JP4403351B2 - Light transmission layer forming sheet member and optical recording medium manufacturing method - Google Patents

Description

【０１３２】
表１から、接着層内に異物が混入した光ディスクの枚数が、第１の比較例による光ディスクにおいて１００枚中１８枚であるのに対し、第１および第２の実施例による第１の光ディスク１０と、第３および第４の実施例による第２の光ディスク２０とにおいては、１枚も存在しないことがわかる。本発明者の検討によれば、これは、第１の比較例による光ディスクの光透過層の形成時において、接着層５１と光透過性シート５５とを別々に供給しているため、第１の離型フィルム５２を剥離した後からディスク基板７に接着層５１を貼り合わせるまでの間、および、第２の離型フィルム５３を剥離した後から接着層５１の露出面に光透過性シート５５を貼り合わせるまでの間に、異物が混入してしまうことが考えられる。この第１の比較例に比して、第１から第４の実施例による光ディスクの光透過層の形成時においては、異物が混入する可能性があるのは、離型フィルムを剥離した後からディスク基板７に貼り合わせるまでの間である。そのため、第１から第４の実施例においては、第１の比較例に比して、異物が混入する確率が非常に低減したことが考えられる。さらに、第１の比較例においては、接着層の貼り合わせと光透過性シートの貼り合わせとを２回行う必要があるが、第１から第４の実施例においては、貼り合わせを１回行うだけであるため、製造タクトを短縮して生産性を向上させることが可能となるとともに、製造設備を簡素化することができる。
【０１３３】
また、接着層内に異物が混入するのは、接着層５１が波状に変形してしまうことも起因していると考えられる。すなわち、第１の比較例による接着層５１は、互いに同質の第１の離型フィルム５２と第２の離型フィルム５３とによって挟まれている。そのため、第１の離型フィルム５２の剥離において、接着層５１が、第１の離型フィルム５３が、部分的に接着状態が持続した後に剥離される場合がある。このような場合、接着層５１自体が波状になり、その表面の状態が劣化してしまい、異物を混入しやすくなってしまう。他方、第１から第４の実施例においては、接着層１１ｂは、光透過性シート１１ａと離型フィルムとにより挟まれている。そのため、離型フィルムと接着層１１ｂとの間の粘着力（剥離力）Ｆ_Aより、接着層１１ｂと光透過性シート１１ａとの間の剥離力Ｆ₀の方を大きく設定することが可能となる。したがって、接着層１１ｂ表面が劣化することがないため、異物の混入を最小限にすることができる。
【０１３４】
また、表１から、光透過性シートの表面に傷が生じた光ディスクの枚数が、第１の比較例による光ディスクにおいて１００枚中７枚であるのに対し、第１の実施例による第１の光ディスク１０において１００枚中６枚、第２の実施例による第１の光ディスクにおいて１００枚中５枚であり、第３および第４の実施例による第２の光ディスク２０においては、１枚も存在しないことがわかる。
【０１３５】
本発明者の検討によれば、この評価結果は、光透過性シート１１ａ自体が、傷や汚れに弱いため、光透過性シート１１ａの表面にハードコート層１１ｃを設けることによって、耐衝撃性や帯電防止などの効果を有するハードコート層１１ｃを設けることによって、異物などの接触による傷の発生が防止されていると考えられる。また、第２の光ディスク２０に示すように、光透過層１１表面をハードコート層１１ｃから構成していることにより、ユーザが光ディスクを使用する際に、異物などと接触した場合でも、その接触による傷の発生を抑制することができる。また、汚れが付着した場合に、クリーニング用の布などで汚れをクリーニング可能とすることができるようになる。
【０１３６】
また、表１から、光透過層１１表面に汚れが存在する光ディスクの枚数が、第１の比較例による光ディスクにおいて１００枚中５枚であるのに対し、第１の実施例による第１の光ディスク１０において１００枚中４枚、第３の実施例による第２の光ディスク２０において１００枚中３枚であり、第２の実施例による第１の光ディスク１０と、第４の実施例による第２の光ディスク２０とにおいては、１枚も存在しないことがわかる。
【０１３７】
この点に関する本発明者の検討によれば、光透過層の形成時において、プロテクタが設けられた供給用シートを用いていることにより、装置や設備に付着したのりなどの粘着剤や付着性の異物は、プロテクタに付着する。そして、このプロテクタは、貼り合わせプロセス後に、粘着剤や付着性異物などの汚れとともに剥離されるため、光透過層１１表面に汚れが付着することはない。したがって、第１の光ディスク１０における光透過層１１の表面を保護することができるのみならず、通常、粘着性を有する異物の付着に弱いハードコート層１１ｃを保護することが可能となる。また、ハードコート層１１ｃの表面を、作業者が布などを用いてクリーニングする必要がなくなるため、生産性を向上させることができるとともに、コストの低減を図ることができる。
【０１３８】
さらに、表１から、製造歩留まりに関しては、第１の比較例による光ディスクにおいて良品率が７０％であるのに対し、第１の実施例において良品率が９０％、第２の実施例において良品率が９５％、第３の実施例において良品率が９７％であり、第４の実施例による第２の光ディスク２０においては、不良品が全く発生しないことがわかる。
【０１３９】
また、本発明者は、第１の光ディスク１０に関して、さらなる評価を行った。すなわち、第１の実施例による第１の供給用シート３１を用いて、新たに第１の光ディスク１０を２０枚製造するとともに、第２の実施例による第２の供給用シート３２を用いて、新たに第１の光ディスク１０を２０枚製造し、それらの光透過層１１表面に生じる欠陥を、ディスク検査機（Dr.Schenk社製、VCD-120-CTLN）を用いて測定した。以下の表２に、その径が８０μｍ以上の傷欠陥が少なくとも１つでも存在した光ディスクの枚数を示す。
【０１４０】
【表２】

【０１４１】
表２に示すように、第１の実施例による第１の供給用シート３１を用いた第１の光ディスクの製造方法により作製された２０枚の光ディスクのうち、欠陥が存在した光ディスクの枚数が３枚であったのに対し、第２の実施例によるプロテクタ３２ａが被着された貼り合わせ用シート４を用いて作製された２０枚の光ディスクにおいて、欠陥が存在した光ディスクは存在しなかった。
【０１４２】
したがって、ディスク基板７の情報信号部７ｃが設けられた一主面に、プロテクタ３２ａが設けられた貼り合わせ用シート４を用いて光透過層１１を形成することにより、貼り合わせ時における光透過層１１表面への異物の付着を防止することができ、これによって、光ディスクにおける傷欠陥の大幅な低減が可能であることが確認された。
【０１４３】
この点における本発明者の知見によれば、従来の製造方法により製造された光ディスクにおける傷欠陥は、光透過性シートを載置する金属製の平面ステージ２と貼り合わせ用シート４との間に、異物が混入したことにより生じた欠陥である。この異物は、主に平面ステージ２上に存在する異物であるため、完全に除去することは困難であるが、平面ステージ２に載置する面側にプロテクタ３２ａを設けた貼り合わせ用シート４を用いることにより、平面ステージ２上に異物が存在していた場合であっても、プロテクタ３２ａにより、異物をプロテクタ３２ａに埋没させることができる。これにより、光透過層１１の最表層を構成する光透過性シート１１ａにまで、異物による影響が及ばないようにすることが可能となる。
【０１４４】
すなわち、一主面に情報信号部７ｃが設けられたディスク基板７上に、貼り合わせにより光透過層１１を形成する場合、プロテクタが設けられた第２の供給用シート３２を供給し、その離型フィルム３２ｂを剥離して得られる貼り合わせ用シート４をディスク基板７の情報信号部７ｃに接着した後、貼り合わせ用シート４からプロテクタを剥離させるようにしていることにより、光透過層１１の表面における傷欠陥の発生を抑制することができる。
【０１４５】
また、第１の比較例による光透過性シート５５の離型フィルム５６がラミネートされた側とは反対側に、第２および第４の実施例におけると同様のプロテクタをラミネートすることにより、光透過性シート５５の表面に傷が入ったり、汚れが付着することを防止することができる。さらに、光透過性シート５５の離型フィルムがラミネートされた側とは反対側に、第３および第４の実施例におけると同様のハードコート層を設けることにより、光透過層表面に傷が入るのを防止することができる。
【０１４６】
また、以上説明したこの第１の実施形態による光透過層形成用シート部材においては、光透過層１１を形成する際のシートの供給形態として、図１７に示すように、ディスク基板７と同様の平面円環状に形成された、離型フィルム６０ａ、接着層１１ｂ、光透過性シート１１ａおよびプロテクタ６０ｂが順次積層されたシート、すなわち全抜き形式の供給用シート６０を用いている。しかしながら、図１８に示すように、連続して離型フィルム６１ａ、接着層１１ｂ、光透過性シート１１ａおよびプロテクタ６１ｂが順次積層されたシート、いわゆるフープ材形式の供給用シート６１を用いることも可能である。また、図１９に示すように、接着層１１ｂを保護するものとして、連続したシートから構成された離型シート６２ａを用い、離型シート６２ａ以外の接着層１１ｂ、光透過性シート１１ａおよびプロテクタ６２ｂの積層構造を平面円環状に形成した、いわゆるハーフ抜き形式の供給用シート６２を用いることも可能である。
【０１４７】
また、図１７から図１９においては、第２の供給用シートの積層構造と同様の構造を例に挙げて説明したが、図１７から図１９において、積層構造を第１の供給用シート３１、第３の供給用シート３３および第４の供給用シート３４の積層構造としてもよい。また、供給用シートの供給形態としては、上述した第１の実施形態で挙げた以外の供給形態を採用することも可能である。
【０１４８】
以上説明したように、この第１の実施形態による光学記録媒体の製造方法によれば、薄型化され、小複屈折で、透明性良好であり、かつ、表面に傷が存在せず、厚さも均一な光透過層を有し、対物レンズの高ＮＡ化に十分対応可能な、高信頼性を有する光ディスクを得ることができる。
【０１４９】
上述したこの第１の実施形態による光学記録媒体の製造方法においては、以上のような作用効果を奏することができるが、本発明者がさらに実験を行った結果、次のような問題が生じることを知見した。
【０１５０】
すなわち、上述の第１の実施形態において説明したように、貼り合わせ用シート４として、平面円環状に打ち抜かれた形状の貼り合わせ用シートを用いる場合、ディスク基板７の主面に貼り合わせる前段階において、離型フィルム３１ａ、３２ｂ，３３ａ，３４ｂを剥離する必要がある。また、プロテクタが設けられた貼り合わせ用シート４の場合には、ディスク基板７の主面に貼り合わせた後の段階において、プロテクタ３２ａ，３４ａを剥離する必要がある。
【０１５１】
そこで、上述の第１の実施形態においては、図２０Ａに示す貼り合わせ用シート４に対する離型フィルム７１側に、図２０Ｂに示す粘着テープ７２の粘着面側を貼りつけ、この粘着テープ７２を所定の角度方向に引くことによって、離型フィルム７１を剥離する方法を採用している。
【０１５２】
また、プロテクタが設けられた貼り合わせ用シート４においても同様に、貼り合わせ後に、プロテクタ（図２０中、図示せず）に粘着テープ７２の粘着面側を貼りつけ、この粘着テープ７２を所定の角度方向に引くことによって、プロテクタを剥離する方法を採用している。
【０１５３】
しかしながら、この粘着テープ７２を用いることによって次のような問題が生じる。すなわち、粘着テープ７２は、剥離に用いられる副資材であるため、コストが増加してしまう。また、図２１に示すように、剥離装置７３として、粘着テープ７２を供給するための粘着テープ供給部７４や、離型フィルム７１などを剥離するための剥離部７５、剥離した離型フィルム７１やプロテクタなどの剥離カス７６とともに、粘着テープ７２を回収するための粘着テープ回収部７７が必要となる。そのため、剥離装置７３自体の大型化や複雑化を招いてしまう。また、粘着テープ７２の粘着面側を離型フィルム７１に貼りつける方法では、粘着テープ７２が離型フィルム７１などに確実に接着しない可能性があり、ディスク基板７との貼り合わせを行うために剥離を要する離型フィルムやプロテクタが、貼り合わせ用シート４に残存してしまうという問題も生じる。さらに、粘着テープ７２を用いる場合には、粘着テープ７２を供給するための段取り時間が発生してしまい、剥離装置７３の稼働率の低下をも招いてしまう。
【０１５４】
そこで、本発明者は、粘着テープを用いることなく、離型フィルムやプロテクタを剥離可能にする方法を検討した結果、第２の実施形態による光透過層形成用シート部材を想起するに至った。以下に、この第２の実施形態による光透過層形成用シート部材について説明する。図２２に、この第２の実施形態による供給用シートを示す。
【０１５５】
図２２Ａに示すように、この第２の実施形態による供給用シート８１は、平面円環形状を有するとともに、この外周部分に、凸形状に突出した第１の把持部８２ａおよび、同様に凸形状に突出した第２の把持部８３ａが設けられている。これらの凸形状に突出した第１の把持部８２ａおよび第２の把持部８３ａは、平面的に重ならない位置に設けられている。すなわち、第１の把持部８２ａと第２の把持部８３ａとは、平面的に互いに重ならない位置に設けられ、図２２Ａにおいては、平面円環状の位相が、互いの第１の把持部８２ａと第２の把持部８３ａとにおいて１８０°ずれた位置に設けられている。また、この第１の把持部８２ａおよび第２の把持部８３ａは、図２２Ｃに示すように、一辺の長さｌ₁，ｌ₂がたとえば１〜３ｃｍの矩形であるが、形状および寸法はこれに限定されるものではない。
【０１５６】
また、第２の実施形態による光透過層形成シート部材の積層構成は、第１の実施形態におけると同様に、少なくとも、光透過性シート１１ａと、この光透過性シートの一面に設けられた接着層１１ｂと、この接着層１１ｂを保護するための離型フィルムとからなる。ここでは、図８に示す第２の供給用シート３２と同様の４層構成を有する供給用シートを例として説明する。
【０１５７】
すなわち、図２２Ｂに示すように、この第２の実施形態による供給用シート８１は、光透過性シート１１ａと接着層１１ｂとにおいて、接着層１１ｂ側に離型フィルム８２がラミネートされているとともに光透過性シート１１ａ側にプロテクタ８３がラミネートされている。
【０１５８】
次に、このように構成された供給用シート８１を用いた光学記録媒体の製造方法について説明する。
【０１５９】
すなわち、図２３Ａに示すように、４層構造の供給用シート８１を貼り合わせプロセスに供給する。そして、図２２Ａに示す離型フィルム８２の第１の把持部８２ａを、剥離用ロボット（図示せず）を用いて把持し、剥離方向に引く。これにより、図２３Ｂに示すように、供給用シート８１から離型フィルム８２が剥離され、接着層１１ｂが露出される。
【０１６０】
次に、この離型フィルム８２が剥離され、接着層１１ｂが露出した状態の供給用シート８１を、第１の実施形態において説明した貼り合わせ装置（図１，図２参照）に搬送する。そして、この供給用シート８１とディスク基板７とを順次貼り合わせ装置の所定の位置に載置し、互いの位置を調整する。その後、第１の実施形態におけると同様の方法により、パッド８によりディスク基板７を押圧することにより、供給用シート８１の接着層１１ｂとディスク基板７の情報信号部７ｃとを対向させた状態で貼り合わせる。これにより、図２３Ｃに示すように、ディスク基板７の一主面上に接着層１１ｂを介して、光透過性シート１１ａとプロテクタ８３とが貼り合わせられる。
【０１６１】
次に、離型フィルム８２の剥離に用いたと同様の剥離用ロボットを用いて、プロテクタ８３における第２の把持部８３ａを把持し、剥離方向に引く。これにより、プロテクタ８３が剥離され、光透過性シート１１ａの表面が露出する。これにより、この第２の実施形態による光ディスクが製造される。なお、この第２の実施形態による光ディスクの構成、および製造プロセスに関しては、第１の実施形態におけると同様であるので、説明を省略する。
【０１６２】
また、本発明者は、上述の第２の実施形態による供給用シートを用いて作製された光ディスク（第５の実施例）と、従来の供給用シートを用いて製造された光ディスク（第２の比較例）に関して、これらの光ディスクをそれぞれ１０００枚製造し、それらの光ディスクにおける離型フィルム８２の剥離不良、およびプロテクタ８３の剥離不良について、それぞれ評価を行った。すなわち、第５の実施例による光ディスクにおいては、上述の第２の実施形態の製造方法により、供給用シート８１を用いて光ディスクを製造し、第２の比較例による光ディスクにおいては、離型フィルムとプロテクタとを粘着テープを用いて剥離する第１の実施形態の製造方法と同様の製造方法により、４層構造で全抜きの供給用シートを用いて光ディスクを製造する。
【０１６３】
これらの上述した第５の実施例の評価結果と第２の比較例の評価結果とを、以下の表３に示す。
【０１６４】
【表３】

【０１６５】
表３から、第２の比較例による光ディスクの製造において、離型フィルムの剥離不良が１０枚の光ディスクにおいて生じたのに対し、この第５の実施例による光ディスクにおいては、離型フィルム８２の剥離不良が１枚も生じないことがわかる。また、第２の比較例による光ディスクの製造において、プロテクタの剥離不良が１７枚の光ディスクに生じたのに対し、第５の実施例による光ディスクにおいては、離型フィルム８２の剥離不良が１枚も生じていないことがわかる。これは、第２の比較例のように、離型フィルムの剥離が、粘着テープと離型フィルムとの接着力に依存することがなく、離型フィルム８２の外周の部分に設けられた第１の把持部８２ａを把持して引くことにより、離型フィルム８２の剥離を行っているため、剥離を確実に行うことが可能となったためである。同様に、プロテクタに関しても、粘着テープとプロテクタとの間の界面で剥離してしまうことがないので、剥離不良の発生を防止することが可能となる。
【０１６６】
また、この第２の実施形態による供給用シートの他の例を図２４に示す。図２４Ａに示すように、この第２の実施形態による供給用シート８４は、上述の供給用シート８１と異なり、離型フィルム８２を矩形に形成し、その上に、図２４Ｂに示すように、接着層１１ｂ、光透過性シート１１ａおよびプロテクタ８３が順次積層された構成を有する。ここで、図２４Ａに示す、この第２の実施形態による供給シートの他の例においては、光透過性シート１１ａ、接着層１１ｂおよびプロテクタ８３の径φをたとえば１２０ｍｍとし、離型フィルム８２が１辺の長さｌが１２３ｍｍの正方形とする。
【０１６７】
そして、この離型フィルム８２における接着層１１ｂ、光透過性シート１１ａおよびプロテクタ８３と平面的に重ならない部分を、剥離用ロボットによって把持可能な外把持部８２ｂとする。なお、この構成は、プロテクタ８３を同様に構成することも可能であるが、把持する領域が重なると剥離用ロボットによる、離型フィルム８２およびプロテクタ８３のうちの一方のみを把持することが困難になる。そのため、プロテクタ８３を矩形とする場合には、離型フィルム８２を光透過性シート１１ａおよび接着層１１ｂと同型の平面円環状にする。すなわち、離型フィルム８２およびプロテクタ８３のうちのどちらか一方のみを矩形状にし、それらの光透過性シート１１ａおよび接着層１１ｂと重ならない領域が把持部とされる。そして、この重ならない把持部を剥離用ロボットによって把持し、剥離方向に引くことにより剥離が行われる。
【０１６８】
以上説明したように、この第２の実施形態による光透過層形成用シート部材においては、第１の実施形態におけると同様の効果を得ることができるとともに、剥離する必要のあるフィルムに把持部を設けるようにしていることにより、離型フィルム８２やプロテクタ８３の剥離不良を確実に防止することができるので、この光透過層形成用シート部材を用いて製造される光ディスクの製造歩留まりを向上させることができるとともに、剥離装置の省スペース化や工程の簡略化を図ることができる。
【０１６９】
また、本発明者は、第１の実施形態において用いられた貼り合わせ装置に光透過層形成用シート部材を載置して貼り合わせを行う場合に、次のような問題が生じることを知見した。
【０１７０】
すなわち、光透過性シート１１ａと接着層１１ｂとの積層構造を有して構成される、全抜きで枚葉形式の貼り合わせ用シート４を用いて貼り合わせを行う場合、図１に示すように、貼り合わせ用シート４を平面ステージ２上に平行に配置する必要がある。そこで、本発明者は、第１の実施形態において用いられた貼り合わせ装置１の平面ステージ２に真空吸着手段を設け、貼り合わせ用シート４を吸着固定する方法を案出した。
【０１７１】
すなわち、図２５に示すように、平面ステージ２において、貼り合わせ用シート４の外周部に位置するところに、吸引孔を有する真空吸着部９１を設ける。そして、この真空吸着部９１内を真空引きするとともに、貼り合わせ用シート４を載置することによって、平面ステージ２の載置面に、平行に保持する。ところが、この真空吸着部９１によって貼り合わせ用シート４を保持する際に、貼り合わせ用シート４が平面ステージ２に正しく固定されない場合に、次のような問題が生じる。
【０１７２】
すなわち、貼り合わせ用シート４が、真空吸着部９１によって、平面ステージ２上に吸着固定されないため、設定された圧力に達せず、貼り合わせ以降のプロセスへの移行が困難になり、一連の製造装置が停止してしまう。また、貼り合わせ用シート４と平面ステージ２との間に気泡が残されている可能性が大幅に高くなり、これによって、ディスク基板７と貼り合わせ用シート４とを貼り合わせたときに、これらの間に気泡が混入したり、光透過層１１にしわが発生してしまう。そして、気泡の混入やしわが生じると、最終製品としての光ディスクにおいて、データの記録や再生の信頼性が低下してしまう。また、貼り合わせ用シート４が平面ステージ２上の正確な位置に保持されないと、ディスク基板７と貼り合わせ用シート４との間に貼り合わせずれが生じてしまう。
【０１７３】
