JP3964939B2

JP3964939B2 - Optical element molding equipment

Info

Publication number: JP3964939B2
Application number: JP08415294A
Authority: JP
Inventors: 征史五十川; 元右三坂
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 1994-03-30
Filing date: 1994-03-30
Publication date: 2007-08-22
Anticipated expiration: 2022-08-22
Also published as: JPH07267657A

Description

【０００１】
【産業上の利用分野】
本発明は、加熱・軟化した光学素材を成形型により加圧成形する光学素子成形装置において上記光学素材を加圧成形可能な状態に加熱・軟化する光学素子の成形用加熱装置に関する。
【０００２】
【従来の技術】
従来、光学素子成形装置に用いられる光学素材加熱装置としては、例えば特開昭６２−１８２１２０号公報に記載されている。この光学素材加熱装置４０は、図１０および図１１に示すように円筒状の断熱部材４１の内周壁に加熱用ヒーター４２を円筒状に配置して構成されている。上記加熱装置４０は、図１０に示すように光学素材５を押圧成形する上下一対の成形型（上型１１、下型１２）を配置した成形室１０へ光学素材５を搬送する搬送路１４の途中に、加熱ヒーター４２を配置した内径部が連通するようにして設けられており、搬送皿６に載せた光学素材５を搬送アーム８によって円筒状の加熱ヒーター４２の内部に搬入し、光学素材５を成形面５ａから直接および外周部から搬送皿６を通じて加熱し得るようになっている。
【０００３】
また、特開平３−１５９９２６号公報には、図１２に示すように下部を開口した円筒状の断熱材２の内壁に円筒状の加熱用ヒーター３を配置した加熱装置４５が記載されている。この加熱装置４５は搬送路１４途中の上壁上に設置され、搬送アーム８によって搬送路１４内で加熱装置４５の下方に搬送された光学素材５を搬送皿６に載せたまま突き上げピン４６で加熱用ヒーター３の内部に挿入することにより、光学素子５を周囲から加熱し得るようになっている。
【０００４】
【発明が解決しようとする課題】
しかしながら、特開昭６２−１８２１２０号公報に記載された加熱装置４０にあっては、光学素材５の搬送路１４の経路を取り巻くように円筒状に配置されており、挿入加熱される光学素材５の中心軸は、加熱装置４０の中心軸に対して垂直であるため、光学素材５は成形面５ａ側からの加熱に加えて外周側からも加熱されるので、加熱装置４０の中心軸に対して外周ほど高温に加熱されることになり、光学素材５内に、中心軸に対して非対称な温度分布が生じる。そのため、成形された光学素子に円周方向のアスやひけが発生する問題点があった。
【０００５】
また、特開平３−１５９９２６号公報に記載された加熱装置４５にあっては、光学素材５を周囲から均等に加熱するので、加熱された光学素材５の温度分布は光学素材５の中心軸に対して円心円状になるものの、加熱後の光学素材５は、突き上げピン４６を下降させることによって搬送路１４内の搬送アーム８に再び載せた後、搬送アーム８により上下両型１１、１２間に搬送する必要があるため、加熱した光学素材５を上下両型１１，１２間まで搬送するのに時間がかかるという問題点があった。さらに、この搬送中に加熱された光学素材５の温度が下がってしまうという問題点があった。また、光学素材５を加熱後、突き上げピン４６の下降によって光学素材５が搬送皿６と共に載せられる搬送アーム８は加熱されていないので温度が低く、光学素材５から熱を奪うので、光学素材５が上下両型１１，１２によって押圧成形されるのに必要な温度を保てないことがあった。
【０００６】
本発明は、上記従来技術の問題点に鑑みてなされたもので、請求項１の発明は、光学素材を被成形面側から加熱用ヒーターにより加熱することによって、光学素材の加熱を被成形面から均一に行うことができる光学素子の成形用加熱装置を用いた光学素子成形装置を提供することを目的とする。また、請求項２の発明は、光学素材の中心軸に対して均一あるいは同心円状の温度分布を持たせて光学素材を加熱することができる光学素子の成形用加熱装置を提供することを目的とする。さらに、請求項３の発明は、光学素材を加熱する際、光学素子の中心軸に対して同心円状の温度分布を光学素材に任意に生じさせることができる光学素子の成形用加熱装置を用いた光学素子成形装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成させるために、請求項１の発明は、光学素材を成形用加熱装置を用いて加熱・軟化し、光学素材の上下の被成形面側から一対の成形型により加圧して光学素子を成形する光学素子成形装置において、前記光学素材を支持して前記成形用加熱装置の上壁および下壁にそれぞれ配置した加熱用ヒーター間と前記一対の成形型間とに搬送する搬送アームと、前記成形用加熱装置の上壁および下壁にそれぞれ配置した各加熱用ヒーターの中心と前記光学素材の中心軸を一致させた位置で前記搬送アームに支持した前記光学素材を所要の時間で停止し得るようにその搬送方向での前記搬送アームの移動を制御する制御装置と、を有し、前記成形用加熱装置の各加熱用ヒーターは、光学素材の上下の被成形面に対向する前記成形用加熱装置の上壁および下壁にのみ配置すると共に、前記各加熱用ヒーターの中心と光学素材の中心軸を一致させた位置での前記光学素材の中心軸を中心にして同心円状の温度分布を生じさせるようにスパイラル状又は同心円状に設けて構成した。また、請求項２の発明は、請求項１における加熱用ヒーターを、加熱・軟化する光学素材の中心軸を中心にして、前記成形用加熱装置の上壁の下面および下壁の上面を平面状、凹面状または凸面状とした面に、前記スパイラル状又は同心円状に設けて構成した。そして、請求項３の発明は、請求項１における加熱用ヒーターを、加熱・軟化する光学素材の中心軸を中心にして平面状かつ同心円状に独立して配置した複数のヒーターからなり、複数のヒーターを個々に出力調整し得るように構成した。また、前記搬送アームは、その先端に前記光学素材を搬送皿に載せて支持する構成とした。また、前記成形用加熱装置は、前記光学素材の搬送方向の両外周壁に搬送路を設ける構成とした。
