JP4312319B2 - Microlens substrate and manufacturing method thereof - Google Patents

Description

【００６４】
ただし、ｎは２以上の整数であり、Ｒ¹，Ｒ²はそれぞれ炭素数１〜１０の置換もしくは非置換のアルキル、アルケニル、アリールあるいはシアノアルキル基であり、モル比で全体の４０％以下がビニル、フェニル、ハロゲン化フェニルである。また、Ｒ¹、Ｒ²がメチル基のものが表面エネルギーが最も小さくなるので好ましく、モル比でメチル基が６０％以上であることが好ましい。また、鎖末端もしくは側鎖には、分子鎖中に少なくとも１個以上の水酸基等の反応性基を有する。
【００６５】
また、上記のオルガノポリシロキサンとともに、ジメチルポリシロキサンのような架橋反応をしない安定なオルガノシリコン化合物をバインダに混合してもよい。
【００６６】
本発明のマイクロレンズ基板においては、このようにオルガノポリシロキサン等の種々のバインダを光触媒含有層に用いることができる。本発明においては、上述したように、このようなバインダおよび光触媒を含む光触媒含有層にフッ素を含有させ、エネルギーをパターン照射することにより光触媒含有層表面のフッ素を低減させ、これにより撥液性領域内に親液性領域を形成するようにしてもよい。この際、光触媒含有層中にフッ素を含有させる必要があるが、このようなバインダを含む光触媒含有層にフッ素を含有させる方法としては、通常高い結合エネルギーを有するバインダに対し、フッ素化合物を比較的弱い結合エネルギーで結合させる方法、比較的弱い結合エネルギーで結合されたフッ素化合物を光触媒含有層に混入させる方法等を挙げることができる。このような方法でフッ素を導入することにより、エネルギーが照射された場合に、まず結合エネルギーが比較的小さいフッ素結合部位が分解され、これによりフッ素を光触媒含有層中から除去することができるからである。
【００６７】
上記第１の方法、すなわち、高い結合エネルギーを有するバインダに対し、フッ素化合物を比較的弱い結合エネルギーで結合させる方法としては、上記オルガノポリシロキサンにフルオロアルキル基を置換基として導入する方法等を挙げることができる。
【００６８】
例えば、オルガノポリシロキサンを得る方法として、上記（１）として記載したように、ゾルゲル反応等によりクロロまたはアルコキシシラン等を加水分解、重縮合して大きな強度を発揮するオルガノポリシロキサンを得ることができる。ここで、この方法においては、上述したように上記一般式：
Ｙ_nＳｉＸ_(4-n)
（ここで、Ｙはアルキル基、フルオロアルキル基、ビニル基、アミノ基、フェニル基またはエポキシ基を示し、Ｘはアルコキシル基、アセチル基またはハロゲンを示す。ｎは０〜３までの整数である。）
で示される珪素化合物の１種または２種以上を、加水分解縮合物もしくは共加水分解縮合することによりオルガノポリシロキサンを得るのであるが、この一般式において、置換基Ｙとしてフルオロアルキル基を有する珪素化合物を用いて合成することにより、フルオロアルキル基を置換基として有するオルガノポリシロキサンを得ることができる。このようなフルオロアルキル基を置換基として有するオルガノポリシロキサンをバインダとして用いた場合は、エネルギーが照射された際、光触媒含有層中の光触媒の作用により、フルオロアルキル基の炭素結合の部分が分解されることから、光触媒含有層表面にエネルギーを照射した部分のフッ素含有量を低減させることができる。
【００６９】
この際用いられるフルオロアルキル基を有する珪素化合物としては、フルオロアルキル基を有するものであれば特に限定されるものではないが、少なくとも１個のフルオロアルキル基を有し、このフルオロアルキル基の炭素数が４から３０、好ましくは６から２０、特に好ましくは６から１６である珪素化合物が好適に用いられる。このような珪素化合物の具体例は上述した通りであるが、中でも炭素数が６から８であるフルオロアルキル基を有する上記珪素化合物、すなわちフルオロアルキルシランが好ましい。
【００７０】
本発明においては、このようなフルオロアルキル基を有する珪素化合物を上述したフルオロアルキル基を有さない珪素化合物と混合して用い、これらの共加水分解縮合物を上記オルガノポリシロキサンとして用いてもよいし、このようなフルオロアルキル基を有する珪素化合物を１種または２種以上用い、これらの加水分解縮合物、共加水分解縮合物を上記オルガノポリシロキサンとして用いてもよい。
