の透明基板１２，１３を一体化することにより得られるものであり、一方の透明基板１２の側壁１４，１５に、はりあわせ樹脂等の接着剤を塗布した後、他方の透明基板１３を重ね合わせて接合することにより、透明基板１２，１３を一体化している。
本発明の第２実施形態としての三次元光記録媒体用基体１１は上述のように構成されているので、三次元光記録媒体の製造にあたっては、まず、上述のようにして透明基板１２，１３を結合して、三次元光記録媒体用基体１を形成する（基体組立工程）。この結果、三次元光記録媒体用基体１１の内部には、図７（ａ），図７（ｂ）に示すように、側壁１４，１５がスペーサとなって透明基板１２，１３により囲まれる内部空間（記録層用空間）１８が形成される。この内部空間１８は、記録層を形成する樹脂を充填するための空間であり、外周側側壁１４に設けられた切り欠き１４ａにより外部と連通している。
【００２９】
したがって、本三次元光記録媒体用基体１１を用いた場合にも、第１実施形態と同様な方法により光記録媒体を製造することが可能になる。つまり、まず、予め基体組立工程で組み立てられた三次元光記録媒体用基体１１の周囲雰囲気を真空雰囲気にし、真空雰囲気下で外周側側壁１４に設けられた切り欠き１４ａを記録層を形成する液状の樹脂が満たされた容器内に浸け、真空雰囲気を解除して三次元光記録媒体用基体１１の周囲雰囲気を大気圧に戻す（樹脂注入工程）。次に、切り欠き１４ａから内部空間１８内に吸引された液状樹脂を光硬化又は熱硬化させて記録層を形成するのである（樹脂硬化工程）。
【００３０】
このように本三次元光記録媒体用基体１１によれば、第１実施形態と同様に均一な厚みの記録層を容易に形成することができ、多層光メモリ，ホログラムメモリ等の厚みのある記録層を有する三次元光記録媒体の製造が容易になるという利点がある。さらに、本三次元光記録媒体用基体１１によれば、透明基板１２とともに一体成形される側壁１４，１５がスペーサとして機能するので、別にスペーサを設ける必要がなく、部品点数を削減することができるという利点もある。
【００３１】
なお、上述の実施形態では、外周側の側壁１４に切り欠き１４ａを設けて、この切り欠き１４ａにより形成される通路から内部空間１８内に記録層を形成する液状樹脂を充填しているが、図８に示すように、内周側の側壁１５に切り欠き１５ａを設けて、この切り欠き１５ａにより形成される通路から内部空間１８内に記録層を形成する液状樹脂を充填してもよい。
【００３２】
また、上述の実施形態では、一方の透明基板１２にのみ側壁１４，１５を設けているが、図９に示すように各透明基板１２，１３に側壁１４，１５，側壁１６，１７を設けるようにしてもよい。ただし、この場合の側壁１４，１５，側壁１６，１７の高さは、本三次元光記録媒体用基体１１の用途に応じた高さ（好ましくは、透明基板１２，１３を重ね合わせた時の高さの和が３０μｍ以上５００μｍ以下）に設定するとともに、側壁１４，１６の少なくとも一方に切れ込みを設けて（図９では、側壁１４，１６にそれぞれ切り欠き１４ａ，１６ａを設けている）、内部空間１８と外部とを連通させる必要がある。
【００３３】
以上説明した第１実施形態，第２実施形態の三次元光記録媒体用基体は、ディスク状の一対の透明基板と、一対の透明基板の外周部間及び内周部間に挟装された二つの円環状のスペーサとからなり、二つのスペーサの何れか一方に開口部が設けられるという構成であるが、本発明の三次元光記録媒体用基体は、以下に説明する第３実施形態，第４実施形態のような構成にすることも可能である。
【００３４】
まず、本発明の第３実施形態としての三次元光記録媒体用基体について説明すると、本三次元光記録媒体用基体２１は、上記の第１実施形態，第２実施形態と同様に、多層光メモリ，ホログラムメモリ等の大容量，高密度の光記録媒体の製造に用いて好適の三次元光記録媒体用基体であり、図１０に示すように、一対の透明基板２２，２３から構成されている。
【００３５】
透明基板２２，２３は、円盤状に形成されており、その中央には外周円と同心の円形の穴を有している。また、透明基板２２，２３の外周部２２ａ及び内周部２３ａには、それぞれ円環状の側壁２４，２５，側壁２６，２７が一体に形成されている。これらの側壁２４，２５，側壁２６，２７は、透明基板２２，２３を重ね合わせた時に、内部の隙間高さを均一に保つスペーサとして機能するものであり、多層光メモリ，ホログラムメモリ等の本三次元光記録媒体用基体２１の用途に応じた高さ（好ましくは、透明基板２２，２３を重ね合わせた時の高さの和が３０μｍ以上５００μｍ以下）に形成されている。また、外周側の側壁２４，２６の外周側縁部は面取りが施され、傾斜面（面取り部）２４ａ，２６ａが設けられており、透明基板２２，２３の外周面よりも内方に窪んだ窪み部が形成されるようになっている。なお、透明基板２２，２３の材質としては、第１実施形態で説明したものを用いることができる。
【００３６】
本発明の第３実施形態としての三次元光記録媒体用基体２１は上述のように構成されているので、図１１に示すように、透明基板２２，２３には、それぞれ側壁２４，２５，側壁２６，２７により囲まれる容積部（記録層用空間）２８，２９が形成される。これらの容積部２８，２９は、記録層を形成する樹脂を充填するための容器として機能するものであり、他方の透明基板２２（又は２３）により蓋をすることができる。
【００３７】
したがって、本三次元光記録媒体用基体２１を用いて光記録媒体を製造する場合には、例えば次のような方法を用いることが可能になる。図１２を参照しながら本三次元光記録媒体の製造方法について説明すると、まず、図１２（ａ）に示すように、一方の透明基板２２の容積部２８内に記録層を形成する液状の樹脂３０を充填する（第一の工程）。
【００３８】
そして、図１２（ｂ）に示すように、三次元光記録媒体用基体２１の周囲雰囲気を真空雰囲気にし、図１２（ｃ）に示すように、真空雰囲気下で液状樹脂３０を充填した透明基板２２の上に他方の透明基板２３を重ね合わせる（第二の工程）。この時、透明基板２３の側壁２６と透明基板２２の側壁２４との重ね合わせ部分から液状樹脂３０がはみ出してくる程度に、十分な量の樹脂３０が容積部２８内に充填されていることが好ましい。
【００３９】
最後に、三次元光記録媒体用基体２１に光又は熱を加えることにより、液状樹脂３０を光硬化又は熱硬化させ、図１２（ｄ）に示すように、透明基板２２，２３を貼り合わせるとともに、記録層３１を形成する（第三の工程）。以上の工程により、光記録媒体が製造される。
このように本三次元光記録媒体用基体２１によれば、透明基板２２，２３の外周部及び内周部にそれぞれ設けられた側壁２４，２５，側壁２６，２７により透明基板２２，２３間の隙間間隔が規制されるとともに、透明基板２２，２３には容積部２８，２９が形成されているので、一方の透明基板２２の容積部２８内に記録層３１を形成する樹脂を充填して、他方の透明基板２３により蓋をするだけで、均一な厚みの記録層３１を容易に形成することができ、多層光メモリ，ホログラムメモリ等の厚みのある記録層３１を有する光記録媒体の製造が容易になるという利点がある。
【００４０】
また、本三次元光記録媒体用基体２１によれば、側壁２４，２５，側壁２６，２７をそれぞれ透明基板２２，２３とともに一体成形しているので、部品点数を削減することができるという利点もある。
さらに、外周側の側壁２４，２６の外周側縁部を面取りすることにより傾斜面２４ａ，２６ａが設けられているので、透明基板２２，２３を重ね合わせた時には、その重ね合わせ部に切り込み（窪み部）が形成されるようになり、図１３に示すように、内部の樹脂３０がはみ出した場合でも、外見上目立つことがなく、外観の悪化を防止することができるという利点もある。
【００４１】
なお、上述の実施形態では、各透明基板２２，２３にそれぞれ側壁２４，２５，側壁２６，２７を設けているが、図１４に示すように一方の透明基板２２のみに側壁２４，２５を設けて容積部２８を形成するようにしてもよい。ただし、この場合にも、側壁２４，２５の高さを、本三次元光記録媒体用基体１１の用途に応じた高さ（好ましくは、３０μｍ以上５００μｍ以下の高さ）に設定するとともに、外周側の側壁２４の外周側縁部には、全域にわたって傾斜面２４ａを設けることが好ましい。
【００４２】
また、上述の実施形態では、外周側の側壁２４，２６の外周側縁部のみを面取りしているが、図１５に示すように、内周側の側壁２５，２７の内周側縁部にも面取りを施してもよく、さらに、各側壁２４，２５，２６，２７の内側の縁部にも面取りを施してもよい。このように内側の縁部にも面取りを施した場合には、三次元光記録媒体用基体２１の内部全域に樹脂を行きわたらせ易く、記録層内に気泡が生じることを防止することができる。
【００４３】
次に、本発明の第４実施形態としての三次元光記録媒体用基体について説明すると、本三次元光記録媒体用基体４１は、図１６に示すように、一対の透明基板４２，４３と、大小一組の円環状のスペーサ４４，４５とから構成されている。透明基板４２，４３は、円盤状に形成されており、その中央には外周円と同心の円形の穴を有している。スペーサ４４，４５は、透明基板４２，４３間の距離を均一に保つための部材であり、多層光メモリ，ホログラムメモリ等の本三次元光記録媒体用基体４１の用途に応じた厚さ（好ましくは、３０μｍ以上５００μｍ以下の厚さ）に形成されている。スペーサ４４の外径は透明基板４２，４３の外径よりもわずかに小径に設定され、スペーサ４５の内径は透明基板４２，４３の内径と略同径に設定されている。なお、透明基板４２，４３の材質及びスペーサ４４，４５の材質としては、第１実施形態で説明したものを用いることができる。