このような貼り合わせずれが生じると、ディスク基板７からはみ出した貼り合わせ用シート４が、光ディスクのカートリッジに衝突して、折れ曲がりや剥がれのきっかけになり、最終的に光ディスクの記録や再生の信頼性の低下や、記録不良および再生不良などが生じる場合がある。また、貼り合わせ用シート４が平面ステージ２上に吸着固定されないと、自動剥離装置を用いて離型フィルムを剥離する際に、貼り合わせ用シート４がディスク基板７に対してずれてしまい、正確な剥離が困難になる。これによって、光透過層１１の貼り合わせが行われなくなってしまう。
【０１７４】
以上のようなことにより、貼り合わせ用シート４を真空吸着部９１によって、正確に吸着固定することは、光ディスクにおける信頼性の向上において、重要である。ところが、本発明者が実際に平面ステージ２上に貼り合わせ用シート４を載置すると、この貼り合わせ用シート４の外周部が真空吸着部９１に吸引されないということが生じることを知見した。
【０１７５】
すなわち、貼り合わせ用シート４は、全抜きされる前の段階の製造時において、ロール形状で供給、ハンドリング、輸送される。そのため、全抜き前の貼り合わせ用シート４は、ロール状に巻かれた方向にカールしてしまう。また、ロール状に巻かれた状態がある程度の時間継続すると、このカールのくせ、いわゆる巻きぐせを直すことが困難になる。たとえば、全抜きを行って貼り合わせ用シート４をそれぞれ枚葉とした後、これらの貼り合わせ用シート４を重ね、さらに上からおもりなどによって圧力を加えて矯正しようとしても、この巻きぐせは残ってしまう。さらに、図２６に示すように、貼り合わせ装置１の平面ステージ２上に載置すると、貼り合わせ用シート４が平面ステージ２側に凸形状になってしまい、外周部が浮き上がってしまう。
【０１７６】
そこで、本発明者は、貼り合わせ用シート４を平面ステージ２上に載置した後、その外周部を細長い棒などによって押さえ真空吸着部９１に吸着させるようにした。ところが、このような方法では、常に作業者によって貼り合わせ用シートの外周部を押さえる必要があり、効率が悪くなってしまう。また、吸着が困難になってしまうと、上述したような光ディスクの信頼性に関わる問題が生じてしまう。そこで、本発明者が鋭意検討を行った結果、この問題を解決する方法を想起した。以下のこの第３の実施形態においては、上述の問題を解決する光ディスクの製造方法について、説明する。なお、この第３の実施形態においては、貼り合わせ用シート４として、４層構造の第２の供給用シート３２（図８参照）を例として説明する。
【０１７７】
まず、この第３の実施形態による第３の比較例による光ディスクの製造方法について、説明する。
【０１７８】
すなわち、図２６Ａに示すように、平面ステージ２上に貼り合わせ用シート４を載置する場合、平面ステージ２側にプロテクタ３２ａが接し、離型フィルム３２ｂがディスク基板７の情報信号部７ｃに対向するように、貼り合わせ用シート４を載置する。そして、平面ステージ２に設けられた上下動ピン５に貼り合わせ用シート４の貫通孔４ａを嵌め合わせた後、ディスク基板７のセンターホール７ａを基板位置出しピン６に嵌め合わせることによって、互いの位置出しを行っている。また、図２６Ｂに示すように、平面ステージ２には、大気中でディスク基板７と貼り合わせ用シート４との接触を防止するために、仮想的な正８角形の各頂点の位置に、平行維持手段９が設けられている。また、平行維持手段９の内周で、平行維持手段９と位相をずらした仮想的な正８角形の各頂点の位置に、真空吸着部９１が設けられている。
【０１７９】
図２６Ａに示す貼り合わせ装置に供給される貼り合わせ用シート４が、全抜きで枚葉式に形成される前の段階においては、この貼り合わせ用シート４の原反は、ロール形状に巻かれている。このロール状に巻かれた状態を、図２７に示す。図２７に示すように、ロール原反１００には、離型フィルム１０１が内周側、プロテクタ１０２が外周側になるように、原反シート１０３が巻き付けられている。このように、離型フィルム１０１が内周側になるように巻き付けられている原反シート１０３を、図２８に示すように、全抜きで平面円環状に抜き出すことにより貼り合わせ用シート４を形成する。そして、この貼り合わせ用シート４を、その貫通孔４ａを上下動ピン５に嵌合させつつ平面ステージ２上に載置すると、図２６Ａに示すように、貼り合わせ用シート４は、平面ステージ２側に向けて中心位置が盛り上がった形状、すなわち下に凸の形状になる。
【０１８０】
このようにして載置された貼り合わせ用シート４とディスク基板７とを貼り合わせる場合には、図２９Ａに示すように、まず、貼り合わせ用シート４の離型フィルム１０１を剥離した後、図２６Ａに示す基板位置出しピン６にディスク基板７を嵌合させて、図２９Ｂに示すように、互いに対向させる。
【０１８１】
その後、図２６Ａに示すパッド８によって、ディスク基板７のレプリカ基板７ｂ側を押圧し、貼り合わせ用シート４とディスク基板７とを圧着する。これによって、図３０Ａに示すように、ディスク基板７の情報信号部７ｃ表面に、接着層１１ｂ、およびプロテクタ１０２に保護された光透過性シート１１ａが形成される。その後、図３０Ｂに示すように、自動剥離装置を用いて、プロテクタ１０２を光透過性シート１１ａから剥離する。以上により、第３の比較例による光ディスクが製造される。
【０１８２】
他方、この第３の実施形態の第６の実施例による光ディスクの製造方法については、まず、図３１に示すように、原反シート１０３は、内周側から外周側に向かって、プロテクタ１０２、光透過性シート１１ａ、接着層１１ｂおよび離型フィルム１０１になるように、ロール原反１００に巻き付けられている。そして、この原反シート１０３の部分を、図２８に示すように、平面円環状に打ち抜くことによって、貼り合わせ用シート４を製造する。
【０１８３】
そして、この貼り合わせ用シート４を、その貫通孔４ａを上下動ピン５に嵌合させつつ平面ステージ２上に載置すると、図３２に示すように、貼り合わせ用シート４は、平面ステージ２に対して、中央部が盛り上がった形状、すなわち上に凸の形状になる。このように平面ステージ２上に載置された貼り合わせ用シート４は、その外周部が平面ステージ２の真空吸着部９１に近接することになる。これによって、真空吸着部９１の内部を減圧して、吸引した際に、貼り合わせ用シート４が吸着されやすくなり、容易に設定した圧力に達する。
【０１８４】
このようにして載置された貼り合わせ用シート４とディスク基板７とを貼り合わせる場合には、図２９Ａに示すように、まず、貼り合わせ用シート４の離型フィルム１０１を剥離した後、図３２に示す基板位置出しピン６にディスク基板７を嵌合させて、図２９Ｂに示すように、互いに対向させる。
【０１８５】
その後、図３２に示すパッド８によって、ディスク基板７のレプリカ基板７ｂ側を押圧し、貼り合わせ用シート４とディスク基板７とを圧着する。これによって、図３０Ａに示すように、ディスク基板７の情報信号部７ｃ表面に、接着層１１ｂ、およびプロテクタ１０２に保護された光透過性シート１１ａが形成される。その後、図３０Ｂに示すように、自動剥離装置を用いて、プロテクタ１０２を光透過性シート１１ａから剥離する。以上により、この第６の実施例による光ディスクが製造される。
【０１８６】
本発明者は、以上の第３の比較例による光ディスクと第６の実施例による光ディスクとをそれぞれ上述の製造方法に従って１００枚製造し、それらの光ディスクにおいて、評価を行った。以下の表４にその評価結果を示す。なお、表４において、気泡混入は、ディスク基板７と貼り合わせ用シート４との間、光ディスクにおいて、特に情報信号部７ｃと光透過層１１との間に気泡が混入した場合を示し、シワ発生は、光透過層１１にシワが生じた場合を示し、吸着不良は、貼り合わせ用シート４が平面ステージ２上に吸着固定されず、これに起因して貼り合わせ装置や他の装置の稼働不良を引き起こした場合を示す。
【０１８７】
【表４】

【０１８８】
表４から、上述の第３の比較例による光ディスクにおいて、気泡混入が１００枚中６枚（６％）、光透過層１１におけるシワの発生が１００枚中９枚（９％）、吸着不良が１００枚中１３枚（１３％）であるのに対し、上述の第６の実施例による光ディスクにおいては、気泡混入、シワ発生、および吸着不良のいずれも発生していないことがわかる。また、第３の比較例による光ディスクにおいて、不良が発生しなかった枚数が１００枚中７１枚であったのに対し、この第６の実施例による光ディスクにおいては、不良な光ディスクが１枚も発生していないことがわかる。
【０１８９】
以上説明したように、この第３の実施形態による光透過層形成用シート部材および光ディスクの製造方法によれば、第１の実施形態におけると同様の効果を得ることができるとともに、貼り合わせ用シート４を、その原反状態のときに離型フィルム１０１が外側になるように巻くことによって、離型フィルム１０１側が盛り上がるようにしていることにより、真空吸着部９１の内部を減圧して、吸引した際に、貼り合わせ用シート４が吸着されやすくなり、容易に設定した圧力に達するため、平面ステージ２と貼り合わせ用シート４との間に気泡が残ることがないので、平面ステージ２と貼り合わせ用シート４とディスク基板７とを平行にセットすることができる。したがって、ディスク基板７と貼り合わせ用シート４との間に気泡が混入したり、光透過層１１がしわになったりすることを防止することができるとともに、貼り合わせ用シート４のシートエッジのはみ出しや、情報信号部７ｃがシートに覆われずに露出してしまうことも防止することができる。
【０１９０】
以上、この発明の実施形態について具体的に説明したが、この発明は、上述の実施形態に限定されるものではなく、この発明の技術的思想に基づく各種の変形が可能である。
【０１９１】
たとえば、上述の実施形態において挙げた数値、材料、光ディスクの構成、情報信号部の構成はあくまでも例に過ぎず、必要に応じてこれと異なる数値、材料、光ディスクの構成、情報信号部の構成を用いてもよい。
【０１９２】
また、たとえば、上述の第１の実施形態においては、あらかじめ接着層１１ｂが設けられた貼り合わせ用シート４を用いて、この貼り合わせ用シート４をディスク基板７に貼り合わせることにより、光ディスクを製造するようにしたが、まず、離型フィルム、光透過性シート１１ａおよびプロテクタが積層されたシートを用意し、ディスク基板７に液状の紫外線硬化樹脂などの液状の接着剤を供給するとともに、シートから離型フィルムを剥離し、このシートの光透過性シート１１ａ側を、紫外線硬化樹脂を介してディスク基板７の一主面に接着させた後、シートからプロテクタを剥離するようにしてもよい。これにより、シートを接着させた状態が図１２に示す状態となり、プロテクタ３２ａを剥離した状態が、図３に示すようになるため、上述の第１の実施形態におけると同様の効果を得ることができる。
【０１９３】
また、たとえば上述の第１の実施形態において、貼り合わせ用シート４をディスク基板７の一主面に接着した後、必要に応じて、ディスク基板７の他主面、すなわちレプリカ基板７ｂの光透過性シート１１ａおよびプロテクタが設けられていない側の主面に、貼り合わせ用シート４をその接着層１１ｂ側で接着させることにより、ディスク基板７の他主面上に光透過層１１を形成することも可能である。これにより、ディスク基板７の表裏両面に光透過性シート１１ａが接着された構成の光学記録媒体を容易に製造することができる。この場合においても、光透過性シート１１ａの接着層１１ｂが設けられた側とは反対側にプロテクタを設けるようにしていることにより、この第１の実施形態におけると同様の効果を得ることができる。また、この際に、レプリカ基板７ｂの表裏両面に凹凸を形成し、これらの両面に情報信号部７ｃを形成するようにすれば、両面において、記録および／または再生可能な光学記録媒体を得ることができる。
【０１９４】
また、上述の第１の実施形態においては、情報信号部７ｃがディスク基板７の一主面に形成されている例について述べたが、この情報信号部７ｃは、貼り合わせ用シート４におけるディスク基板７の一主面との対向面に形成されていてもよい。また、この場合において、情報信号部７ｃを、ディスク基板７ではなく、貼り合わせ用シート４に形成することも可能である。さらには、ディスク基板７の一主面にのみ情報信号部７ｃを形成しておき、この上層に貼り合わせ用シート４を接着し、ディスク基板７の他主面に接着する第２のシートを、情報信号部が形成されたシートとし、この第２のシートをディスク基板７の他主面に接着して、ディスク基板７の他主面に情報信号部７ｃを設けるようにすることも可能である。
【０１９５】
また、上述の第１の実施形態においては、弾性体からなるパッド８と平面ステージ２とを用いて、ディスク基板７上に光透過性シート１１ａを貼り合わせるようにしているが、これ以外の装置を用いることも可能であり、具体的には、たとえば、２枚の金属平板を用いて、ディスク基板７と光透過性シート１１ａとを貼り合わせるようにしても良く、また、ローラを用いて、ディスク基板７の一主面上に光透過性シートをラミネートするようにしても良い。
【０１９６】
また、上述の第１の実施形態においては、光透過性シートとプロテクタとを微粘着性接着剤を介して接着しているが、プロテクタを、光透過性シートやハードコート層上に載置することも可能である。
【０１９７】
また、上述の第１の実施形態においては、反射膜の材料の例としてＡｌ合金を挙げたが、反射層の材料として、Ａｌ合金以外にも、Ａｌ、銀（Ａｇ）、Ａｇ合金、銅（Ｃｕ）、Ｃｕ合金などを挙げることができる。また、相変化記録層として、ＧｅＳｂＴｅ合金層を用いることも可能である。また、光磁気記録を採用した光ディスクにおいては、記録層として、ＴｂＦｅＣｏ、ＴｂＦｅＣｒ、ＦｅＴｂＣｏＣｒ、ＦｅＧｄＣｏ、ＦｅＤｙＣｏ、またはＦｅＧｄＣｏＳｉなどの合金層を用いることが可能である。
【０１９８】
また、たとえば上述の第２および第３の実施形態においては、４層構造の貼り合わせ用シートを供給して、光ディスクを製造するようにしているが、４層構造以外のシートを用いることも可能であり、具体的には、たとえば図７に示す、離型フィルム３１ａと接着層１１ｂと光透過性シート１１ａとの積層構造を有する、第１の供給用シート３１と同様の積層構造を有する貼り合わせ用シートや、図９に示す、光透過性シート１１ａの接着層１１ｂ側に離型フィルム３３ａが設けられ、光透過性シート１１ａの表面にハードコート層１１ｃが設けられた積層構造を有する、第３の供給用シート３３と同様の積層構造を有する貼り合わせ用シートや、さらにプロテクタ３４ａが設けられた図１０に示す、第４の供給用シート３４と同様の積層構造を有する貼り合わせシートを用いることが可能である。
【０１９９】
【発明の効果】
以上説明したように、この発明の第１の発明による光透過層形成用シート部材によれば、少なくとも、光透過性シートと、光透過性を有する第１の接着層と、離型フィルムとからなり、光透過性シートの基板に接着させる面に第１の接着層が設けられているとともに、第１の接着層が設けられた面に、剥離可能な離型フィルムが設けられていることにより、光学記録媒体における光透過層の形成において、光透過層と基板との間への異物の入り込みを防止することができる。また、光透過性シートに対して第１の接着層が設けられた面とは反対側の面に、保護フィルムを設けることによって、光透過性シートの表面や、光透過層表面への異物の付着を防止することができるとともに、光透過性シート表面の傷の発生や汚れを防止することができる。
【０２００】
また、この発明の第２の発明および第３の発明による光学記録媒体の製造方法によれば、光透過性シートの一面に離型フィルムが設けられたシートを用い、シートにおける光透過性シート側を、接着層を介して基板表面に接着する接着工程と、シートから離型フィルムを剥離する剥離工程とを有していることにより、貼り合わせにより光透過層を形成する場合であっても、異物が光透過性シートにまで影響を及ぼすのを防止することができ、また、離型フィルムを剥離させた段階で、付着した異物もともに剥離されるので、光透過層表面に傷が入るのを防止することができるとともに、記録／再生時に用いられる対物レンズの高ＮＡ化に対応可能で、小複屈折、透明性良好で均一な膜厚の光透過層を有する光学記録媒体を製造することができる。
【図面の簡単な説明】
【図１】この発明の第１の実施形態による貼り合わせ用シートとディスク基板との貼り合わせに用いられる、貼り合わせ装置を示す略線図である。
【図２】この発明の第１の実施形態による貼り合わせ用シートとディスク基板との貼り合わせに用いられる、貼り合わせ装置の他の例を示す略線図である。
【図３】この発明の第１の実施形態による光透過層が設けられた第１の光ディスクを示す断面図である。
【図４】この発明の第１の実施形態によるハードコート層を有する光透過層が設けられた第２の光ディスクを示す断面図である。
【図５】この発明の第１の実施形態による光ディスクの製造方法を説明するためのフローチャートである。
【図６】この発明の第１の実施形態による光透過層が形成されるディスク基板を示す断面図である。
【図７】この発明の第１の実施形態による光透過層の形成に用いられる、第１の実施例による第１の供給用シートを示す断面図である。
【図８】この発明の第１の実施形態による光透過層の形成に用いられる、第２の実施例による第２の供給用シートを示す断面図である。
【図９】この発明の第１の実施形態による光透過層の形成に用いられる、第３の実施例による第３の供給用シートを示す断面図である。
【図１０】この発明の第１の実施形態による光透過層の形成に用いられる、第４の実施例による第４の供給用シートを示す断面図である。
【図１１】この発明の第１の実施形態による第１の光ディスクの製造における、ディスク基板と貼り合わせ用シートとの貼り合わせ方法を説明するための略線図である。
【図１２】この発明の第１の実施形態による第１の光ディスクの製造における、ディスク基板と貼り合わせ用シートとを貼り合わせた直後の状態を示す断面図である。
【図１３】この発明の第１の実施形態による第２の光ディスクの製造における、ディスク基板と貼り合わせ用シートとの貼り合わせ方法を説明するための略線図である。
【図１４】この発明の第１の実施形態による第２の光ディスクの製造における、ディスク基板と貼り合わせ用シートとを貼り合わせた直後の状態を示す装置を示す略線図である。
【図１５】この発明の第１の実施形態による光ディスクをクランプするチャッキング部を示す断面図である。
【図１６】第１の実施形態における第１の比較例による光ディスクの製造に用いられる供給用シートを示す断面図である。
【図１７】この発明の第１の実施形態による供給用シートの供給形態のうちの、全抜き形式の供給用シートを示す断面図である。
【図１８】この発明の第１の実施形態による供給用シートの供給形態のうちの、フープ材形式の供給用シートを示す断面図である。
【図１９】この発明の第１の実施形態による供給用シートの供給形態のうちの、ハーフ抜き形式の供給用シートを示す断面図である。
【図２０】離型フィルムを剥離する方法を説明するための平面図である。
【図２１】離型フィルムを剥離する方法と問題点を説明するための略線図である。
【図２２】この発明の第２の実施形態による光透過層形成用シート部材を示す平面図および断面図と把持部を示す平面図である。
【図２３】この発明の第２の実施形態による光透過層を形成する際のプロセスを説明するための略線図である。
【図２４】この発明の第２の実施形態による光透過層形成用シート部材を示す平面図および断面図である。
【図２５】この発明の第３の実施形態による貼り合わせ用シートとディスク基板と貼り合わせに用いられる貼り合わせ装置を示す略線図である。
【図２６】この発明の第３の実施形態の比較例によるディスク基板と貼り合わせ用シートとの貼り合わせ方法を説明するための略線図と、平面ステージの真空吸着部および平行維持手段の配置を示す平面図である。
【図２７】この第３の実施形態の比較例による原反シートの巻き方を説明するための略線図である。
【図２８】この第３の実施形態による原反シートから貼り合わせ用シートを全抜きで抜き出す方法を説明するための略線図である。
【図２９】この発明の第３の実施形態による貼り合わせ用シートとディスク基板との貼り合わせプロセスを説明するための略線図である。
【図３０】この発明の第３の実施形態による貼り合わせ用シートとディスク基板との貼り合わせプロセスを説明するための略線図である。
【図３１】この第３の実施形態の実施例による原反シートの巻き方を説明するための略線図である。
【図３２】この発明の第３の実施形態の実施例によるディスク基板と貼り合わせ用シートとの貼り合わせ方法を説明するための略線図である。
【符号の説明】
１・・・貼り合わせ装置、２・・・平面ステージ、３・・・可動ステージ、４・・・貼り合わせ用シート、４ａ，５０ａ，５４ａ・・・貫通孔、５・・・上下動ピン、６・・・基板位置出しピン、７・・・ディスク基板、７ａ・・・センターホール、７ｂ・・・レプリカ基板、７ｃ・・・情報信号部、８・・・パッド、９・・・平行維持手段、１０・・・第１の光ディスク、１１・・・光透過層、１１ａ，５５・・・光透過性シート、１１ｂ，５１・・・接着層、１１ｃ・・・ハードコート層、１２・・・クランプ領域、１２ａ・・・クランプ基準面、２０・・・第２の光ディスク、３１・・・第１の供給用シート、３２・・・第２の供給用シート、３３・・・第３の供給用シート、３４・・・第４の供給用シート、３１ａ，３２ｂ，３３ａ，３４ｂ，５２，５３，５６，６１ａ，７１，８２，１０１・・・離型フィルム、３２ａ，３４ａ，６０ｂ，６１ｂ，６２ｂ，８３，１０２・・・プロテクタ、５０・・・接着層用供給シート、５４・・・光透過性シート用供給シート、６０，６１，６２，８１，８４・・・供給用シート、６０ａ，６２ａ・・・剥離シート、７２・・・粘着テープ、７３・・・剥離装置、７４・・・粘着テープ供給部、７５・・・剥離部、７６・・・剥離カス、７７・・・粘着テープ回収部、８２ａ・・・第１の把持部、８２ｂ・・・外把持部、８３ａ・・・第２の把持部、９１・・・真空吸着部、１００・・・ロール原反、１０３・・・原反シート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light transmissive layer forming sheet member and an optical recording medium manufacturing method, and in particular, to an optical recording medium in which a light transmissive layer is formed by laminating a light transmissive sheet on a disk substrate. Is preferred.