【００７１】
このようにして得られるフルオロアルキル基を有するオルガノポリシロキサンにおいては、このオルガノポリシロキサンを構成する珪素化合物の内、上記フルオロアルキル基を有する珪素化合物が０．０１モル％以上、好ましくは０．１モル％以上含まれていることが好ましい。
【００７２】
フルオロアルキル基がこの程度含まれることにより、光触媒含有層上の撥液性を高くすることができ、エネルギーを照射して親液性領域とした部分との濡れ性の差異を大きくすることができるからである。
【００７３】
また、上記（２）に示す方法では、撥水牲や撥油性に優れた反応性シリコーンを架橋することによりオルガノポリシロキサンを得るのであるが、この場合も同様に、上述した一般式中のＲ¹，Ｒ²のいずれかもしくは両方をフルオロアルキル基等のフッ素を含有する置換基とすることにより、光触媒含有層中にフッ素を含ませることが可能であり、またエネルギーが照射された場合に、シロキサン結合より結合エネルギーの小さいフルオロアルキル基の部分が分解されるため、エネルギー照射により光触媒含有層表面におけるフッ素の含有量を低下させることができる。
【００７４】
一方、後者の例、すなわち、バインダの結合エネルギーより弱いエネルギーで結合したフッ素化合物を導入させる方法としては、例えば、低分子量のフッ素化合物を導入させる場合は、例えばフッ素系の界面活性剤を混入する方法等を挙げることができ、また高分子量のフッ素化合物を導入させる方法としては、バインダ樹脂との相溶性の高いフッ素樹脂を混合する等の方法を挙げることができる。
【００７５】
本発明において光触媒含有層には上記の光触媒、バインダの他に、界面活性剤を含有させることができる。具体的には、日光ケミカルズ（株）製ＮＩＫＫＯＬＢＬ、ＢＣ、ＢＯ、ＢＢの各シリーズ等の炭化水素系、デュポン社製ＺＯＮＹＬ ＦＳＮ、ＦＳＯ、旭硝子（株）製サーフロンＳ−１４１、１４５、大日本インキ化学工業（株）製メガファックＦ−１４１、１４４、ネオス（株）製フタージェントＦ−２００、Ｆ２５１、ダイキン工業（株）製ユニダインＤＳ−４０１、４０２、スリーエム（株）製フロラードＦＣ−１７０、１７６等のフッ素系あるいはシリコーン系の非イオン界面活性剤を挙げることかでき、また、カチオン系界面活性剤、アニオン系界面活性剤、両性界面活性剤を用いることもできる。
【００７６】
また、光触媒含有層には上記の界面活性剤の他にも、ポリビニルアルコール、不飽和ポリエステル、アクリル樹脂、ポリエチレン、ジアリルフタレート、エチレンプロピレンジエンモノマー、エポキシ樹脂、フェノール樹脂、ポリウレタン、メラミン樹脂、ポリカーボネート、ポリ塩化ビニル、ポリアミド、ポリイミド、スチレンブタジエンゴム、クロロプレンゴム、ポリプロピレン、ポリブチレン、ポリスチレン、ポリ酢酸ビニル、ポリエステル、ポリブタジエン、ポリベンズイミダゾール、ポリアクリルニトリル、エピクロルヒドリン、ポリサルファイド、ポリイソプレン等のオリゴマー、ポリマー等を含有させることができる。
【００７７】
光触媒含有層中の光触媒の含有量は、５〜６０重量％、好ましくは２０〜４０重量％の範囲で設定することができる。また、光触媒含有層の厚みは、０．０５〜１０μｍの範囲内が好ましく、特に好ましくは、０．１〜０．２μｍである。
【００７８】
上記光触媒含有層は、光触媒とバインダを必要に応じて他の添加剤とともに溶剤中に分散して塗布液を調製し、この塗布液を塗布することにより形成することができる。使用する溶剤としては、エタノール、イソプロパノール等のアルコール系の有機溶剤が好ましい。塗布はスピンコート、スプレーコート、ディップコート、ロールコート、ビードコート等の公知の塗布方法により行うことができる。バインダとして紫外線硬化型の成分を含有している場合、紫外線を照射して硬化処理を行うことにより光触媒含有層を形成することかできる。
【００７９】
（マイクロレンズ）
本発明においては、図１に示すように濡れ性可変層３、中でも上述した光触媒含有層上に複数のマイクロレンズ４が設けられたところに特徴を有するものである。本発明では、上記光触媒含有層において露光され、液体との接触角が低い親液性領域に、マイクロレンズ形成用塗料により所定のパターンでマイクロレンズが形成される。
【００８０】
本発明においては、基板上に形成されたマイクロレンズが、規則的にマイクロレンズが配列されたマイクロレンズアレイとされていることが好ましい。マイクロレンズの主たる用途である液晶ディスプレイや撮像素子等においては、マイクロレンズアレイとして用いられる場合が多いからである。この規則的な配列パターンは、それぞれ用いられる素子等の態様により決定される。