【０００８】
【作用】
請求項１の発明にあっては、搬送皿に載せられた光学素材は、搬送アームによって成形用加熱装置内に搬送され、搬送皿および搬送アームと共に、加熱される。このとき、成形用加熱装置の加熱用ヒーターは光学素材の被成形面と対向した位置にあり、加熱は光学素材の被成形面から直接行われるのみで、光学素材の被成形面を重点的に加熱することができる。そして、所望の時間を加熱された光学素材は、同時に加熱された搬送皿上で同じく同時に加熱された搬送アームによって成形室内の成形型間にそのまま搬送できるため、搬送アームによって光学素材が冷却されることなく成形型で押圧成形することができる。
また、請求項２の発明にあっては、搬送皿に載せられた光学素材は、搬送アームによって成形用加熱装置内に搬送され、搬送皿および搬送アームと共に加熱される。加熱は光学素材の被成形面に対向して配置した、光学素材の中心軸に対して対称な形状の加熱用ヒーターで行うことで、光学素材の中心軸に対して同心円状で加熱でき、光学素材の温度分布は中心軸に対して同心円状になる。
さらに、請求項３の発明にあっては、搬送皿に載せられた光学素材は、搬送アームによって成形用加熱装置内に搬送され、搬送皿および搬送アームと共に加熱される。加熱は光学素材の被成形面に対向して、光学素材の中心軸に対して同心円状にかつ平面上に配置され、かつ個々に電気的出力を調整できる複数のヒーターによって行われる。このとき、複数のヒーターを個々に調整することで加熱用ヒーターは光学素材の中心軸に対して同心円状の温度分布をつくり出すことができ、加熱された光学素材は中心軸を中心に同心円状の温度分布で加熱される。
【０００９】
【実施例１】
図１から図３は本発明の実施例１の光学素子の成形用加熱装置（以下、光学素材加熱装置という）を示し、図１は光学素材加熱装置を具備し、光学素材の中心軸を上下方向に設置して光学素子を成形する成形装置を示す概略断面図、図２は光学素材加熱装置の外観を示す斜視図、図３は光学素材加熱装置に備えた加熱用ヒーターの形状を説明するための平面図である。
まず、図１を用いて本実施例の光学素材加熱装置１を設けた成形装置の概略構成を説明する。
図において１０は成形室で、成形室１０内には光学素材５を押圧成形する成形型（上型１１、下型１２）が同一軸上で上下に対向して設けられている。上型１１と下型１２は図示を省略した駆動源により、相対的に接近・離反自在に設けられており、例えば上型１１と下型１２が移動自在あるいは上型１１が成形室１０の上壁面に固設され、下型１２が上型１１に対して移動し得るようになっている。成形室１０の一側壁（図においては右側壁）には、光学素材５を上下両型１１，１２間に搬入しかつ押圧成形した後の光学素子を搬出する搬出入口１３が設けられ、この搬出入口１３に光学素材５等の搬送路１４が取り付けられている。搬送路１４の途中における成形室１０に近接した位置には、光学素材加熱装置１が設けられている。また、光学素材５を載置した搬送皿６を支持する搬送皿支持部材７を先端に設けた搬送アーム８が設けられている。搬送アーム８は、エアシリンダ等の駆動源（図示省略）により搬送路１４内を図１における左右方向の搬送方向に移動されるとともに、図示を省略した制御装置により光学素材加熱装置１の中心（詳しくは光学素材加熱装置１の加熱ヒーター３の中心）および上下両型１１，１２の軸線に対して光学素材５の中心軸Ｓを一致させる位置に光学素材５を搬送し、かつその位置で所要の時間を停止し得るようにその移動が制御されるようになっている。
【００１０】
上記光学素材加熱装置１は、円筒状の断熱部材２に加熱ヒーター３（ニクロム線）を取り付けてなっており、図２に示すように断熱部材２の対向する両外周壁に上記搬送路１４を取り付けて搬送路１４中に設けられている。断熱部材２の内部には、搬送アーム８に支持された光学素材５を加熱するため空間部４が上記搬送路１４と連通するように設けられている。上記空間部４の上下は、光学素材５の搬送方向と平行な上壁２ａ、下壁２ｂにより閉塞されており、上壁２ａの下面および下壁２ｂの上面に加熱用ヒーター３が配置され、搬送アーム８に支持された光学素材５をその被成形面５ａの方向から加熱し得るようになっている。
加熱用ヒーター３は、図１および図３に示すように平面状かつスパイラル状に配置され、その中心は搬送アーム８に支持した光学素材５の中心軸Ｓ上になるように設けられている。
【００１１】
次に、上記構成からなる本実施例の作用を図１から図４を用いて説明する。