[0002]
[Prior art]
In recent years, in the field of information recording, various researches and developments regarding optical information recording methods have been advanced. This optical information recording system has an advantage that recording and / or reproduction can be performed in a non-contact manner, and a recording density higher by one digit or more than that of the magnetic recording system can be achieved. In addition, this optical information recording method has an additional advantage that it can be adapted to each memory form such as a read-only type, a write-once type, and a rewritable type. For this reason, as a method that enables realization of an inexpensive large-capacity file, application to a wide range of applications from industrial use to consumer use is considered.
[0003]
Among them, digital audio discs (DAD), optical video discs, and the like, which are optical discs compatible with a read-only memory format, are widely used.
[0004]
An optical disk such as a digital audio disk has a reflective film made of a metal thin film such as an aluminum (Al) film on a transparent optical disk substrate on which concave and convex patterns such as pits and grooves indicating information signals are formed. Moisture in the atmosphere (H ₂ O) and oxygen (O ₂ ) Is provided on the reflective film. When reproducing the information signal on this optical disc, the reproduction light such as a laser beam is irradiated from the optical disc substrate side toward the concave / convex pattern, and the information signal is detected by the difference in reflectance between the incident light and the return light due to this reproduction light. To do.
[0005]
When manufacturing such an optical disk, first, an optical disk substrate having a concavo-convex pattern is formed by an injection molding method. Next, a reflective film made of a metal thin film is formed on the optical disk substrate by vacuum deposition. Next, a protective film is formed by applying an ultraviolet curable resin to the upper layer.
[0006]
In the optical information recording system as described above, in recent years, further higher recording density has been demanded. In order to meet the demand for higher recording density, a technique for reducing the spot diameter of the reproduction light by increasing the numerical aperture (NA) of the objective lens used when the reproduction light of the optical pickup is irradiated. Was proposed. While the NA of the objective lens used when reproducing a conventional digital audio disk is 0.45, the optical system such as a DVD (Digital Versatile Disc) having a recording capacity 6 to 8 times that of the conventional digital audio disk is used. The spot diameter is reduced by setting the NA of the objective lens used when reproducing the video disc to about 0.60.
[0007]
As the NA of such an objective lens increases, it is necessary to make the disk substrate of the optical recording medium thinner in order to transmit the irradiated reproduction light. This is because the tolerance of the angle (tilt angle) that deviates from the disk surface perpendicular to the optical axis of the optical pickup becomes small. This tilt angle is affected by aberrations and birefringence due to the thickness of the disk substrate. This is because it is easy. Therefore, the tilt angle is made as small as possible by making the disk substrate thinner. For example, in the digital audio disk described above, the thickness of the substrate is about 1.2 mm. On the other hand, in an optical video disk having a recording capacity 6 to 8 times that of a digital audio disk such as a DVD, the thickness of the substrate is about 0.6 mm.
[0008]
In consideration of future demands for higher recording density, it is necessary to make the substrate thinner. Therefore, an irregularity is formed on one main surface of the substrate to form an information signal portion, and a reflective film and a light transmission layer made of a thin film capable of transmitting light are sequentially laminated on the information signal portion, and the light transmission layer side is There has been proposed an optical recording medium configured to reproduce an information signal by irradiating reproduction light. In such an optical recording medium in which information signals are reproduced by irradiating reproduction light from the light transmitting layer side, the NA of the objective lens can be increased by reducing the thickness of the light transmitting layer. Can do.
[0009]
However, if the light-transmitting layer is thinned, it becomes difficult to form the light-transmitting layer by an injection molding method using a thermoplastic resin that is generally used for manufacturing an optical disc. That is, in the conventional technique, it is very difficult to form a light transmission layer of about 0.1 mm that maintains good transparency while keeping birefringence small. Accordingly, a method has been devised in which the light transmission layer is formed of an ultraviolet curable resin.
[0010]
[Problems to be solved by the invention]
However, when the light transmission layer is formed of an ultraviolet curable resin, it is very difficult to make the light transmission layer have a uniform film thickness on the substrate surface. Therefore, it becomes difficult to stably reproduce the information signal.
[0011]
In addition, a sheet having a film thickness of 0.1 mm, laminated with a release film on a light-transmitting sheet made of a thermoplastic resin, or a sheet in which a light-transmitting sheet is sandwiched between two release films, and two pressure-sensitive adhesive layers A method of forming a light transmission layer by using a sheet sandwiched between a plurality of films and affixing to the substrate surface by roller pressing is also considered. However, in this method, deformation of the sheet at the time of pressure bonding or protrusion of the adhesive layer to the reading surface side occurs, or between the light-transmitting sheet and the pressure-sensitive adhesive layer, or between the pressure-sensitive adhesive layer and the substrate. Foreign matter is likely to be mixed in. As a result, it becomes difficult to form a light transmissive layer with a uniform film thickness and to form a highly reliable light transmissive layer, and it is more difficult to stably reproduce an information signal. turn into.
[0012]
Accordingly, an object of the present invention is to prevent the entry of foreign matter between the light transmissive layer and the substrate and the adhesion of foreign matter to the surface of the light transmissive layer in the formation of the light transmissive layer in the optical recording medium. An object of the present invention is to provide a light transmissive layer forming sheet member that can prevent scratches and contamination on the surface of the conductive sheet.
[0013]
Another object of the present invention is to provide a light-transmitting layer having a uniform film thickness, keeping the birefringence small, less fouling, and having good transparency, corresponding to the high NA of the objective lens. It is an object of the present invention to provide a method for manufacturing an optical recording medium capable of obtaining a good optical recording medium without producing a scratch on a light transmission layer when the optical recording medium is manufactured.
[0014]
[Means for Solving the Problems]
The present inventor has intensively studied to solve the above-described problems. The outline will be described below.
[0015]
That is, the present inventor has recalled that it is necessary to prevent the number of processes from increasing as much as possible in order to prevent foreign substances from entering. And recalling a method of forming a light transmissive layer of about 0.1 mm by laminating a light transmissive sheet made of a thermoplastic resin with a pressure sensitive adhesive applied to one surface to a substrate, It came to devise the sheet | seat member used for formation of such a light transmissive layer.
[0016]
Therefore, in order to achieve the above object, the first invention of the present invention is:
A substrate, an information signal portion configured to record and / or reproduce an information signal on one main surface of the substrate, and a light transmission layer capable of transmitting at least the laser light applied to the information signal portion are sequentially provided. A light transmission layer forming sheet member used for forming a light transmission layer in a configured optical recording medium,
At least a light transmissive sheet, a first adhesive layer having a light transmissive property, Release film And consist of
A first adhesive layer is provided on the side of the light transmissive sheet to be bonded to the substrate, and on the first adhesive layer side, Release film Is provided so that it can be peeled off,
A light-transmitting sheet having a laminated structure and a first adhesive layer; Release film In the previous stage used for bonding, Release film Is wound around the winding core so as to be on the outer peripheral side from the light-transmitting sheet
It is characterized by this.
[0017]
In this first invention, Release film In order to facilitate the peeling of Release film A release agent is applied to the first adhesive layer side.
[0018]
In this first invention, on the surface opposite to the surface on which the first adhesive layer is provided with respect to the light transmissive sheet, Protective film And preferably this Protective film Is made of polyethylene resin.
[0019]
In this first invention, Release film In order to prevent the first adhesive layer from becoming wavy when peeling Release film The adhesive force between the first adhesive layer and the light-transmitting sheet Protective film Less than the adhesive strength between. That is, on the premise of the magnitude relationship of this adhesive force, specifically, Release film The magnitude of the force required for peeling is 0.10 N / 5 cm or more and 1.00 N / 5 cm or less, Protective film The magnitude of the force required for peeling is 0.15 N / 5 cm or more and 2.00 N / 5 cm or less. In addition, the magnitude | size of the force required for this peeling is defined as a force required when peeling the adhere | attached sheet | seat of 5 cm width.
[0020]
In the first aspect of the invention, when the light transmission layer of the optical recording medium is formed using the light transmission layer forming sheet member, the surface of the light transmission layer of the manufactured optical disk is prevented from being damaged. In addition, typically, a hard coat layer is provided on the side opposite to the side on which the first adhesive layer of the light transmissive sheet is provided. In the first invention, typically, on the side of the light transmissive sheet on which the hard coat layer is provided. Protective film Is preferably provided. Protective film Is made of polyethylene resin. In the first invention, in order to prevent the hard coat layer, the light transmissive sheet, and the first adhesive layer from becoming wavy after the protective sheet is peeled off, typically, Release film The adhesive force between the first adhesive layer and the hard coat layer Protective film Under the premise of the magnitude relationship of this adhesive strength, Protective film The magnitude of the force required for peeling is 0.15 N / 5 cm or more and 2.00 N / 5 cm or less, Release film The magnitude of the force required for peeling is 0.10 N / 5 cm or more and 1.00 N / 5 cm or less. In addition, the hard coat layer is formed of an ultraviolet curable resin in order to easily form and suppress an increase in cost by diverting a commonly used apparatus, but diamond-like carbon ( It can also be composed of diamond-like carbon (DLC).
[0021]
In this first invention, Release film In order to easily and reliably peel off, typically, Release film In addition, a convex portion that can be gripped is provided. In the first invention, preferably, on the surface opposite to the surface on which the first adhesive layer is provided with respect to the light transmissive sheet, Protective film Is provided, and Protective film In addition, a convex portion that can be gripped is provided. In the first aspect of the invention, the light transmission layer has a planar annular shape and is similar to this shape. Release film 1 is provided with a first gripping portion that can be gripped on the outer periphery of the planar annular shape. Moreover, in this 1st invention, Preferably, it has a plane annular shape in the surface on the opposite side to the surface in which the 1st contact bonding layer was provided with respect to the light transmissive sheet | seat. Protective film Is provided. Protective film A second gripping portion that can be gripped is provided on the outer peripheral portion of the plane annular shape of, and in order to facilitate gripping by the peeling device, preferably, Release film A first gripping portion of Protective film The second grip portion is provided at a position that does not overlap with each other in a planar manner.
[0022]
In the first invention, typically, a hard coat layer is provided on a surface opposite to the adhesive layer of the light transmissive sheet, and preferably, the light transmissive sheet having the laminated structure and the first adhesive layer. When Release film In the previous stage used for bonding, Release film Is wound around the winding core so as to be on the outer peripheral side from the light-transmitting sheet. And in this 1st invention, in the front | former stage used for bonding, on the surface on the opposite side to the side in which the 1st contact bonding layer of the light transmissive sheet | seat was provided. Protective film Is provided, Protective film Is wound around the winding core so as to be on the inner peripheral side.
[0023]
Here, when this inventor sticks a light transmissive sheet | seat on a board | substrate using the sheet | seat member for light transmissive layer formation as mentioned above, it carries out using the pad which consists of an elastic body, and the plane stage which consists of metal. Recalled that is preferred. That is, on the flat stage, the light-transmitting sheet coated with the pressure-sensitive adhesive is placed so that the side coated with the pressure-sensitive adhesive faces the substrate, and through this pressure-sensitive adhesive, A method in which the substrate and the light transmissive sheet are pressure-bonded with a pad to form a light transmissive layer on the substrate is desirable.
[0024]
Further, the present inventor provides at least the light-transmitting sheet and the light-transmitting first adhesive layer described above. Release film The first adhesive layer is provided on the surface to be bonded to the substrate of the light transmissive sheet, and the first adhesive layer is peelable on the surface provided with the first adhesive layer. Release film Various optical discs were manufactured using the light transmissive layer forming sheet member provided with. And when this inventor observed about these optical disks, it discovered that a damage might arise on the exposed surface of a light transmissive layer.
[0025]
Therefore, the present inventor has made various studies on the scratches generated in the light transmissive layer, and foreign substances are likely to be present on the press surface on which the light transmissive sheet is placed. It has been found that scratches are caused by the foreign matter existing on the press surface, and the light transmission layer is scratched. Such a scratch on the light transmission layer impairs the transparency and hinders the production of a good optical disc. As a result, the present inventor recalls that it is preferable to protect at least the light transmissive sheet so that the occurrence of scratches can be suppressed in order to prevent foreign matter from adhering to the light transmissive sheet. It came.
[0026]
Therefore, the second invention of this invention is
On one main surface of the board,
An information signal unit configured to record and / or reproduce an information signal;
A light transmission layer capable of transmitting at least the laser beam irradiated to the information signal portion is sequentially laminated and provided.
By irradiating the information signal part with laser light from the light transmission layer side, the information signal can be recorded and / or reproduced.
A method of manufacturing an optical recording medium in which a light transmissive layer is provided on one principal surface of a substrate by bonding the one principal surface of the substrate and the light transmissive layer,
The light transmission layer comprises at least a light transmission sheet and a first adhesive layer having light transmission,
The first adhesive layer is provided on the surface of the light transmissive sheet to be bonded to the substrate, and on the opposite side of the light transmissive sheet from the side on which the first adhesive layer is provided Protective film Using a sheet for bonding,
After bonding the first adhesive layer in the bonding sheet to one main surface of the substrate, from the bonding sheet Protective film Having a peeling step to peel off,
Laminated structure light transmissive sheet and adhesive layer Protective film In the previous stage used for bonding, Protective film Is wound around the winding core so as to be on the inner peripheral side from the light-transmitting sheet
It is characterized by this.
[0027]
In the second invention, typically, Protective film And the light transmissive sheet are configured to be bonded to each other via the second adhesive layer, Protective film Compared to the adhesive force between the light transmitting sheet and Protective film Adhesive with high adhesive strength Protective film After adhering to the exposed surface of, through the adhesive Protective film By pulling in the peeling direction, Protective film Preferably, the second adhesive layer is configured to peel at the interface between the light transmissive sheet and the second adhesive layer. In particular, Protective film The magnitude of the force required for peeling is 0.15 N / 5 cm or more and 2.00 N / 5 cm or less.
[0028]
In the second invention, typically, Protective film Compared to the adhesive strength between the light transmitting sheet and Protective film Adhesive with high adhesive strength, Protective film After adhering to the exposed surface of, through the adhesive, Protective film By pulling in the peeling direction, Protective film To peel off.
[0029]
In the second aspect of the invention, typically, an adhesive film having an adhesive applied to at least one surface is used, and the surface of the adhesive film having the adhesive applied is used. Protective film By adhering to the exposed surface of the film, and pulling the adhesive film in the direction of 90 ° or more and 180 ° or less with respect to the surface of the bonding sheet, Protective film To peel off.
[0030]
In the second aspect of the invention, the substrate has a planar annular shape, and the bonding sheet has a planar annular shape. Preferably, the inner diameter of the bonding sheet is larger than the inner diameter of the substrate. In addition, the outer diameter of the bonding sheet is configured to be equal to or smaller than the outer diameter of the substrate.
[0031]
In the second aspect of the invention, typically, in the stage before the bonding sheet is used for bonding, the surface of the first adhesive layer of the bonding sheet is used. Release film Is provided to form a first supply sheet, preferably, Release film The adhesive force between the first adhesive layer and the light-transmitting sheet Protective film Less than the adhesive strength between. In particular, Release film The magnitude of the force required for peeling is 0.10 N / 5 cm or more and 1.00 N / 5 cm or less. In the second invention, typically, Release film Has a planar annular shape, Release film A second gripping portion that can be gripped is provided on the outer peripheral portion of the substrate, and before the first adhesive layer in the bonding sheet is bonded to one main surface of the substrate, the second gripping portion is gripped, Release film By pulling in the peeling direction, Release film To peel off.
[0032]
In the second invention, Protective film In order to easily peel off, preferably, Protective film A first gripping portion that can be gripped is provided on the outer peripheral portion of the planar annular shape. In the second invention, Release film A first gripping portion of Protective film The second grip portion is provided at a position that does not overlap with each other in a planar manner.
[0033]
In the second aspect of the invention, typically, the light transmission layer is configured by sequentially laminating the first adhesive layer, the light transmission sheet, and the hard coat layer. Although made of an ultraviolet curable resin, other resins, diamond-like carbon (diamond-like carbon, DLC), or the like can also be used.
[0034]
In the second aspect of the invention, typically, the bonding sheet includes the first adhesive layer, the light transmissive sheet, the hard coat layer, and the Protective film Are provided in order, and in the previous stage of using the bonding sheet for bonding, the surface of the first adhesive layer of the bonding sheet is Release film Is provided to constitute a second supply sheet. In the second invention, preferably, Release film The adhesive force between the first adhesive layer and the hard coat layer Protective film Less than the adhesive strength between. In the second invention, preferably, Protective film The magnitude of the force required for peeling is 0.15 N / 5 cm or more and 2.00 N / 5 cm or less. In the second invention, preferably, Release film The magnitude of the force required for peeling is 0.10 N / 5 cm or more and 1.00 N / 5 cm or less. Also with hard coat layer Protective film Is bonded via an adhesive. In the second invention, preferably, Protective film Is provided with a first gripper that can be gripped, and by gripping the first gripper and pulling it in a predetermined direction, Protective film To peel off. The light transmission layer has a planar annular shape, Release film A second gripping portion that can be gripped is provided at the outer periphery of the planar annular shape of the first gripping portion, and the second gripping portion is gripped before the first adhesive layer in the bonding sheet is bonded to one main surface of the substrate do it, Release film By pulling in a predetermined direction, Release film The process of performing peeling. In the second invention, typically, Protective film A first gripping portion that can be gripped is provided on the outer peripheral portion of the planar annular shape. In this second invention, using an automatic peeling device, Protective film Or Release film In order not to interfere with each other when gripping each gripping part of Protective film A first gripping portion of Release film The second grip portion is provided at a position that does not overlap with each other in a planar manner.
[0035]
In the second invention, in order to protect the outermost layer of the light transmissive sheet, a hard coat layer is provided on the surface opposite to the adhesive layer of the light transmissive sheet.
[0036]
In this second invention, a light-transmitting sheet having a laminated structure, an adhesive layer, Protective film In the previous stage used for bonding, Protective film Is wound around the winding core so as to be on the outer peripheral side from the light transmissive sheet. Specifically, in the previous stage used for bonding, the side opposite to the side where the adhesive layer of the light transmissive sheet is provided On the face Protective film Is provided, Protective film Is wound around the winding core so as to be on the inner peripheral side.