【００８１】
また、各マイクロレンズの底面、すなわち基板との接触面の形状は特に限定されるものではなく、円形のみならず、多角形のものであってもよい。この場合、マイクロレンズ底面の形状を多角形とすることにより、円形のものと比較してマイクロレンズが形成されていない領域の面積を小さくすることができることから、開口率の高いマイクロレンズを容易に得ることができる。
【００８２】
本発明のマイクロレンズ基板上における、マイクロレンズが配置されている部位と、配置されていない部位との面積比は、用いられる機能性素子や要求特性により大きく異なるものではあるが、一般的な的には、１００００：１〜１：１００００の範囲内であるとすることができる。また、マイクロレンズ基板の用途によって大幅に異なるものではあるが、一般にマイクロレンズの焦点距離は１００〜２５００μｍの範囲内であり、またマイクロレンズの形成ピッチは１０〜１０００μｍの範囲内である。
【００８３】
さらに、本発明のマイクロレンズ基板においては、マイクロレンズの焦点距離を種々変化させたマイクロレンズ基板とすることができる。すなわち、本発明のマイクロレンズ基板においては、マイクロレンズ形成用塗料の基板への付着量を調整することにより、容易に焦点距離を変化させたマイクロレンズを得ることができ、種々焦点距離を有するマイクロレンズを容易に形成することができるのである。以下、この点ついて、図２を用いて具体的に説明する。
【００８４】
図２（ａ）は、マイクロレンズ形成用塗料を少量塗布したケースを示すものである。すなわち、基板２上に形成された濡れ性可変層３において、親液性領域とされたマイクロレンズ形成部５上に少量のマイクロレンズ形成用塗料を塗布し、曲率の小さいマイクロレンズ４を形成したものである。本発明のマイクロレンズ基板においては、マイクロレンズ４が親液性とされたマイクロレンズ形成部５上に形成されていることから、図２（ａ）に示すような少量のマイクロレンズ形成用塗料を塗布した場合であっても、塗布されたマイクロレンズ形成用塗料がマイクロレンズ形成部５全体にひろがる。したがって、曲率の小さい焦点距離の長いマイクロレンズを塗布量を少量とすることにより容易に形成することができる。
【００８５】
図２（ｂ）は、（ａ）よりも曲率が大きく焦点距離の短いマイクロレンズ４を示すものである。本発明においては、マイクロレンズ４の底面となるマイクロレンズ形成部５の面積が定まっていることから、このマイクロレンズ形成部５内に塗布するマイクロレンズ形成用塗料の量により、マイクロレンズ４の曲率および焦点距離を決定することができる。図２（ｂ）は、（ａ）より多い量のマイクロレンズ形成用塗料を塗布した例を示すものであり、このように本発明においては、マイクロレンズ形成用塗料の量を調整することにより、種々の曲率および焦点距離を有するマイクロレンズを容易に得ることができる。
【００８６】
図２（ｃ）は、さらに曲率が大きく焦点距離の短いマイクロレンズ４を示すものである。この場合、親液性領域であるマイクロレンズ形成部５と撥液性領域である濡れ性可変層３との濡れ性の差が大きければ、マイクロレンズ形成用塗料をある程度多量に塗布しても、マイクロレンズ形成部５以外の部分にマイクロレンズ形成用塗料がはみ出ることなくマイクロレンズを形成することができる。このように、本発明においては、濡れ性可変層の親液性領域と撥液性領域、すなわち図２（ｃ）では、親液性領域とされたマイクロレンズ形成部５とその他の濡れ性可変層３との濡れ性の差を大きくするすることにより、曲率の大きい焦点距離の短いマイクロレンズを容易に形成することができる。
【００８７】
また、本発明のマイクロレンズ基板上のマイクロレンズは有色のマイクロレンズとすることも可能である。このようにマイクロレンズを有色とすることにより、通常カラー液晶ディスプレイ等の用いられるカラーフィルタとしての機能およびマイクロレンズとしての機能の両機能を有することができる。したがって、得られる機能性素子を小型化、低コスト化させることが可能となるといった利点を有する。
【００８８】