【００４４】
本三次元光記録媒体用基体４１は、一方の透明基板４２の外周部及び内周部に、それぞれスペーサ４４，４５を接合することにより円環状の側壁を形成したものであり、透明基板４２の外周部上，内周部上にスペーサ４４，４５を積層した後、透明基板４２とスペーサ４４，４５との接触部に光又は熱を当てて部分的に硬化させることによって、透明基板４２とスペーサ４４，４５とを接合している。
【００４５】
本発明の第４実施形態としての三次元光記録媒体用基体４１は上述のように構成されているので、図１７に示すように、一方の透明基板４２には、スペーサ４４，４５により囲まれる容積部（記録層用空間）４６が形成される。この容積部４６は、記録層を形成する樹脂を充填するための容器として機能するものであり、他方の透明基板４３により蓋をすることができる。
【００４６】
したがって、本三次元光記録媒体用基体２１を用いた場合にも、第３実施形態と同様な方法により光記録媒体を製造することが可能になる。つまり、まず、スペーサ４４，４５に囲まれた容積部４６内に記録層を形成する液状の樹脂を充填し（第一の工程）、周囲雰囲気を真空雰囲気にした上で液状樹脂を充填した透明基板４２の上に他方の透明基板４３を重ね合わせ（第二の工程）、光又は熱を加えることにより、スペーサ４４，４５及び容積部４６内の液状樹脂を光硬化又は熱硬化させ、透明基板４３とスペーサ４４，４５とを貼り合わせるとともに記録層を形成するのである（第三の工程）。
【００４７】
このように本三次元光記録媒体用基体４１によれば、一方の透明基板４２の外周部及び内周部に接合されたスペーサ４４，４５により透明基板４２，４３間の隙間間隔が規制されるとともに、透明基板４２とスペーサ４４，４５とにより容積部４６が形成されているので、容積部４６内に記録層を形成する樹脂を充填して、他方の透明基板４３により蓋をするだけで、均一な厚みの記録層を容易に形成することができ、多層光メモリ，ホログラムメモリ等の厚みのある記録層を有する三次元光記録媒体の製造が容易になるという利点がある。
【００４８】
また、本三次元光記録媒体用基体４１によれば、光硬化性又は熱硬化性フィルムからなる円環状のスペーサ４４，４５を透明基板４２，４３の外周部及び内周部に積層し、スペーサ４４，４５の透明基板４２，４３との接触部を部分的に光硬化又は熱硬化させることにより側壁を形成しているので、従来の透明基板をそのまま用いることができるという利点がある。
【００４９】
さらに、外周側のスペーサ４４の外径は、透明基板４２，４３の外径よりもわずかに小径に設定されているので、透明基板４３により蓋をしたときに容積部４６内から樹脂がはみ出した場合でも、外見上目立つことがなく、外観の悪化を防止することができるという利点もある。
以上、本発明の三次元光記録媒体用基体について、第１〜第４実施形態を説明したが、本発明は上述の実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲内で種々変形して実施することができる。例えば、本発明の三次元光記録媒体用基体が適用できる三次元光記録媒体は、上述した各実施形態のような円形ディスク形に限定されるものではなく、メモリカードのようなカード形の三次元光記録媒体等、種々の形状の光記録媒体に適用することができる。例えば、図１８に示すようなカード型の三次元光記録媒体６０に適用する場合には、カード型の一対の透明基板６１，６２の間に環状のスペーサ６３を挟装し、スペーサ６３の一部に内部（記録層用空間）と連通する切れ目（開口部）６４を設けたような構成にしてもよく、また、図１９に示す三次元光記録媒体７０のように、カード型の一対の透明基板７１，７２の一方の外周部に環状のスペーサ７３を固設したような構成にしてもよい。
【００５０】
また、三次元光記録媒体の製造時に、真空雰囲気を用いているが、真空まで達しない減圧雰囲気を用いてもよく、また、必ずしもこのような減圧処理を行なわなくてもよい。
さらに、スペーサの縁部外周に形成する窪み部の形状は、上述の実施形態に限定されるものではなく、記録層用空間内からの樹脂のはみ出しを目立たなくできるような形状であればよい。
【００５１】
【発明の効果】
以上詳述したように、本発明の三次元光記録媒体用基体（請求項１〜４）によれば、一対の透明基板とスペーサとにより記録層を形成する記録層用空間が区画形成されるので、区画形成された記録層用空間内に記録層を形成する樹脂を注入するだけで、均一な厚みの記録層を容易に形成することができ、多層光メモリ，ホログラムメモリ等の厚みのある記録層を有する三次元光記録媒体の製造が容易になるという利点がある。
【００５２】
また、スペーサに設けた開口部により記録層用空間と外部とを連通させた場合には、記録層用空間内を減圧するだけで記録層を形成する樹脂を記録層用空間内に引き込むことが可能になり、均一な厚みの記録層をより容易に形成することができという利点がある。
特に、スペーサとして光硬化性又は熱硬化性フィルムを用いる場合には、透明基板との接合が容易になり、また、従来の透明基板をそのまま用いることができるという利点がある（請求項１）。
【００５３】
また、スペーサを一対の透明基板のうちの少なくとも一方に予め一体に形成した場合には、部品点数を削減することができるという利点がある。
さらに、スペーサの縁部外周に、一対の透明基板の縁部外周よりも窪んだ窪み部が形成した場合には、記録層用空間内の樹脂がはみ出した場合でも外見上目立つことがなく、外観の悪化を防止することができるという利点がある（請求項２〜４）。
【００５４】
そして、本発明の三次元光記録媒体の製造方法（請求項５）によれば、上記のような三次元光記録媒体用基体（請求項１）を用いることにより、多層光メモリ，ホログラムメモリ等の厚みのある記録層を有する三次元光記録媒体を容易に製造することができるという利点がある。
また、別の本発明の三次元光記録媒体の製造方法（請求項６，７）によれば、上記のような三次元光記録媒体用基体を用いることにより、多層光メモリ，ホログラムメモリ等の厚みのある記録層を有する三次元光記録媒体を容易に製造することができるという利点がある。
【図面の簡単な説明】
【図１】本発明の第１実施形態としての三次元光記録媒体用基体の構成を示す斜視図であり、各構成要素毎に分解して示している。
【図２】本発明の第１実施形態としての三次元光記録媒体用基体の構成を示す断面図であり、（ａ）は水平断面図、（ｂ）は縦断面図である。
【図３】本発明の第１実施形態としての三次元光記録媒体用基体を用いた三次元光記録媒体の製造方法を説明するための図であり、（ａ）〜（ｄ）の順に製造工程を示している。
【図４】本発明の第１実施形態としての三次元光記録媒体用基体の他の構成を示す斜視図であり、各構成要素毎に分解して示している。
【図５】本発明の第１実施形態としての三次元光記録媒体用基体の他の構成を示す縦断面図である。
【図６】本発明の第２実施形態としての三次元光記録媒体用基体の構成を示す斜視図であり、各構成要素毎に分解して示している。
【図７】本発明の第２実施形態としての三次元光記録媒体用基体の構成を示す断面図であり、（ａ）は水平断面図、（ｂ）は縦断面図である。
【図８】本発明の第２実施形態としての三次元光記録媒体用基体の他の構成を示す斜視図であり、各構成要素毎に分解して示している。
【図９】本発明の第２実施形態としての三次元光記録媒体用基体の他の構成を示す縦断面図である。
【図１０】本発明の第３実施形態としての三次元光記録媒体用基体の構成を示す斜視図である。
【図１１】本発明の第３実施形態としての三次元光記録媒体用基体の構成を示す縦断面図である。
【図１２】本発明の第３実施形態としての三次元光記録媒体用基体を用いた三次元光記録媒体の製造方法を説明するための図であり、（ａ）〜（ｄ）の順に製造工程を示している。
【図１３】本発明の第３実施形態としての三次元光記録媒体用基体の要部構成を示す縦断面図である。
【図１４】本発明の第３実施形態としての三次元光記録媒体用基体の他の構成を示す縦断面図である。
【図１５】本発明の第３実施形態としての三次元光記録媒体用基体の他の構成を示す縦断面図である。
【図１６】本発明の第４実施形態としての三次元光記録媒体用基体の構成を示す斜視図である。
【図１７】本発明の第４実施形態としての三次元光記録媒体用基体の構成を示す縦断面図である。
【図１８】本発明の三次元光記録媒体用基体の他の実施形態を示す斜視図であり、各構成要素毎に分解して示している。
【図１９】本発明の三次元光記録媒体用基体の他の実施形態を示す斜視図である。
【図２０】本発明の適用対象の一つである多層光メモリの構成を示す模式図である。
【図２１】本発明の適用対象の一つであるホログラムメモリの構成を示す模式図である。
【符号の説明】
１三次元光記録媒体用基体
２，３透明基板
４，５スペーサ
４ａ切れ目（開口部）
６内部空間（記録層用空間）
８記録層を形成する液状の樹脂
９記録層
１１三次元光記録媒体用基体
１２，１３透明基板
１４，１５側壁（スペーサ）
１４ａ切れ込み（開口部）
１８内部空間（記録層用空間）
２１三次元光記録媒体用基体
２２，２３透明基板
２４〜２７側壁（スペーサ）
２８，２９内部空間（記録層用空間）
３０記録層を形成する液状の樹脂
３１記録層
４１三次元光記録媒体用基体
４２，４３透明基板
４４，４５スペーサ