[0037]
The third invention of the present invention is:
On one main surface of the substrate,
An information signal part capable of recording and / or reproducing an information signal;
A light transmission layer capable of transmitting the laser light applied to the information signal portion is sequentially laminated and provided.
By irradiating the information signal part with laser light from the light transmission layer side, the information signal can be recorded and / or reproduced.
In the method of manufacturing an optical recording medium in which a light transmission layer is formed on one main surface of a substrate by bonding,
The light transmission layer includes a light transmission sheet and a first adhesive layer having light transmission,
On the surface opposite to the surface to be bonded to the substrate of the light transmissive sheet Protective film Using a sheet for bonding,
A supplying step of supplying an adhesive constituting the first adhesive layer on the substrate;
A bonding step of bonding the light-transmitting sheet side of the bonding sheet to one main surface of the substrate via an adhesive;
From the adhesive sheet after the adhesive is cured Protective film And a peeling step for peeling
With a light-transmitting sheet of laminated structure Protective film In the previous stage used for bonding, the light transmissive sheet is Protective film It is wound around the winding core so that it is closer to the outer circumference
It is characterized by this.
[0038]
In the third aspect of the invention, typically, the substrate has a planar annular shape, and the sheet has a planar annular shape. And in this 3rd invention, in order to form the light transmissive layer which has a light transmissive sheet | seat, typically after supplying an adhesive agent on a board | substrate, it is a sheet | seat for bonding through this adhesive agent Is placed. In the third aspect of the invention, in order to prevent peeling of the sheet from the substrate after the adhesive is cured, the inner diameter of the sheet having a planar annular shape is preferably set to the substrate having the planar annular shape. The outer diameter of the sheet having a planar annular shape is configured to be equal to or smaller than the outer diameter of the substrate having the planar annular shape. Further, when the clamp reference plane is set in a plane annular shape on the surface of the light transmission layer, the inner diameter of the sheet having a plane annular shape is set to be equal to or less than the innermost circumference of the clamp region determined by the clamp reference plane. To do.
[0039]
In the third invention, typically, Protective film And the light transmissive sheet are bonded to each other via the second adhesive layer to form a sheet, Protective film Compared with the adhesive strength between the transparent sheet and the light-transmitting sheet, a pressure-sensitive adhesive having a large adhesive strength with the protective film, Protective film By attaching it to the exposed surface of and pulling in the peeling direction, Protective film To peel off. In the present invention, a film having an adhesive applied to at least one surface is used, and the surface to which the adhesive is applied is Protective film Adhering to the exposed surface of the film, pulling the film in the direction of 90 ° to 180 ° with respect to the surface of the bonding sheet, from the bonding sheet Protective film To peel off.
[0040]
In this invention, the material used for the adhesive layer and the first adhesive layer is typically a pressure-sensitive adhesive, but other materials such as an ultraviolet curable resin can also be used. Specifically, it is possible to use an ultraviolet curable resin such as acrylate, thiol, epoxy, or silicon. In the present invention, a suitable curing method is selected for the material selected as the first adhesive layer.
[0041]
In the present invention, typically, the light transmissive sheet is made of a thermoplastic resin having light transmissive properties. In the present invention, typically, Protective film Is typically made of polyethylene-based resin, specifically, polyethylene terephthalate (PET). Moreover, in this invention, it is provided in the surface of the 1st contact bonding layer in the 1st sheet | seat for supply in the step before bonding. Release film Is typically made of a polyethylene-based resin, specifically, PET (polyethylene terephthalate).
[0042]
In the present invention, in order to minimize warpage and distortion in the manufactured optical recording medium, the light-transmitting sheet is preferably made of the same material as that used for the substrate. The thickness of the light transmissive sheet is typically configured to be smaller than the thickness of the substrate, and specifically, is selected from 30 μm to 150 μm. In the present invention, typically, the substrate and the light-transmitting sheet are made of a light-transmitting thermoplastic resin, specifically, a low water-absorbing resin such as polycarbonate (PC) or cycloolefin polymer. Is used. As a material used for the substrate, for example, a substrate made of a metal such as aluminum (Al), a glass substrate, or a substrate made of a resin such as polyolefin, polyimide, polyamide, polyphenylene sulfide, or PET can be used. is there.
[0043]
In the present invention, typically, the light-transmitting sheet is a GaN-based semiconductor laser (emission wavelength: 400 nm band, blue emission), ZnSe-based semiconductor laser (emission wavelength: 500 nm band, used for recording / reproducing information signals at least. Green) or an AlGaInP-based semiconductor laser (emission wavelength of about 635 to 680 nm, red) or the like, which is made of a nonmagnetic material that can transmit light. It consists of a thermoplastic resin. In the present invention, preferably, the protective film is made of polyethylene terephthalate (PET), and specifically, the second pressure-sensitive adhesive is attached to at least one surface of the PET. Moreover, the sheet | seat mounted on a board | substrate is manufactured by adhere | attaching the surface to which this 2nd adhesive was adhered to one surface of a translucent sheet | seat.
[0044]
The present invention preferably uses a DVR (Digital Video Recording) configured to record information using an objective lens whose NA is increased to about 0.85 by combining two lenses in series. so-called DVR-red using a semiconductor laser having an emission wavelength of about 650 nm, which can be applied to an optical recording medium having a light transmission layer such as a system), a sheet used for manufacturing the optical recording medium, and the like. It can be applied to an optical recording medium such as a so-called DVR-blue using a semiconductor laser having an emission wavelength of about 400 nm.
[0045]
According to the sheet member for forming a light transmissive layer according to the first aspect of the present invention configured as described above, at least a light transmissive sheet, a first adhesive layer having light transmittance, Release film The first adhesive layer is provided on the side to be bonded to the substrate of the light transmissive sheet, and can be peeled off on the surface provided with the first adhesive layer. Release film Since the first adhesive layer does not come into contact with the outside until immediately before being used for bonding, it is possible to reduce the foreign matter adhering to the first adhesive layer.
[0046]
Further, according to the method for manufacturing an optical recording medium according to the second and third inventions of the present invention, the light-transmitting sheet has a surface opposite to the surface to be bonded to the substrate. Protective film After bonding the bonding sheet to the surface of the substrate using the bonding sheet provided with, the protective film is peeled off from the bonding sheet so that the substrate and the light-transmitting sheet are bonded. Even when foreign matter adheres to the mounting surface of the laminating sheet, the protective film can absorb the deformation caused by the foreign matter, so that the light-transmitting sheet constituting the light-transmitting layer Up to this point, it is possible to prevent the occurrence of scratches due to foreign matters, thereby preventing the scratches from occurring on the surface of the light transmission layer.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to the drawings. In all the drawings of the first embodiment below, the same or corresponding parts are denoted by the same reference numerals.
[0048]
First, a bonding apparatus used when manufacturing the optical disk according to the first embodiment by bonding will be described. FIG. 1 shows this bonding apparatus.
[0049]
As shown in FIG. 1, in the bonding apparatus 1 according to the first embodiment, a planar stage 2 and a movable stage 3 are installed at positions facing each other.
[0050]
The planar stage 2 is for mounting the supplied bonding sheet 4 and is configured to be able to mount the bonding sheet 4. That is, a vertical movement pin 5 that is movable in a direction protruding and buried with respect to the planar stage 2 is provided at a portion of the planar stage 2 facing the movable stage 3. The diameter of the vertical movement pin 5 is configured to be equal to the diameter of the through hole 4a of the bonding sheet 4 described above. Then, the bonding sheet 4 can be placed on the flat stage 2 by fitting the through holes 4 a of the bonding sheet 4 to the vertical movement pins 5. A substrate positioning pin 6 protruding in a columnar shape is provided on the upper part of the vertical movement pin 5. The diameter of the substrate positioning pin 6 is configured to be substantially equal to the diameter of the center hole 7 a of the disk substrate 7. The disk positioning pins 6 support the disk substrate 7 at the stepped portion with the vertical movement pins 5 while aligning the center thereof. The planar stage 2 configured in this manner is configured to fit the vertical movement pin 5 on the planar stage 2 so that the bonding sheet 4 can be placed, and the disk substrate 7 is positioned. It is configured to be able to be supported at the stepped portion with the pin 6 by being fitted to the pin 6.
[0051]
A pad 8 made of an elastic material such as silicone rubber is provided on the surface of the movable stage 3 facing the flat stage 2. The pad 8 has, for example, a partial spherical shape or a conical shape composed of one portion when the sphere is divided by a predetermined plane, and a plane portion in the partial spherical shape or the conical shape is opposed to the planar stage 2. The movable stage 3 is fixed to one surface.
[0052]
As described above, the laminating apparatus 1 used for laminating sheets in the first embodiment is configured.
[0053]
In addition, as shown in FIG. 2, for example, a parallel maintaining means 9 including a plurality of columnar pins may be provided in the vicinity of the placement portion of the bonding sheet 4 on the planar stage 2 of the bonding apparatus 1. Is possible. By providing such a parallel maintaining means 9, the disk substrate 7 and the bonding sheet 4 can be held in parallel with each other, and the disk substrate 7 can be bonded to the disk substrate 7 at an undesired stage before bonding. Since the contact with the alignment sheet 4 can be prevented, the blocking phenomenon can be prevented.
[0054]
Next explained is an optical disk according to the first embodiment of the invention. Two types of optical disks will be described as the optical disk according to the first embodiment.
[0055]
That is, as shown in FIG. 3, in the first optical disc 10 according to the first embodiment, the disc substrate 7 has irregularities on one main surface of the replica substrate 7b in which the center hole 7a is formed at the center. In addition, an information signal portion 7c is provided on the one main surface. In the first optical disk 10, a light transmission layer 11 is provided on the disk substrate 7. The light transmissive layer 11 is configured by adhering a light transmissive sheet 11a through an adhesive layer 11b, and a through hole 4a is provided at the center thereof.
[0056]
A clamp region 12 is set in an annular shape around the through hole 4a on the main surface of the light transmissive layer 11 on the light transmissive sheet 11a side. A clamp reference surface 12a for setting the first optical disc 10 on a spindle of a recording / reproducing apparatus to be described later is set on the main surface of the light transmitting layer 11 in the clamp region 12 on the light transmitting sheet 11a side. . Here, the light-transmitting sheet 11a is configured to be bonded onto the disk substrate 7 via the adhesive layer 11b, and the clamp reference surface 12a is set on a portion on one main surface of the light-transmitting layer 11. In consideration of the above, the diameter of the through hole 4a is selected to be larger than the diameter of the center hole 7a of the disk substrate 7, for example, 15 mm or more. Further, the innermost peripheral diameter of the annular clamp region 12 is, for example, 23 mm, and the outermost peripheral diameter is, for example, 33 mm. Then, considering that the clamp reference surface 12a is composed of the main surface portion of the light transmitting layer 11 on the light transmitting sheet 11a side, the diameter of the through hole 4a is equal to or less than the innermost circumference of the clamp region 12. For example, it is 22 mm or less. Further, when it is necessary to increase the frictional force generated when clamping and rotating, it is possible to roughen the clamp reference surface 12a. This roughening is selectively performed with respect to the clamp reference surface 12a. Specifically, the roughening is performed so that the surface roughness Ra is, for example, 30 nm or more, preferably 120 nm or more.
[0057]
As described above, the first optical disc 10 according to the first embodiment is configured.
[0058]
Next, the second optical disc according to the first embodiment will be described. FIG. 4 shows the second optical disc 20.
[0059]
As shown in FIG. 4, in the second optical disc 20, a hard coat layer 11 c is further provided on the surface of the light transmissive sheet 11 a of the first optical disc 10. That is, the light transmissive layer 11 includes a light transmissive sheet 11a, an adhesive layer 11b attached to the surface of the light transmissive sheet 11a to be bonded to the disk substrate 7, and an adhesive layer 11b of the light transmissive sheet 11a. And a hard coat layer 11c provided on the surface opposite to the provided side. The hard coat layer 11c is made of a material having lubricity and high hardness, specifically, an ultraviolet curable resin (UV resin), diamond-like carbon (DLC), or the like. A clamp reference surface 12a is set on the surface of the hard coat layer 11c in the clamp region 12 set on the second optical disc 20. At least a part of the clamp reference surface 12a is roughened. Specifically, the surface roughness Ra is, for example, 30 nm or more, preferably 120 nm or more. Since the configuration of the other optical disks is the same as that of the first optical disk 10, the description thereof is omitted.
[0060]
Next, a method for manufacturing the first optical disc 10 and the second optical disc 20 according to the first embodiment configured as described above will be described. FIG. 5 shows a flowchart of an optical disk manufacturing process according to the first embodiment, and FIG. 6 shows a disk substrate.
[0061]
First, the disk substrate 7 shown in FIG. 6 is manufactured through the formation of the replica substrate 7b in step ST1 shown in FIG. 5 and the formation of the laminated film in step ST2. Further, the disk substrate 7 is configured by forming a center hole 7a in the central portion of the replica substrate 7b, and an uneven groove track is formed on one main surface of the disk substrate 7. An information signal portion 7c is provided on the surface.
[0062]
The replica substrate 7b is manufactured by an injection molding method using a predetermined stamper. The thickness of the replica substrate 7b is, for example, 0.6 to 1.2 mm. Further, as a material of the replica substrate 7b, a low water-absorbing resin such as polycarbonate or cycloolefin polymer (for example, ZEONEX (registered trademark)) is used. For example, a substrate made of a metal such as Al, a glass substrate, or a substrate made of a resin such as polyolefin, polyimide, polyamide, polyphenylene sulfide, or PET can be used as the replica substrate 7b. In addition, a recording film, a reflective film, and the like are formed on the concavo-convex portion formed on one main surface of the replica substrate 7b, thereby forming an information signal portion 7c. The information signal portion 7c is made of a reflective film, a film made of a magneto-optical material, a film made of a phase change material, or an organic dye film. Among these, as the material of the reflective film, for example, an Al alloy or a silver (Ag) alloy is used.
[0063]
Specifically, when the optical disc as the final product is a read-only (ROM) optical disc, the information signal portion 7c is a single layer film or a laminated film having at least a reflective layer made of, for example, an Al alloy. Consists of On the other hand, when the optical disc as the final product is a rewritable optical disc, the information signal portion 7c is composed of a single layer film or a laminated film having at least a film made of a magneto-optical material or a film made of a phase change material. In the case of a write-once optical disc, it is composed of a single layer film or a laminated film having at least a film made of an organic dye material and a film made of a phase change material. Further, as the replica substrate 7b, it is possible to use a substrate configured such that a portion of the clamp region around the center hole 7a is thicker than other portions.
[0064]
Here, in the disk substrate 7 according to the first embodiment, specifically, for example, a disk-shaped PC substrate having a thickness of 1.1 mm is used as the replica substrate 7b, and the diameter (outer diameter) of the PC substrate is used. ) Is set to 120 mm, for example, and the opening diameter (inner diameter) of the center hole 7a is set to 15 mm, for example. As the information signal portion 7c, a reflective layer made of an Al alloy with a film thickness of 100 nm, zinc sulfide (ZnS) and silicon oxide (SiO2) with a film thickness of 18 nm are formed on the region where the unevenness of the replica substrate 7b is formed. ₂ (ZnS-SiO) ₂ ), A phase change recording layer made of a GeInSbTe alloy layer with a film thickness of 24 nm, and a ZnS-SiO film with a film thickness of 100 nm. ₂ A laminated film in which the second dielectric layers made of are sequentially laminated is used.
[0065]
As described above, in step ST1, the replica substrate 7b is formed by the injection molding method, and in step ST2, the information signal portion 7c is formed by forming a laminated film on one main surface on which the unevenness is formed. After manufacturing the disk substrate 7, the process proceeds to step ST3 shown in FIG.
[0066]
In step ST3 shown in FIG. 5, a sheet preparation process is performed in which the bonding sheet 4 is put into a state where it can be bonded to one main surface of the disk substrate 7 via the adhesive layer 11b. Here, the supply sheet used when forming the light transmission layer 11 of the optical disc according to the first embodiment will be described. In the first embodiment, as a supply sheet, a first supply sheet having a three-layer structure (first example), two types of second supply sheets having a four-layer structure (second embodiment) Example) and a third supply sheet (third embodiment), and a four-layer supply sheet (fourth embodiment) having a five-layer structure will be described.
[0067]
First embodiment
First, the first embodiment will be described. FIG. 7 shows a first supply sheet 31 according to the first embodiment. As shown in FIG. 7, the first supply sheet 31 in the first embodiment includes a light-transmitting sheet 11a and an adhesive layer 11b that become the light-transmitting layer 11, and a separation for protecting the adhesive layer 11b. It consists of a mold film 31a. This release film 31a prevents the adhesive layer 11b of the first supply sheet 31 from being exposed to the atmosphere as much as possible, and prevents foreign matter or the like from adhering to the contact surface of the adhesive layer 11b with the disk substrate 7. It is for preventing.
[0068]
The first supply sheet 31 has the same shape as that of the disk substrate 7, that is, a structure formed by being punched into a planar ring shape, and a through hole 4a is formed at the center. Here, regarding the dimensions of the first supply sheet 31, the diameter (outer diameter) of the first supply sheet 31 is, for example, 120 mm, which is equal to or smaller than the outer diameter of the replica substrate 7b, and the diameter (inner diameter) of the through hole 4a. The hole diameter is larger than the inner diameter of the center hole 7a and smaller than the diameter of the innermost circumference of the clamp region 12 set in an annular shape, specifically, for example, 23 mm.
[0069]
In addition, the light transmissive sheet 11a in the first supply sheet 31 is made of a thermoplastic resin having light transmittance and satisfying at least optical characteristics capable of transmitting laser light used for recording / reproduction. Specifically, this thermoplastic resin is a methacrylic resin such as PC or polymethyl methacrylate (polymethyl methacrylate). The thickness of the light transmissive sheet 11a is, for example, 70 μm. The thickness of the light transmissive sheet 11 a is determined in consideration of the film thickness of the light transmissive layer 11.
[0070]
The adhesive layer 11b is made of, for example, a pressure sensitive adhesive (PSA) made of methacrylic resin. The thickness of the adhesive layer 11b is, for example, 30 μm. The thickness of the adhesive layer 11b is determined in consideration of the film thickness of the light transmission layer 11.
[0071]
A release agent (not shown) is applied to the side of the release film 31a that is in contact with the adhesive layer 11b. This release agent is for facilitating peeling of the release film 31a from the adhesive layer 11b when the release film 31a is peeled off. That is, when the release film 31a is peeled off, an adhesive tape having an adhesive attached on one side is usually used. First, the surface of the pressure-sensitive adhesive tape to which the pressure-sensitive adhesive is applied is adhered to the exposed surface of the release film 31a (the surface opposite to the adhesive layer 11b). Next, the adhesive tape is pulled in the direction in which the release film 31a is peeled off. As a result, the release film 31 a is peeled from the first supply sheet 31. And the sheet | seat which consists of the translucent sheet | seat 11a and the adhesive layer 11b after peeling the release film 31a by this 1st Example is used as the sheet | seat 4 for bonding in a 1st Example.
[0072]
The release film 31a is peeled off using an automatic peeling device. At this time, adhesive force (peeling force) F between the light-transmitting sheet 11a and the adhesive layer 11b ₀ More, adhesive force (peeling force) F between the adhesive layer 11b and the release film 31a _A Is large, the peeling is performed in a state where the adhesive layer 11b is adhered to the release film 31a. Therefore, the peeling force between the adhesive layer 11b and the release film 31a is made much smaller than the peeling force between the light transmissive sheet 11a and the adhesive layer 11b. On the other hand, the 1st sheet | seat 31 for supply is stored in the state wound by roll shape in the step before supplying to the bonding apparatus mentioned above. Therefore, the peeling force F between the adhesive layer 11b and the release film 31a _A If it is made small, each layer which comprises the 1st sheet | seat 31 for supply may peel partially in the state wound by roll shape. Thereby, peeling force F _A Is specifically selected from the range of 0.10 to 1.00 N / 5 cm, preferably 0.1 to 0.2 N / 5 cm. In this first embodiment, the adhesive strength F _A = 0.16 N / 5 cm. In addition, adhesive force F between the light transmissive sheet 11a and the adhesive layer 11b ₀ Is adhesive strength F _A Very large compared to
[0073]
Then, in step ST <b> 3 shown in FIG. 5, the first supply sheet 31 configured as described above is brought into a state where it can be used for bonding to the disk substrate 7.