まず、所望する光学素子に近似する形状に研削・研磨加工された光学素材５をその被成形面５ａが上下になるようにして搬送皿６に載せ搬送アーム８の先端に設けた搬送皿支持部７に載せて搬送アーム８で支持する。次に、図示を省略した駆動源により搬送アーム８を搬送路１４内で光学素材加熱装置１の方向に移動し、光学素材５を載せた搬送皿６を光学素材加熱装置１内に搬送する。そして、光学素材５の中心軸Ｓと加熱用ヒーター３の中心とが合致した位置で搬送アーム８による光学素材５の搬送を停止し、所望する時間の加熱を行って、光学素材５を成形可能な状態にまで軟化する。このとき、光学素材５は、被成形面５ａに対向して平面状かつスパイラル状に配置された加熱用ヒーター３によって、光学素材５の中心軸Ｓを中心として同心円状に加熱されるため、光学素材５の温度分布は中心軸Ｓに対して同心円状になるとともに、光学素材５の温度分布は図４に示すようになる。なお、図中Ｘは光学素材５の搬送方向、Ｙは搬送方向に直交する方向である。この光学素材５の加熱と同時に、光学素材５を搬送する搬送皿６および搬送アーム８先端の搬送皿支持部７も光学素材５と略同一温度に加熱される。この加熱が完了した後、再び駆動源を作動し、加熱された光学素材５を搬送皿６に載せたまま搬送アーム８によって光学素材加熱装置１内から搬送路１４に連設した成形室１０内に搬送する。そして、光学素材５の中心軸Ｓと上下両型１１，１２の軸心とが合致した位置で搬送アーム８を停止し、上下両型１１，１２を相対的に接近させ、上下両型１１，１２の成形面で光学素材５の被成形面５ａを押圧して所望の光学素子を成形する。
【００１２】
本実施例によれば、光学素材５の中心軸Ｓを中心にして同心円状の温度分布を生じさせるように光学素材５を加熱することができるので、円周方向におけるアスやひけの無い光学素子を成形することができる。また、光学素材５の加熱と同時に加熱される搬送皿６上で同じく同時に加熱される搬送皿支持部７に載せたまま搬送アーム８によって、加熱した光学素材５を成形室１０内の上下両成形型１１，１２間に搬送することができるので、加熱された温度を上下両型１１，１２で押圧するまで保持することができる。
【００１３】
なお、本実施例の加熱用ヒーター３は、ニクロム線を例示してあるが、カンタル線やシリコニットのように電気的な調整で出力を制御できるものならば例示したものに限られるものではない。
【００１４】
【実施例２】
図５は本発明の実施例２の光学素子の成形用加熱装置（以下、光学素材加熱装置という）を示す縦断側面図、図６は本実施例の変形例を示す縦断側面図である。なお、以下の説明においては本実施例と変形例を一緒に説明する。
本実施例の光学素材加熱装置２０は、断熱部材２の上壁２ａ下面および下壁２ｂ上面を凸面状に形成し、この上壁２ａ下面、下壁２ｂ上面に図４で示す実施例１における加熱用ヒーター３を配置して凸面状に設け、光学素材５の被成形面５ａに対向するように搬送路１４の上下に配置して構成した点が異なり、その他の構成は実施例１と同様であるので同一構成部分には同一番号を付してその説明を省略する。
また、変形例の光学素材加熱装置２１は、本実施例の断熱部材２の上壁２ａ下面、下壁２ｂ上面を凹面状に形成して加熱用ヒーター３（図４参照）を凹面状に設け、光学素材５の被成形面５ａに対向するように搬送路１４の上下に配置して構成されており、その他の構成は同一である。
【００１５】
次に、上記構成からなる本実施例および変形例の作用を図５から図８を用いて説明する。
まず、所望する光学素子に近似する形状に研削・研磨加工された光学素材５をその被成形面５ａが上下になるようにして搬送皿６に載せ、この搬送皿６を搬送アーム８の先端に設けた搬送皿支持部７に載せて搬送アーム８で支持する。次に、搬送アーム８を移動して光学素材５を光学素材加熱装置２０、２１内に搬送する。そして、光学素材５の中心軸Ｓと加熱用ヒーター３の中心とが合致した位置で搬送アーム８による光学素材５の搬送を停止し、光学素材５を成形可能な状態に加熱する。この加熱は光学素材５の上下にある被成形面５ａにそれぞれ対向配置される加熱用ヒーター３によって行われ、光学素材５はその中心軸Ｓに対して同心円状に加熱される。このとき、本実施例の凸面状に配置した加熱用ヒーター３によって加熱される場合には、光学素材５は、その中心軸Ｓに対して中心部ほど加熱用ヒーター３との距離が短いためよく加熱され、外周部ほど加熱用ヒーター３との距離が長いため、あまり加熱されず、光学素材５の温度分布は図７に示すようになる。一方、変形例の凹面状に配置した加熱用ヒーター３による場合は、凸面状の加熱用ヒーター３とは逆に、光学素材５の中心軸Ｓに対して外周部ほどよく加熱され、中心部はあまり加熱されず、光学素材５の温度分布は図８に示すようになる。このように、光学素材５の温度分布は加熱用ヒーター３と被成形面５ａの部分的な距離によって中心軸Ｓに対して同心円状で調整することができる。
【００１６】
本実施例および変形例によれば、前記実施例１の効果に加え、光学素材５の温度分布を成形の目的に合わせて作ることができ、例えば成形時の光学素材の流動量の大きい光学素材の成形では、凸レンズを押圧成形する場合、光学素材５の外周部の温度を高くし、凹レンズを押圧成形する場合、中心部の温度を高くすることによって薄肉部の流動性を高くさせることにより、変形量の大きい光学素子の成形を可能とすることができる。
【００１７】
【実施例３】
図９は本発明の実施例３の光学素子の成形用加熱装置（以下、光学素材加熱装置という）を示し、図においては断熱部材の上壁下面（下壁上面）に設けた加熱用ヒーターの配置状態を表してある。
本実施例の光学素材加熱装置３０は、断熱部材２の上壁２ａ下面および下壁２ｂ上面に独立した複数（本実施例にあっては３個）の加熱用ヒーター３１，３２，３３を平面状かつ同心円状に配置し、光学素材５の被成形面５ａ（図１等参照）に対向するように搬送路１４の上下に設けてあるとともに、光学素材加熱装置３０外で加熱用ヒーター３１，３２，３３の出力を独立して調整するヒーター出力調整器３４，３５，３６をそれぞれ導線３７により加熱用ヒーター３１，３２，３３に接続して構成した点が異なり、他の構成は実施例１と同様であるため同一部材には同一番号を付して、その説明を省略する。