このような本発明に用いられるマイクロレンズを構成する材料としては、形成時には液状であり、濡れ性可変層上に塗布可能かつその後硬化可能なものであり、さらに硬化後レンズとしての機能を有し得る電磁波等のエネルギー線に対して透過性を有する材料であれば特に限定されるものではない。このような樹脂としては、上記透過性を有する樹脂を溶媒に熔解した溶液を塗布した後溶剤を除去するようにしたもの、熱可塑性樹脂、熱硬化性樹脂、光硬化性樹脂等種々の樹脂を挙げることができるが、硬化が容易でかつ迅速であり、さらには硬化時にレンズ成形材料および基材が高温とならない点で光硬化性樹脂が好ましい。
【００８９】
このような光硬化性樹脂は、通常少なくとも１個以上の官能基を有し、光重合開始剤に硬化エネルギー線を照射することにより発生するイオンまたはラジカルによりイオン重合、ラジカル重合を行い、分子量を増加させ必要であれば架橋構造の形成を行うモノマーやオリゴマーと、光重合開始剤とを少なくとも有する樹脂組成物を硬化させたものである。ここでいう官能基とは、ビニル基、カルボキシル基、水酸基などの反応の原因となる原子団もしくは結合様式をいう。
【００９０】
このようなモノマー、オリゴマーとしては、不飽和ポリエステル型、エンチオール型、アクリル型等が挙げられ、中でも硬化速度、物性選択の幅の広さからアクリル型が好ましい。このようなアクリル型のモノマー、オリゴマーの内、単官能基のものとしては、２−エチルヘキシルアクリレート、２−エチルヘキシルＥＯ付加物アクリレート、エトキシジエチレングリコールアクリレート、２−ヒドロキシエチルアクリレート、２−ヒドロキシプロピルアクリレート、２−ヒドロキシエチルアクリレートのカプロラクトン付加物、２−フェノキシエチルアクリレート、フェノキシジエチレングリコールアクリレート、ノニルフェノールＥＯ付加物アクリレート、ノニルフェノールＥＯ付加物にカプロラクトン付加したアクリレート、２−ヒドロキシ−３−フェノキシプロピルアクリレート、テトラヒドロフルフリルアクリレート、フルフリルアルコールのカプロラクトン付加物アクリレート、アクリロイルモルホリン、ジシクロペンテニルアクリレート、ジシクロペンタニルアクリレート、ジシクロペンテニルオキシエチルアクリレート、イソボニルアクリレート、４，４−ジメチル−１，３−ジオキソランのカプロラクトン付加物のアクリレート、３−メチル−５，５−ジメチル−１，３−ジオキソランのカプロラクトン付加物のアクリレート等を挙げることができる。
【００９１】
また、アクリル型のモノマー、オリゴマーの内、多官能のものとしては、ヘキサンジオールアクリレート、ネオペンチルグリコールジアクリレート、ポリエチレングリコールジアクリレート、トリプロピレングリコールジアクリレート、ヒドロキシピバリン酸ネオペンチルグリコールエステルジアクリレート、ヒドロキシピバリン酸ネオペンチルグリコールエステルのカプロラクトン付加物ジアクリレート、１，６−ヘキサンジオールのジグリシジルエーテルのアクリル酸付加物、ヒドロキシピバルアルデヒドとトリメチロールプロパンのアセタール化合物のジアクリレート、２，２−ビス［４−（アクリロイロキシジエトキシ）フェニル］プロパン、２，２−ビス［４−（アクリロイロキシジエトキシ）フェニル］メタン、水添ビスフェノールエチレンオキサイド付加物のジアクリレート、トリシクロデカンジメタノールジアクリレート、トリメチロールプロパントリアクリレート、ペンタエリスリトールトリアクリレート、トリメチロールプロパンプロピレンオキサイド付加物トリアクリレート、グリセリンプロピレンオキサイド付加物トリアクリレート、ジペンタエリスリトールヘキサアクリレートペンタアクリレート混合物、ジペンタエリスリトールのカプロラクトン付加物アクリレート、トリス（アクリロイロキシエチル）イソシアヌレート、２−アクリロイロキシエチルホスフェート等を挙げることができる。
【００９２】
さらに、上記光重合開始剤としては、アセトフェノン系、ベンゾフェノン系、ミヒラーケトン系、ベンジル系、ベンゾイン系、ベンゾインエーテル系、ベンジルジメチルケタール系、ベンゾインベンゾエート系、α−アシロキシムエステル系等のカルボニル化合物、テトラメチルチウラムモノサルファイド、チオキサントン類等のイオウ化合物、２，４，６−トリメチルベンゾイルジフェニルフォスフィノキシド等のリン系化合物を挙げることができる。
【００９３】
その他必要に応じて脂肪族アミン、芳香族アミン等の光開始助剤、チオキサンソン等の光鋭感剤等を添加しても良い。
【００９４】
また、熱可塑性樹脂としては、特に可視光域に透明性が高く、屈折率、分散特性、複屈折率などの光学的特性に優れたものが好ましい。具体的には、ポリカーボネート、ポリメチルメタクリレート、メチルフタレート単独重合体または共重合体、ポリエチレンテレフタレート、ポリスチレン、ジエチレングリコール、ビスアリルカーボネート、アクリロニトリル・スチレン共重合体、メチルメタクリレート・スチレン共重合体、ポリ（−４−メチルペンテン−１）等を挙げることができる。