[0074]
That is, first, in step S1 of another process, the adhesive film 11b is exposed by peeling the release film 31a from the first supply sheet 31 using the automatic peeling device described above. And the sheet | seat 4 for bonding in the state from which this release film 31a was peeled is conveyed to the bonding apparatus 1 (refer FIG. 1) mentioned above, and is mounted in a predetermined position. Thereafter, the disk substrate 7 is transported to the bonding apparatus 1 and placed at a predetermined position. At this time, each bonding sheet 4 and the disk substrate 7 are mounted such that one main surface of the disk substrate 7 provided with the information signal portion 7c and the adhesive layer 11b of the bonding sheet 4 face each other. Placed. In this way, the sheet preparation process (step ST3) ends.
[0075]
Thereafter, the process proceeds to step ST4, and the light transmission layer 11 is formed using the first supply sheet 31 configured as described above. In the first embodiment, a method of forming a light transmission layer by bonding the disk substrate 7 and the first supply sheet 31 will be described. Moreover, as a bonding apparatus used, the bonding apparatus 1 shown in FIG. 1 is used.
[0076]
That is, first, the laminating sheet 4 from which the release film 31a has been peeled off from the first supply sheet 31 is placed on the flat stage 2 with the through holes 4a fitted to the vertical movement pins 5. . At this time, the bonding sheet 4 is placed so that the adhesive layer 11 b side of one surface faces the movable stage 3. Thereafter, the disk substrate 7 is placed so as to be supported by the vertical movement pins 5 while being fitted to the substrate positioning pins 6. At this time, the disk substrate 7 is supported and placed on the vertical movement pin 5 so that one main surface provided with the information signal portion 7c faces the adhesive layer 11b.
[0077]
Next, the movable stage 3 is moved toward the flat stage 2 (downward in FIG. 1). Then, the substrate positioning pin 6 is first pressed by the pad 8, and then the vertical movement pin 5 is caused to enter the flat stage 2 through the disk substrate 7. Thereby, as shown in FIG. 5, one main surface of the disc substrate 7 on the side where the information signal portion 7 c is provided and the adhesive layer 11 b of the bonding sheet 4 are pressure-bonded. After this pressure bonding is stabilized, the movable stage 3 shown in FIG. 1 is released in a direction away from the flat stage 2. Thereafter, the bonded disc substrate 7 and the bonding sheet 4 are unloaded from the flat stage 2 using a predetermined conveying device (not shown).
[0078]
As described above, as shown in FIG. 3, the information signal portion 7c and the light transmission layer 11 including the adhesive layer 11b and the light transmission sheet 11a are provided on one main surface of the replica substrate 7b where the irregularities are formed. The first optical disc 10 is manufactured, and the manufacture of the optical disc itself is completed. Thereafter, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like as necessary.
[0079]
Second embodiment
Next, a second embodiment will be described. FIG. 8 shows a second supply sheet 32 according to the second embodiment. As shown in FIG. 8, the second supply sheet 32 in the second embodiment is laminated on the surface of the light transmissive sheet 11a and the light transmissive sheet 11a and the adhesive layer 11b to be the light transmissive layer 11. The As protective film It consists of a protector 32a and a release film 32b laminated on the surface of the adhesive layer 11b.
[0080]
The second supply sheet 32 has the same shape as that of the disk substrate 7, that is, a structure formed by being punched into a planar ring shape, and a through hole 4a is formed at the center. Here, in the dimensions of the second supply sheet 32, the diameter (outer diameter) of the second supply sheet 32 is 120 mm or less, for example, equal to or smaller than the outer diameter of the replica substrate 7b, and the diameter of the through hole 4a (inner diameter). ) Is smaller than the inner diameter of the center hole 7a and smaller than the innermost diameter of the clamp region 12 set in an annular shape, specifically, for example, 23 mm.
[0081]
Further, the material and film thickness of the light transmissive sheet 11a and the adhesive layer 11b in the second supply sheet 32 are determined in consideration of the film thickness of the light transmissive layer 11 as in the first embodiment. . The release film 32b is the same as the release film 31a according to the first embodiment. The protector 32a is made of, for example, PET similar to the release film 32b.
[0082]
A release agent (not shown) is applied to the side of the release film 32b that contacts the adhesive layer 11b. This release agent is for facilitating peeling of the release film 32b from the adhesive layer 11b when the release film 32b is peeled off. And the sheet | seat which consists of the light-transmitting sheet 11a, the adhesive layer 11b, and the protector 32a which peeled the release film 32b by this 2nd Example is used as the sheet | seat 4 for bonding in a 2nd Example.
[0083]
The release film 32b is peeled off using an automatic peeling device. At this time, the peeling force F between the adhesive layer 11b and the release film 32b _A Is the adhesive force (peeling force) F between the light-transmitting sheet 11a and the protector 32a. _B If it is much larger, the release film 32b does not peel from the second supply sheet 32, and the protector 32a is peeled off while the light-transmitting sheet 11a and the adhesive layer 11b are attached to the release film 32b. I will be broken. Further, when these adhesive forces are substantially equal, when the release film 32b is peeled off, the part that is attached to the protector 32a and the part that is attached to the release film 32b in the light transmissive sheet 11a and the adhesive layer 11b Will occur. In such a state, the light-transmitting sheet 11a and the adhesive layer 11b after the release film 32b is peeled off may be wavy, and the protector 32a may be partially peeled off. It will no longer play a role. Therefore, the peeling force F between the adhesive layer 11b and the release film 32b _A Peel force F between the light-transmitting sheet 11a and the protector 32a _B Make it smaller. On the other hand, the 2nd sheet | seat 32 for supply is stored in the state wound by roll shape in the step before being supplied to the bonding apparatus 1 mentioned above. Therefore, the peeling force F between the adhesive layer 11b and the release film 32b _A If it is very small, there is a possibility that the release film 32b of the second supply sheet 32 and the adhesive layer 11b are partially peeled in a state of being rolled. Therefore, peeling force F _A Is specifically selected from the range of 0.10 to 1.00 N / 5 cm, preferably 0.1 to 0.2 N / 5 cm, and in this second embodiment, it is 0.16 N / 5 cm. To be elected. Moreover, the peeling force F between the light-transmitting sheet 11a and the protector 32a _B Is a peeling force F between at least the release film 32b and the adhesive layer 11b. _A Greater than. That is, in the second supply sheet 32, the peeling force F _A And peeling force F _B F between _B > F _A Assuming that the configuration is such that the peeling force F _B Is specifically selected from the range of 0.15 to 2.00 N / 5 cm, preferably 0.2 to 0.4 N / 5 cm. In this second embodiment, for example, 0.22 N / 5 cm. To be elected.
[0084]
In step ST3 shown in FIG. 5, the second supply sheet 32 configured as described above is brought into a state that can be used for bonding to the disk substrate 7.
[0085]
That is, first, in step S1 of another process, the adhesive film 11b is exposed by peeling the release film 32b from the second supply sheet 32 using the automatic peeling device described above. And the sheet | seat 4 for bonding in the state from which this release film 32b was peeled is conveyed to the bonding apparatus 1 (refer FIG. 1) mentioned above, and is mounted in a predetermined position. Thereafter, the disk substrate 7 is transported to the bonding apparatus 1 and placed at a predetermined position. At this time, each bonding sheet 4 and the disk substrate 7 are mounted such that one main surface of the disk substrate 7 provided with the information signal portion 7c and the adhesive layer 11b of the bonding sheet 4 face each other. Placed. In this way, the sheet preparation process (step ST3) ends.
[0086]
Thereafter, the process proceeds to step ST4, where the light transmission layer 11 is formed using the second supply sheet 32 configured as described above. In the second embodiment, the light transmitting layer 11 is formed by bonding the disk substrate 7 and the bonding sheet 4 from which the release film 32b has been peeled off from the second supply sheet 32. Will be described.
[0087]
That is, first, the laminating sheet 4 from which the release film 32b has been peeled off from the second supply sheet 32 is placed on the flat stage 2 with the through holes 4a fitted to the vertical movement pins 5. . At this time, the bonding sheet 4 is placed so that the adhesive layer 11 b side of one surface faces the movable stage 3. Thereafter, the disk substrate 7 is placed so as to be supported by the vertical movement pins 5 while being fitted to the substrate positioning pins 6. At this time, the disk substrate 7 is supported and placed on the vertical movement pin 5 so that one main surface provided with the information signal portion 7c faces the adhesive layer 11b. Further, FIG. 11A shows the positional relationship between the disk substrate 7 and the bonding sheet 4 at this time.
[0088]
Next, the movable stage 3 shown in FIG. 1 is moved toward the flat stage 2 (downward in FIG. 1). Then, the substrate positioning pin 6 is first pressed by the pad 8, and then the vertical movement pin 5 is caused to enter the flat stage 2 through the disk substrate 7. As a result, as shown in FIG. 11B, one main surface of the disc substrate 7 on the side where the information signal portion 7 c is provided and the adhesive layer 11 b of the bonding sheet 4 are pressure-bonded.
[0089]
Then, after this pressure bonding is stabilized, the movable stage 3 shown in FIG. 1 is opened in a direction away from the flat stage 2. Thereafter, the bonded disc substrate 7 and the bonding sheet 4 are unloaded from the flat stage 2 using a predetermined conveying device (not shown).
[0090]
Thus, as shown in FIG. 11B, the bonding sheet 4 is bonded onto the disk substrate 7, and as shown in FIG. 12, the information signal portion 7c is provided on one main surface of the replica substrate 7b. In a region covering the portion 7c, the light transmission layer 11 including the adhesive layer 11b and the light transmission sheet 11a is provided, and a protector 32a is further provided. Thereafter, the process proceeds to step ST5 shown in FIG.
[0091]
Next, on the main surface opposite to the surface to be bonded to the disk substrate 7 in the protector 32a, an adhesive having an adhesive force larger than the adhesive force of the slightly adhesive adhesive between the protector 32a and the light transmissive sheet 11a. A pressure-sensitive adhesive sheet (not shown) to which the agent is applied is adhered. Here, the adhesive force between the protector 32a and the adhesive sheet is, for example, 9.8 × 10. ^-1 N / 20 mm (100 gf / 20 mm) (180 ° peel strength (JIS Z-0237)). Then, as shown in FIG. 11C, this adhesive sheet is pulled in a direction of 90 ° to 180 ° with respect to the surface of the disk substrate 7. Thereby, the protector 32a is peeled from the bonding sheet 4. At this time, the protector 32a is peeled off with a slightly adhesive adhesive (not shown) attached thereto. That is, the release surface is an interface between the light transmissive sheet and the layer made of the slightly tacky adhesive.
[0092]
As described above, the information signal portion 7c and the light transmission layer 11 including the adhesive layer 11b and the light transmission sheet 11a are provided on one main surface on which the unevenness of the replica substrate 7b is formed as shown in FIG. The first optical disk 10 is manufactured, and the manufacture of the optical disk itself is completed. Thereafter, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like as necessary.
[0093]
Third embodiment
Next, a third supply sheet according to the third embodiment will be described. FIG. 9 shows a third supply sheet 33 according to the third embodiment. As shown in FIG. 9, the third supply sheet 33 in the third embodiment is a light transmissive sheet 11, a light transmissive sheet 11 a, an adhesive layer 11 b, and an adhesive layer 11 b of the light transmissive sheet 11 a. The hard coat layer 11c is provided on the surface opposite to the side where the is provided, and the release film 33a is laminated on the surface of the adhesive layer 11b. Since the release film 33a constituting the third supply sheet 33 is the same as the release film 31a according to the first embodiment, the description thereof is omitted.
[0094]
The third supply sheet 33 has the same shape as that of the disk substrate 7, that is, a structure formed by being punched into a planar ring shape, and a through hole 4a is formed at the center. Here, in the dimensions of the third supply sheet 32, the diameter (outer diameter) of the third supply sheet 33 is 120 mm or less, for example, equal to or less than the outer diameter of the replica substrate 7b, and the diameter of the through hole 4a (inner diameter). ) Is smaller than the inner diameter of the center hole 7a and smaller than the innermost diameter of the clamp region 12 set in an annular shape, specifically, for example, 23 mm.
[0095]
Further, the materials and film thicknesses of the light transmitting sheet 11a and the adhesive layer 11b in the third supply sheet 33 are the same as those in the first embodiment, and are determined in consideration of the film thickness of the light transmitting layer 11. The The release film 33a is the same as the release film 31a according to the first embodiment. The hard coat layer 11c is made of, for example, an ultraviolet curable resin. The hard coat layer 11c is made of an ultraviolet curable resin using methoxypropanol as a diluent solvent, and the viscosity of the ultraviolet curable resin is, for example, 1.5 × 10. ^-2 Pa · s (15 cps), surface tension is, for example, 2.4 × 10 ^-2 The pencil hardness is, for example, F when a resin having a film thickness of 1 μm is formed on a polycarbonate substrate with N / m (24 dyn / cm). The hard coat layer 11c is formed on the surface of the light transmissive sheet 11a by using a roll coater (not shown) having a gravure coater.
[0096]
A release agent (not shown) is applied to the side of the release film 33a that contacts the adhesive layer 11b. This release agent is for facilitating peeling of the release film 33a from the adhesive layer 11b when the release film 33a is peeled off. And the sheet | seat which consists of the light-transmitting sheet 11a, the adhesive layer 11b, and the hard-coat layer 11c which peeled this release film 33a is used as the sheet | seat 4 for bonding in a 3rd Example.
[0097]
Further, as in the first embodiment, the third supply sheet 33 is stored in a rolled state before being supplied to the bonding apparatus 1 described above. Thereby, peeling force F between the adhesive layer 11b and the release film 33a _A If it is very small, there is a possibility that the release film 33a and the adhesive layer 11b in the third supply sheet 33 are partially peeled in a state of being rolled. Accordingly, the peeling force F between the adhesive layer 11b and the release film 33a. _A Is specifically selected from the range of 0.10 to 1.00 N / 5 cm, preferably 0.1 to 0.2 N / 5 cm. In this third embodiment, 0.16 N / 5 cm is selected. It is.
[0098]
Then, in step ST <b> 3 shown in FIG. 5, the third supply sheet 33 configured as described above is brought into a state where it can be used for bonding to the disk substrate 7.
[0099]
That is, first, in step S1 of another process, the adhesive film 11b is exposed by peeling the release film 33a from the third supply sheet 33 using the automatic peeling device described above. And the sheet | seat 4 for bonding in the state from which this release film 33a was peeled is conveyed to the bonding apparatus 1 (refer FIG. 1) mentioned above, and is mounted in a predetermined position. Thereafter, the disk substrate 7 is transported to the bonding apparatus 1 and placed at a predetermined position. At this time, each bonding sheet 4 and the disk substrate 7 are mounted such that one main surface of the disk substrate 7 provided with the information signal portion 7c and the adhesive layer 11b of the bonding sheet 4 face each other. Placed. In this way, the sheet preparation process (step ST3) ends.
[0100]
Thereafter, the process proceeds to step ST4, and a method of forming the light transmission layer 11 using the third supply sheet 33 configured as described above will be described.
[0101]
That is, first, the laminating sheet 4 from which the release film 33a has been peeled off from the third supply sheet 33 is placed on the flat stage 2 with the through holes 4a fitted to the vertical movement pins 5. . At this time, the bonding sheet 4 is placed so that the adhesive layer 11 b side of one surface faces the movable stage 3. Thereafter, the disk substrate 7 is placed so as to be supported by the vertical movement pins 5 while being fitted to the substrate positioning pins 6. At this time, the disk substrate 7 is supported and placed on the vertical movement pin 5 so that one main surface provided with the information signal portion 7c faces the adhesive layer 11b.
[0102]
Next, the movable stage 3 is moved toward the flat stage 2 (downward in FIG. 1). Then, the substrate positioning pin 6 is first pressed by the pad 8, and then the vertical movement pin 5 is caused to enter the flat stage 2 through the disk substrate 7. Thereby, as shown in FIG. 5, one main surface of the disc substrate 7 on the side where the information signal portion 7 c is provided and the adhesive layer 11 b of the bonding sheet 4 are pressure-bonded. After this pressure bonding is stabilized, the movable stage 3 shown in FIG. 1 is released in a direction away from the flat stage 2. Thereafter, the bonded disc substrate 7 and the bonding sheet 4 are unloaded from the flat stage 2 using a predetermined conveying device (not shown).
[0103]
As described above, the bonding sheet 4 is bonded onto the disk substrate 7, and as shown in FIG. 4, the information signal portion 7c is provided on one main surface of the replica substrate 7b. In the region covering the information signal portion 7c, Then, the second optical disk 20 provided with the light transmission layer 11 including the adhesive layer 11b, the light transmission sheet 11a, and the hard coat layer 11c is manufactured, and the manufacture of the optical disk itself is completed. Thereafter, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like as necessary.
[0104]
Fourth embodiment
Next, a fourth embodiment will be described. FIG. 10 shows a fourth supply sheet 34 according to the fourth embodiment. As shown in FIG. 10, the fourth supply sheet 34 in the fourth embodiment is similar to the third embodiment in the light transmissive sheet 11a, the adhesive layer 11b, and the hard layer that become the light transmissive layer 11. It consists of a coat layer 11c, a protector 34a laminated on the surface of the hard coat layer 11c, and a release film 34b laminated on the surface of the adhesive layer 11b.
[0105]
The fourth supply sheet 34 has the same shape as that of the disk substrate 7, that is, a structure formed by being punched into a planar ring shape, and a through hole 4a is formed at the center. Here, in the dimensions of the fourth supply sheet 34, the outer diameter of the fourth supply sheet 34 is 120 mm or less, for example, equal to or smaller than the outer diameter of the replica substrate 7b, and the inner hole diameter of the through hole 4a is the center hole 7a. Is smaller than the innermost diameter of the clamp region 12 set in an annular shape, specifically, for example, 23 mm.
[0106]
The materials and film thicknesses of the light transmissive sheet 11a and the adhesive layer 11b in the fourth supply sheet 34 are the same as those in the first embodiment, and are determined in consideration of the film thickness of the light transmissive layer 11. The Further, the hard coat layer 11c of the fourth supply sheet 34 is the same as that in the third embodiment, and the description thereof is omitted. Further, the protector 34a and the release film 34b constituting both surfaces of the fourth supply sheet 34 are the same as those in the protector 32a according to the second embodiment and the release film 31a according to the first embodiment, respectively. Is omitted.
[0107]
A release agent (not shown) is applied to the side of the release film 34b that contacts the adhesive layer 11b. This release agent is for facilitating peeling of the release film 34b from the adhesive layer 11b when the release film 34b is peeled off. And the sheet | seat which consists of the light-transmitting sheet | seat 11a, the adhesive layer 11b, the hard-coat layer 11c, and the protector 34a which peeled this release film 34b is used as the bonding sheet | seat 4 in a 4th Example.
[0108]
The release film 32b is peeled off using an automatic peeling device. At this time, the peeling force F between the adhesive layer 11b and the release film 34b _A Is the adhesive force (peeling force) F between the hard coat layer 11c and the protector 34a. _C If it is much larger, the release film 34b does not peel from the fourth supply sheet 34, and the protector is in a state where the light-transmitting sheet 11a, the adhesive layer 11b, and the hard coat layer 11c are attached to the release film 34b. 34a is peeled off. Further, when these adhesive forces are substantially equal, when the release film 34b is peeled off, in the light transmissive sheet 11a, the adhesive layer 11b, and the hard coat layer 11c, the part attached to the protector 34a and the release film 34b The part sticking to will occur. In such a state, after peeling off the release film 34b, the sheet portion composed of the light transmissive sheet 11a, the adhesive layer 11b, and the hard coat layer 11c becomes wavy. Furthermore, since the protector 34a is partially peeled off, the protector 34a can no longer function. Therefore, the peeling force F between the adhesive layer 11b and the release film 34b _A Peel force F between the hard coat layer 11c and the protector 34a _C Make it smaller. On the other hand, the 2nd sheet | seat 34 for supply is stored in the state wound by roll shape in the step before being supplied to the bonding apparatus mentioned above. Therefore, the peeling force F between the adhesive layer 11b and the release film 34b _A If it is very small, there is a possibility that the release film 34b of the fourth supply sheet 34 and the adhesive layer 11b are partially peeled in a state of being rolled. Therefore, peeling force F _A Is specifically selected from the range of 0.10 to 1.00 N / 5 cm, preferably 0.1 to 0.2 N / 5 cm, and in this fourth embodiment, 0.16 N / 5 cm. To be elected. Further, the peeling force F between the hard coat layer 11c and the protector 34a _C Is at least the peeling force F between the release film 34b and the adhesive layer 11b. _A Greater than. That is, in the fourth supply sheet 34, the peeling force F _A And peeling force F _C F between _C > F _A Assuming that the configuration is such that the peeling force F _C Is specifically selected from the range of 0.15 to 2.00 N / 5 cm, preferably 0.2 to 0.4 N / 5 cm. In this fourth embodiment, F is _A For example, 0.32 N / 5 cm is selected.