【００１８】
次に、本実施例の作用を図１および図９を用いて説明する。
まず、所望する光学素子に近似する形状に研削・研磨加工された光学素材５をその被成形面５ａが上下になるようにして搬送皿６に載せ、この搬送皿６を搬送アーム８の先端に設けた搬送皿支持部７に載せて搬送アーム８で支持する。次に、搬送アーム８を移動して光学素材５を光学素材加熱装置３０内に搬送する。そして、光学素材５の中心軸Ｓと加熱用ヒーター３１，３２，３３の中心とが合致した位置で搬送アーム８による光学素材５の搬送を停止し、光学素材５を成形可能な状態に加熱する。この加熱は、光学素材５の上下にある被成形面５ａにそれぞれ対向配置される加熱用ヒーター３１，３２，３３によって加熱される。この時、加熱用ヒーター３１，３２，３３はヒーター出力調整器３４，３５，３６でそれぞれ独立して電圧を調整することによりヒーター出力が調整され、光学素材５の中心軸Ｓを中心にして光学素材５の温分布が同心円状に得られるように設定されている。これにより、加熱される光学素材５は、加熱用ヒーター３１，３２，３３によって中心軸Ｓに対して同心円状で加熱され、光学素材５の温度分布は、加熱用ヒーター３１，３２，３３の出力に応じて中心軸Ｓに対して同心円状になる。
【００１９】
本実施例によれば、前記実施例１の効果に加え、成形品の形状・寸法に合わせて加熱される光学素材５の温度分布を、各部の加熱用ヒーター３１，３２，３３の出力を電気的に調整することによって同心円状とすることができる。
【００２０】
本発明にあっては、光学素子を加熱・軟化する加熱用ヒーターを光学素材の被成形面に対向する方向にのみ配置するとともに、上記加熱用ヒーターを加熱・軟化する光学素材の中心軸を中心にして平面状かつ同心円状に独立して設けた複数のヒーターとし、上記複数のヒーターにそれぞれヒーター出力調整手段を連結し、上記複数のヒーターを個々に出力調整し得るように構成する。これにより複数のヒーターを個々に調整することで加熱用ヒーターは光学素材の中心軸に対して同心円状で温度分布を作り出すことができ、加熱された光学素材は中心軸を中心に同心円状の温度分布で加熱される。
【００２１】
【発明の効果】
請求項１の発明によれば、加熱用ヒーターを光学素子の被成形面に対向する成形用加熱装置の上壁および下壁にのみ配置したので、成形に必要な熱量を最低限に押さえることができ、また光学素材の中心軸を中心にして同心円状の温度分布を生じさせるように光学素材を加熱することができるので、円周方向におけるアスやひけの無い光学素子を成形することができる他、光学素材の搬送路中に加熱装置を設けたので、加熱完了後に直ちに光学素材を加熱後の温度を下げることなく加熱装置から成形型間まで搬送でき、成形に十分な温度を維持できる。また、請求項２の発明によれば、加熱用ヒーターを加熱・軟化する光学素材の中心軸を中心にして前記成形用加熱装置の上壁の下面および下壁の上面を平面状、凹面状または凸面状とした面に、前記スパイラル状又は同心円状に配置したので、光学素材の加熱を、光学素材の中心軸に対して同心円状で均一あるいは温度分布を持つように加熱することができるため、光軸（中心軸）に対して円周方向のアスやひけのない光学素子の成形ができる。さらに、請求項３の発明は、複数のヒーターを同心円状に配置するとともに、複数のヒーターを個々に出力調整し得るようにしたので、光学素材の中心軸に対して同心円状に任意の温度分布を光学素材を生じさせることができ、光学素材を押圧成形する際の流動性を成形する光学素子の形状に合わせて調整することができる。
【図面の簡単な説明】
【図１】本発明の実施例１の成形用加熱装置を装備した成形装置を示す概略断面図である。
【図２】本発明の実施例１の成形用加熱装置の外観を示す斜視図である。
【図３】本発明の実施例１の成形用加熱装置に備えた加熱用ヒーターの形状を説明するための平面図である。
【図４】本発明の実施例１の成形用加熱装置により加熱した光学素材の温度分布を示す説明図である。
【図５】本発明の実施例２の成形用加熱装置を示す断面図である。
【図６】本発明の実施例２の変形例を示す断面図である。
【図７】本発明の実施例２の成形用加熱装置により加熱した光学素材の温度分布を示す説明図である。
【図８】本発明の実施例２の変形例により加熱した光学素材の温度分布を示す説明図である。
【図９】本発明の実施例３の成形用加熱装置における加熱用ヒーターの配置状態を示す説明図である。
【図１０】従来技術の加熱装置を装備した成形装置を示す断面図である。
【図１１】図１０における加熱装置の端面図である。
【図１２】従来技術の加熱装置を装備した成形装置を示す断面図である。
【符号の説明】
１，２０，２１，３０光学素材加熱装置
３，３１，３２，３３加熱用ヒーター
５光学素材
１１上型
１２下型
３４，３５，３６ヒーター出力調整器[0001]
[Industrial application fields]
The present invention relates to a heating device for molding an optical element that heats and softens the optical material to a state in which the optical material can be pressure-molded in an optical element molding apparatus that press-molds the heated and softened optical material with a molding die.
