JP4171936B2

JP4171936B2 - Resin-molding mold for resin-bonded optical element and manufacturing method

Info

Publication number: JP4171936B2
Application number: JP14526198A
Authority: JP
Inventors: 恵都夫田村
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 1998-05-27
Filing date: 1998-05-27
Publication date: 2008-10-29
Anticipated expiration: 2018-05-27
Also published as: JPH11333862A

Description

【０００１】
【発明の属する技術分野】
本発明は、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型の光学素子を製造するための樹脂成形用金型と、樹脂接合型光学素子の製造方法に関するものである。
【０００２】
【従来の技術】
光学素子であるレンズには、表面形状が非球面の非球面レンズがある。非球面レンズは、球面レンズによる球面収差や広角レンズにおけるディストーションを除去できる等、球面レンズでは得られない優れた性能を有することから重用されている。
【０００３】
現在、量産性に優れた非球面レンズとして樹脂接合型非球面レンズがある。このレンズは、図３に示すような薄い（例えば、5〜 100μm の厚さの）樹脂硬化層３２と基体たるレンズ３１により構成されている。
なお、図３のレンズでは、レンズ基材３１が球面を有し、その球面上に樹脂硬化層３２が非球面を形成するような厚さ分布をもって接合されている。
【０００４】
この様な樹脂接合型非球面レンズは、例えば図４に示す製法により製造される。
図４は、図３に示す樹脂接合型非球面レンズを製造する従来の方法を示す工程図である。尚、以下の工程説明において、括弧内の数字は図４の工程（１）〜工程（４）に対応する。
【０００５】
（１）所定の表面形状（平面、球面、非球面等）の金型面を有する金型４３を水平に置き、前記金型面の中央部に所定量の光硬化型樹脂液４２ａを垂らす。
（２）光学素子基材４１を金型４３に向かって降下させ、光学素子基材４１を金型４３に接近させることにより、樹脂液４２ａを基材４１と金型４３の間隙で押し広げる。
【０００６】
ここで、光学素子基材４１の材料としては、ガラスや結晶性光学材料を用いる。
（３）光学素子基材４１と金型４３との間隔が所定値となるように両者を接近させ、この状態を保持して、光（紫外線）４４を基材４１を通して樹脂液４２ａに照射する。樹脂液４２ａは、重合反応により硬化して硬化樹脂層４２が形成される。
【０００７】
（４）基材４１と一体化された硬化樹脂層４２を金型４３との界面から剥離して離型する。
以上のような製法（工程）により、樹脂接合型光学素子を得ることができる。
【０００８】
【発明が解決しようとする課題】
前記製法により樹脂接合型光学素子を製造すると、硬化樹脂層４２の形成時に樹脂層４２と金型４３の金型面とがオプティカル・コンタクトにより非常に強く密着する。
そして、この密着した樹脂層４２と金型４３とを光学素子基材４１の外周部の一部または全部に荷重を加えることにより引き離そうとすると（即ち、樹脂接合型光学素子を金型から離型しようとすると）、非常に大きな力が必要となり、光学素子基材４１が破壊されたり、樹脂層４２が基材４１から剥がれるおそれがあって問題となっていた。
【０００９】
そこで、この問題を解決すべく離型を小さな力で可能にする方法として、金型面に離型剤を塗布する方法が一般的に知られている。また、塗布方法としては、スピン法やハケによる塗布方法が知られている。
或いは、前記問題を解決すべく、特開平4-317435には、金型面に同心円状のＶ型溝を複数本設けることにより、小さな力で離型を可能にする方法が提案されている。
【００１０】
しかし、離型剤を塗布する方法では、塗布工程が増えてサイクルタイムが長くなる、離型剤層の制御が難しく塗布ムラが生じる、所望の成形面を安定して形成することができないという問題があった。
また、特開平4-317435に提案されている方法は、金型面に溝を設けることにより、金型面と樹脂との間にオプティカル・コンタクト状態から解放される微少領域を何点か生じさせ、その領域を起点にして小さな力で離型する方法である。
【００１１】
しかし、溝が同心円状に設けられており、オプティカル・コンタクト状態から解放される溝付近の空間は外気とリークしていないので、離型動作を進めると、前記空間の体積が大きくなって空間内の気圧が減少する。
そして、その結果、離型を妨げる方向に力が働いて十分な離型効果を得ることができないという問題があった。
【００１２】
本発明はかかる問題に鑑みてなされたものであり、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型の光学素子を製造する際に、高精度な樹脂層の成形面を安定して形成することが可能であり、また成形物を容易に小さな力で離型することができる樹脂成形用金型と、これを用いた樹脂接合型光学素子の製造方法を提供することを目的とする。
【００１３】
【課題を解決するための手段】
そのため、本発明は第一に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型において、前記樹脂層の光学有効径部分の外側に位置する光学有効径周辺部を成形する金型面領域から、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない金型面領域まで達する溝を少なくとも１カ所以上に設けたことを特徴とする樹脂接合型光学素子の樹脂成形用金型（請求項１）」を提供する。
【００１４】
また、本発明は第二に「前記樹脂層は非球面を有することを特徴とする請求項１記載の樹脂成形用金型（請求項２）」を提供する。
また、本発明は第三に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
前記光学素子基材と前記金型との間に光硬化型樹脂液を挟み、かつ前記基材と前記金型との間隔を制御することにより、前記樹脂液を前記基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記基材とを一体化させることにより、所望の表面形状を有する樹脂接合型光学素子を作製する工程と、
前記樹脂接合型光学素子を前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項３）」を提供する。
【００１５】
また、本発明は第四に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
金型面を上に向けて前記金型を水平（または略水平）に設置する工程と、
前記金型面に所定量の光硬化型樹脂液を滴下する工程と、
光学素子基材を前記樹脂液の上に水平（または略水平）に載置し、かつ前記基材と前記金型との間隔を制御することにより、前記樹脂液を前記基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記基材とを一体化させることにより、所望の表面形状を有する樹脂接合型光学素子を作製する工程と、
前記樹脂接合型光学素子を前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項４）」を提供する。
【００１６】
また、本発明は第五に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
金型面を上に向けて前記金型を水平（または略水平）に設置する工程と、
前記第１金型面領域に所定量の光硬化型樹脂液を滴下する工程と、
球面形状または非球面形状を有するレンズ基材を前記樹脂液の上に、前記球面または非球面の中央部（または中央付近）が前記樹脂液に接触するように、水平（または略水平）に載置し、かつ前記レンズ基材と前記金型との間隔を制御することにより、前記樹脂液を前記レンズ基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記レンズ基材とを一体化させることにより、所望の非球面形状を有する樹脂接合型レンズを作製する工程と、