[0109]
Then, in step ST3 shown in FIG. 5, the fourth supply sheet 34 configured as described above is brought into a state where it can be used for bonding to the disk substrate 7.
[0110]
That is, first, in step S1 of another process, the adhesive film 11b is exposed by peeling the release film 34b from the fourth supply sheet 34 using the automatic peeling device described above. And the sheet | seat 4 for bonding in the state from which this release film 34b was peeled is conveyed to the bonding apparatus 1 (refer FIG. 1) mentioned above, and is mounted in a predetermined position. Thereafter, the disk substrate 7 is transported to the bonding apparatus 1 and placed at a predetermined position. At this time, each bonding sheet 4 and the disk substrate 7 are mounted such that one main surface of the disk substrate 7 provided with the information signal portion 7c and the adhesive layer 11b of the bonding sheet 4 face each other. Placed. In this way, the sheet preparation process (step ST3) ends.
[0111]
Thereafter, the process proceeds to step ST4, and the light transmission layer 11 is formed using the fourth supply sheet 34 configured as described above.
[0112]
That is, first, the laminating sheet 4 from which the release film 34 b has been peeled off from the fourth supply sheet 34 is placed on the flat stage 2 with the through holes 4 a fitted to the vertical movement pins 5. . At this time, the bonding sheet 4 is placed so that the adhesive layer 11 b side of one surface faces the movable stage 3. Thereafter, the disk substrate 7 is placed so as to be supported by the vertical movement pins 5 while being fitted to the substrate positioning pins 6. At this time, the disk substrate 7 is supported and placed on the vertical movement pin 5 so that one main surface provided with the information signal portion 7c faces the adhesive layer 11b. Further, FIG. 13A shows the positional relationship between the disk substrate 7 and the bonding sheet 4 at this time.
[0113]
Next, the movable stage 3 shown in FIG. 1 is moved toward the flat stage 2 (downward in FIG. 1). Then, the substrate positioning pin 6 is first pressed by the pad 8, and then the vertical movement pin 5 is caused to enter the flat stage 2 through the disk substrate 7. As a result, as shown in FIG. 13B, one main surface of the disc substrate 7 on the side where the information signal portion 7 c is provided and the adhesive layer 11 b of the bonding sheet 4 are pressure-bonded.
[0114]
After this pressure bonding is stabilized, the movable stage 3 shown in FIG. 1 is released in a direction away from the flat stage 2. Thereafter, the bonded disc substrate 7 and the bonding sheet 4 are unloaded from the flat stage 2 using a predetermined conveying device (not shown).
[0115]
As described above, as shown in FIG. 13B, the bonding sheet 4 is bonded onto the disk substrate 7, and as shown in FIG. 14, the information signal portion 7c is provided on one main surface of the replica substrate 7b. In the region covering the portion 7c, the light transmissive layer 11 including the adhesive layer 11b, the light transmissive sheet 11a, and the hard coat layer 11c is provided, and the protector 34a is further provided.
[0116]
Next, a pressure-sensitive adhesive having an adhesive force larger than that of the adhesive between the protector 34a and the light-transmitting sheet 11a is applied to the main surface of the protector 34a opposite to the surface to be bonded to the disk substrate 7. The attached adhesive sheet (not shown) is adhered. Here, the adhesive force between the protector 34a in this adhesive sheet is, for example, 9.8 × 10. ^-1 N / 20 mm (100 gf / 20 mm) (180 ° peel strength (JIS Z-0237)). Then, as shown in FIG. 13C, this adhesive sheet is pulled in the direction of 90 ° to 180 ° with respect to the surface of the disk substrate 7. Thereby, the protector 32a is peeled from the bonding sheet 4. At this time, the protector 32a is peeled off with a slightly adhesive adhesive (not shown) attached thereto. That is, the release surface is an interface between the light transmissive sheet and the layer made of the slightly tacky adhesive.
[0117]
As described above, the light transmissive layer 11 including the adhesive layer 11b, the light transmissive sheet 11a, and the hard coat layer 11c is provided on one main surface of the replica substrate 7b on which the information signal portion 7c is formed, as shown in FIG. The second optical disc 20 is manufactured, and the manufacture of the optical disc itself is completed. Thereafter, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like as necessary.
[0118]
Next, a case where the first optical disk 10 and the second optical disk 20 manufactured as described above are clamped by the chucking portion will be described. FIG. 15 shows the chucking unit according to the first embodiment.
[0119]
As shown in FIG. 15, in the chucking unit 40 according to the first embodiment, a disk mounting table 42, a center positioning pin 43, and a magnetic metal plate 44 are sequentially connected to an upper portion of a rotating shaft 41. Has been provided.
[0120]
The rotating shaft 41 is connected to a motor (not shown), and is configured to be able to rotate around the center in a cross section perpendicular to the longitudinal direction of the rotating shaft 41.
[0121]
The disk mounting table 42 is for mounting an optical disk. The optical disc is placed in contact with the main surface of the light transmission layer 11 in the clamp region 12, that is, the clamp reference surface 12a. The upper surface of the disk mounting table 42 on which the optical disk is mounted has an annular shape, and the innermost diameter is 26 mm, for example, and the outermost diameter is 32 mm, for example. Further, for example, a permanent magnet (not shown) is embedded in the disk mounting table 42, and specifically, the permanent magnet is covered with a resin such as polyimide.
[0122]
The center positioning pin 43 is for positioning the center of the optical disk. Further, the center positioning pin 43 can be inserted into the center hole of the optical disc (center hole 7a of the disc substrate 7), and the center thereof is configured to substantially coincide with the rotation center of the rotating shaft 41.
[0123]
The magnetic metal plate 44 is made of a magnetic material and is used for clamping the optical disk placed on the disk placement table 42 from the disk substrate 7 side. Here, the cross section of the magnetic metal plate 44 along the plane parallel to the mounting surface of the disk mounting table 42 has an annular shape, and the innermost periphery of the annular shape is, for example, 26 mm, and the outermost periphery is For example, it is 32 mm.
[0124]
Then, a permanent magnet is embedded, and the optical disk is sandwiched in the clamp region 12 by the disk mounting table 42 in contact with the light transmission layer 11 side and the magnetic metal plate 44 in contact with the disk substrate 7 side, so that clamping is possible. It is configured. Further, the force when the optical disk is sandwiched between the disk mounting table 42 and the magnetic metal plate 44, that is, the clamping force in the chucking section 40 is 2N for consumer use and 10N for business use, for example.
[0125]
The optical disk is clamped by the chucking unit 40 configured as described above. Recording / reproduction with respect to the information signal unit 7c is performed by laser light L that has passed through the second group lens from a semiconductor laser (not shown). ₁ Is performed by irradiating the information signal portion 7c from the light transmission layer 11 side of the optical disc.
[0126]
In addition, the inventor of the present invention manufactured optical discs (first optical disc 10 and second optical disc 20) based on the manufacturing method according to the first to fourth embodiments described above, and manufactured by a conventional technique. 100 optical discs manufactured according to the method (first comparative example) were manufactured, and the presence of foreign matter in the adhesive layer 11b and the occurrence of scratches on the surface of the light transmitting layer 11 in these optical discs were manufactured. , And the adhesion of dirt on the surface of the light transmission layer 11 were evaluated. In each evaluation, regarding even one place in the recording area of the optical disk, if there is foreign matter, dirt, or scratches, it is considered to be defective, and regarding the supply sheet when manufacturing the optical disk used for evaluation, F _B > F _A , F _C > F _A Thus, the so-called peeling force consistency is achieved.
[0127]
Here, the supply sheet supplied in the first comparative example will be described. FIG. 16 shows a supply sheet according to the first comparative example. The light transmission layer of the optical disc according to the first comparative example is manufactured by separately supplying two supply sheets.
[0128]
That is, as shown in FIG. 16A, the adhesive layer supply sheet 50 has the first release film 52 and the second release film 53 laminated on both sides thereof, with the adhesive layer 51 sandwiched therebetween. It is composed of a sheet having a three-layer structure. Further, the adhesive layer supply sheet 50 has a planar annular shape, and a through hole 50a is formed at the center thereof. As shown in FIG. 16B, the light-transmitting sheet supply sheet 54 is composed of a sheet having a two-layer structure in which a release film 56 is laminated on one surface of the light-transmitting sheet 55. The light-transmitting sheet supply sheet 54 also has the same shape as that of the adhesive layer supply sheet 50, and a through hole 54 a having substantially the same diameter as the through hole 50 a is formed at the center.
[0129]
When a light transmission layer is formed on one main surface of the disk substrate 7, first, the first release film 52 in the adhesive layer supply sheet 50 is peeled off, and the adhesive layer 51 is formed on one main surface of the disk substrate 7. Glue. Next, the second release film is peeled off, and the release film 56 is peeled from the light transmitting sheet supply sheet 54. The light transmissive sheet 55 is bonded to the exposed surface of the adhesive layer 51. The light transmission layer of the optical disc according to the first comparative example is formed through the above process.
[0130]
Table 1 below shows the evaluation results of the first to fourth examples and the evaluation result of the first comparative example.
[0131]
[Table 1]

[0132]
From Table 1, the number of optical discs in which foreign matter is mixed in the adhesive layer is 18 out of 100 in the optical disc according to the first comparative example, whereas the first optical disc 10 according to the first and second embodiments is used. It can be seen that none of the second optical disks 20 according to the third and fourth embodiments exist. According to the study of the present inventor, this is because the adhesive layer 51 and the light transmissive sheet 55 are separately supplied when forming the light transmissive layer of the optical disc according to the first comparative example. After the release film 52 is peeled off until the adhesive layer 51 is bonded to the disk substrate 7, and after the second release film 53 is peeled off, the light transmitting sheet 55 is placed on the exposed surface of the adhesive layer 51. It is conceivable that foreign matter is mixed in before the attachment. Compared with the first comparative example, when forming the light transmission layer of the optical disc according to the first to fourth embodiments, foreign matter may be mixed after the release film is peeled off. This is until the disk substrate 7 is bonded. For this reason, in the first to fourth embodiments, it is conceivable that the probability that foreign matters are mixed is greatly reduced as compared with the first comparative example. Furthermore, in the first comparative example, it is necessary to perform bonding of the adhesive layer and bonding of the light-transmitting sheet twice, but in the first to fourth examples, bonding is performed once. Therefore, the manufacturing tact can be shortened to improve the productivity, and the manufacturing equipment can be simplified.
[0133]
In addition, it is considered that the foreign matter is mixed in the adhesive layer because the adhesive layer 51 is deformed in a wave shape. That is, the adhesive layer 51 according to the first comparative example is sandwiched between the first release film 52 and the second release film 53 having the same quality. Therefore, when the first release film 52 is peeled off, the adhesive layer 51 may be peeled off after the first release film 53 is partially maintained in an adhesive state. In such a case, the adhesive layer 51 itself becomes wavy, the surface state of the adhesive layer 51 deteriorates, and foreign matter is likely to be mixed. On the other hand, in the first to fourth embodiments, the adhesive layer 11b is sandwiched between the light transmissive sheet 11a and the release film. Therefore, adhesive force (peeling force) F between the release film and the adhesive layer 11b _A From the above, the peeling force F between the adhesive layer 11b and the light transmissive sheet 11a ₀ Can be set larger. Therefore, the surface of the adhesive layer 11b does not deteriorate, so that foreign matter can be minimized.
[0134]
Also, from Table 1, the number of optical discs with scratches on the surface of the light-transmitting sheet is 7 out of 100 in the optical disc according to the first comparative example, while the first example according to the first example. 6 out of 100 in the optical disk 10 and 5 out of 100 in the first optical disk according to the second embodiment, and there is no one in the second optical disk 20 according to the third and fourth embodiments. I understand that.
[0135]
According to the inventor's study, this evaluation result shows that the light-transmitting sheet 11a itself is vulnerable to scratches and dirt, and therefore by providing the hard coat layer 11c on the surface of the light-transmitting sheet 11a, By providing the hard coat layer 11c having an effect such as antistatic, it is considered that the occurrence of scratches due to contact with foreign matters is prevented. Further, as shown in the second optical disc 20, since the surface of the light transmission layer 11 is composed of the hard coat layer 11c, even when the user uses the optical disc, even if it comes into contact with foreign matter, the contact is caused. The occurrence of scratches can be suppressed. In addition, when dirt is attached, the dirt can be cleaned with a cleaning cloth or the like.
[0136]
Further, from Table 1, the number of optical discs on the surface of the light transmission layer 11 with contamination is 5 out of 100 in the optical disc according to the first comparative example, whereas the first optical disc according to the first embodiment. 10 out of 100 sheets and 3 out of 100 sheets in the second optical disk 20 according to the third embodiment. The first optical disk 10 according to the second embodiment and the second optical disk according to the fourth embodiment. It can be seen that no optical disk 20 exists.
[0137]
According to the inventor's examination on this point, by using a supply sheet provided with a protector at the time of forming the light transmission layer, an adhesive such as glue adhered to an apparatus or facility, or adhesive property can be obtained. Foreign matter adheres to the protector. And since this protector peels with dirt, such as an adhesive and an adhering foreign material, after a bonding process, dirt does not adhere to the surface of the light transmission layer 11. Therefore, not only can the surface of the light transmission layer 11 in the first optical disc 10 be protected, but it is also possible to protect the hard coat layer 11c that is usually sensitive to adhesion of foreign substances having adhesiveness. In addition, since it is not necessary for the operator to clean the surface of the hard coat layer 11c with a cloth or the like, productivity can be improved and cost can be reduced.
[0138]
Further, from Table 1, regarding the manufacturing yield, the non-defective rate is 70% in the optical disc according to the first comparative example, whereas the non-defective rate is 90% in the first example, and the non-defective rate is in the second example. Is 95%, and the non-defective product rate is 97% in the third embodiment, and it can be seen that no defective product is generated in the second optical disc 20 according to the fourth embodiment.
[0139]
In addition, the inventor performed further evaluation on the first optical disc 10. That is, using the first supply sheet 31 according to the first embodiment, 20 new optical disks 10 are newly manufactured, and using the second supply sheet 32 according to the second embodiment, Twenty new optical disks 10 were newly manufactured, and defects generated on the surface of the light transmission layer 11 were measured using a disk inspection machine (Dr. Schenk, VCD-120-CTLN). Table 2 below shows the number of optical disks on which at least one scratch defect having a diameter of 80 μm or more was present.
[0140]
[Table 2]

[0141]
As shown in Table 2, among the 20 optical disks produced by the first optical disk manufacturing method using the first supply sheet 31 according to the first embodiment, the number of optical disks with defects is 3 On the other hand, in the 20 optical disks produced using the bonding sheet 4 to which the protector 32a according to the second embodiment was adhered, there was no optical disk with defects.
[0142]
Therefore, the light transmission layer 11 is formed on the main surface of the disk substrate 7 provided with the information signal portion 7c by using the bonding sheet 4 provided with the protector 32a. 11, it was confirmed that foreign matter could be prevented from adhering to the surface, and that it was possible to greatly reduce scratch defects in the optical disk.
[0143]
According to the knowledge of the present inventor in this respect, the flaw defect in the optical disk manufactured by the conventional manufacturing method is between the metal flat stage 2 on which the light transmitting sheet is placed and the bonding sheet 4. This is a defect caused by foreign matter mixed in. Since this foreign matter is mainly a foreign matter existing on the flat stage 2, it is difficult to completely remove the foreign matter, but the bonding sheet 4 provided with the protector 32a on the surface side to be placed on the flat stage 2 is provided. By using it, even if a foreign substance exists on the flat stage 2, the foreign substance can be buried in the protector 32a by the protector 32a. Thereby, it is possible to prevent the light-transmitting sheet 11a constituting the outermost layer of the light-transmitting layer 11 from being affected by the foreign matter.
[0144]
That is, when the light transmission layer 11 is formed by bonding on the disk substrate 7 provided with the information signal portion 7c on one main surface, the second supply sheet 32 provided with the protector is supplied and separated. After the bonding sheet 4 obtained by peeling the mold film 32b is bonded to the information signal portion 7c of the disk substrate 7, the protector is peeled off from the bonding sheet 4, so that the light transmitting layer 11 It is possible to suppress the occurrence of scratch defects on the surface.
[0145]
Further, by laminating the same protector as in the second and fourth embodiments on the side opposite to the side where the release film 56 of the light transmissive sheet 55 according to the first comparative example is laminated, It is possible to prevent the surface of the adhesive sheet 55 from being scratched or contaminated. Further, by providing the same hard coat layer as in the third and fourth embodiments on the side opposite to the side where the release film of the light transmissive sheet 55 is laminated, the surface of the light transmissive layer is damaged. Can be prevented.
[0146]
Further, in the sheet member for forming a light transmission layer according to the first embodiment described above, the sheet supply form when forming the light transmission layer 11 is the same as that of the disk substrate 7 as shown in FIG. A sheet 60 in which a release film 60a, an adhesive layer 11b, a light-transmitting sheet 11a, and a protector 60b, which are formed in a planar annular shape, are sequentially stacked, that is, a fully-feed type supply sheet 60 is used. However, as shown in FIG. 18, it is also possible to use a sheet 61 in which a release film 61a, an adhesive layer 11b, a light transmissive sheet 11a, and a protector 61b are sequentially laminated, that is, a so-called hoop material type supply sheet 61. It is. Further, as shown in FIG. 19, a release sheet 62a composed of a continuous sheet is used to protect the adhesive layer 11b, and the adhesive layer 11b other than the release sheet 62a, the light transmissive sheet 11a, and the protector 62b. It is also possible to use a so-called half-punched supply sheet 62 in which the laminated structure is formed in a planar annular shape.
[0147]
Also, in FIGS. 17 to 19, the same structure as the laminated structure of the second supply sheet has been described as an example. However, in FIGS. 17 to 19, the laminated structure is the first supply sheet 31, A laminated structure of the third supply sheet 33 and the fourth supply sheet 34 may be used. Further, as a supply form of the supply sheet, a supply form other than those mentioned in the first embodiment can be adopted.
[0148]
As described above, according to the manufacturing method of the optical recording medium according to the first embodiment, the thickness is reduced, the small birefringence is good, the transparency is good, the surface is not scratched, and the thickness is also small. It is possible to obtain an optical disk having a uniform light transmission layer and having a high reliability that can sufficiently cope with a high NA of the objective lens.
[0149]
In the method of manufacturing the optical recording medium according to the first embodiment described above, the above-described effects can be obtained. However, as a result of further experiments by the inventor, the following problems occur. I found out.
[0150]
That is, as described in the first embodiment, when a bonding sheet having a shape punched into a flat annular shape is used as the bonding sheet 4, a stage before bonding to the main surface of the disk substrate 7. , It is necessary to peel the release films 31a, 32b, 33a, 34b. Further, in the case of the bonding sheet 4 provided with a protector, it is necessary to peel off the protectors 32a and 34a at a stage after being bonded to the main surface of the disk substrate 7.
[0151]
Therefore, in the first embodiment described above, the adhesive surface side of the adhesive tape 72 shown in FIG. 20B is attached to the release film 71 side of the bonding sheet 4 shown in FIG. A method of peeling the release film 71 by pulling in the angle direction is adopted.
[0152]
Similarly, also in the bonding sheet 4 provided with the protector, after bonding, the adhesive surface side of the adhesive tape 72 is bonded to the protector (not shown in FIG. 20), and the adhesive tape 72 is attached to the predetermined sheet. A method of peeling the protector by pulling in the angle direction is adopted.
[0153]
However, the use of the adhesive tape 72 causes the following problems. That is, since the adhesive tape 72 is a secondary material used for peeling, the cost increases. Further, as shown in FIG. 21, as the peeling device 73, an adhesive tape supply part 74 for supplying the adhesive tape 72, a peeling part 75 for peeling the release film 71, etc., a peeled release film 71, An adhesive tape recovery part 77 for recovering the adhesive tape 72 is required together with the peeling residue 76 such as a protector. For this reason, the peeling device 73 itself is increased in size and complexity. Further, in the method of attaching the adhesive surface side of the adhesive tape 72 to the release film 71, there is a possibility that the adhesive tape 72 does not adhere securely to the release film 71 or the like. The problem that the release film and protector which require peeling will remain in the bonding sheet 4 also arises. Furthermore, when the adhesive tape 72 is used, a setup time for supplying the adhesive tape 72 is generated, and the operating rate of the peeling device 73 is also lowered.
[0154]
Therefore, as a result of studying a method for making it possible to peel off a release film and a protector without using an adhesive tape, the present inventor has come up with the light transmission layer forming sheet member according to the second embodiment. The light transmission layer forming sheet member according to the second embodiment will be described below. FIG. 22 shows a supply sheet according to the second embodiment.