[0002]
[Prior art]
Conventionally, an optical material heating device used in an optical element molding apparatus is described in, for example, Japanese Patent Application Laid-Open No. 62-182120. As shown in FIGS. 10 and 11, the optical material heating device 40 is configured by arranging a heating heater 42 in a cylindrical shape on the inner peripheral wall of a cylindrical heat insulating member 41. As shown in FIG. 10, the heating device 40 includes a conveyance path 14 that conveys the optical material 5 to a molding chamber 10 in which a pair of upper and lower molding dies (upper die 11 and lower die 12) that press-molds the optical material 5 is disposed. In the middle, an inner diameter portion where the heater 42 is disposed is provided so as to communicate with each other, and the optical material 5 placed on the transport tray 6 is carried into the cylindrical heater 42 by the transport arm 8, and the optical material 5 can be heated through the conveying tray 6 directly from the molding surface 5a and from the outer periphery.
[0003]
Japanese Patent Application Laid-Open No. 3-159926 discloses a heating device 45 in which a cylindrical heater 3 is arranged on the inner wall of a cylindrical heat insulating material 2 having a lower opening as shown in FIG. The heating device 45 is installed on the upper wall in the middle of the conveyance path 14, and the optical material 5 conveyed below the heating device 45 in the conveyance path 14 by the conveyance arm 8 is placed on the conveyance tray 6 with a push-up pin 46. The optical element 5 can be heated from the surroundings by being inserted into the heater 3.
[0004]
[Problems to be solved by the invention]
However, in the heating device 40 described in Japanese Patent Application Laid-Open No. 62-182120, the optical material 5 that is inserted and heated is arranged in a cylindrical shape so as to surround the transport path 14 of the optical material 5. Since the optical material 5 is heated from the outer peripheral side in addition to the heating from the molding surface 5a side, the central axis of the heating device 40 is perpendicular to the central axis of the heating device 40. Thus, the outer periphery is heated to a higher temperature, and an asymmetric temperature distribution is generated in the optical material 5 with respect to the central axis. For this reason, there has been a problem that circumferential asses and sink marks are generated in the molded optical element.
[0005]
Further, in the heating device 45 described in JP-A-3-159926, the optical material 5 is evenly heated from the surroundings, so that the temperature distribution of the heated optical material 5 is centered on the optical material 5. On the other hand, the heated optical material 5 is placed on the transport arm 8 in the transport path 14 by lowering the push-up pin 46, and then the upper and lower molds 11 and 12 are transported by the transport arm 8. There is a problem that it takes time to transport the heated optical material 5 between the upper and lower molds 11 and 12 because it is necessary to transport them between them. Furthermore, there is a problem that the temperature of the optical material 5 heated during the conveyance is lowered. Further, after heating the optical material 5, the transport arm 8 on which the optical material 5 is placed together with the transport tray 6 by the lowering of the push-up pin 46 is not heated, so the temperature is low and heat is taken away from the optical material 5. However, the temperature required to be press-molded by the upper and lower molds 11 and 12 may not be maintained.
[0006]
The present invention has been made in view of the above-mentioned problems of the prior art, and the invention of claim 1 is directed to heating the optical material by heating the optical material with a heater for heating from the molding surface side. It is an object of the present invention to provide an optical element molding apparatus using a heating apparatus for molding an optical element that can be uniformly performed. Another object of the present invention is to provide a heating device for molding an optical element capable of heating an optical material with a uniform or concentric temperature distribution with respect to the central axis of the optical material. To do. Furthermore, the invention of claim 3 uses a heating device for molding an optical element that can arbitrarily generate a concentric temperature distribution in the optical material with respect to the central axis of the optical element when the optical material is heated . An object is to provide an optical element molding apparatus .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is an optical element in which an optical material is heated and softened using a molding heating device, and is pressed by a pair of molding dies from the upper and lower surfaces to be molded of the optical material. In the optical element molding apparatus for molding, a transport arm that supports the optical material and transports between the heating heaters disposed on the upper wall and the lower wall of the molding heating apparatus and between the pair of molding dies, The optical material supported by the transfer arm is stopped at a required time at a position where the center of each heating heater arranged on the upper wall and lower wall of the molding heating device and the center axis of the optical material coincide with each other. A control device for controlling the movement of the transfer arm in the transfer direction so that each heating heater of the heating device for molding opposes the upper and lower surfaces to be molded of the optical material . Heating device The rewritable arranged only in the upper and lower walls, causing the said optical concentric temperature distribution around the central axis of the material at a position to match the center axis of the center of the optical material of each heater Thus, it was configured to be spiral or concentric. According to a second aspect of the present invention, the lower surface of the upper wall and the upper surface of the lower wall of the heating heater according to the first aspect are planar with the central axis of the optical material to be heated and softened. The spiral surface or the concentric circle is provided on the concave or convex surface . Further, the invention of claim 3 comprises a plurality of heaters in which the heater for heating in claim 1 is independently arranged in a planar and concentric manner around the central axis of the optical material to be heated and softened. The heater was configured so that the output could be adjusted individually. Moreover, the said conveyance arm was set as the structure which mounts and supports the said optical raw material on the conveyance tip at the front-end | tip. Moreover, the said heating apparatus for shaping | molding was set as the structure which provides a conveyance path in the both outer peripheral walls of the conveyance direction of the said optical raw material .
[0008]
[Action]
In the invention of claim 1, the optical material placed on the transport tray is transported into the molding heating device by the transport arm, and is heated together with the transport tray and the transport arm. At this time, the heating heater of the molding heating device is in a position facing the molding surface of the optical material, and heating is performed directly from the molding surface of the optical material, and the molding surface of the optical material is focused. Can be heated. The optical material heated for a desired time can be directly transferred between the molds in the molding chamber by the transfer arm heated at the same time on the transfer plate heated at the same time, so that the optical material is cooled by the transfer arm. It can press-mold with a shaping | molding die, without.
In the invention of claim 2, the optical material placed on the transport tray is transported into the molding heating device by the transport arm and heated together with the transport tray and the transport arm. Heating is performed concentrically with respect to the central axis of the optical material by using a heating heater that is arranged opposite to the molding surface of the optical material and symmetrical with respect to the central axis of the optical material. The temperature distribution of the material is concentric with the central axis.