４６内部空間（記録層用空間）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate for a three-dimensional optical recording medium and a method for manufacturing the three-dimensional optical recording medium, which are suitable for manufacturing a large-capacity, high-density optical recording medium such as a multilayer optical memory and a hologram memory.
[0002]
[Prior art]
Conventionally, a spin coating method is known as a method for manufacturing a disk-shaped optical recording medium such as a CD-R. In this method, a coating solution prepared by dissolving an organic dye as a recording material in an appropriate organic solvent is dropped on the information surface of a disk-shaped substrate where prepits and pregrooves are formed, and then the substrate is rotated and centrifuged. The excess coating solution is removed from the information surface by force to form a recording layer.
[0003]
[Problems to be solved by the invention]
By the way, in recent years, as a response to the coming multimedia information age, research and development for further increasing the capacity and density of optical recording media has been carried out. For example, as shown in FIG. 20, the recording layer 101 laminated on the transparent substrate 103 is made thicker than the focal depth of the focused laser beam 102, and the focal position is shifted so that the recording layer 101 is three-dimensional in the depth direction in the medium. As shown in FIG. 21, a multilayer recording type optical recording medium (multilayer optical memory) 100 that performs recording, or a recording layer 108 sandwiched between a pair of transparent substrates 109 and 110, reflects light from an object, signals, and the like. By irradiating a signal beam 106 representing information and a reference beam 107 for causing interference with the signal beam 106 in the recording layer 108, the incident angle of the reference beam 107 is changed little by little, so that Like a hologram type optical recording medium (hologram memory) 105 that multiplex-records a plurality of holograms at the same location, not only in the plane of the recording layer but also in the thickness direction three-dimensionally. Three-dimensional optical recording medium having improved recording capacity by recording have been developed.
[0004]
Both the multilayer optical memory 100 and the hologram memory 105 contain a large amount of synthetic resin (90% by weight or more) in the recording layer, and light utilizing the structural change caused by heat or light of the resin and the accompanying change in optical properties. It is a recording medium, and the thickness of the recording layer is several tens to several hundreds μm, which is very thick compared to a conventional optical recording medium. Also, these optical recording media require three-dimensional recording in the thickness direction of the recording layer, so that the uniformity of the recording layer thickness is more stringent than conventional optical recording media that record in a plane. Is done. That is, the three-dimensional optical recording medium must have a thicker recording layer and a more uniform thickness than a two-dimensional one.
[0005]
As a method for forming a layer having a uniform thickness with a material containing a large amount of synthetic resin, the above-described spin coating method is generally used. However, if the layer is a relatively thin layer of less than 10 μm, such as a CD-R. Although it can be formed uniformly, the coating liquid spreads due to the action of centrifugal force, so it is difficult to form a thicker layer, particularly 100 μm or more. Further, if the substrate is rotated at a low speed in order to form a thick layer, the film thickness of the edge portion of the disk becomes particularly large, and it becomes impossible to ensure the uniformity of the thickness. Further, although a method of increasing the viscosity of the coating solution is also conceivable, it is often difficult to change the composition of the coating solution for viscosity control in view of the influence on the recording characteristics of the medium.