前記樹脂接合型レンズを前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項５）」を提供する。
【００１７】
また、本発明は第六に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
光学素子基材をその表面を上に向けて水平（または略水平）に設置する工程と、
前記基材の表面に所定量の光硬化型樹脂液を滴下する工程と、
前記金型の金型面と前記樹脂液を接触させ、かつ前記基材と前記金型との間隔を制御することにより、前記樹脂液を前記基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記基材とを一体化させることにより、所望の表面形状を有する樹脂接合型光学素子を作製する工程と、
前記樹脂接合型光学素子を前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項６）」を提供する。
【００１８】
また、本発明は第七に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
光学素子基材をその表面を上に向けて水平（または略水平）に設置する工程と、
前記基材の表面に所定量の光硬化型樹脂液を滴下する工程と、
前記基材を反転させて、前記光硬化型樹脂液が滴下された表面を下向きにする工程と、
前記金型の金型面と前記樹脂液を接触させ、かつ前記基材と前記金型との間隔を制御することにより、前記樹脂液を前記基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記基材とを一体化させることにより、所望の表面形状を有する樹脂接合型光学素子を作製する工程と、
前記樹脂接合型光学素子を前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項７）」を提供する。
【００１９】
また、本発明は第八に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
球面形状または非球面形状を有するレンズ基材を、該球面または非球面を上に向けて水平（または略水平）に設置する工程と、
前記球面または非球面の中央部（または中央付近）に所定量の光硬化型樹脂液を滴下する工程と、
前記金型の第１金型面領域と前記樹脂液を接触させ、かつ前記レンズ基材と前記金型との間隔を制御することにより、前記樹脂液を前記レンズ基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記レンズ基材とを一体化させることにより、所望の非球面形状を有する樹脂接合型レンズを作製する工程と、
前記樹脂接合型レンズを前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項８）」を提供する。
【００２０】
また、本発明は第九に「光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、
前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、
前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型を用意する工程と、
球面形状または非球面形状を有するレンズ基材を、該球面または非球面を上に向けて水平（または略水平）に設置する工程と、
前記球面または非球面の中央部（または中央付近）に所定量の光硬化型樹脂液を滴下する工程と、
前記レンズ基材を反転させて、前記光硬化型樹脂液が滴下された面を下向きにする工程と、
前記金型の第１金型面領域と前記樹脂液を接触させ、かつ前記レンズ基材と前記金型との間隔を制御することにより、前記樹脂液を前記レンズ基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる工程と、
前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記レンズ基材とを一体化させることにより、所望の非球面形状を有する樹脂接合型レンズを作製する工程と、
前記樹脂接合型レンズを前記金型から取り外す工程と、
を備えた樹脂接合型光学素子の製造方法（請求項９）」を提供する。
また、本発明は第十に「前記樹脂液に光を照射して硬化させる際、前記硬化樹脂層は硬化収縮して形成されることを特徴とする請求項３〜９のいずれかに記載の樹脂接合型光学素子の製造方法（請求項１０）」を提供する。
【００２１】
【発明の実施の形態】
本発明者が鋭意研究した結果、樹脂成形用金型を用いて、光学素子基材上に所定形状の樹脂層を成形して設けることにより、樹脂接合型の光学素子を製造する際に、成形物を金型から容易に小さな力で離型するには、１）小さな力により樹脂層と金型とが剥離する部分を生じさせること、２）その剥離した部分（空間）と外気とをリークさせること、が極めて有効であることを見いだした。
【００２２】
そこで、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための本発明（請求項１〜９）にかかる樹脂成形用金型においては、
前記樹脂層の光学有効径部分の外側に位置する光学有効径周辺部を成形する金型面領域から、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない金型面領域まで達する溝を少なくとも１カ所以上に設けることとした。
【００２３】
本発明にかかる樹脂成形用金型は、例えば図１に示す様な金型面を有し、この金型面は、前記樹脂層の光学有効径内（光学有効径部分）を成形する第１金型面領域１１と、光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部（光学有効径外）を成形する第２金型面領域１２と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域（樹脂層が到達するより外側の領域）１３とに分けられる。
【００２４】
そして、この金型面には、前記第２金型面領域１２から前記第３金型面領域に１３まで達する溝１４が設けられている。
そして、この様な金型（本発明にかかる樹脂成形用金型の一例）を用いて樹脂接合型光学素子を製造すると、樹脂成形物の離型時に小さな力により樹脂層と金型とが剥離する部分が生じるので、その剥離した部分（空間）と外気とをリークさせることにより、成形物を金型から容易に小さな力で離型することができる。また、高精度な樹脂層の成形面を安定して形成することも可能となる。
【００２５】
前記金型（本発明にかかる樹脂成形用金型の一例）を用いて樹脂接合型光学素子を製造する工程例（請求項３）を以下に示す。
第１工程：光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための樹脂成形用金型であり、前記樹脂層の光学有効径部分を成形する第１金型面領域と、前記光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部を成形する第２金型面領域と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域とを有し、前記第２金型面領域から前記第３金型面領域まで達する溝を金型面の少なくとも１カ所以上に設けた樹脂成形用金型（図１）を用意する。
【００２６】
第２工程：前記光学素子基材と前記金型との間に光硬化型樹脂液を挟み、かつ前記基材と前記金型との間隔を制御することにより、前記樹脂液を前記基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる。
第３工程：前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記基材とを一体化させることにより、所望の表面形状を有する樹脂接合型光学素子を作製する。