[0155]
As shown in FIG. 22A, the supply sheet 81 according to the second embodiment has a planar annular shape, and a first gripping portion 82a protruding in a convex shape on the outer peripheral portion, and a convex shape similarly. A second gripping portion 83a is provided so as to protrude from the top. The first gripping portion 82a and the second gripping portion 83a that protrude in the convex shape are provided at positions that do not overlap in plan view. That is, the first gripping portion 82a and the second gripping portion 83a are provided at positions where they do not overlap each other in a plan view. In FIG. 22A, the planar annular phase is the same as that of the first gripping portion 82a. It is provided at a position shifted by 180 ° from the second gripping portion 83a. Further, the first gripping portion 82a and the second gripping portion 83a have a side length l as shown in FIG. 22C. ₁ , L ₂ Is a rectangle of 1 to 3 cm, for example, but the shape and dimensions are not limited thereto.
[0156]
The laminated structure of the light transmissive layer forming sheet member according to the second embodiment is similar to that in the first embodiment. At least the light transmissive sheet 11a and the adhesive provided on one surface of the light transmissive sheet. It consists of a layer 11b and a release film for protecting the adhesive layer 11b. Here, a supply sheet having the same four-layer configuration as the second supply sheet 32 shown in FIG. 8 will be described as an example.
[0157]
That is, as shown in FIG. 22B, the supply sheet 81 according to the second embodiment includes a light transmissive sheet 11a and an adhesive layer 11b in which a release film 82 is laminated on the adhesive layer 11b side, A protector 83 is laminated on the transparent sheet 11a side.
[0158]
Next, a method for manufacturing an optical recording medium using the thus configured supply sheet 81 will be described.
[0159]
That is, as shown in FIG. 23A, a supply sheet 81 having a four-layer structure is supplied to the bonding process. Then, the first holding portion 82a of the release film 82 shown in FIG. 22A is held using a peeling robot (not shown) and pulled in the peeling direction. Thereby, as shown in FIG. 23B, the release film 82 is peeled from the supply sheet 81, and the adhesive layer 11b is exposed.
[0160]
Next, the supply sheet 81 in a state where the release film 82 is peeled and the adhesive layer 11b is exposed is conveyed to the bonding apparatus (see FIGS. 1 and 2) described in the first embodiment. Then, the supply sheet 81 and the disk substrate 7 are sequentially placed at predetermined positions of the laminating apparatus, and their positions are adjusted. Thereafter, the disk substrate 7 is pressed by the pad 8 by the same method as in the first embodiment, so that the adhesive layer 11b of the supply sheet 81 and the information signal portion 7c of the disk substrate 7 face each other. to paste together. As a result, as shown in FIG. 23C, the light transmissive sheet 11a and the protector 83 are bonded to one main surface of the disk substrate 7 via the adhesive layer 11b.
[0161]
Next, using the same peeling robot as that used for peeling the release film 82, the second gripping portion 83a in the protector 83 is gripped and pulled in the peeling direction. Thereby, the protector 83 is peeled and the surface of the light transmissive sheet 11a is exposed. As a result, the optical disc according to the second embodiment is manufactured. Note that the configuration and manufacturing process of the optical disc according to the second embodiment are the same as those in the first embodiment, and a description thereof will be omitted.
[0162]
In addition, the inventor of the present invention uses an optical disc (fifth example) manufactured using the supply sheet according to the second embodiment described above and an optical disc manufactured using a conventional supply sheet (second example). With respect to the comparative example), 1000 of each of these optical discs were manufactured, and evaluation was performed on the separation failure of the release film 82 and the separation failure of the protector 83 on each of the optical disks. That is, in the optical disk according to the fifth example, an optical disk is manufactured using the supply sheet 81 by the manufacturing method of the second embodiment described above, and in the optical disk according to the second comparative example, a release film and An optical disk is manufactured using a supply sheet that is completely removed with a four-layer structure, by a manufacturing method similar to the manufacturing method of the first embodiment in which the protector is peeled off using an adhesive tape.
[0163]
The evaluation results of the above-described fifth example and the evaluation results of the second comparative example are shown in Table 3 below.
[0164]
[Table 3]

[0165]
From Table 3, in the manufacture of the optical disc according to the second comparative example, the peeling failure of the release film occurred in 10 optical discs, whereas in the optical disc according to the fifth embodiment, the release film 82 was peeled off. It can be seen that no defect occurs. Further, in the manufacture of the optical disc according to the second comparative example, the failure of the protector peeling occurred on 17 optical discs, whereas in the optical disc according to the fifth embodiment, the release film 82 had no peeling failure. It turns out that it has not occurred. This is because, as in the second comparative example, the peeling of the release film does not depend on the adhesive force between the adhesive tape and the release film, and the first provided on the outer peripheral portion of the release film 82. This is because the release film 82 is peeled by gripping and pulling the gripping portion 82a, so that the peeling can be surely performed. Similarly, since the protector does not peel at the interface between the adhesive tape and the protector, it is possible to prevent the occurrence of peeling failure.
[0166]
FIG. 24 shows another example of the supply sheet according to the second embodiment. As shown in FIG. 24A, the supply sheet 84 according to the second embodiment is different from the above-described supply sheet 81, in which a release film 82 is formed in a rectangular shape, and on top of that, as shown in FIG. 24B, The adhesive layer 11b, the light transmissive sheet 11a, and the protector 83 are sequentially stacked. Here, in another example of the supply sheet according to the second embodiment shown in FIG. 24A, the diameter φ of the light transmissive sheet 11a, the adhesive layer 11b, and the protector 83 is, for example, 120 mm, and the release film 82 is 1 It is assumed that the side 1 is a square having a length of 123 mm.
[0167]
A portion of the release film 82 that does not overlap with the adhesive layer 11b, the light transmissive sheet 11a, and the protector 83 in a plane is defined as an outer gripping portion 82b that can be gripped by the peeling robot. In this configuration, the protector 83 can be similarly configured. However, when the gripping areas overlap, it is difficult to grip only one of the release film 82 and the protector 83 by the peeling robot. Become. Therefore, when the protector 83 has a rectangular shape, the release film 82 is formed into a planar annular shape of the same type as the light transmissive sheet 11a and the adhesive layer 11b. That is, only one of the release film 82 and the protector 83 is rectangular, and a region that does not overlap the light-transmitting sheet 11a and the adhesive layer 11b is defined as a grip portion. Then, the non-overlapping gripping portion is gripped by a peeling robot, and peeling is performed by pulling in the peeling direction.
[0168]
As described above, in the light transmissive layer forming sheet member according to the second embodiment, the same effect as in the first embodiment can be obtained, and the grip portion is provided on the film that needs to be peeled off. By providing, the peeling failure of the release film 82 and the protector 83 can be surely prevented, so that the manufacturing yield of the optical disk manufactured using this light transmission layer forming sheet member can be improved. In addition, it is possible to save the space of the peeling device and simplify the process.
[0169]
In addition, the present inventor has found that the following problems occur when the light transmission layer forming sheet member is mounted on the bonding apparatus used in the first embodiment for bonding. .
[0170]
That is, when bonding is performed using a single-wafer type bonding sheet 4 that is configured to have a laminated structure of a light-transmitting sheet 11a and an adhesive layer 11b, as shown in FIG. The bonding sheet 4 needs to be arranged in parallel on the flat stage 2. Therefore, the present inventor has devised a method of providing a vacuum suction means on the planar stage 2 of the bonding apparatus 1 used in the first embodiment, and fixing the bonding sheet 4 by suction.
[0171]
That is, as shown in FIG. 25, a vacuum suction portion 91 having a suction hole is provided in the planar stage 2 at the outer peripheral portion of the bonding sheet 4. Then, the inside of the vacuum suction portion 91 is evacuated and the bonding sheet 4 is placed, so that it is held parallel to the placement surface of the flat stage 2. However, when the bonding sheet 4 is held by the vacuum suction portion 91 and the bonding sheet 4 is not correctly fixed to the flat stage 2, the following problem occurs.
[0172]
That is, since the bonding sheet 4 is not sucked and fixed on the flat stage 2 by the vacuum suction unit 91, the set pressure is not reached, and it is difficult to shift to the process after the bonding, and a series of manufacturing apparatuses. Will stop. Further, the possibility that air bubbles are left between the bonding sheet 4 and the flat stage 2 is greatly increased, so that when the disk substrate 7 and the bonding sheet 4 are bonded together, Air bubbles may be mixed in between or the light transmission layer 11 may be wrinkled. If air bubbles are mixed in or wrinkled, the reliability of data recording and reproduction is deteriorated in the optical disc as the final product. Further, if the bonding sheet 4 is not held at an accurate position on the flat stage 2, a bonding shift occurs between the disk substrate 7 and the bonding sheet 4.
[0173]
When such misalignment occurs, the laminating sheet 4 protruding from the disk substrate 7 collides with the optical disk cartridge to cause bending or peeling, and finally the reliability of recording and reproduction of the optical disk. Decrease, recording failure and reproduction failure may occur. If the bonding sheet 4 is not fixed by suction on the flat stage 2, an automatic peeling device is used. Mold release When the film is peeled off, the laminating sheet 4 is displaced with respect to the disk substrate 7, and accurate peeling becomes difficult. As a result, the light transmission layer 11 is not bonded.
[0174]
As described above, it is important to improve the reliability of the optical disk by accurately adsorbing and fixing the bonding sheet 4 by the vacuum adsorbing portion 91. However, it has been found that when the inventor actually places the bonding sheet 4 on the flat stage 2, the outer periphery of the bonding sheet 4 is not sucked by the vacuum suction portion 91.
[0175]
That is, the laminating sheet 4 is supplied, handled, and transported in a roll shape at the time of manufacturing before being fully extracted. For this reason, the laminating sheet 4 before being completely removed is curled in the direction wound in a roll shape. Further, if the state of being wound in a roll shape continues for a certain period of time, it becomes difficult to correct the curling, so-called curling. For example, even if it is completely removed to make the bonding sheets 4 into single sheets, and these bonding sheets 4 are stacked and further corrected by applying pressure with a weight or the like from above, this wrapping remains. End up. Furthermore, as shown in FIG. 26, when it is placed on the planar stage 2 of the laminating apparatus 1, the laminating sheet 4 becomes convex on the planar stage 2 side, and the outer periphery rises.
[0176]
In view of this, the inventor placed the bonding sheet 4 on the flat stage 2, and then pressed the outer periphery of the bonding sheet 4 with an elongated bar or the like so as to be adsorbed to the vacuum suction portion 91. However, in such a method, it is necessary to always press the outer peripheral portion of the bonding sheet by an operator, and the efficiency is deteriorated. Further, when the adsorption becomes difficult, the above-described problems relating to the reliability of the optical disc occur. Therefore, as a result of intensive studies by the present inventors, a method for solving this problem has been recalled. In the following third embodiment, an optical disk manufacturing method that solves the above-described problems will be described. In the third embodiment, the second supply sheet 32 (see FIG. 8) having a four-layer structure will be described as an example of the bonding sheet 4.
[0177]
First, an optical disk manufacturing method according to a third comparative example according to the third embodiment will be described.
[0178]
That is, as shown in FIG. 26A, when the bonding sheet 4 is placed on the flat stage 2, the protector 32a is in contact with the flat stage 2 side, and the release film 32b faces the information signal portion 7c of the disk substrate 7. Then, the bonding sheet 4 is placed. Then, after fitting the through hole 4 a of the bonding sheet 4 to the vertical movement pin 5 provided on the flat stage 2, the center hole 7 a of the disk substrate 7 is fitted to the substrate positioning pin 6, thereby Positioning is being performed. As shown in FIG. 26B, the planar stage 2 is parallel to the position of each vertex of a virtual regular octagon in order to prevent contact between the disk substrate 7 and the bonding sheet 4 in the atmosphere. Maintenance means 9 are provided. A vacuum suction portion 91 is provided at the position of each vertex of a virtual regular octagon whose phase is shifted from that of the parallel maintaining means 9 on the inner periphery of the parallel maintaining means 9.
[0179]
In the stage before the laminating sheet 4 supplied to the laminating apparatus shown in FIG. 26A is formed into a single-wafer type without being completely removed, the original sheet of the laminating sheet 4 is wound into a roll shape. ing. The state wound in this roll shape is shown in FIG. As shown in FIG. 27, an original sheet 103 is wound around the roll original fabric 100 so that the release film 101 is on the inner peripheral side and the protector 102 is on the outer peripheral side. In this way, as shown in FIG. 28, the raw sheet 103 wound so that the release film 101 is on the inner peripheral side is fully extracted to form a planar sheet 4 to form a bonding sheet 4. To do. Then, when the bonding sheet 4 is placed on the flat stage 2 with the through-holes 4a fitted to the vertical movement pins 5, the bonding sheet 4 is transferred to the flat stage 2 as shown in FIG. 26A. The center position rises toward the side, that is, the shape is convex downward.
[0180]
When laminating the laminating sheet 4 and the disk substrate 7 placed in this manner, as shown in FIG. 29A, first, after the release film 101 of the laminating sheet 4 is peeled off, The disk substrate 7 is fitted to the substrate positioning pins 6 shown in FIG. 26A and face each other as shown in FIG. 29B.
[0181]
Then, the replica substrate 7b side of the disk substrate 7 is pressed by the pad 8 shown in FIG. As a result, as shown in FIG. 30A, the light transmitting sheet 11 a protected by the adhesive layer 11 b and the protector 102 is formed on the surface of the information signal portion 7 c of the disk substrate 7. Thereafter, as shown in FIG. 30B, the protector 102 is peeled from the light-transmitting sheet 11a using an automatic peeling device. Thus, the optical disc according to the third comparative example is manufactured.
[0182]
On the other hand, as for the optical disk manufacturing method according to the sixth example of the third embodiment, first, as shown in FIG. 31, the raw fabric sheet 103 is moved from the inner peripheral side toward the outer peripheral side, with the protector 102, The roll is wound around the roll 100 so that the light transmissive sheet 11a, the adhesive layer 11b, and the release film 101 are formed. And the sheet | seat 4 for bonding is manufactured by punching out the part of this original fabric sheet 103 in a plane annular shape, as shown in FIG.
[0183]
When the laminating sheet 4 is placed on the planar stage 2 with the through-holes 4a fitted to the vertical movement pins 5, the laminating sheet 4 is placed on the planar stage 2 as shown in FIG. On the other hand, the center portion is raised, that is, has a convex shape. Thus, the bonding sheet 4 placed on the flat stage 2 has an outer peripheral portion close to the vacuum suction portion 91 of the flat stage 2. Thereby, when the inside of the vacuum suction part 91 is depressurized and sucked, the bonding sheet 4 is easily sucked and reaches a set pressure easily.
[0184]
When laminating the laminating sheet 4 and the disk substrate 7 placed in this manner, as shown in FIG. 29A, first, after the release film 101 of the laminating sheet 4 is peeled off, The disk substrate 7 is fitted to the substrate positioning pins 6 shown in FIG. 32 and opposed to each other as shown in FIG. 29B.
[0185]
Thereafter, the pad 8 shown in FIG. 32 is used to press the replica substrate 7b side of the disk substrate 7 so that the bonding sheet 4 and the disk substrate 7 are pressure-bonded. As a result, as shown in FIG. 30A, the light transmitting sheet 11 a protected by the adhesive layer 11 b and the protector 102 is formed on the surface of the information signal portion 7 c of the disk substrate 7. Thereafter, as shown in FIG. 30B, the protector 102 is peeled from the light-transmitting sheet 11a using an automatic peeling device. Thus, the optical disc according to the sixth embodiment is manufactured.
[0186]
The inventor manufactured 100 optical disks according to the third comparative example and the optical disk according to the sixth example, respectively, according to the manufacturing method described above, and evaluated these optical disks. The evaluation results are shown in Table 4 below. In Table 4, air bubbles are included in the case where air bubbles are mixed between the disk substrate 7 and the bonding sheet 4 and in the optical disk, particularly between the information signal portion 7c and the light transmission layer 11, and wrinkles are generated. Indicates a case where wrinkles are generated in the light transmission layer 11, and the adsorption failure is that the bonding sheet 4 is not fixed to the plane stage 2 by suction, and the operation failure of the bonding apparatus or other apparatus is caused by this. The case that caused
[0187]
[Table 4]

[0188]
From Table 4, in the optical disc according to the third comparative example described above, air bubbles mixed in 6 out of 100 sheets (6%), wrinkle generation in the light transmission layer 11 out of 100 sheets (9%), and poor adsorption. While it is 13 out of 100 (13%), it can be seen that in the optical disc according to the above-described sixth embodiment, none of air bubbles, wrinkles, or poor suction occurs. In addition, in the optical disk according to the third comparative example, the number of defects that did not occur was 71 out of 100, whereas in the optical disk according to the sixth embodiment, even one defective optical disk was generated. You can see that they are not.
[0189]
As described above, according to the light transmitting layer forming sheet member and the optical disk manufacturing method according to the third embodiment, the same effect as in the first embodiment can be obtained, and the laminating sheet can be obtained. 4 is wound so that the release film 101 is on the outside in the original fabric state, so that the release film 101 side is raised so that the inside of the vacuum suction portion 91 is decompressed and sucked. At this time, the laminating sheet 4 is easily adsorbed and reaches a set pressure, so that no bubbles remain between the planar stage 2 and the laminating sheet 4. Sheet 4 and disk substrate 7 can be set in parallel. Therefore, air bubbles can be prevented from being mixed between the disk substrate 7 and the bonding sheet 4 and the light transmission layer 11 can be wrinkled, and the sheet edge of the bonding sheet 4 can be prevented from protruding. In addition, it is possible to prevent the information signal portion 7c from being exposed without being covered with the sheet.
[0190]
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.
[0191]
For example, the numerical values, materials, the configuration of the optical disc, and the configuration of the information signal unit given in the above embodiment are merely examples, and if necessary, different numerical values, materials, the configuration of the optical disc, and the configuration of the information signal unit may be used. It may be used.
[0192]
Further, for example, in the first embodiment described above, an optical disk is manufactured by bonding the bonding sheet 4 to the disk substrate 7 using the bonding sheet 4 provided with the adhesive layer 11b in advance. First of all, Mold release A sheet in which a film, a light transmissive sheet 11a and a protector are laminated is prepared, and a liquid adhesive such as a liquid ultraviolet curable resin is supplied to the disk substrate 7, and a release film is peeled from the sheet. After the light transmissive sheet 11a side is adhered to one main surface of the disk substrate 7 via an ultraviolet curable resin, the protector may be peeled from the sheet. Thereby, the state where the sheet is bonded becomes the state shown in FIG. 12, and the state where the protector 32a is peeled becomes as shown in FIG. 3, so that the same effect as in the above-described first embodiment can be obtained. it can.
[0193]
Further, for example, in the above-described first embodiment, after bonding the bonding sheet 4 to one main surface of the disk substrate 7, if necessary, the other main surface of the disk substrate 7, that is, the light transmission of the replica substrate 7b. The light transmitting layer 11 is formed on the other main surface of the disk substrate 7 by adhering the bonding sheet 4 to the main surface on the side where the protective sheet 11a and the protector are not provided on the adhesive layer 11b side. Is also possible. Thereby, an optical recording medium having a configuration in which the light transmissive sheets 11a are bonded to both the front and back surfaces of the disk substrate 7 can be easily manufactured. Also in this case, the same effect as in the first embodiment can be obtained by providing the protector on the side opposite to the side on which the adhesive layer 11b of the light transmissive sheet 11a is provided. . At this time, if the concave and convex portions are formed on both the front and back surfaces of the replica substrate 7b and the information signal portion 7c is formed on both surfaces, an optical recording medium capable of recording and / or reproducing on both surfaces can be obtained. Can do.
[0194]
In the first embodiment, the example in which the information signal portion 7c is formed on one main surface of the disk substrate 7 has been described. However, the information signal portion 7c is a disk substrate in the bonding sheet 4. 7 may be formed on a surface facing one main surface. In this case, the information signal portion 7 c can be formed not on the disk substrate 7 but on the bonding sheet 4. Further, the information signal portion 7c is formed only on one main surface of the disk substrate 7, the bonding sheet 4 is bonded to the upper layer, and a second sheet bonded to the other main surface of the disk substrate 7 is formed. It is also possible to form a sheet on which the information signal portion is formed, and to bond the second sheet to the other main surface of the disk substrate 7 so as to provide the information signal portion 7c on the other main surface of the disk substrate 7. .
[0195]
In the first embodiment described above, the light transmissive sheet 11a is bonded to the disk substrate 7 by using the pad 8 made of an elastic body and the flat stage 2, but other devices are used. Specifically, for example, two metal flat plates may be used to bond the disk substrate 7 and the light transmissive sheet 11a together, or using a roller, A light transmissive sheet may be laminated on one main surface of the disk substrate 7.
[0196]
Moreover, in the above-mentioned 1st Embodiment, although the light transmissive sheet | seat and the protector are adhere | attached through the slightly adhesive adhesive, a protector is mounted on a light transmissive sheet | seat or a hard-coat layer. It is also possible.