[0006]
The present invention was devised in view of the above-mentioned problems, and a three-dimensional optical recording medium substrate which can easily manufacture a three-dimensional optical recording medium having a relatively thick recording layer containing a large amount of synthetic resin, and It is an object to provide a method for manufacturing a three-dimensional optical recording medium.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, the substrate for a three-dimensional optical recording medium of the present invention is a substrate for a three-dimensional optical recording medium that records information three-dimensionally in a recording layer containing a large amount of synthetic resin. And a pair of transparent substrates that form both sides of the recording layer space forming the recording layer and the pair of transparent substrates, and couple the pair of transparent substrates at a predetermined distance. And a spacer for defining an edge of the recording layer space.Further, the spacer is made of a photo-curable or thermosetting film, and the film is interposed between the pair of transparent substrates, and is photo-cured or thermo-cured, whereby the pair of transparent substrates and the film are used. The spacer is integrated(Claim 1).
[0008]
  Here, it is preferable that the spacer is provided with an opening that opens the recording layer space to the outside.TheThe pair of transparent substrates are disk-shaped, the recording layer space is formed in an annular shape, and the spacers are provided on the outer peripheral edge and the inner peripheral edge of the annular recording layer space, respectively. More preferredYes.
[0009]
  Further, it is preferable that the spacer is integrally formed in advance on at least one of the pair of transparent substrates.Yes.
  Also,Another substrate for a three-dimensional optical recording medium of the present invention is a substrate for a three-dimensional optical recording medium for recording information three-dimensionally in a recording layer containing a large amount of synthetic resin, A pair of transparent substrates that form both sides of the recording layer space to be formed and the pair of transparent substrates are interposed between the pair of transparent substrates, and the pair of transparent substrates are coupled with a predetermined distance. And a spacer that defines the edge,On the outer periphery of the edge of the spacer, a recess is formed that is recessed from the outer periphery of the edge of the pair of transparent substrates.(Claim 2).
  hereMore preferably, the recess is formed by setting the entire outer edge surface of the spacer to a position displaced from the outer edge surfaces of the pair of transparent substrates into the space forming the recording layer. Preferred (claims)3). Alternatively, it is more preferable that the hollow portion is constituted by a chamfered portion formed by chamfering the outer surface of the edge portion of the spacer.4).
[0010]
  The method for producing a three-dimensional optical recording medium of the present invention comprises the above-described substrate for a three-dimensional optical recording medium (claims).1)A substrate for a three-dimensional optical recording medium, wherein the spacer is provided with an opening for opening the recording space to the outside.A method of manufacturing a three-dimensional optical recording medium using a substrate, the base assembly step of assembling the base for three-dimensional optical recording medium by combining the pair of transparent substrates and the spacer, A resin injection step of injecting a photocurable or thermosetting liquid resin for forming the recording layer into the recording layer space, and a photocuring or thermosetting of the liquid resin injected into the recording medium space. And a resin curing process to be performed (claims)5).
[0011]
  Furthermore, another method for producing a three-dimensional optical recording medium of the present invention is a substrate for a three-dimensional optical recording medium for recording information three-dimensionally in a recording layer containing a large amount of synthetic resin, A pair of transparent substrates that form both sides of a recording layer space for forming a recording layer, and the pair of transparent substrates are interposed between the pair of transparent substrates, and the pair of transparent substrates are coupled to each other with a predetermined distance. A method of manufacturing a three-dimensional optical recording medium using a three-dimensional optical recording medium substrate comprising a spacer that defines an edge of a working space, wherein one of the pair of transparent substrates is one of the spacers. A first step of filling the space for the recording layer on one transparent substrate with a part or the whole thereof with a photocurable or thermosetting liquid resin for forming the recording layer, and the liquid resin The second process of superimposing the other substrate on the one transparent substrate And a third step of photocuring or thermosetting the liquid resin filled between the spacers, and prior to the second step, the periphery of the substrate for the three-dimensional optical recording medium is made a vacuum atmosphere. It is characterized by having a process (claim 6).
  Here, it is preferable that the spacer is made of a photocurable or thermosetting film, and the spacer is cured together with the liquid resin in the third step, and the transparent substrate and the spacer are bonded together.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
First, the three-dimensional optical recording medium substrate as the first embodiment of the present invention will be described. Note that the three-dimensional optical recording medium according to the present embodiment has a disk shape, and the recording layer is formed in an annular shape (doughnut shape).
[0014]
The substrate 1 for a three-dimensional optical recording medium is a substrate for a three-dimensional optical recording medium suitable for use in manufacturing a large-capacity, high-density three-dimensional optical recording medium such as a multilayer optical memory or a hologram memory, and is shown in FIG. In this way, it is composed of a pair of transparent substrates 2 and 3 and a pair of large and small annular spacers 4 and 5.
The transparent substrates 2 and 3 are formed in a disk shape, and have a circular hole concentric with the outer circumference circle at the center thereof. As the material of the transparent substrates 2 and 3, glass or transparent resin (for example, polycarbonate resin, acrylic resin, methacrylic resin, polystyrene resin, vinyl chloride resin, epoxy resin, polyester resin, amorphous polyolefin, etc.) can be used.
[0015]
The spacers 4 and 5 are members for keeping the distance between the transparent substrates 2 and 3 uniform in a predetermined size, and are in accordance with the use of the substrate for the three-dimensional optical recording medium 1 such as a multilayer optical memory or a hologram memory. It is formed to a thickness (preferably, a thickness of 30 μm to 500 μm). The spacer 4 is interposed between the outer peripheral portions 2 a and 3 a of the transparent substrates 2 and 3, and the outer diameter of the spacer 4 is set to be substantially the same as the outer diameter of the transparent substrates 2 and 3. The spacer 5 is interposed between the inner peripheral portions 2 b and 3 b of the transparent substrates 2 and 3, and the inner diameter of the spacer 5 is set to be substantially the same as the inner diameter of the transparent substrates 2 and 3. The spacer 4 is partially provided with a cut 4a, and an opening of the spacer 4 is formed in the cut 4a.
[0016]
The material of the spacers 4 and 5 may be a photo-curing or thermosetting resin such as an acrylic resin, an epoxy resin, an isocyanate resin, etc., but preferably the refraction of the resin forming the recording layer. Try to select the one that is close to the rate. In addition, as the spacer according to the first embodiment of the present invention, it is preferable to use spacers 4 and 5 that have been independently formed in advance as shown in FIG. The spacer may be applied on the other substrate, bonded to the other substrate, and then cured.
[0017]
In the case where the spacers are formed independently in advance, for example, a photo-curing or thermosetting resin is used with a predetermined thickness according to the application using a known method such as a die casting method, a dip coating method, or a roll coating method. After the film is partially cured with light or heat, the spacers 4 and 5 can be obtained as annular resin films by punching into an appropriate shape. Alternatively, an annular resin can also be obtained by injecting a photocurable or thermosetting resin into a mold according to the shape of the spacers 4 and 5, partially curing with light or heat, and then removing from the mold. Spacers 4 and 5 can be obtained as a film.
[0018]
The three-dimensional optical recording medium substrate 1 is integrally formed by sandwiching spacers 4 and 5 between the outer peripheral portions 2a and 3a and the inner peripheral portions 2b and 3b of the transparent substrates 2 and 3, respectively. After the spacers 4 and 5 are laminated on the outer peripheral part 3a or 2a and the inner peripheral part 3b or 2b of one transparent substrate 2, respectively, the other transparent substrate 3 is further laminated and photocurable. Alternatively, it is formed by further curing by applying light or heat to the spacers 4 and 5 which are thermosetting resin films.