【００２７】
第４工程：前記樹脂接合型光学素子を前記金型から取り外す。
ここで、前記金型（本発明にかかる樹脂成形用金型の一例）を用いた場合の離型工程の一例を図２を用いて説明する。
図２（１）は光学素子基材２１と金型２３が所定の距離（ここでは100μｍ）に設置されており、光学素子基材２１と金型２３の間に光硬化型樹脂液２２ａ（硬化収縮率:10％）が充填されている状態を示す拡大断面図である。
【００２８】
金型２３には、前記第２金型面領域から前記第３金型面領域まで達する溝（幅100μｍ、深さ50μｍ）２４が設けられている。
この状態で樹脂液２２ａに光を照射して硬化させると、図２（２）に示す様に光学素子基材２１と金型２３の間で樹脂液２２ａが硬化して樹脂層２２が形成されるが、この際に樹脂層２２が硬化収縮するので、光学素子基材２１と金型２３の距離が近くなる。
【００２９】
この時の光学素子基材２１と金型２３の距離は、溝２４以外のほとんどの金型面の面積を占めている部分における樹脂層の厚さによって決められ、ここでは90μｍとなる。そのため、光学素子基材２１と溝２４の底までの距離は140μｍとなる。
一方、溝部分の樹脂液２２ａの厚さは150μｍであり、樹脂層が硬化収縮して形成されることにより、その部分の樹脂層の厚さは135μｍになる。
【００３０】
つまり、樹脂液２２ａが硬化して形成される樹脂層の硬化収縮により、溝２４の底部分において樹脂層２２と金型２３との剥離部分２５が発生するか、或いは剥離部分２５が発生しない場合でも溝２４の底部分において、剥がれようとする方向に樹脂層２２内に応力が生じる。
そのため、樹脂接合型光学素子を金型から離型するための外力を加える前に、或いは僅かな外力を加えるだけで、容易に溝２４の底部分において金型２３と樹脂層２２の剥離部分２５を生じさせることができる。
【００３１】
また、溝を光硬化型樹脂液が完全には侵入できない形状にすると、樹脂液の状態で、溝と樹脂液の間に部分的に隙間ができた状態になる。そして、この場合には、前記硬化収縮が無くても、最初から部分的な剥離部分が生じている状態が得られる。
なお、金型の溝形状への樹脂液の追従性は、樹脂液の粘性、樹脂液と金型とのぬれ性、溝の幅、深さ、溝の底の形状（角度）、樹脂液が金型の溝と接触してから樹脂液を固めるまでの経過時間、光学素子成形時に金型面が向いている方向（例えば、鉛直上向き）等、多数の因子によって決定され、実験的に求められるものである。
【００３２】
前述したように、樹脂接合型光学素子を金型から離型するための外力を加える前に、或いは僅かな力を加えるだけで、溝の底において樹脂層と金型の間に部分的な剥離状態（空間：剥離部分）を得ることができるが、この後に、外力を加えて離型を進めると、樹脂層と金型との間にできた空間の体積が増大する。
このとき、この空間が外気から閉ざされていると、空間の体積が増大するにつれて空間内の気圧は減圧となって離型を妨げる方向に力が働くので、離型を進行させるには大きな力が必要となる。
【００３３】
しかし、本発明にかかる金型には、前記第２金型面領域から前記第３金型面領域まで達する溝が設けられており（図１）、このように金型面の溝１４を樹脂層が到達しない領域１３まで延長しておくことにより、樹脂層と金型の間にできた空間（剥離部分）を外気とリークさせることができる。
そして、離型動作により金型と樹脂層の間の空間が増大しても、空間に外気が供給されるので減圧にならず、離型工程を小さな力で速やかに進行させることができる。
【００３４】
本発明にかかる樹脂成形用金型は、例えば、光学素子基材上に非球面形状を有する樹脂層を成形して設ける場合に効果的である（請求項２）。
また、本発明にかかる樹脂成形用金型を用いて樹脂接合型光学素子を製造する方法としては、前記例（請求項３）の他に請求項４〜９の製法が使用できる。
なお、請求項７、９にかかる発明においては、樹脂液が塗布された光学素子基材を反転させて、基材表面（下向き）上の樹脂液と金型面（上向き）を接触させる構成になっている。
【００３５】
かかる構成にすると、樹脂液と金型面が最初に接触する際の接触領域が一体状となり、複数の島状とならないので、気泡を巻き込むことがない。そのため、気泡のない硬化樹脂層が得られるので好ましい。
本発明（請求項１〜９）によれば、従来と比較して非常に小さな外力で樹脂成形物を成形金型から離型できるので、光学素子基材や樹脂層を破損することがない。
【００３６】
また、本発明（請求項１〜９）によれば、従来と比較してサイクルタイムが長くならないので、成形品の低コスト化が容易に実現可能であり、量産性に優れている。
また、従来の金型を変更すれば（金型面に本発明にかかる溝を設ければ）、本発明（請求項１〜９）を実施できるので、従来の成形装置を利用することが可能であり、成形装置改造のためのコストを殆ど要しない。
【００３７】
本発明（請求項１〜９）によれば、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型の光学素子を製造する際に、高精度な樹脂層の成形面を安定して形成することが可能であり、また成形物を容易に小さな力で離型することができる。
以下、本発明を実施例により具体的に説明するが、本発明はこの例に限定されるものではない。
【００３８】
【実施例】
光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型光学素子を製造するための本実施例にかかる樹脂成形用金型は、図１に示す金型面を有し、この金型面は、前記樹脂層の光学有効径内（光学有効径部分）を成形する第１金型面領域１１と、光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部（光学有効径外）を成形する第２金型面領域１２と、前記樹脂層の末端部分の外側に位置し、樹脂層を成形しない第３金型面領域（樹脂層が到達するより外側の領域）１３とに分けられる。
【００３９】
そして、この金型面には、前記第２金型面領域１２から前記第３金型面領域に１３まで達する溝１４が設けられている。即ち、溝１４は光学有効径外部を成形する領域１２から始まり、樹脂層が到達する位置より外側の領域１３まで達する様に設けられている。
また、溝１４の形状は幅約100μｍ、深さ約50μｍ、長さ500μｍであり、溝の底はＵ字形をしている。
【００４０】
以下に、本実施例にかかる樹脂成形用金型を用いて樹脂接合型光学素子を製造する工程を示す。
第１工程：前記樹脂成形用金型の金型面を上に向けて前記金型を水平（または略水平）に設置する。
第２工程：前記第１金型面領域に所定量の光硬化型樹脂液を滴下する。
【００４１】
第３工程：球面形状または非球面形状を有するレンズ基材を前記樹脂液の上に、前記球面または非球面の中央部（または中央付近）が前記樹脂液に接触するように、水平（または略水平）に載置し、かつ前記レンズ基材と前記金型との間隔を制御することにより、前記樹脂液を前記レンズ基材と前記金型との間隙において、前記第１金型面領域から前記第２金型面領域まで押し広げる。
【００４２】
第４工程：前記第２金型面領域まで押し広げられた樹脂液に光を照射して硬化させ、硬化樹脂層と前記レンズ基材とを一体化させることにより、所望の非球面形状を有する樹脂接合型レンズを作製する。
第５工程：前記樹脂接合型レンズを前記金型から取り外す（離型する）。
ここで、離型工程について図２を用いて説明する。
【００４３】
発明の実施の形態において前述したように、樹脂液２２ａが硬化して形成される樹脂層２２の硬化収縮により、溝２４の底部分において樹脂層２２と金型２３との剥離部分２５が発生するか、或いは剥離部分２５が発生しない場合でも溝２４の底部分において、剥がれようとする方向に樹脂層内に応力が生じる。
そのため、樹脂接合型光学素子を金型から離型するための外力を加える前に、或いは僅かな外力を加えるだけで、容易に溝２４の底部分において金型２３と樹脂層２２の剥離部分２５を生じさせることができる。
【００４４】
この後に、外力を加えて離型を進めると、樹脂層と金型との間にできた空間の体積が増大する。
本実施例にかかる金型には、前記第２金型面領域から前記第３金型面領域まで達する溝が設けられており（図１）、このように金型面の溝１４を樹脂層が到達しない領域１３まで延長しておくことにより、樹脂層と金型の間にできた空間（剥離部分）を外気とリークさせることができる。