Furthermore, in the invention of claim 3, the optical material placed on the transport plate is transported into the molding heating device by the transport arm and heated together with the transport plate and the transport arm. Heating is performed by a plurality of heaters that are arranged concentrically and on a plane with respect to the center axis of the optical material, facing the molding surface of the optical material, and that can individually adjust the electrical output. At this time, by adjusting each of the plurality of heaters, the heating heater can create a concentric temperature distribution with respect to the central axis of the optical material, and the heated optical material has a concentric circular shape around the central axis. Heated with temperature distribution.
[0009]
[Example 1]
1 to 3 show a heating device for molding an optical element (hereinafter referred to as an optical material heating device) according to Embodiment 1 of the present invention. FIG. 1 includes the optical material heating device, and the central axis of the optical material is moved up and down. FIG. 2 is a perspective view showing an external appearance of the optical material heating device, and FIG. 3 is a diagram for explaining the shape of the heating heater provided in the optical material heating device. FIG.
First, a schematic configuration of a molding apparatus provided with the optical material heating apparatus 1 of the present embodiment will be described with reference to FIG.
In the figure, reference numeral 10 denotes a molding chamber. In the molding chamber 10, molding dies (upper die 11 and lower die 12) for press-molding the optical material 5 are provided on the same axis so as to be opposed to each other vertically. The upper mold 11 and the lower mold 12 are provided so as to be relatively close to and away from each other by a drive source (not shown). For example, the upper mold 11 and the lower mold 12 are movable or the upper mold 11 is located above the molding chamber 10. The lower mold 12 is fixed to the wall surface so that the lower mold 12 can move with respect to the upper mold 11. On one side wall (right side wall in the figure) of the molding chamber 10 is provided with a carry-in / out port 13 for carrying the optical material 5 between the upper and lower molds 11 and 12 and carrying out the optical element after press molding. A conveyance path 14 for the optical material 5 or the like is attached to the entrance 13. The optical material heating device 1 is provided at a position near the molding chamber 10 in the middle of the conveyance path 14. Further, a transport arm 8 provided with a transport tray support member 7 that supports the transport tray 6 on which the optical material 5 is placed is provided at the tip. The transport arm 8 is moved in the transport path 14 in the left-right transport direction in FIG. 1 by a driving source (not shown) such as an air cylinder, and the center ( Specifically, the optical material 5 is transported to a position where the center axis S of the optical material 5 coincides with the axes of the heaters 3 of the optical material heating apparatus 1 and the upper and lower molds 11 and 12, and required at that position. The movement is controlled so that the time can be stopped.
[0010]
The optical material heating apparatus 1 has a heater 3 (nichrome wire) attached to a cylindrical heat insulating member 2, and the conveying path 14 is provided on both outer peripheral walls of the heat insulating member 2 as shown in FIG. It is attached and provided in the conveyance path 14. Inside the heat insulating member 2, a space 4 is provided so as to communicate with the transport path 14 in order to heat the optical material 5 supported by the transport arm 8. The upper and lower sides of the space portion 4 are closed by an upper wall 2a and a lower wall 2b parallel to the conveying direction of the optical material 5, and a heater 3 is disposed on the lower surface of the upper wall 2a and the upper surface of the lower wall 2b. The optical material 5 supported by the transport arm 8 can be heated from the direction of the molding surface 5a.
As shown in FIGS. 1 and 3, the heating heater 3 is arranged in a planar shape and a spiral shape, and the center thereof is provided on the central axis S of the optical material 5 supported by the transport arm 8.
[0011]
Next, the operation of this embodiment having the above configuration will be described with reference to FIGS.
First, an optical material 5 that has been ground and polished to a shape approximating a desired optical element is placed on the conveyance tray 6 with its molding surface 5a up and down, and a conveyance tray support section provided at the tip of the conveyance arm 8 7 is supported by the transfer arm 8. Next, the transport arm 8 is moved in the transport path 14 in the direction of the optical material heating device 1 by a drive source (not shown), and the transport tray 6 on which the optical material 5 is placed is transported into the optical material heating device 1. The optical material 5 can be molded by stopping the conveyance of the optical material 5 by the conveyance arm 8 at a position where the center axis S of the optical material 5 coincides with the center of the heater 3 and heating it for a desired time. Softens even to a certain state. At this time, the optical material 5 is heated concentrically around the central axis S of the optical material 5 by the heating heater 3 arranged in a planar and spiral shape facing the molding surface 5a. The temperature distribution of the material 5 is concentric with respect to the central axis S, and the temperature distribution of the optical material 5 is as shown in FIG. In the figure, X is the transport direction of the optical material 5, and Y is the direction orthogonal to the transport direction. Simultaneously with the heating of the optical material 5, the transport plate 6 for transporting the optical material 5 and the transport plate support part 7 at the tip of the transport arm 8 are also heated to substantially the same temperature as the optical material 5. After this heating is completed, the drive source is actuated again, and the heated optical material 5 is placed on the transport plate 6 and the inside of the molding chamber 10 connected to the transport path 14 from the optical material heating device 1 by the transport arm 8. Transport to. Then, the transport arm 8 is stopped at a position where the center axis S of the optical material 5 and the axis centers of the upper and lower molds 11 and 12 coincide with each other, and the upper and lower molds 11 and 12 are relatively approached. The molding surface 5a of the optical material 5 is pressed with the 12 molding surfaces to mold a desired optical element.
[0012]
According to the present embodiment, since the optical material 5 can be heated so as to generate a concentric temperature distribution around the central axis S of the optical material 5, an optical element free from asses and sink marks in the circumferential direction Can be molded. In addition, the heated optical material 5 is formed in both the upper and lower molds in the molding chamber 10 by the transfer arm 8 while being placed on the transfer tray support 7 which is also heated at the same time on the transfer tray 6 heated simultaneously with the heating of the optical material 5. Since it can convey between the type | molds 11 and 12, it can hold | maintain until the heated temperature is pressed with the upper and lower type | molds 11 and 12. FIG.