【００９５】
さらに、上述したように本発明のマイクロレンズ基板上のマイクロレンズを有色化することも可能であるが、この有色化に際して用いられる着色剤としては、染料、無機顔料、有機顔料等を挙げることができ、通常有色フィルタに用いられている着色剤であれば特に限定されるものではない。本発明においては、中でも高い濃度を与えることができ、レンズ硬化時や、マイクロレンズ基板としての使用時に退色の起きにくい材料が好ましい。
【００９６】
具体的な着色剤としては、染料としては、アゾ系染料、アントラキノン系染料、インジゴイド系染料、フタロシアニン系染料、カルボニウム系染料、キノンイミン系染料、メチン系染料、キノリン系染料、ニトロ系染料、ベンゾキノン系染料、ナフトキノン系染料、ナフタルイミド系染料、ペリノン系染料、ピリリウム系染料、チアピリリウム系染料、アズレニウム系染料、スクアリリウム塩系染料等を挙げることができる。また、顔料としては、ジアントラキノン、ハロゲン化銅フタロシアニン、銅フタロシアニン、その他フタロシアニン系顔料、ペリレン系顔料、ピラントロン系顔料等の多環キノン系顔料、インジゴ系顔料、キナクリドン系顔料、ピロール系顔料、ピロロピロール系顔料、アゾ系顔料等の有機系顔料を挙げることができる。
【００９７】
（基板）
本発明のマイクロレンズ基板に用いられる基板は、マイクロレンズ基板の用途によりその材質は大きく異なるものである。例えば、液晶ディスプレイや撮像素子等に用いられる場合は、基板もマイクレンズ同様に可視光等に対する透明性を求められるので、透明基板である必要がある。一方、マイクロレンズ基板を鋳型として用いる場合や、マイクロレンズ基板に対して光等を透過させて用いるのではなく反射させて用いる場合等においては、透明基板である必要はない。
【００９８】
このように、本発明に用いられる基板は、その用途に応じて、金属材料、半導体材料、有機材料等種々のものを用いることが可能である。しかしながら、現在、最も一般的なマイクロレンズ基板の用途が、液晶ディスプレイ、撮像素子等のマイクロレンズ基板に対して光を透過させて用いるケースが多いことから、本発明においては、基板が透明基板であることが好ましい。
【００９９】
このような透明基板としては、特に限定されるものでなく、可視光を透過できる材料であれば、無機材料であっても有機材料であってもよい。中でも好ましい材料としては、ソーダガラス、石英ガラス、光学ガラス（例えば、ＨＯＹＡ（株）製、ＢＳＣ７（商品名）等）、電子工学用ガラス（無アルカリガラス等）、透光性セラミックス、ポリカーボネート、メチルメタクリレート単重合体または共重合体、ポリエチレンテレフタレート、ポリスチレンなどのプラスチックフィルム、プラスチックシート等を挙げることができる。
【０１００】
本発明における上記基板の厚みは特に限定さえるものではなく、マイクロレンズ基板の用いられる用途に応じた厚みとすることができる。
【０１０１】
（遮光部）
本発明のマイクロレンズ基板には、必要に応じて遮光部を設けてもよい。この遮光部は、通常レンズ周囲の不要な光線がレンズに入射しないように設けられるものである。この遮光部について図３および図４を用いて説明する。
【０１０２】
図３は、本発明のマイクロレンズ基板のマイクロレンズが設けられた面と反対側の面に遮光部を設けた例を示すものである。図３に示すマイクロレンズ基板１は、図１に示すマイクロレンズ基板と同様に基板２上に濡れ性可変層３を設け、濡れ性可変層３中に親液性領域としたマイクロレンズ形成部５を形成し、ここにマイクロレンズ４を設けたものである。図３に示すマイクロレンズ基板１には、さらにこのマイクロレンズ４が形成された面と反対側の面に遮光部６が形成されている。図３に示す例において、遮光部６はマイクロレンズ４が形成された面と同様に濡れ性可変層３が設けられ、その濡れ性可変層３中に親液性領域とした遮光部形成部７を形成し、ここに遮光部６を設けたものである。
【０１０３】
このような遮光部４は、図４に示すようにマイクロレンズ４で収束された光の透過部分のみ開口部とするように形成されてもよく、この例ではマイクロレンズ４の中央部に相当する部位を開口部８としている。
【０１０４】