【００４５】
そして、離型動作により金型と樹脂層の間の空間が増大しても、空間に外気が供給されるので減圧にならず、離型工程を小さな力で速やかに進行させることができる。
離型時に加えた力をロードセルにより実際に測定したところ、従来の溝を設けていない金型を用いた場合には、離型に約120kgfの力が必要であったのに対して、本実施例にかかる金型を用いた場合には、約70kgfという小さな力で離型することができた。
【００４６】
本実施例によれば、従来に比べて非常に小さな外力で離型できるので、光学素子基材や樹脂を破損することがなかった。
また、従来の製法と比較してもサイクルタイムが長くならないので、成形品の低コスト化が容易に実現できた。
このように、本実施例によれば、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型の光学素子を製造する際に、高精度な樹脂層の成形面を安定して形成することが可能であり、また成形物を容易に小さな力で離型することができた。
【００４７】
【発明の効果】
本発明（請求項１〜９）によれば、従来と比較して非常に小さな外力で樹脂成形物を成形金型から離型できるので、光学素子基材や樹脂層を破損することがない。
また、本発明（請求項１〜９）によれば、従来と比較してサイクルタイムが長くならないので、成形品の低コスト化が容易に実現可能であり、量産性に優れている。
【００４８】
また、従来の金型を変更すれば（金型面に本発明にかかる溝を設ければ）、本発明（請求項１〜９）を実施できるので、従来の成形装置を利用することが可能であり、成形装置改造のためのコストを殆ど要しない。
本発明（請求項１〜９）によれば、光学素子基材上に所定形状の樹脂層を成形して設けることにより樹脂接合型の光学素子を製造する際に、高精度な樹脂層の成形面を安定して形成することが可能であり、また成形物を容易に小さな力で離型することができる。
【図面の簡単な説明】
【図１】は実施例にかかる金型が有する金型面を示す概略平面図である。
【図２】は実施例にかかる金型が有する金型面に設けた溝２４等を示す概略断面図である。
【図３】は樹脂接合型非球面レンズの構造を示す断面図である。
【図４】は従来の樹脂接合型非球面レンズの製造方法を示す工程図である。
【符号の説明】
１１・・・樹脂成形用金型の金型面のうち、樹脂層の光学有効径内（光学有効径部分）を成形する第１金型面領域
１２・・・樹脂成形用金型の金型面のうち、光学有効径部分の外側に位置する前記樹脂層の光学有効径周辺部（光学有効径外）を成形する第２金型面領域
１３・・・樹脂成形用金型の金型面のうち、樹脂層を成形しない第３金型面領域（樹脂層が到達するより外側の領域）
１４，２４・・・溝
２１，４１・・・光学素子基材
２２，３２，４２・・・硬化樹脂層
２２ａ，４２ａ・・・光硬化型樹脂液
２３，４３・・・金型
２５・・・剥離部分
３１・・・ガラスレンズ
４４・・・光（紫外線）以上[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molding die for manufacturing a resin-bonded optical element by forming a resin layer having a predetermined shape on an optical element substrate, and a method for manufacturing the resin-bonded optical element. It is.
[0002]
[Prior art]
As a lens which is an optical element, there is an aspherical lens whose surface shape is an aspherical surface. Aspherical lenses are used because they have excellent performance that cannot be obtained with spherical lenses, such as removal of spherical aberration caused by spherical lenses and distortion in wide-angle lenses.
[0003]
Currently, there is a resin-bonded aspheric lens as an aspheric lens excellent in mass productivity. This lens is composed of a thin resin cured layer 32 (for example, 5 to 100 μm in thickness) as shown in FIG.
In the lens of FIG. 3, the lens base 31 has a spherical surface, and the resin cured layer 32 is bonded on the spherical surface with a thickness distribution that forms an aspherical surface.
[0004]
Such a resin-bonded aspherical lens is manufactured, for example, by the manufacturing method shown in FIG.
FIG. 4 is a process diagram showing a conventional method for manufacturing the resin-bonded aspherical lens shown in FIG. In the following description of the steps, the numbers in parentheses correspond to steps (1) to (4) in FIG.
[0005]
(1) A mold 43 having a mold surface with a predetermined surface shape (planar, spherical, aspherical, etc.) is placed horizontally, and a predetermined amount of photocurable resin liquid 42a is hung on the center of the mold surface.
(2) The optical element base material 41 is lowered toward the mold 43 and the optical element base material 41 is brought close to the mold 43 to push the resin liquid 42a through the gap between the base material 41 and the mold 43.
[0006]
Here, as the material of the optical element substrate 41, glass or a crystalline optical material is used.
(3) The optical element base material 41 and the metal mold 43 are brought close to each other so that the distance between the optical element base material 41 and the mold 43 becomes a predetermined value. . The resin liquid 42a is cured by a polymerization reaction to form a cured resin layer 42.