[0013]
In addition, although the heater 3 for a heater of a present Example has illustrated the nichrome wire, if it can control an output by electrical adjustment like a Kanthal wire or a siliconite, it will not be restricted to what was illustrated.
[0014]
[Example 2]
FIG. 5 is a longitudinal side view showing a heating device for molding an optical element (hereinafter referred to as an optical material heating device) of Example 2 of the present invention, and FIG. 6 is a longitudinal side view showing a modification of the present example. In the following description, this embodiment and modification examples will be described together.
The optical material heating apparatus 20 of the present embodiment forms the lower surface of the upper wall 2a and the upper surface of the lower wall 2b of the heat insulating member 2 in a convex shape, and the lower surface of the upper wall 2a and the upper surface of the lower wall 2b in the first embodiment shown in FIG. The heater 3 for heating is arrange | positioned and it provides in convex shape, and the point which has arrange | positioned and comprised on the upper and lower sides of the conveyance path 14 so that the to-be-molded surface 5a of the optical raw material 5 may be opposed differs, and other structures are the same as Example 1. Therefore, the same components are denoted by the same reference numerals and the description thereof is omitted.
Further, the optical material heating device 21 of the modified example is provided with the heater 3 for heating (see FIG. 4) in a concave shape by forming the lower surface of the upper wall 2a and the upper surface of the lower wall 2b of the heat insulating member 2 of the present embodiment in a concave shape. The optical material 5 is arranged above and below the conveyance path 14 so as to face the molding surface 5a of the optical material 5, and the other configurations are the same.
[0015]
Next, the operation of this embodiment and the modification having the above-described configuration will be described with reference to FIGS.
First, the optical material 5 that has been ground and polished to a shape approximating the desired optical element is placed on the transport tray 6 with the molding surface 5a up and down, and this transport tray 6 is placed at the tip of the transport arm 8. It is placed on the provided transport tray support 7 and supported by the transport arm 8. Next, the transport arm 8 is moved to transport the optical material 5 into the optical material heating devices 20 and 21. Then, the conveyance of the optical material 5 by the conveyance arm 8 is stopped at a position where the center axis S of the optical material 5 coincides with the center of the heater 3 for heating, and the optical material 5 is heated to a formable state. This heating is performed by the heating heaters 3 disposed opposite to the molding surfaces 5a above and below the optical material 5, and the optical material 5 is heated concentrically with respect to the central axis S thereof. At this time, in the case where the optical material 5 is heated by the heating heater 3 arranged in a convex shape according to the present embodiment, the optical material 5 is good because the distance from the heating heater 3 toward the central portion is shorter with respect to the central axis S. Since the distance from the heating heater 3 is longer as the outer peripheral portion is heated, it is not heated so much and the temperature distribution of the optical material 5 is as shown in FIG. On the other hand, in the case of the heating heater 3 arranged in a concave shape in the modified example, the outer peripheral portion is heated better with respect to the central axis S of the optical material 5, contrary to the convex heating heater 3. The temperature distribution of the optical material 5 is as shown in FIG. Thus, the temperature distribution of the optical material 5 can be adjusted concentrically with respect to the central axis S by the partial distance between the heater 3 and the molding surface 5a.
[0016]
According to the present embodiment and the modification, in addition to the effects of the first embodiment, the temperature distribution of the optical material 5 can be made in accordance with the purpose of molding, for example, an optical material having a large flow amount of the optical material during molding. In this molding, when the convex lens is press-molded, the temperature of the outer peripheral portion of the optical material 5 is increased, and when the concave lens is press-molded, the fluidity of the thin portion is increased by increasing the temperature of the central portion. It is possible to mold an optical element having a large deformation amount.
[0017]
[Example 3]
FIG. 9 shows a heating device for molding an optical element (hereinafter referred to as an optical material heating device) of Example 3 of the present invention. In the figure, the heating heater provided on the lower surface (upper surface of the lower wall) of the heat insulating member is shown. The arrangement state is shown.
The optical material heating device 30 according to the present embodiment is provided with a plurality of independent (three in the present embodiment) heating heaters 31, 32, and 33 on the upper surface 2 a lower surface and the lower wall 2 b upper surface of the heat insulating member 2. And concentrically arranged, provided above and below the conveying path 14 so as to face the molding surface 5a of the optical material 5 (see FIG. 1 and the like), and a heater 31 for heating outside the optical material heating device 30, The heater output regulators 34, 35, and 36 that independently adjust the outputs of the heaters 32 and 33 are connected to the heaters 31, 32, and 33 by heating wires 37, respectively. Therefore, the same members are denoted by the same reference numerals, and the description thereof is omitted.
[0018]
Next, the effect | action of a present Example is demonstrated using FIG. 1 and FIG.
First, the optical material 5 that has been ground and polished to a shape approximating the desired optical element is placed on the transport tray 6 with the molding surface 5a up and down, and this transport tray 6 is placed at the tip of the transport arm 8. It is placed on the provided transport tray support 7 and supported by the transport arm 8. Next, the transport arm 8 is moved to transport the optical material 5 into the optical material heating device 30. Then, the conveyance of the optical material 5 by the conveyance arm 8 is stopped at a position where the center axis S of the optical material 5 coincides with the center of the heaters 31, 32, 33, and the optical material 5 is heated to a formable state. . This heating is performed by heating heaters 31, 32, and 33 arranged to face the molding surfaces 5 a above and below the optical material 5. At this time, the heater outputs 31, 32, 33 are adjusted by the heater output adjusters 34, 35, 36 independently to adjust the heater output, and the optical power is adjusted around the central axis S of the optical material 5. The temperature distribution of the material 5 is set so as to be obtained concentrically. Thereby, the heated optical material 5 is heated concentrically with respect to the central axis S by the heating heaters 31, 32, 33, and the temperature distribution of the optical material 5 is the output of the heating heaters 31, 32, 33. Accordingly, it becomes concentric with respect to the central axis S.