本発明のマイクロレンズ基板において、遮光部を形成する位置は特に限定されるものではないが、図３および図４に示すように、基板のマイクロレンズが形成された面と反対側の面に形成されることが好ましい。
【０１０５】
本発明における遮光部は、例えばスパッタリング法等によりクロム等の金属薄膜を形成し、これをパターニングする方法等の従来の方法で設けられてもよいが、例えば上記図３に示すように透明基板上に濡れ性可変層、好ましくは光触媒含有層を設け、その濡れ性の変化を利用して形成するようにしてもよい。
【０１０６】
本発明の遮光部を形成する材料としては、上述したようなクロム等の金属、樹脂バインダ中にカーボン微粒子、金属酸化物、無機顔料、有機顔料等の遮光性粒子を含有させた有機材料等を挙げることができる。このような樹脂バインダとしては、ポリイミド樹脂、アクリル樹脂、エポキシ樹脂、ポリアクリルアミド、ポリビニルアルコール、ゼラチン、カゼイン、セルロース等の樹脂を１種または２種以上混合したものや、感光性樹脂、さらにはＯ／Ｗエマルジョン型の樹脂組成物、例えば、反応性シリコーンをエマルジョン化したもの等を用いることができる。
【０１０７】
Ｂ．マイクロレンズ基板の製造方法について
次に、本発明のマイクロレンズ基板の製造法について詳しく説明する。本発明のマイクロレンズ基板の製造方法は、
（１）基板上にエネルギー照射により照射部分の濡れ性が液体との接触角が低下する方向に変化する光触媒含有層を設ける工程と、
（２）上記基板上に設けられた光触媒含有層上のマイクロレンズを形成する部位であるマイクロレンズ形成部に、エネルギーをパターン照射してマイクロレンズ用露光部を形成する工程と、
（３）このマイクロレンズ用露光部にマイクロレンズ形成用塗料を塗布し、マイクロレンズを形成する工程と
を有するものである。
【０１０８】
まず、第１の工程である光触媒含有層を設ける工程について説明する。この光触媒含有層の形成は、上述したような光触媒とバインダとを必要に応じて他の添加剤とともに溶剤中に分散して塗布液を調製し、この塗布液を塗布した後、加水分解、重縮合反応を進行させてバインダ中に光触媒を強固に固定することにより形成される。使用する溶剤としては、エタノール、イソプロルパノール等のアルコール系の有機溶剤が好ましく、塗布はスピンコート、スプレーコート、ディップコート、ロールコート、ビードコート等の公知の塗布方法により行うことかできる。また、結合剤として、紫外線硬化型の成分を含有している場合には、紫外線を照射して硬化処理を行うことにより、基材上に光触媒含有層を形成することができる。
【０１０９】
次に第２の工程である、マイクロレンズ用露光部の形成工程について説明する。第１の工程により基材上に光触媒含有層が形成され、この光触媒含有層にエネルギーを照射してマイクロレンズ用露光部を形成するのであるが、このマイクロレンズ用露光部の形成部位の形状、配置等は、上述したマイクロレンズが形成される部位・配置等と同様であるのでここでの説明は省略する。
【０１１０】
本発明において照射されるエネルギーとしては、紫外光を含む光を用いることができる。このような紫外光を含む光源としては、例えば、水銀ランプ、メタルハライドランプ、キセノンランプ等を挙げることができる。この露光に用いる光の波長は４００ｎｍ以下の範囲、好ましくは３８０ｎｍ以下の範囲から設定することができ、また、露光に際しての光の照射量は、露光された部位が光触媒の作用により親液性を発現するのに必要な照射量とすることができる。
【０１１１】
エネルギーの照射に際してパターン照射が必要な場合は、上述したような光源を用い、フォトマスクを介したパターン照射により行うことができるが、他の方法として、エキシマ、ＹＡＧ等のレーザーを用いてパターン状に描画照射する方法を用いることも可能である。しかしながら、このような方法は、装置が高価、取り扱いが困難、さらには連続出力ができない等の問題を有する場合がある。
【０１１２】
したがって、本発明においては、光触媒含有層に対し、光触媒反応開始エネルギーを加え、この光触媒反応開始エネルギーが加えられた領域内に反応速度増加エネルギーをパターン状に加えることにより親液性領域のパターンを形成するようにしてもよい。このようなエネルギーの照射方法を用いてパターンを形成することにより、パターン形成に際して、赤外線レーザ等の比較的安価で取り扱いが容易である反応速度増加エネルギーを用いることができ、これにより上述したような問題が生じないからである。
【０１１３】