[0007]
(4) The cured resin layer 42 integrated with the base material 41 is peeled off from the interface with the mold 43 and released.
A resin-bonded optical element can be obtained by the manufacturing method (step) as described above.
[0008]
[Problems to be solved by the invention]
When a resin-bonded optical element is manufactured by the above-described manufacturing method, the resin layer 42 and the mold surface of the mold 43 are very closely adhered to each other by optical contact when the cured resin layer 42 is formed.
Then, when the resin layer 42 and the mold 43 are in close contact with each other by applying a load to part or all of the outer peripheral portion of the optical element substrate 41 (that is, the resin bonded optical element is released from the mold). When trying to do so, a very large force is required, and the optical element base material 41 may be broken, or the resin layer 42 may be peeled off from the base material 41.
[0009]
In order to solve this problem, a method of applying a release agent to a mold surface is generally known as a method for enabling release with a small force. As a coating method, a spin method or a brush coating method is known.
Alternatively, in order to solve the above problem, Japanese Patent Application Laid-Open No. 4-317435 proposes a method that enables release with a small force by providing a plurality of concentric V-shaped grooves on the mold surface.
[0010]
However, in the method of applying the release agent, there are problems that the application process increases and the cycle time becomes longer, the release agent layer is difficult to control and uneven application occurs, and the desired molding surface cannot be stably formed. was there.
In addition, the method proposed in Japanese Laid-Open Patent Publication No. 4-317435 provides some small areas that are released from the optical contact state between the mold surface and the resin by providing grooves on the mold surface. In this method, the mold is released with a small force starting from the region.
[0011]
However, since the grooves are provided concentrically and the space near the groove released from the optical contact state does not leak with outside air, the volume of the space increases as the mold release operation proceeds, The atmospheric pressure decreases.
As a result, there is a problem that a force is exerted in the direction of preventing the mold release and a sufficient mold release effect cannot be obtained.
[0012]
The present invention has been made in view of such a problem. When a resin-bonded optical element is produced by molding a resin layer having a predetermined shape on an optical element substrate, a highly accurate resin layer is provided. Provided is a mold for resin molding capable of stably forming a molding surface and easily releasing a molded product with a small force, and a method for producing a resin-bonded optical element using the mold The purpose is to do.
[0013]
[Means for Solving the Problems]
Therefore, the first aspect of the present invention is “in a resin molding die for producing a resin-bonded optical element by molding a resin layer having a predetermined shape on an optical element substrate, and the optically effective resin layer” At least one or more grooves that extend from the mold surface area that molds the peripheral portion of the optical effective diameter located outside the diameter portion to the outside of the end portion of the resin layer and reach the mold surface area that does not mold the resin layer A resin-molding mold for a resin-bonded optical element (Claim 1) ”is provided.
[0014]
A second aspect of the present invention provides a “molding die for resin molding according to claim 1 (invention 2), wherein the resin layer has an aspherical surface ”.
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Thirdly,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
By sandwiching a photocurable resin liquid between the optical element base material and the mold, and controlling the distance between the base material and the mold, the resin liquid is separated from the base material and the mold. In the gap between the first mold surface region and the second mold surface region,
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 3) ”.
[0015]
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Fourth,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the mold horizontally (or substantially horizontally) with the mold surface facing up,
Dropping a predetermined amount of photocurable resin liquid onto the mold surface;
An optical element substrate is placed horizontally (or substantially horizontally) on the resin liquid, and the distance between the substrate and the mold is controlled, whereby the resin liquid is mixed with the substrate and the mold. In the gap between the first mold surface region and the second mold surface region,
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 4) ”.
[0016]
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Fifth,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the mold horizontally (or substantially horizontally) with the mold surface facing up,
Dropping a predetermined amount of a photocurable resin liquid on the first mold surface region;
A lens substrate having a spherical shape or an aspherical shape is mounted horizontally (or substantially horizontally) on the resin liquid so that the central portion (or the vicinity of the center) of the spherical surface or aspheric surface is in contact with the resin liquid. And by controlling the distance between the lens base and the mold, the resin liquid is passed from the first mold surface region to the second mold in the gap between the lens base and the mold. A process of expanding to the mold surface area,
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 5) ”.
[0017]
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Sixth,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the optical element substrate horizontally (or substantially horizontally) with its surface facing up,
Dropping a predetermined amount of a photocurable resin liquid onto the surface of the substrate;
The resin liquid is brought into contact with the resin liquid in the gap between the base and the mold by bringing the mold liquid surface of the mold into contact with the resin liquid and controlling the distance between the base and the mold. Expanding from one mold surface area to the second mold surface area;
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 6) ”.
[0018]
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Seventh,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the optical element substrate horizontally (or substantially horizontally) with its surface facing up,
Dropping a predetermined amount of a photocurable resin liquid onto the surface of the substrate;
Reversing the base material so that the surface onto which the photocurable resin liquid has been dropped is directed downward;
The resin liquid is brought into contact with the resin liquid in the gap between the base and the mold by bringing the mold liquid surface of the mold into contact with the resin liquid and controlling the distance between the base and the mold. Expanding from one mold surface area to the second mold surface area;
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 7) ”.
[0019]
Further, the present invention is a resin molding die for manufacturing a resin bonding type optical element by providing by molding a resin layer of a predetermined shape on "optical element substrate Eighth,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Placing the lens substrate having a spherical shape or an aspherical shape horizontally (or substantially horizontal) with the spherical surface or the aspherical surface facing upward;
Dropping a predetermined amount of a photocurable resin liquid onto the central part (or near the center) of the spherical or aspherical surface;
By bringing the first mold surface area of the mold into contact with the resin liquid and controlling the distance between the lens base material and the mold, the resin liquid is allowed to flow between the lens base material and the mold. Expanding in the gap from the first mold surface region to the second mold surface region;
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 8) ”.
[0020]
Further, the present invention is ninthly a resin molding die for producing a resin-bonded optical element by molding and providing a resin layer having a predetermined shape on an optical element substrate.