[0019]
According to the present embodiment, in addition to the effects of the first embodiment, the temperature distribution of the optical material 5 to be heated in accordance with the shape and dimensions of the molded product is obtained, and the outputs of the heaters 31, 32, and 33 are electrically It can be made a concentric circle by adjusting it.
[0020]
In the present invention, the heater for heating / softening the optical element is disposed only in the direction facing the molding surface of the optical material, and the center axis of the optical material for heating / softening the heating heater is centered. Thus, a plurality of heaters provided independently in a planar and concentric manner are provided, and a heater output adjusting means is connected to each of the plurality of heaters so that the outputs of the plurality of heaters can be individually adjusted. By adjusting multiple heaters individually, the heating heater can create a temperature distribution concentrically with respect to the central axis of the optical material, and the heated optical material has a concentric temperature around the central axis. Heated with distribution.
[0021]
【The invention's effect】
According to the invention of claim 1, since the heater for heating is disposed only on the upper wall and the lower wall of the molding heating device facing the molding surface of the optical element, the amount of heat necessary for molding can be minimized. In addition, the optical material can be heated so as to generate a concentric temperature distribution around the central axis of the optical material, so that it is possible to mold an optical element free of asses and sink marks in the circumferential direction. Since the heating device is provided in the conveyance path of the optical material, the optical material can be conveyed from the heating device to the mold without decreasing the temperature after heating immediately after the heating is completed, and a temperature sufficient for molding can be maintained. According to the invention of claim 2, the lower surface of the upper wall and the upper surface of the lower wall of the molding heating device are planar, concave or centered around the central axis of the optical material that heats and softens the heater. Since the spiral or concentric arrangement is arranged on the convex surface, the heating of the optical material can be performed so as to be uniform or have a temperature distribution concentrically with respect to the central axis of the optical material. It is possible to mold an optical element free from asses and sink marks in the circumferential direction with respect to the optical axis (center axis). Furthermore, in the invention of claim 3, since the plurality of heaters are arranged concentrically and the outputs of the plurality of heaters can be adjusted individually, any temperature distribution can be concentrically with respect to the central axis of the optical material. An optical material can be produced, and the fluidity when pressing the optical material can be adjusted in accordance with the shape of the optical element to be molded.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a molding apparatus equipped with a molding heating apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a perspective view showing an appearance of a molding heating apparatus according to Embodiment 1 of the present invention.
FIG. 3 is a plan view for explaining the shape of a heating heater provided in the molding heating apparatus according to the first embodiment of the present invention.
4 is an explanatory diagram showing a temperature distribution of an optical material heated by a molding heating apparatus according to Example 1 of the present invention. FIG.
FIG. 5 is a cross-sectional view showing a molding heating apparatus according to Embodiment 2 of the present invention.
FIG. 6 is a cross-sectional view showing a modification of the second embodiment of the present invention.
7 is an explanatory diagram showing a temperature distribution of an optical material heated by a molding heating apparatus according to Example 2 of the present invention. FIG.
FIG. 8 is an explanatory diagram showing a temperature distribution of an optical material heated according to a modification of Example 2 of the present invention.
FIG. 9 is an explanatory diagram showing an arrangement state of heating heaters in the molding heating apparatus according to the third embodiment of the present invention.
FIG. 10 is a cross-sectional view showing a molding apparatus equipped with a conventional heating device.
11 is an end view of the heating device in FIG.
FIG. 12 is a cross-sectional view showing a molding apparatus equipped with a conventional heating device.
[Explanation of symbols]
1, 20, 21, 30 Optical material heating device 3, 31, 32, 33 Heating heater 5 Optical material 11 Upper mold 12 Lower mold 34, 35, 36 Heater output adjuster

Claims

In an optical element molding apparatus that molds an optical element by heating and softening an optical material using a molding heating device and pressing with a pair of molding dies from the upper and lower molding surface sides of the optical material,
A transport arm that supports the optical material and transports between the heaters disposed on the upper wall and the lower wall of the molding heating device and between the pair of molding dies,
The optical material supported by the transfer arm is stopped at a required time at a position where the center of each heating heater arranged on the upper wall and lower wall of the molding heating device and the center axis of the optical material coincide with each other. A control device for controlling movement of the transfer arm in the transfer direction so as to obtain;
It has a respective heater for heating of the molding heating device The rewritable disposed only on the upper wall and the lower wall of the molding heating device facing onto the molding surface of the upper and lower optical material, wherein the heater An optical element characterized by being provided in a spiral or concentric shape so as to generate a concentric temperature distribution around the central axis of the optical material at a position where the center of the optical material coincides with the central axis of the optical material Molding equipment.

The heating heater has a flat surface, a concave surface or a convex surface on the lower surface of the upper wall and the upper surface of the lower wall of the molding heating device , with the center axis of the optical material to be heated and softened as a center. 2. The optical element molding apparatus according to claim 1, wherein the optical element molding apparatus is provided in a spiral shape or a concentric shape .

The heating heater consists of a plurality of heaters arranged independently in a flat and concentric manner around the central axis of the optical material to be heated and softened, and the output of each of the heaters can be adjusted individually. The optical element molding apparatus according to claim 1, wherein:

The optical element molding apparatus according to claim 1, wherein the transport arm supports the optical material placed on a transport tray at a tip thereof.

The optical element molding apparatus according to any one of claims 1 to 3, wherein the molding heating apparatus includes conveyance paths on both outer peripheral walls in the conveyance direction of the optical material .