このようなエネルギーを加えることにより濡れ性の変化した親液性領域のパターンが形成できるのは、以下の理由による。すなわち、まずパターンを形成する領域に対して光触媒反応開始エネルギーを加えることにより、光触媒含有層に対する光触媒の触媒反応を開始させる。そして、この光触媒反応開始エネルギーが加えられた領域内に、反応速度増加エネルギーを加える。このように反応速度増加エネルギーを加えることにより、既に光触媒反応開始エネルギーが加えられ、光触媒の触媒作用により反応が開始されている光触媒含有層内の反応が、急激に促進される。そして所定の時間、反応速度増加エネルギーを加えることにより、特性変化層内の特性の変化を所望の範囲まで変化させ、反応速度増加エネルギーが加えられたパターンを濡れ性の変化した親液性領域のパターンとすることができるのである。
【０１１４】
ここで、まず上記光触媒反応開始エネルギーについて説明する。このエネルギー照射方法に用いられる光触媒反応開始エネルギーとは、光触媒が光触媒含有層中の化合物に対して、その特性を変化させるための触媒反応を開始させるエネルギーをいう。
【０１１５】
ここで加える光触媒反応開始エネルギーの量は、光触媒含有層中の濡れ性の変化を急激に生じない程度の量である。加えられる光触媒反応開始エネルギーの量が少ない場合は、反応速度増加エネルギーを加えてパターンを形成する際の感度が低下するため好ましくなく、またこの量が多すぎると、光触媒反応開始エネルギーを加えた光触媒含有層の特性の変化の度合いが大きくなりすぎて、反応速度増加エネルギーを加えた領域との差異が不明確となってしまうため好ましくない。この加えるエネルギーの量に関しては、予めエネルギーを加える量と光触媒含有層中の濡れ性の変化量との予備実験等を行うことにより決定される。
【０１１６】
この方法における光触媒反応開始エネルギーとしては、光触媒反応を開始させることができるエネルギーであれば特に限定されるものではないが、中でも光であることが好ましい。
【０１１７】
本発明において用いられる光触媒は、そのバンドギャップによって触媒反応を開始する光の波長が異なる。例えば、硫化カドニウムであれば４９６ｎｍ、また酸化鉄であれば５３９ｎｍの可視光であり、二酸化チタンであれば３８８ｎｍの紫外光である。したがって、光であれば可視光であれ紫外光であれ本発明で用いることができる。しかしながら、上述したようにバンドギャップエネルギーが高いため光触媒として有効であり、かつ化学的にも安定で毒性もなく、入手も容易といった理由から光触媒としては二酸化チタンが好適に用いられる関係上、この二酸化チタンの触媒反応を開始させる紫外光を含む光であることが好ましい。具体的には、４００ｎｍ以下の範囲、好ましくは３８０ｎｍ以下の範囲の紫外光が含まれることが好ましい。
【０１１８】
このような紫外光を含む光の光源としては、水銀ランプ、メタルハライドランプ、キセノンランプ、エキシマランプ等の種々の紫外線光源を挙げることができる。
【０１１９】
本発明においては、この光触媒反応開始エネルギーが加えられる範囲は、光触媒含有層の一部分であってもよく、例えばこの光触媒反応開始エネルギーをパターン状に加え、さらに後述する反応速度増加エネルギーもパターン状に加えることにより、濡れ性が変化した親液性領域のパターンを形成することも可能であるが、工程の簡略化、単純化等の理由から、この光触媒反応開始エネルギーをパターンを形成する領域全面にわたって加えることが好ましく、このように全面にわたって光触媒反応開始エネルギーが加えられた領域に反応速度増加エネルギーをパターン状に加えることにより、光触媒含有層上に親液性領域のパターンを形成するようにすることが好ましい。
【０１２０】
次に、この方法に用いられる反応速度増加エネルギーについて説明する。この方法に用いられる反応速度増加エネルギーとは、上記光触媒反応開始エネルギーによって開始された光触媒含有層の濡れ性を変化させる反応の反応速度を増加させるためのエネルギーをいう。本発明においては、このような作用を有するエネルギーであればいかなるエネルギーであっても用いることができるが、中でも熱エネルギーを用いることが好ましい。
【０１２１】
このような熱エネルギーをパターン状に光触媒含有層に加える方法としては、光触媒含有層上に熱によるパターンが形成できる方法であれば特に限定されるものではないが、赤外線レーザによる方法や感熱ヘッドによる方法等を挙げることができる。このような赤外線レーザとしては、例えば指向性が強く、照射距離が長いという利点を有する赤外線ＹＡＧレーザ（１０６４ｎｍ）や、比較的安価であるという利点を有するダイオードレーザ（ＬＥＤ；８３０ｎｍ、１０６４ｎｍ、１１００ｎｍ）等の他、半導体レーザ、Ｈｅ−Ｎｅレーザ、炭酸ガスレーザ等を挙げることができる。