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Placing the lens substrate having a spherical shape or an aspherical shape horizontally (or substantially horizontal) with the spherical surface or the aspherical surface facing upward;
Dropping a predetermined amount of a photocurable resin liquid onto the central part (or near the center) of the spherical or aspherical surface;
Reversing the lens substrate and directing the surface on which the photocurable resin liquid is dropped;
By bringing the first mold surface area of the mold into contact with the resin liquid and controlling the distance between the lens base material and the mold, the resin liquid is allowed to flow between the lens base material and the mold. Expanding in the gap from the first mold surface region to the second mold surface region;
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising: (Claim 9) ”.
Further, the present invention according to any one of claims 3-9 which when cured by irradiating light to "the resin liquid Tenth, the cured resin layer is characterized by being formed by curing shrinkage A method for producing a resin-bonded optical element (claim 10) "is provided.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies by the present inventors, a resin-molding mold is used to mold a resin layer having a predetermined shape on an optical element substrate, thereby forming a resin-bonded optical element. In order to easily release an object from a mold with a small force, 1) to generate a part where the resin layer and the mold are separated by a small force, and 2) to leak the separated part (space) and outside air. It has been found to be extremely effective.
[0022]
Therefore, in the mold for resin molding according to the present invention (claims 1 to 9) for producing a resin-bonded optical element by molding and providing a resin layer having a predetermined shape on the optical element substrate,
From the mold surface region that molds the peripheral portion of the optical effective diameter located outside the optical effective diameter portion of the resin layer to the mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer It was decided to provide at least one groove.
[0023]
The resin molding die according to the present invention has, for example, a mold surface as shown in FIG. 1, and this mold surface molds an optically effective diameter portion (optically effective diameter portion) of the resin layer. A mold surface region 11, a second mold surface region 12 for molding a peripheral portion (outside the optical effective diameter) of the resin layer located outside the optical effective diameter portion, and an end portion of the resin layer. It is divided into a third mold surface region (region outside the resin layer reaching) 13 which is located outside and does not mold the resin layer.
[0024]
The mold surface is provided with a groove 14 extending from the second mold surface region 12 to the third mold surface region 13.
When a resin bonded optical element is manufactured using such a mold (an example of a resin molding mold according to the present invention), the resin layer and the mold are peeled off with a small force when the resin molded product is released. Therefore, the molded product can be easily released from the mold with a small force by leaking the peeled portion (space) and outside air. In addition, it is possible to stably form a molding surface of a highly accurate resin layer.
[0025]
A process example (Claim 3) for producing a resin-bonded optical element using the mold (an example of a resin mold according to the present invention) will be described below.
First step: A resin molding die for producing a resin-bonded optical element by forming a resin layer having a predetermined shape on an optical element substrate, and molding an optically effective diameter portion of the resin layer A first mold surface region, a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optical effective diameter portion, and an outer portion of the end portion of the resin layer. And a third mold surface region on which the resin layer is not molded, and a groove reaching from the second mold surface region to the third mold surface region is provided in at least one location on the mold surface A mold (FIG. 1) is prepared.
[0026]
Second Step: A photocurable resin liquid is sandwiched between the optical element base material and the mold, and the distance between the base material and the mold is controlled, whereby the resin liquid is separated from the base material. In the gap with the mold, it is spread from the first mold surface area to the second mold surface area.
Third step: Resin bonding having a desired surface shape by irradiating and curing the resin liquid spread to the second mold surface region and integrating the cured resin layer and the substrate. A mold optical element is produced.
[0027]
Fourth step: The resin bonded optical element is removed from the mold.
Here, an example of a mold release process in the case of using the mold (an example of a resin molding mold according to the present invention) will be described with reference to FIG.
In FIG. 2 (1), the optical element base 21 and the mold 23 are placed at a predetermined distance (here, 100 μm), and the photocurable resin liquid 22 a (cured) is interposed between the optical element base 21 and the mold 23. FIG. 10 is an enlarged cross-sectional view showing a state in which a shrinkage rate of 10% is filled.
[0028]
The mold 23 is provided with a groove (width 100 μm, depth 50 μm) 24 extending from the second mold surface region to the third mold surface region.
In this state, when the resin liquid 22a is irradiated with light and cured, the resin liquid 22a is cured between the optical element base 21 and the mold 23 to form the resin layer 22 as shown in FIG. However, since the resin layer 22 is cured and contracted at this time, the distance between the optical element base 21 and the mold 23 is reduced.
[0029]
The distance between the optical element substrate 21 and the mold 23 at this time is determined by the thickness of the resin layer in the portion that occupies the area of most mold surfaces other than the grooves 24, and is 90 μm here. Therefore, the distance between the optical element substrate 21 and the bottom of the groove 24 is 140 μm.
On the other hand, the thickness of the resin liquid 22a in the groove portion is 150 μm. When the resin layer is formed by curing and shrinking, the thickness of the resin layer in that portion becomes 135 μm.
[0030]
That is, when the resin layer 22 formed by curing the resin liquid 22a is cured and contracted, a separation portion 25 between the resin layer 22 and the mold 23 is generated at the bottom portion of the groove 24, or the separation portion 25 is not generated. However, stress is generated in the resin layer 22 in the direction of peeling at the bottom portion of the groove 24.
Therefore, the peeling portion 25 between the mold 23 and the resin layer 22 can be easily formed at the bottom portion of the groove 24 before applying an external force for releasing the resin-bonded optical element from the mold or by applying a slight external force. Can be generated.
[0031]
Further, if the groove is shaped so that the photocurable resin liquid cannot completely penetrate, a gap is partially formed between the groove and the resin liquid in the state of the resin liquid. And in this case, even if there is no said hardening shrinkage, the state in which the partial peeling part has arisen from the beginning is obtained.
In addition, the followability of the resin liquid to the groove shape of the mold is the viscosity of the resin liquid, the wettability between the resin liquid and the mold, the width and depth of the groove, the shape (angle) of the groove bottom, Determined by many factors such as the elapsed time from the contact with the mold groove until the resin liquid hardens, the direction in which the mold surface faces during molding of the optical element (for example, vertically upward), etc. Is.
[0032]
As described above, partial peeling between the resin layer and the mold at the bottom of the groove is performed before applying an external force for releasing the resin-bonded optical element from the mold or by applying a slight force. Although the state (space: peeled portion) can be obtained, if an external force is applied thereafter to release the mold, the volume of the space formed between the resin layer and the mold increases.