[0019]
Since the three-dimensional optical recording medium substrate 1 according to the first embodiment of the present invention is configured as described above, in manufacturing the three-dimensional optical recording medium, first, as described above, the transparent substrates 2 and 3 are used. The three-dimensional optical recording medium substrate 1 is formed by combining the spacers 4 and 5 (substrate assembling step). As a result, inside the three-dimensional optical recording medium substrate 1, as shown in FIGS. 2A and 2B, an internal space (recording) surrounded by the transparent substrates 2 and 3 and the spacers 4 and 5 is recorded. Layer space) 6 is formed. The internal space 6 is a space for filling the resin forming the recording layer, and communicates with the outside through a cut (opening) 4 a formed in the outer spacer 4.
[0020]
Therefore, when manufacturing an optical recording medium using the substrate for three-dimensional optical recording medium 1, for example, the following method can be used. The manufacturing method of the present three-dimensional optical recording medium will be described with reference to FIG. 3. First, as shown in FIG. 3A, the periphery of the substrate 1 for a three-dimensional optical recording medium assembled in advance in the base assembly process. Create a vacuum atmosphere. Then, as shown in FIG. 3B, the cut 4a formed in the spacer 4 is immersed in a container 7 filled with a liquid resin 8 forming a recording layer in a vacuum atmosphere.
[0021]
As the resin 8 forming the recording layer, a photo-curing or thermosetting resin, for example, a polymer that is polymerized by a radical reaction of an ethylenically unsaturated double bond-containing compound such as an acrylic or methacrylic resin, or an epoxy resin A material containing a photo-curable monomer such as a photo-reactive cation, and a binder resin that can be photo-cured or heat-cured as necessary, a combination of poly (p-hydroxystyrene) and hexamethoxymethylmelamine Although such a thing can be considered, specifically, it selects suitably according to a recording system.
[0022]
Next, as shown in FIG. 3C, the vacuum atmosphere is released and the ambient atmosphere of the three-dimensional optical recording medium substrate 1 is returned to atmospheric pressure. As a result, the liquid resin 8 in the container 7 is filled into the internal space 6 that is pressed by the atmospheric pressure and is in a vacuum state from the cut 4a (the resin injection step).
Then, by applying light or heat to the substrate 1 for a three-dimensional optical recording medium, the liquid resin 8 sucked into the internal space 6 from the cut 4a is photocured or thermally cured, as shown in FIG. 3 (d). Then, the recording layer 9 is formed (resin curing step). The optical recording medium is manufactured through the above steps.
[0023]
As described above, according to the substrate 1 for a three-dimensional optical recording medium, the gap between the transparent substrates 2 and 3 is set in advance by the spacers 4 and 5 at a predetermined interval, and the space in which the recording layer 9 is formed is a spacer. Since the closed space communicates with the outside only by the four cuts 4a, the recording layer 9 having a uniform thickness can be formed by simply drawing the resin for forming the recording layer in the closed space (internal space) 6 in a vacuum atmosphere. There is an advantage that it can be easily formed, and manufacturing of a three-dimensional optical recording medium having a thick recording layer 9 such as a multilayer optical memory or a hologram memory becomes easy.
[0024]
Further, by using a photocurable or thermosetting film as the spacers 4 and 5, there is an advantage that joining with the transparent substrates 2 and 3 is facilitated, and a conventional transparent substrate can be used as it is.
In the above-described embodiment, the outer spacer 4 is provided with a cut 4a, and the cut 4a is used as a passage for filling the liquid resin forming the recording layer in the internal space 6. FIG. As shown, a cut (opening) 5a may be provided in the inner circumferential spacer 5 and the cut 5a may be used as a passage for filling the internal space 6 with a liquid resin that forms a recording layer.
[0025]
In the above-described embodiment, the spacers 4 and 5 are formed of a photocurable or thermosetting resin film and bonded to the transparent substrates 2 and 3 using photocuring or thermosetting. As shown, the spacers 4 and 5 may be bonded to the transparent substrates 2 and 3 using a bonding resin 10. In this case, the material of the spacers 4 and 5 does not have to be a photo-curing or thermosetting resin. For example, the materials mentioned above as the substrate material or a polyamide-based resin can be used. In this case, however, the refractive index of the bonding resin 10 and the spacers 4 and 5 is preferably close to the refractive index of the resin forming the recording layer.
[0026]
The outer diameter of the spacer 4 on the outer peripheral side is set to be slightly smaller than the outer diameter of the transparent substrates 2 and 3 in order to prevent deterioration of the appearance due to the sticking of the bonding resin 10. It is preferable to form a recessed portion that is recessed from the outer peripheral surface of the substrate. Furthermore, the inner diameter of the spacer 5 on the inner peripheral side is also set to be slightly larger than the inner diameter of the transparent substrates 2 and 3 to form a hollow portion that is recessed from the inner peripheral surface of the transparent substrates 2 and 3. It is preferable.
[0027]
Next, the three-dimensional optical recording medium substrate according to the second embodiment of the present invention will be described. The three-dimensional optical recording medium substrate 11 includes a pair of transparent substrates 12 and 13 as shown in FIG. Has been.
The transparent substrates 12 and 13 are formed in a disc shape, and have a circular hole concentric with the outer circumference circle at the center thereof. In addition, annular side walls 14 and 15 are integrally formed on the outer peripheral portion and the inner peripheral portion of one transparent substrate 12, respectively. These side walls 14 and 15 function as spacers that keep the internal gap height uniform when the transparent substrates 12 and 13 are overlapped, and are used for this three-dimensional optical recording medium such as a multilayer optical memory or a hologram memory. The substrate 1 is formed to have a height (preferably, a height of 30 μm or more and 500 μm or less) according to the application. Further, the outer side wall 14 is partially provided with a notch 14a, and an opening is formed in the notch 14a.
[0028]
The substrate 11 for the three-dimensional optical recording medium is obtained by integrating the transparent substrates 12 and 13 described above, and an adhesive such as a bonding resin is applied to the side walls 14 and 15 of the one transparent substrate 12. After the application, the transparent substrates 12 and 13 are integrated by overlapping and bonding the other transparent substrate 13.
Since the three-dimensional optical recording medium substrate 11 according to the second embodiment of the present invention is configured as described above, in manufacturing the three-dimensional optical recording medium, first, as described above, the transparent substrates 12, 13 are used. Are combined to form a substrate 1 for a three-dimensional optical recording medium (substrate assembly step). As a result, inside the substrate 11 for the three-dimensional optical recording medium, as shown in FIGS. 7A and 7B, the side walls 14 and 15 serve as spacers and are surrounded by the transparent substrates 12 and 13. A space (recording layer space) 18 is formed. The internal space 18 is a space for filling the resin forming the recording layer, and communicates with the outside through a notch 14 a provided in the outer peripheral side wall 14.
[0029]
Therefore, even when the three-dimensional optical recording medium substrate 11 is used, it is possible to manufacture the optical recording medium by the same method as in the first embodiment. That is, first, the ambient atmosphere of the three-dimensional optical recording medium substrate 11 assembled in advance in the substrate assembling process is set to a vacuum atmosphere, and the notch 14a provided on the outer peripheral side wall 14 is formed in the vacuum atmosphere to form a recording layer. In a container filled with the resin, the vacuum atmosphere is released and the ambient atmosphere of the three-dimensional optical recording medium substrate 11 is returned to atmospheric pressure (resin injection step). Next, the liquid resin sucked into the internal space 18 from the notch 14a is photocured or thermally cured to form a recording layer (resin curing step).