[0197]
In the first embodiment described above, the Al alloy is given as an example of the material of the reflective film. However, as the material of the reflective layer, Al, silver (Ag), Ag alloy, copper (in addition to the Al alloy) Cu), Cu alloys and the like. Further, a GeSbTe alloy layer can be used as the phase change recording layer. In an optical disk employing magneto-optical recording, an alloy layer such as TbFeCo, TbFeCr, FeTbCoCr, FeGdCo, FeDyCo, or FeGdCoSi can be used as the recording layer.
[0198]
Further, for example, in the second and third embodiments described above, a four-layered laminating sheet is supplied to manufacture an optical disc, but a sheet other than a four-layered structure can also be used. Specifically, for example, as shown in FIG. 7, the laminate having the same laminated structure as the first supply sheet 31 having the laminated structure of the release film 31a, the adhesive layer 11b, and the light transmissive sheet 11a. The laminated sheet shown in FIG. 9 has a laminated structure in which a release film 33a is provided on the adhesive layer 11b side of the light transmissive sheet 11a and a hard coat layer 11c is provided on the surface of the light transmissive sheet 11a. A laminated sheet similar to the fourth supply sheet 34 shown in FIG. 10 is provided with a bonding sheet having the same laminated structure as the third supply sheet 33 and a protector 34a. It is possible to use a bonding sheet having a.
[0199]
【The invention's effect】
As described above, according to the sheet member for forming a light transmissive layer according to the first aspect of the present invention, at least the light transmissive sheet, the first adhesive layer having light transmittance, Release film The first adhesive layer is provided on the surface to be bonded to the substrate of the light transmissive sheet, and the first adhesive layer is peelable on the surface provided with the first adhesive layer. Release film Thus, it is possible to prevent foreign matter from entering between the light transmission layer and the substrate in the formation of the light transmission layer in the optical recording medium. Further, on the surface opposite to the surface on which the first adhesive layer is provided with respect to the light transmissive sheet, Protective film By providing this, it is possible to prevent adhesion of foreign matter to the surface of the light transmissive sheet and the surface of the light transmissive layer, and it is also possible to prevent generation of scratches and contamination on the surface of the light transmissive sheet.
[0200]
Further, according to the method for manufacturing an optical recording medium according to the second and third inventions of the present invention, on one side of the light transmissive sheet Release film From the sheet, a bonding step of bonding the light-transmitting sheet side of the sheet to the substrate surface via an adhesive layer Release film And having a peeling step to peel off, even when the light transmissive layer is formed by bonding, it is possible to prevent foreign matter from affecting the light transmissive sheet, Release film At the stage of peeling, the adhered foreign matter is also peeled off, so that the surface of the light transmission layer can be prevented from being scratched and the objective lens used for recording / reproducing can be made to have a high NA. In addition, an optical recording medium having a small birefringence, good transparency, and a light transmission layer having a uniform film thickness can be produced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a bonding apparatus used for bonding a bonding sheet and a disk substrate according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram showing another example of a bonding apparatus used for bonding a bonding sheet and a disk substrate according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a first optical disc provided with a light transmission layer according to the first embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a second optical disc provided with a light transmission layer having a hard coat layer according to the first embodiment of the present invention.
FIG. 5 is a flowchart for explaining an optical disk manufacturing method according to the first embodiment of the present invention;
FIG. 6 is a cross-sectional view showing a disk substrate on which a light transmission layer according to the first embodiment of the present invention is formed.
FIG. 7 is a cross-sectional view showing a first supply sheet according to a first example used for forming a light transmission layer according to the first embodiment of the present invention;
FIG. 8 is a cross-sectional view showing a second supply sheet according to a second example used for forming a light transmission layer according to the first embodiment of the present invention;
FIG. 9 is a cross-sectional view showing a third supply sheet according to a third example used for forming a light transmission layer according to the first embodiment of the present invention;
FIG. 10 is a cross-sectional view showing a fourth supply sheet according to a fourth example used for forming a light transmission layer according to the first embodiment of the present invention;
FIG. 11 is a schematic diagram for explaining a method of bonding a disk substrate and a bonding sheet in manufacturing a first optical disk according to the first embodiment of the present invention;
FIG. 12 is a cross-sectional view showing a state immediately after the disk substrate and the bonding sheet are bonded in the manufacture of the first optical disk according to the first embodiment of the present invention.
FIG. 13 is a schematic diagram for explaining a method of bonding a disk substrate and a bonding sheet in manufacturing a second optical disk according to the first embodiment of the present invention.
FIG. 14 is a schematic diagram showing an apparatus showing a state immediately after the disk substrate and the bonding sheet are bonded in the production of the second optical disk according to the first embodiment of the present invention;
FIG. 15 is a sectional view showing a chucking portion for clamping the optical disc according to the first embodiment of the invention.
FIG. 16 is a cross-sectional view showing a supply sheet used for manufacturing an optical disc according to a first comparative example in the first embodiment.
FIG. 17 is a cross-sectional view showing a fully-fed type supply sheet in the supply form of the supply sheet according to the first embodiment of the present invention.
FIG. 18 is a cross-sectional view showing a hoop material type supply sheet in the supply form of the supply sheet according to the first embodiment of the present invention.
FIG. 19 is a cross-sectional view showing a half-punch type supply sheet in the supply form of the supply sheet according to the first embodiment of the present invention.
FIG. 20 is a plan view for explaining a method of peeling the release film.
FIG. 21 is a schematic diagram for explaining a method and a problem of peeling a release film.
FIG. 22 is a plan view showing a light transmissive layer forming sheet member according to a second embodiment of the present invention, a cross-sectional view, and a plan view showing a gripping portion.
FIG. 23 is a schematic diagram for explaining a process for forming a light transmission layer according to the second embodiment of the present invention;
FIGS. 24A and 24B are a plan view and a cross-sectional view showing a light transmissive layer forming sheet member according to a second embodiment of the present invention. FIGS.
FIG. 25 is a schematic diagram showing a laminating apparatus used for laminating a laminating sheet and a disk substrate according to a third embodiment of the present invention.
FIG. 26 is a schematic diagram for explaining a method of laminating a disk substrate and a laminating sheet according to a comparative example of the third embodiment of the present invention, and an arrangement of a vacuum suction portion and parallel maintaining means of a planar stage. FIG.
FIG. 27 is a schematic diagram for explaining a method of winding an original sheet according to a comparative example of the third embodiment.
FIG. 28 is a schematic diagram for explaining a method of fully extracting a bonding sheet from an original fabric sheet according to the third embodiment.
FIG. 29 is a schematic diagram for explaining a bonding process between a bonding sheet and a disk substrate according to a third embodiment of the present invention;
FIG. 30 is a schematic diagram for explaining a bonding process between a bonding sheet and a disk substrate according to a third embodiment of the present invention;
FIG. 31 is a schematic diagram for explaining a method of winding an original sheet according to an example of the third embodiment.
FIG. 32 is a schematic diagram for explaining a method of bonding a disk substrate and a bonding sheet according to an example of the third embodiment of the present invention;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Bonding apparatus, 2 ... Planar stage, 3 ... Movable stage, 4 ... Sheet for bonding, 4a, 50a, 54a ... Through-hole, 5 ... Vertical movement pin, 6 ... Substrate positioning pin, 7 ... Disc substrate, 7a ... Center hole, 7b ... Replica substrate, 7c ... Information signal section, 8 ... Pad, 9 ... Parallel maintenance Means: 10 ... first optical disk, 11 ... light transmission layer, 11a, 55 ... light transmission sheet, 11b, 51 ... adhesion layer, 11c ... hard coat layer, 12 ... Clamp region, 12a: clamp reference surface, 20 ... second optical disk, 31 ... first supply sheet, 32 ... second supply sheet, 33 ... third Supply sheet, 34... Fourth supply sheet, 31a, 32b, 33a 34b, 52, 53, 56, 61a, 71, 82, 101 ... release film, 32a, 34a, 60b, 61b, 62b, 83, 102 ... protector, 50 ... supply sheet for adhesive layer, 54 ... Supply sheet for light transmissive sheet, 60, 61, 62, 81, 84 ... Supply sheet, 60a, 62a ... Release sheet, 72 ... Adhesive tape, 73 ... Release device 74 ... adhesive tape supply part, 75 ... peeling part, 76 ... peeling residue, 77 ... adhesive tape recovery part, 82a ... first gripping part, 82b ... outer gripping part 83a ... second gripping part, 91 ... vacuum suction part, 100 ... roll original, 103 ... original sheet

Claims (48)

A light transmission layer capable of transmitting at least the laser light applied to the information signal portion is provided on a substrate provided with an information signal portion configured to record and / or reproduce information signals on one main surface. A light transmission layer forming sheet member used for forming the light transmission layer in the optical recording medium configured as described above,
At least a light-transmitting sheet, a first adhesive layer having light transmittance, and a release film ,
The first adhesive layer is provided on the side to be bonded to the substrate of the light transmissive sheet, and the release film is detachably provided and bonded to the first adhesive layer side. Become
In the previous stage in which the light-transmitting sheet, the first adhesive layer, and the release film having a laminated structure are used for the bonding, the release film is positioned on the outer peripheral side of the light-transmitting sheet. A light transmission layer forming sheet member wound around a winding core. 2. The light transmissive layer forming sheet member according to claim 1, wherein a release agent is applied to the first adhesive layer side of the release film . The light-transmitting layer forming sheet according to claim 1, wherein a protective film is provided on a surface opposite to the surface on which the first adhesive layer is provided with respect to the light-transmitting sheet. Element. 4. The light transmission layer forming sheet member according to claim 3, wherein the protective film is made of a polyethylene resin. 4. The light transmitting layer formation according to claim 3, wherein an adhesive force between the release film and the first adhesive layer is smaller than an adhesive force between the light transmissive sheet and the protective film. Sheet member.   2. The light transmitting layer forming sheet member according to claim 1, wherein a hard coat layer is provided on a surface opposite to the surface on which the first adhesive layer of the light transmitting sheet is provided. . The light transmission layer forming sheet member according to claim 6, wherein a protective film is provided on a surface of the hard coat layer. The sheet member for forming a light transmission layer according to claim 7, wherein the protective film is made of a polyethylene resin. 8. The light transmission layer forming method according to claim 7, wherein an adhesive force between the release film and the first adhesive layer is smaller than an adhesive force between the hard coat layer and the protective film . Sheet member. The light release layer forming sheet member according to claim 1, wherein the release film is provided with a graspable convex portion. The sheet member for forming a light transmissive layer according to claim 10, wherein a protective film is provided on a surface opposite to a surface on which the first adhesive layer is provided with respect to the light transmissive sheet. The sheet member for forming a light transmission layer according to claim 11, wherein the protective film is provided with a grippable convex portion. 11. The light transmitting layer forming sheet according to claim 10, wherein the light transmitting layer has a planar annular shape, and a first gripping portion that can be gripped is provided at a peripheral portion of the planar annular shape of the release film. Element. The above surface opposite to the first adhesive layer is provided face to said light transmitting sheet, the protective film is provided having a planar annular shape, the portion of the planar annular outer periphery of the protective film The light transmissive layer forming sheet member according to claim 13, wherein a second gripping portion that can be gripped is provided. The light transmission layer forming sheet member according to claim 14, wherein the first grip portion of the release film and the second grip portion of the protective film are provided at positions that do not overlap each other in a planar manner.   The sheet member for forming a light transmissive layer according to claim 10, wherein a hard coat layer is provided on a surface of the light transmissive sheet opposite to the adhesive layer. In the previous stage used for the bonding, a protective film is provided on the surface of the light transmissive sheet opposite to the side on which the first adhesive layer is provided, so that the protective film is on the inner peripheral side. The sheet member for forming a light transmission layer according to claim 1, wherein the sheet member is wound around the winding core. On one main surface of the board,
An information signal unit configured to record and / or reproduce an information signal;
A light transmission layer capable of transmitting at least the laser light applied to the information signal unit is sequentially laminated and provided.
The information signal can be recorded and / or reproduced by irradiating the information signal portion with the laser light from the light transmission layer side,
A method for producing an optical recording medium, wherein the light transmission layer is provided on the one main surface of the substrate by bonding the one main surface of the substrate and the light transmission layer,
The light transmissive layer comprises at least a light transmissive sheet and a first adhesive layer having light transmissive properties,
The first adhesive layer is provided on the surface of the light transmissive sheet to be bonded to the substrate, and on the opposite side of the light transmissive sheet from the side on which the first adhesive layer is provided. Using a sheet for bonding provided with a protective film ,
After the first adhesive layer in the bonding sheet is bonded to the one main surface of the substrate, it has a peeling step of peeling the protective film from the bonding sheet,
The light-transmitting sheet, the adhesive layer, and the protective film having a laminated structure are wound around a winding core so that the protective film is located on the inner peripheral side of the light-transmitting sheet in the previous stage used for the bonding. A method for manufacturing an optical recording medium. The protective film and the light transmissive sheet are configured to be bonded to each other through a second adhesive layer, and in the peeling step, compared to the adhesive force between the protective film and the light transmissive sheet. after the adhesive force is large adhesive between the protective film adhered to the exposed surface of the protective film, by pulling the protective film to the peeling direction via the pressure-sensitive adhesive, so as to perform peeling of the protective film The method for producing an optical recording medium according to claim 18.   The method for manufacturing an optical recording medium according to claim 19, wherein the second adhesive layer is configured to be peeled off at an interface between the light transmissive sheet and the second adhesive layer. Using an adhesive film with an adhesive applied to at least one surface, the surface of the adhesive film to which the adhesive is applied is adhered to the exposed surface of the protective film , and the adhesive film is attached to the surface of the bonding sheet. The method for producing an optical recording medium according to claim 18, wherein the protective film is peeled off by pulling in a direction of 90 ° or more and 180 ° or less.   The method of manufacturing an optical recording medium according to claim 18, wherein the substrate has a planar annular shape, and the bonding sheet has a planar annular shape.   The optical recording medium according to claim 22, wherein an inner diameter of the bonding sheet is configured to be larger than an inner diameter of the substrate, and an outer diameter of the bonding sheet is set to be equal to or smaller than an outer diameter of the substrate. Method. The first supply sheet is configured by providing a release film on the surface of the first adhesive layer of the laminating sheet in a stage before using the laminating sheet for the laminating. The manufacturing method of the optical recording medium of description. 25. The method of manufacturing an optical recording medium according to claim 24, wherein an adhesive force between the release film and the first adhesive layer is smaller than an adhesive force between the light transmissive sheet and the protective film . The release film has a planar annular shape, and a second gripping portion that can be gripped is provided on an outer peripheral portion of the release film , and the first adhesive layer in the laminating sheet is attached to the substrate. 25. The optical device according to claim 24, wherein the release film is peeled by gripping the second grip portion and pulling the release film in a peeling direction before bonding to the one main surface. A method for manufacturing a recording medium. 25. The method of manufacturing an optical recording medium according to claim 24, wherein a first gripping portion that can be gripped is provided at a peripheral portion of the planar annular shape of the protective film . The first supply sheet has a planar annular shape, and a first gripping portion that can be gripped is provided on an outer peripheral portion of the protective film , and a first gripper that can be gripped on an outer peripheral portion of the release film . 2 grips are provided,
25. The method of manufacturing an optical recording medium according to claim 24, wherein the first grip portion of the protective film and the second grip portion of the release film are provided at positions that do not overlap each other in a planar manner.   19. The method of manufacturing an optical recording medium according to claim 18, wherein the light transmission layer is configured by sequentially laminating the first adhesive layer, the light transmission sheet, and a hard coat layer.   30. The method of manufacturing an optical recording medium according to claim 29, wherein the hard coat layer is made of an ultraviolet curable resin. The bonding sheet is configured by sequentially providing the first adhesive layer, the light-transmitting sheet, the hard coat layer, and the protective film, and in the stage before using the bonding sheet for the bonding 19. The method for producing an optical recording medium according to claim 18, wherein a release film is provided on the surface of the first adhesive layer of the laminating sheet to constitute a second supply sheet. 32. The method of manufacturing an optical recording medium according to claim 31, wherein an adhesive force between the release film and the first adhesive layer is smaller than an adhesive force between the hard coat layer and the protective film . 32. The method for producing an optical recording medium according to claim 31, wherein the hard coat layer and the protective film are bonded via an adhesive. 32. The protective film according to claim 31, wherein the protective film is provided with a first gripper that can be gripped, and the protective film is peeled off by gripping the first gripper and pulling in a predetermined direction. A method for producing an optical recording medium. The light-transmitting layer has a planar annular shape, and a second gripping portion that can be gripped is provided on the outer peripheral portion of the planar annular shape of the release film , and the first adhesive layer in the laminating sheet A step of peeling the release film by gripping the second gripping part and pulling the release film in a predetermined direction before adhering to the one main surface of the substrate. Item 32. A method for producing an optical recording medium according to Item 31. 32. The method of manufacturing an optical recording medium according to claim 31, wherein a first gripping portion that can be gripped is provided on a portion of the outer periphery of the planar annular shape of the protective film . The second supply sheet has a planar annular shape, and a first gripping portion that can be gripped is provided on an outer peripheral portion of the protective film , and a second gripper can be gripped on an outer peripheral portion of the release film . 2 grips are provided,
32. The method of manufacturing an optical recording medium according to claim 31, wherein the first grip portion of the protective film and the second grip portion of the release film are provided at positions that do not overlap each other in a planar manner.   32. The method for producing an optical recording medium according to claim 31, wherein a hard coat layer is provided on a surface of the light transmissive sheet opposite to the adhesive layer. 19. The release stage according to claim 18, wherein a release film is provided on a surface of the first adhesive layer and is wound around the winding core so that the release film is located on an outer peripheral side in a previous stage used for the bonding. A method for producing an optical recording medium. On one main surface of the substrate,
An information signal part capable of recording and / or reproducing an information signal;
A light transmission layer capable of transmitting the laser light applied to the information signal portion is sequentially stacked;
By irradiating the information signal portion with laser light from the light transmission layer side, the information signal can be recorded and / or reproduced.
In the manufacturing method of the optical recording medium in which the light transmission layer is formed on the one main surface of the substrate by bonding,
The light transmissive layer comprises a light transmissive sheet and a first adhesive layer having light transmissive properties,
Using a bonding sheet in which a protective film is provided on the surface opposite to the surface to be bonded to the substrate of the light transmissive sheet,
A supplying step of supplying an adhesive constituting the first adhesive layer on the substrate;
An adhesion step of adhering the light-transmitting sheet side of the bonding sheet to one main surface of the substrate via the adhesive;
After curing of the adhesive, and having a peeling step of peeling the protective film from the laminating sheet,
Optical recording in which the light-transmitting sheet and the protective film having a laminated structure are wound around a winding core so that the light-transmitting sheet is located on the outer peripheral side of the protective film in the previous stage used for the bonding. A method for producing a medium. The protective film and the light transmissive sheet are configured to be bonded to each other through a second adhesive layer, and in the peeling step, compared to the adhesive force between the protective film and the light transmissive sheet. the adhesive force is large adhesive between the protective film, was adhered to the exposed surface of the protective film, by pulling the protective film to the peeling direction via the pressure-sensitive adhesive, so as to perform peeling of the protective film The method for producing an optical recording medium according to claim 40. 42. The method for producing an optical recording medium according to claim 41, wherein the protective film is configured to be peelable at an interface between the light transmissive sheet and the second adhesive layer.   Compared to the adhesive force between the protective film and the light-transmitting sheet, the adhesive having a large adhesive force with the protective film is bonded to the exposed surface of the protective film, and then the adhesive is passed through the adhesive. The method for producing an optical recording medium according to claim 40, wherein the protective film is peeled off by pulling the protective film in the peeling direction. Using an adhesive film with an adhesive applied to at least one surface, the surface of the adhesive film to which the adhesive is applied is adhered to the exposed surface of the protective film, and the adhesive film is attached to the surface of the bonding sheet. The method for producing an optical recording medium according to claim 40, wherein the protective film is peeled by pulling in a direction of 90 ° to 180 °.   41. The method of manufacturing an optical recording medium according to claim 40, wherein the substrate has a planar annular shape, and the bonding sheet has a planar annular shape.   The manufacturing method of an optical recording medium according to claim 45, wherein an inner diameter of the bonding sheet is configured to be larger than an inner diameter of the substrate, and an outer diameter of the bonding sheet is set to be equal to or smaller than an outer diameter of the substrate. Method.   41. The method of manufacturing an optical recording medium according to claim 40, wherein the light transmission layer is configured by sequentially laminating the first adhesive, the light transmission sheet, and a hard coat layer.   48. The method of manufacturing an optical recording medium according to claim 47, wherein the hard coat layer is made of an ultraviolet curable resin.

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