At this time, if this space is closed from the outside air, as the volume of the space increases, the atmospheric pressure in the space is reduced and the force acts in a direction that prevents the mold release. Is required.
[0033]
However, the mold according to the present invention is provided with a groove extending from the second mold surface region to the third mold surface region (FIG. 1). By extending to the region 13 where the layer does not reach, the space (peeled portion) formed between the resin layer and the mold can be leaked from the outside air.
And even if the space between the mold and the resin layer is increased by the mold release operation, the outside air is supplied to the space, so that the pressure is not reduced and the mold release process can be rapidly advanced with a small force.
[0034]
The resin molding die according to the present invention is effective, for example, when a resin layer having an aspherical shape is formed on an optical element substrate (Claim 2).
Moreover, as a method for producing a resin-bonded optical element using the resin molding die according to the present invention, the production methods of claims 4 to 9 can be used in addition to the above example (claim 3).
In the inventions according to claims 7 and 9, the optical element substrate to which the resin liquid is applied is reversed, and the resin liquid on the substrate surface (downward) and the mold surface (upward) are brought into contact with each other. It has become.
[0035]
With this configuration, the contact region when the resin liquid and the mold surface first contact each other is integrated, and does not form a plurality of islands, so that bubbles are not involved. Therefore, a cured resin layer having no bubbles is obtained, which is preferable.
According to the present invention (Claims 1 to 9), since the resin molded product can be released from the molding die with an extremely small external force compared to the conventional one, the optical element substrate and the resin layer are not damaged.
[0036]
In addition, according to the present invention (claims 1 to 9), since the cycle time does not become longer than in the prior art, the cost reduction of the molded product can be easily realized, and the mass productivity is excellent.
Further, if the conventional mold is changed (if the groove according to the present invention is provided on the mold surface), the present invention (Claims 1 to 9) can be carried out, so that the conventional molding apparatus can be used. Therefore, almost no cost for remodeling the molding apparatus is required.
[0037]
According to the present invention (Claims 1 to 9), when a resin-bonded optical element is manufactured by forming a resin layer having a predetermined shape on an optical element substrate, a highly accurate resin layer is formed. The surface can be stably formed, and the molded product can be easily released with a small force.
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
[0038]
【Example】
The mold for resin molding according to the present embodiment for producing a resin-bonded optical element by forming a resin layer having a predetermined shape on an optical element substrate has a mold surface shown in FIG. The mold surface includes a first mold surface region 11 for molding the optical effective diameter inside (optical effective diameter portion) of the resin layer, and the optical effective diameter periphery of the resin layer positioned outside the optical effective diameter portion. A second mold surface region 12 for molding a portion (outside the optical effective diameter), and a third mold surface region that is located outside the terminal portion of the resin layer and does not mold the resin layer (outside from the resin layer reaching) Area) 13).
[0039]
The mold surface is provided with a groove 14 extending from the second mold surface region 12 to the third mold surface region 13. That is, the groove 14 is provided so as to start from the region 12 where the outside of the optical effective diameter is molded and reach the region 13 outside the position where the resin layer reaches.
The groove 14 has a width of about 100 μm, a depth of about 50 μm, and a length of 500 μm, and the bottom of the groove is U-shaped.
[0040]
The process for producing a resin-bonded optical element using the resin molding die according to this example will be described below.
First step: The mold is placed horizontally (or substantially horizontally) with the mold surface of the resin molding mold facing upward.
Second step: A predetermined amount of a photocurable resin liquid is dropped onto the first mold surface region.
[0041]
Third step: A lens substrate having a spherical shape or an aspherical shape is placed horizontally (or substantially) so that the central part (or the vicinity of the center) of the spherical or aspherical surface is in contact with the resin liquid on the resin liquid. The resin liquid is placed in the gap between the lens base material and the mold from the first mold surface area by being placed horizontally) and by controlling the distance between the lens base material and the mold. Push to the second mold surface area.
[0042]
Fourth step: The resin liquid spread to the second mold surface region is irradiated with light and cured, and the cured resin layer and the lens base material are integrated to have a desired aspherical shape. A resin-bonded lens is produced.
Fifth step: The resin-bonded lens is removed from the mold (released).
Here, a mold release process is demonstrated using FIG.
[0043]
As described above in the embodiment of the present invention, the peeling portion 25 between the resin layer 22 and the mold 23 is generated at the bottom portion of the groove 24 due to the curing shrinkage of the resin layer 22 formed by curing the resin liquid 22a. Even if the peeling portion 25 does not occur, stress is generated in the resin layer in the direction in which the bottom portion of the groove 24 is to peel off.
Therefore, the peeling portion 25 between the mold 23 and the resin layer 22 can be easily formed at the bottom portion of the groove 24 before applying an external force for releasing the resin-bonded optical element from the mold or by applying a slight external force. Can be generated.
[0044]
Thereafter, when releasing the mold by applying an external force, the volume of the space formed between the resin layer and the mold increases.
The mold according to this example is provided with a groove extending from the second mold surface region to the third mold surface region (FIG. 1), and thus the groove 14 on the mold surface is formed as a resin layer. By extending to the region 13 where no reaches, the space (peeling portion) formed between the resin layer and the mold can be leaked with outside air.
[0045]
Even if the space between the mold and the resin layer is increased by the mold release operation, the outside air is supplied to the space, so that the pressure is not reduced, and the mold release process can be rapidly advanced with a small force.
When the force applied at the time of mold release was actually measured with a load cell, when using a conventional mold with no groove, the force required for mold release was approximately 120 kgf. When the mold according to the example was used, the mold could be released with a small force of about 70 kgf.
[0046]
According to the present embodiment, the mold can be released with a very small external force as compared with the prior art, so that the optical element substrate and the resin are not damaged.
In addition, since the cycle time does not become longer compared with the conventional manufacturing method, the cost of the molded product can be easily reduced.
As described above, according to this example, when a resin-bonded optical element is manufactured by forming a resin layer having a predetermined shape on the optical element substrate, the molding surface of the high-precision resin layer is provided. It was possible to form stably, and the molded product could be easily released with a small force.
[0047]
【The invention's effect】
According to the present invention (Claims 1 to 9), since the resin molded product can be released from the molding die with an extremely small external force compared to the conventional one, the optical element substrate and the resin layer are not damaged.