[0030]
Thus, according to the substrate 11 for a three-dimensional optical recording medium, a recording layer having a uniform thickness can be easily formed as in the first embodiment, and a thick recording layer such as a multilayer optical memory or a hologram memory can be formed. There is an advantage that it is easy to manufacture a three-dimensional optical recording medium having Furthermore, according to the substrate 11 for the three-dimensional optical recording medium, the side walls 14 and 15 formed integrally with the transparent substrate 12 function as spacers, so that it is not necessary to provide a separate spacer and the number of parts can be reduced. There is also an advantage.
[0031]
In the above-described embodiment, the notch 14a is provided in the outer peripheral side wall 14, and the liquid resin for forming the recording layer is filled in the internal space 18 from the passage formed by the notch 14a. As shown in FIG. 8, a notch 15a may be provided in the inner peripheral side wall 15, and a liquid resin forming a recording layer may be filled into the internal space 18 from a passage formed by the notch 15a.
[0032]
In the above-described embodiment, the side walls 14 and 15 are provided only on one transparent substrate 12, but the side walls 14 and 15 and the side walls 16 and 17 are provided on each transparent substrate 12 and 13, as shown in FIG. It may be. However, the height of the side walls 14 and 15 and the side walls 16 and 17 in this case is the height corresponding to the use of the substrate 11 for the three-dimensional optical recording medium (preferably when the transparent substrates 12 and 13 are superposed. The height is set to 30 μm or more and 500 μm or less), and at least one of the side walls 14 and 16 is provided with a cut (in FIG. 9, the side walls 14 and 16 are provided with notches 14a and 16a, respectively) It is necessary to communicate the space 18 with the outside.
[0033]
The three-dimensional optical recording medium substrate according to the first embodiment and the second embodiment described above includes a pair of disc-shaped transparent substrates and two sandwiched between the outer peripheral portion and the inner peripheral portion of the pair of transparent substrates. The three-dimensional optical recording medium substrate according to the present invention has a configuration in which one of the two spacers is provided with an opening, and the three-dimensional optical recording medium substrate according to the present invention is described below in a third embodiment. It is also possible to adopt a configuration as in the fourth embodiment.
[0034]
First, a three-dimensional optical recording medium substrate according to a third embodiment of the present invention will be described. The three-dimensional optical recording medium substrate 21 is a multi-layer optical memory, as in the first and second embodiments. , A base for a three-dimensional optical recording medium suitable for use in the production of a large-capacity, high-density optical recording medium such as a holographic memory, and is composed of a pair of transparent substrates 22 and 23 as shown in FIG. .
[0035]
The transparent substrates 22 and 23 are formed in a disk shape, and have a circular hole concentric with the outer circumference circle at the center thereof. In addition, annular side walls 24 and 25 and side walls 26 and 27 are integrally formed on the outer peripheral portion 22a and the inner peripheral portion 23a of the transparent substrates 22 and 23, respectively. The side walls 24 and 25 and the side walls 26 and 27 function as spacers that keep the internal gap height uniform when the transparent substrates 22 and 23 are overlaid. The original optical recording medium substrate 21 is formed to have a height (preferably, the sum of the height when the transparent substrates 22 and 23 are overlapped is 30 μm or more and 500 μm or less). Further, the outer peripheral side edges of the outer peripheral side walls 24 and 26 are chamfered, and inclined surfaces (chamfered portions) 24a and 26a are provided, which are recessed inward from the outer peripheral surfaces of the transparent substrates 22 and 23. A recess is formed. In addition, as a material of the transparent substrates 22 and 23, what was demonstrated in 1st Embodiment can be used.
[0036]
Since the three-dimensional optical recording medium substrate 21 according to the third embodiment of the present invention is configured as described above, the transparent substrates 22 and 23 have side walls 24 and 25, respectively, as shown in FIG. Volume portions (recording layer spaces) 28 and 29 surrounded by 26 and 27 are formed. These volume portions 28 and 29 function as containers for filling the resin forming the recording layer, and can be covered with the other transparent substrate 22 (or 23).
[0037]
Therefore, when manufacturing an optical recording medium using the substrate 21 for the three-dimensional optical recording medium, for example, the following method can be used. The manufacturing method of the three-dimensional optical recording medium will be described with reference to FIG. 12. First, as shown in FIG. 12A, a liquid resin for forming a recording layer in the volume portion 28 of one transparent substrate 22. 30 is filled (first step).
[0038]
Then, as shown in FIG. 12B, the ambient atmosphere of the substrate 21 for the three-dimensional optical recording medium is made a vacuum atmosphere, and as shown in FIG. 12C, the transparent substrate filled with the liquid resin 30 in the vacuum atmosphere. The other transparent substrate 23 is overlaid on 22 (second step). At this time, the volume portion 28 should be filled with a sufficient amount of the resin 30 such that the liquid resin 30 protrudes from the overlapping portion of the side wall 26 of the transparent substrate 23 and the side wall 24 of the transparent substrate 22. preferable.
[0039]
Finally, the liquid resin 30 is photocured or heat cured by applying light or heat to the three-dimensional optical recording medium substrate 21, and the transparent substrates 22 and 23 are bonded together as shown in FIG. Then, the recording layer 31 is formed (third step). The optical recording medium is manufactured through the above steps.
As described above, according to the substrate 21 for the three-dimensional optical recording medium, the side walls 24 and 25 and the side walls 26 and 27 respectively provided on the outer peripheral portion and the inner peripheral portion of the transparent substrates 22 and 23 are provided between the transparent substrates 22 and 23. The gap interval is regulated, and the volume portions 28 and 29 are formed in the transparent substrates 22 and 23. Therefore, the resin for forming the recording layer 31 is filled in the volume portion 28 of one transparent substrate 22, By simply covering with the other transparent substrate 23, the recording layer 31 having a uniform thickness can be easily formed, and an optical recording medium having a thick recording layer 31 such as a multilayer optical memory or a hologram memory can be easily manufactured. There is an advantage of becoming.
[0040]
Further, according to the substrate 21 for the three-dimensional optical recording medium, the side walls 24 and 25 and the side walls 26 and 27 are integrally formed with the transparent substrates 22 and 23, respectively, so that the number of parts can be reduced. is there.
Further, since the inclined surfaces 24a and 26a are provided by chamfering the outer peripheral side edge portions of the outer peripheral side walls 24 and 26, when the transparent substrates 22 and 23 are overlapped, a cut (dent) is formed in the overlapped portion. 13), as shown in FIG. 13, even when the internal resin 30 protrudes, there is an advantage that the appearance is not noticeable and deterioration of the appearance can be prevented.
[0041]
In the above-described embodiment, the transparent substrates 22 and 23 are provided with the side walls 24 and 25 and the side walls 26 and 27, respectively, but the side walls 24 and 25 are provided only on one transparent substrate 22 as shown in FIG. Thus, the volume portion 28 may be formed. However, also in this case, the height of the side walls 24 and 25 is set to a height (preferably, a height of 30 μm or more and 500 μm or less) according to the application of the substrate 11 for the three-dimensional optical recording medium. It is preferable to provide an inclined surface 24a over the entire outer peripheral side edge of the side wall 24 on the side.
[0042]
In the above-described embodiment, only the outer peripheral side edges of the outer peripheral side walls 24 and 26 are chamfered. However, as shown in FIG. 15, the inner peripheral side edges of the inner peripheral side walls 25 and 27 are chamfered. Also, chamfering may be performed, and chamfering may also be performed on the inner edges of the side walls 24, 25, 26, 27. When the inner edge portion is chamfered in this way, the resin can be easily distributed throughout the entire interior of the three-dimensional optical recording medium substrate 21, and bubbles can be prevented from being generated in the recording layer.
[0043]
Next, a three-dimensional optical recording medium substrate as a fourth embodiment of the present invention will be described. The three-dimensional optical recording medium substrate 41 includes a pair of transparent substrates 42 and 43, as shown in FIG. It comprises a pair of large and small annular spacers 44 and 45. The transparent substrates 42 and 43 are formed in a disk shape, and have a circular hole concentric with the outer circumference circle at the center thereof. The spacers 44 and 45 are members for keeping the distance between the transparent substrates 42 and 43 uniform, and have a thickness (preferably, depending on the use of the substrate for a three-dimensional optical recording medium 41 such as a multilayer optical memory or a hologram memory). , 30 μm or more and 500 μm or less in thickness). The outer diameter of the spacer 44 is set to be slightly smaller than the outer diameter of the transparent substrates 42 and 43, and the inner diameter of the spacer 45 is set to be approximately the same as the inner diameter of the transparent substrates 42 and 43. As the material of the transparent substrates 42 and 43 and the material of the spacers 44 and 45, those described in the first embodiment can be used.
[0044]
The substrate for a three-dimensional optical recording medium 41 has annular side walls formed by bonding spacers 44 and 45 to the outer peripheral portion and inner peripheral portion of one transparent substrate 42, respectively. After the spacers 44 and 45 are stacked on the outer peripheral portion and the inner peripheral portion, the transparent substrate 42 and the spacer are partially cured by applying light or heat to the contact portion between the transparent substrate 42 and the spacers 44 and 45. 44 and 45 are joined.
[0045]
Since the three-dimensional optical recording medium substrate 41 according to the fourth embodiment of the present invention is configured as described above, one transparent substrate 42 is surrounded by spacers 44 and 45 as shown in FIG. A volume (recording layer space) 46 is formed. The volume portion 46 functions as a container for filling the resin forming the recording layer, and can be covered with the other transparent substrate 43.
[0046]
Accordingly, even when this three-dimensional optical recording medium substrate 21 is used, an optical recording medium can be manufactured by the same method as in the third embodiment. That is, first, a liquid resin for forming a recording layer is filled in the volume portion 46 surrounded by the spacers 44 and 45 (first step), and the transparent atmosphere is filled with the liquid resin after setting the ambient atmosphere to a vacuum atmosphere. The other transparent substrate 43 is overlaid on the substrate 42 (second step), and the liquid resin in the spacers 44 and 45 and the volume portion 46 is photocured or thermocured by applying light or heat to form a transparent substrate. 43 and spacers 44 and 45 are bonded together and a recording layer is formed (third step).
[0047]
As described above, according to the substrate for a three-dimensional optical recording medium 41, the gap interval between the transparent substrates 42 and 43 is regulated by the spacers 44 and 45 bonded to the outer peripheral portion and the inner peripheral portion of one transparent substrate 42. At the same time, since the volume portion 46 is formed by the transparent substrate 42 and the spacers 44 and 45, the resin for forming the recording layer is filled in the volume portion 46 and the other transparent substrate 43 is simply covered. There is an advantage that a recording layer having a uniform thickness can be easily formed, and a three-dimensional optical recording medium having a thick recording layer such as a multilayer optical memory or a hologram memory can be easily manufactured.
[0048]
Further, according to the substrate for a three-dimensional optical recording medium 41, annular spacers 44 and 45 made of a photocurable or thermosetting film are laminated on the outer peripheral portion and the inner peripheral portion of the transparent substrates 42 and 43, and the spacer Since the side walls are formed by partially photocuring or thermosetting the contact portions of 44 and 45 with the transparent substrates 42 and 43, there is an advantage that a conventional transparent substrate can be used as it is.
[0049]
Further, since the outer diameter of the spacer 44 on the outer peripheral side is set to be slightly smaller than the outer diameter of the transparent substrates 42 and 43, the resin protrudes from the inside of the volume portion 46 when the transparent substrate 43 is covered. Even in this case, there is an advantage that the appearance is not conspicuous and deterioration of the appearance can be prevented.
The first to fourth embodiments of the substrate for a three-dimensional optical recording medium of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and does not depart from the spirit of the present invention. Various modifications can be made. For example, the three-dimensional optical recording medium to which the substrate for the three-dimensional optical recording medium of the present invention can be applied is not limited to the circular disk shape as in each of the embodiments described above, but a card-shaped tertiary such as a memory card. The present invention can be applied to optical recording media of various shapes such as original optical recording media. For example, when applied to a card-type three-dimensional optical recording medium 60 as shown in FIG. 18, an annular spacer 63 is sandwiched between a pair of card-type transparent substrates 61, 62, and A section (opening) 64 that communicates with the interior (recording layer space) may be provided in the part, and a pair of card-types may be provided as in the three-dimensional optical recording medium 70 shown in FIG. A configuration in which an annular spacer 73 is fixed to one outer peripheral portion of the transparent substrates 71 and 72 may be employed.
[0050]
In addition, a vacuum atmosphere is used when manufacturing the three-dimensional optical recording medium. However, a reduced pressure atmosphere that does not reach the vacuum may be used, and such a reduced pressure process is not necessarily performed.
Further, the shape of the recess formed on the outer periphery of the edge of the spacer is not limited to the above-described embodiment, and may be any shape that makes the protrusion of the resin from the recording layer space inconspicuous.
[0051]
【The invention's effect】
  As described in detail above, the substrate for a three-dimensional optical recording medium of the present invention4), The recording layer space for forming the recording layer is partitioned by the pair of transparent substrates and the spacers. Therefore, the resin for forming the recording layer can be injected into the partitioned recording layer space. Therefore, there is an advantage that a recording layer having a uniform thickness can be easily formed, and a three-dimensional optical recording medium having a thick recording layer such as a multilayer optical memory or a hologram memory can be easily manufactured.
[0052]
  Further, when the recording layer space is communicated with the outside through the opening provided in the spacer, the resin for forming the recording layer can be drawn into the recording layer space simply by reducing the pressure in the recording layer space. This makes it possible to form a recording layer with a uniform thickness more easily.The
  In particular, when a photocurable or thermosetting film is used as the spacer, there is an advantage that joining with a transparent substrate is facilitated, and a conventional transparent substrate can be used as it is (claims).1).
[0053]
  In addition, when the spacer is integrally formed in advance on at least one of the pair of transparent substrates, there is an advantage that the number of parts can be reduced.The
  In addition, when a recess is formed on the outer periphery of the spacer, which is recessed from the outer periphery of the pair of transparent substrates, even if the resin in the recording layer space protrudes, the appearance does not stand out. Can be prevented from deteriorating (claims)2~4).
[0054]
  According to the method for manufacturing a three-dimensional optical recording medium of the present invention (Claim 5), a multilayer optical memory, a hologram memory, or the like can be obtained by using the above three-dimensional optical recording medium substrate (Claim 1). There is an advantage that a three-dimensional optical recording medium having a thick recording layer can be easily manufactured.