In addition, according to the present invention (claims 1 to 9), since the cycle time does not become longer than in the prior art, the cost reduction of the molded product can be easily realized, and the mass productivity is excellent.
[0048]
Further, if the conventional mold is changed (if the groove according to the present invention is provided on the mold surface), the present invention (Claims 1 to 9) can be carried out, so that the conventional molding apparatus can be used. Therefore, almost no cost for remodeling the molding apparatus is required.
According to the present invention (Claims 1 to 9), when a resin-bonded optical element is manufactured by forming a resin layer having a predetermined shape on an optical element substrate, a highly accurate resin layer is formed. The surface can be stably formed, and the molded product can be easily released with a small force.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a mold surface of a mold according to an embodiment.
FIG. 2 is a schematic cross-sectional view showing a groove 24 and the like provided on the mold surface of the mold according to the embodiment.
FIG. 3 is a cross-sectional view showing the structure of a resin-bonded aspheric lens.
FIG. 4 is a process diagram showing a conventional method for producing a resin-bonded aspheric lens.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... 1st metal mold | die area | region 12 which shape | molds the optical effective diameter inside (optical effective diameter part) of a resin layer among the metal mold | die surfaces of a resin molding metal mold ... Mold of resin molding metal mold Among the surfaces, a second mold surface region 13 for molding a peripheral portion (outside the optical effective diameter) of the resin layer located outside the optical effective diameter portion. Mold surface of the mold for resin molding Of these, the third mold surface area where the resin layer is not molded (the area outside the resin layer reaches)
14, 24 ... grooves 21, 41 ... optical element base materials 22, 32, 42 ... cured resin layers 22a, 42a ... photocurable resin liquids 23, 43 ... mold 25 ...・ Peeling part 31 ... glass lens 44 ... light (ultraviolet)

Claims

In a resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
From the mold surface region that molds the peripheral portion of the optical effective diameter located outside the optical effective diameter portion of the resin layer to the mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer A resin molding die for a resin-bonded optical element, wherein at least one groove is provided.

The mold for resin molding according to claim 1, wherein the resin layer has an aspherical surface.

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
By sandwiching a photocurable resin liquid between the optical element base material and the mold, and controlling the distance between the base material and the mold, the resin liquid is separated from the base material and the mold. In the gap between the first mold surface region and the second mold surface region,
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the mold horizontally (or substantially horizontally) with the mold surface facing up,
Dropping a predetermined amount of photocurable resin liquid onto the mold surface;
An optical element substrate is placed horizontally (or substantially horizontally) on the resin liquid, and the distance between the substrate and the mold is controlled, whereby the resin liquid is mixed with the substrate and the mold. In the gap between the first mold surface region and the second mold surface region,
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the mold horizontally (or substantially horizontally) with the mold surface facing up,
Dropping a predetermined amount of a photocurable resin liquid on the first mold surface region;
A lens substrate having a spherical shape or an aspherical shape is mounted horizontally (or substantially horizontally) on the resin liquid so that the central portion (or the vicinity of the center) of the spherical surface or aspheric surface is in contact with the resin liquid. And by controlling the distance between the lens base and the mold, the resin liquid is passed from the first mold surface region to the second mold in the gap between the lens base and the mold. A process of expanding to the mold surface area,
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the optical element substrate horizontally (or substantially horizontally) with its surface facing up,
Dropping a predetermined amount of a photocurable resin liquid onto the surface of the substrate;
The resin liquid is brought into contact with the resin liquid in the gap between the base and the mold by bringing the mold liquid surface of the mold into contact with the resin liquid and controlling the distance between the base and the mold. Expanding from one mold surface area to the second mold surface area;
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Installing the optical element substrate horizontally (or substantially horizontally) with its surface facing up,
Dropping a predetermined amount of a photocurable resin liquid onto the surface of the substrate;
Reversing the base material so that the surface onto which the photocurable resin liquid has been dropped is directed downward;
The resin liquid is brought into contact with the resin liquid in the gap between the base and the mold by bringing the mold liquid surface of the mold into contact with the resin liquid and controlling the distance between the base and the mold. Expanding from one mold surface area to the second mold surface area;
A resin-bonded optical element having a desired surface shape is obtained by irradiating the resin liquid spread to the second mold surface region with light to cure it, and integrating the cured resin layer and the substrate. Manufacturing process;
Removing the resin-bonded optical element from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Placing the lens substrate having a spherical shape or an aspherical shape horizontally (or substantially horizontal) with the spherical surface or the aspherical surface facing upward;
Dropping a predetermined amount of a photocurable resin liquid onto the central part (or near the center) of the spherical or aspherical surface;
By bringing the first mold surface area of the mold into contact with the resin liquid and controlling the distance between the lens base material and the mold, the resin liquid is allowed to flow between the lens base material and the mold. Expanding in the gap from the first mold surface region to the second mold surface region;
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising:

A resin molding die for producing a resin-bonded optical element by molding and providing a resin layer of a predetermined shape on an optical element substrate,
A first mold surface region for molding an optically effective diameter portion of the resin layer; a second mold surface region for molding a peripheral portion of the optical effective diameter of the resin layer located outside the optically effective diameter portion; A third mold surface region that is located outside the end portion of the resin layer and does not mold the resin layer;
Preparing a resin molding die provided with a groove extending from the second mold surface region to the third mold surface region at at least one location on the mold surface;
Placing the lens substrate having a spherical shape or an aspherical shape horizontally (or substantially horizontal) with the spherical surface or the aspherical surface facing upward;
Dropping a predetermined amount of a photocurable resin liquid onto the central part (or near the center) of the spherical or aspherical surface;
Reversing the lens substrate and directing the surface on which the photocurable resin liquid is dropped;
By bringing the first mold surface area of the mold into contact with the resin liquid and controlling the distance between the lens base material and the mold, the resin liquid is allowed to flow between the lens base material and the mold. Expanding in the gap from the first mold surface region to the second mold surface region;
A resin-bonded lens having a desired aspherical shape by irradiating and curing the resin liquid spread to the second mold surface area and integrating the cured resin layer and the lens substrate. A step of producing
Removing the resin-bonded lens from the mold;
A method for producing a resin-bonded optical element comprising:

The method for producing a resin-bonded optical element according to any one of claims 3 to 9, wherein when the resin liquid is cured by irradiating light, the cured resin layer is cured and contracted.