  Another method for producing a three-dimensional optical recording medium of the present invention (claim 6)., 7), It is possible to easily manufacture a three-dimensional optical recording medium having a thick recording layer, such as a multilayer optical memory or a hologram memory, by using the substrate for a three-dimensional optical recording medium as described above. There is.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a substrate for a three-dimensional optical recording medium as a first embodiment of the present invention, which is disassembled for each component.
2A and 2B are cross-sectional views showing a configuration of a substrate for a three-dimensional optical recording medium as a first embodiment of the present invention, wherein FIG. 2A is a horizontal cross-sectional view and FIG. 2B is a vertical cross-sectional view.
FIG. 3 is a diagram for explaining a method of manufacturing a three-dimensional optical recording medium using the three-dimensional optical recording medium substrate as the first embodiment of the present invention, manufactured in the order of (a) to (d). The process is shown.
FIG. 4 is a perspective view showing another configuration of the substrate for a three-dimensional optical recording medium as the first embodiment of the present invention, which is disassembled for each component.
FIG. 5 is a longitudinal sectional view showing another configuration of the three-dimensional optical recording medium substrate according to the first embodiment of the present invention.
FIG. 6 is a perspective view showing a configuration of a substrate for a three-dimensional optical recording medium as a second embodiment of the present invention, which is disassembled for each component.
7A and 7B are cross-sectional views showing a configuration of a substrate for a three-dimensional optical recording medium as a second embodiment of the present invention, wherein FIG. 7A is a horizontal cross-sectional view and FIG. 7B is a vertical cross-sectional view.
FIG. 8 is a perspective view showing another configuration of a substrate for a three-dimensional optical recording medium as a second embodiment of the present invention, which is disassembled for each component.
FIG. 9 is a longitudinal sectional view showing another configuration of a substrate for a three-dimensional optical recording medium as a second embodiment of the present invention.
FIG. 10 is a perspective view showing a configuration of a substrate for a three-dimensional optical recording medium as a third embodiment of the present invention.
FIG. 11 is a longitudinal sectional view showing a configuration of a substrate for a three-dimensional optical recording medium as a third embodiment of the present invention.
FIG. 12 is a diagram for explaining a method of manufacturing a three-dimensional optical recording medium using a substrate for a three-dimensional optical recording medium as a third embodiment of the present invention, manufactured in the order of (a) to (d). The process is shown.
FIG. 13 is a longitudinal cross-sectional view showing the main configuration of a three-dimensional optical recording medium substrate according to a third embodiment of the present invention.
FIG. 14 is a longitudinal sectional view showing another configuration of a three-dimensional optical recording medium substrate according to a third embodiment of the present invention.
FIG. 15 is a longitudinal sectional view showing another configuration of a substrate for a three-dimensional optical recording medium as a third embodiment of the present invention.
FIG. 16 is a perspective view showing a configuration of a substrate for a three-dimensional optical recording medium as a fourth embodiment of the present invention.
FIG. 17 is a longitudinal sectional view showing a configuration of a substrate for a three-dimensional optical recording medium as a fourth embodiment of the present invention.
FIG. 18 is a perspective view showing another embodiment of the substrate for a three-dimensional optical recording medium of the present invention, which is disassembled for each component.
FIG. 19 is a perspective view showing another embodiment of the substrate for a three-dimensional optical recording medium of the present invention.
FIG. 20 is a schematic diagram showing the configuration of a multilayer optical memory that is one of the objects to which the present invention is applied.
FIG. 21 is a schematic diagram showing the configuration of a hologram memory that is one of the objects to which the present invention is applied.
[Explanation of symbols]
1 Substrate for three-dimensional optical recording medium
2, 3 Transparent substrate
4,5 spacer
4a Cut (opening)
6 Internal space (recording layer space)
8 Liquid resin forming the recording layer
9 Recording layer
11 Substrate for three-dimensional optical recording medium
12, 13 Transparent substrate
14,15 Side wall (spacer)
14a notch (opening)
18 Internal space (recording layer space)
21 Substrate for three-dimensional optical recording medium
22, 23 Transparent substrate
24-27 Side Wall (Spacer)
28, 29 Internal space (recording layer space)
30 Liquid resin forming the recording layer
31 Recording layer
41 Substrate for three-dimensional optical recording medium
42, 43 Transparent substrate
44, 45 Spacer
46 Internal space (recording layer space)

Claims

A substrate for a three-dimensional optical recording medium for recording information three-dimensionally in a recording layer containing a large amount of synthetic resin,
A pair of transparent substrates that form both sides of a recording layer space for forming the recording layer;
The spacer is interposed between the pair of transparent substrates, and is configured to couple the pair of transparent substrates with a predetermined distance, and to form an edge of the recording layer space.
The spacer is made of a photocurable or thermosetting film, and the film is interposed between the pair of transparent substrates, and is photocured or thermoset, whereby the pair of transparent substrates and the spacer made of the film A substrate for a three-dimensional optical recording medium, wherein the substrate is integrated.

A substrate for a three-dimensional optical recording medium for recording information three-dimensionally in a recording layer containing a large amount of synthetic resin,
A pair of transparent substrates that form both sides of a recording layer space for forming the recording layer;
The spacer is interposed between the pair of transparent substrates, and is configured to couple the pair of transparent substrates with a predetermined distance, and to form an edge of the recording layer space.
A substrate for a three-dimensional optical recording medium, characterized in that a recess is formed in the outer periphery of the edge of the spacer, which is recessed from the outer periphery of the edge of the pair of transparent substrates.

The recess is formed by setting the entire outer edge surface of the spacer at a position displaced from the outer surface of the edge of the pair of transparent substrates into the space for forming the recording layer. The substrate for a three-dimensional optical recording medium according to claim 2.

3. The substrate for a three-dimensional optical recording medium according to claim 2, wherein the hollow portion is constituted by a chamfered portion formed by chamfering an outer surface of an edge portion of the spacer.

2. The three-dimensional optical recording medium substrate according to claim 1, wherein the spacer is provided with an opening for opening the recording space to the outside. A method of manufacturing
A base assembly process for assembling the three-dimensional optical recording medium base by combining the pair of transparent substrates and the spacer;
A resin injection step of injecting a photocurable or thermosetting liquid resin for forming the recording layer into the recording layer space from the opening;
A method for producing a three-dimensional optical recording medium, comprising: a resin curing step in which a liquid resin injected into the recording medium space is photocured or thermally cured.

A substrate for a three-dimensional optical recording medium for recording information three-dimensionally in a recording layer containing a large amount of synthetic resin, and a pair of sections for forming both sides of a recording layer space for forming the recording layer A three-dimensional structure composed of a transparent substrate and a spacer that is interposed between the pair of transparent substrates, joins the pair of transparent substrates with a predetermined distance, and defines an edge of the recording layer space. A method for producing a three-dimensional optical recording medium using an optical recording medium substrate,
Of the pair of transparent substrates, the space for the recording layer on one transparent substrate on which a part or all of the spacer is mounted is filled with a photocurable or thermosetting liquid resin for forming the recording layer. The first step to
A second step of superimposing the other substrate on the one transparent substrate filled with a liquid resin;
And a third step of photocuring or thermosetting the liquid resin filled between the spacers,
A method for producing a three-dimensional optical recording medium, comprising the step of creating a vacuum atmosphere around the substrate for the three-dimensional optical recording medium prior to the second step.

The spacer is made of a photocurable or thermosetting film,
In the third step, the spacer is cured together with the liquid resin, and the transparent substrate and the spacer are bonded together.
The method for producing a three-dimensional optical recording medium according to claim 6.