【０１２２】
この方法においては、上述した光触媒反応開始エネルギーを加えることにより、光触媒を活性化させて光触媒含有層内の触媒反応による濡れ性の変化を開始させ、この濡れ性の変化が生じた部分に反応速度増加エネルギーを加えてその部分の触媒反応を促進させることにより、反応速度増加エネルギーが加えられた領域と、加えられなかった領域との反応速度の差により、親液性領域のパターンを形成することができる。
【０１２３】
最後に、基板上にマイクロレンズを形成する第３の工程について説明する。この工程で用いられるマイクロレンズ形成用塗料とは、上述したマイクロレンズの材料が含まれている塗料であり、マイクロレンズ用露光部（マイクロレンズ形成部）に塗布することが可能であり、その後硬化することにより、マイクロレンズとしての機能を有するものであれば特に限定されるものではない。マイクロレンズが光硬化性樹脂からなるものである場合、このマイクロレンズ形成用塗料の形態としては、モノマーと光重合開始剤とが溶解または分散している液体、オリゴマーと光重合開始剤とが溶解または分散している液体、モノマーおよびオリゴマーと光重合開始剤とが溶解もしくは分散している液体等を挙げることができる。また、マイクロレンズが上述したような有色マイクロレンズである場合は、上記マイクロレンズ形成用塗料に上述した着色剤を混合した材料が用いられる。
【０１２４】
このようなマイクロレンズ形成用塗料のマイクロレンズ用露光部（マイクロレンズ形成部）への塗布方法は、特に限定されるものではないが、具体的には、ディップコーティング、ロールコーティング、ビードコーティング、スピンコーティング、エアドクターコーティング、ブレードコーティング、ナイフコーティング、ロッドコーティング、グラビアコーティング、ロータリースクリーンコーティング、キスコーティング、スロットオリフィスコーティング、スプレーコーティング、キャストコーティング、押出コーティングなどの方法を用いることができ、これらは短時間に大量のマイクロレンズを形成することができる点で好ましい。
【０１２５】
また、本発明においては、上記マイクロレンズ形成用塗料をマイクロレンズ用露光部に塗布する際して、ノズル吐出による方法を用いてもよい。このようなノズル吐出方法としては、例えばマイクロシリンジ、ディスペンサー、インクジェット、針先よりマイクロレンズ形成用塗料を電界などの外部刺激により飛ばす方法、外部刺激により振動するピエゾ素子などの振動素子を用いて素子よりマイクロレンズ形成用塗料を飛ばす方法、針先に付着させたマイクロレンズ形成用塗料を基材表面に付着させる方法等を用いることができる。これらは接触角が大きく高さの高いレンズ形状物を形成する場合に好適である。
【０１２６】
本発明では、上述した塗布方法の中でも、塗布の正確性および迅速性等の観点からインクジェット方式でマイクロレンズ用塗料が塗布されることが好ましい。この場合用いられるインクジェット装置としては、特に限定されるものではないが、帯電したインクを連続的に噴射し磁場によって制御する方法、圧電素子を用いて間欠的にインクを噴射する方法、インクを加熱しその発泡を利用して間欠的に噴射する方法等の各種の方法を用いたインクジェット装置を用いることができる。
【０１２７】
このインクジェット方式でのマイクロレンズ形成用塗料の塗布は、マイクロレンズ形成用塗料に着色剤が混合された有色マイクロレンズ形成用塗料の場合にも有効である。
【０１２８】
このようにしてマイクロレンズ用露光部内に塗布されたマイクロレンズ形成用塗料を硬化させることによりマイクロレンズが基板上に形成され、マイクロレンズ基板が形成される。本発明において、マイクロレンズ形成用塗料の硬化は用いる原料の種類により種々の方法により行われる。例えば、溶剤に溶解した塗料であれば加熱等することにより溶剤を除去して固化が行われる。
【０１２９】
このマイクロレンズ形成用塗料の硬化工程を考慮すると、本発明に用いられるマイクロレンズの材料の種類としては、光硬化性樹脂であることが好ましい。これは、光硬化性樹脂を用いたマイクロレンズ形成用塗料でであれば光を照射することにより、素早くマイクロレンズ形成用塗料を硬化することができるので、マイクロレンズ基板の製造時間を短縮することができるからである。
【０１３０】
上述したように、マイクロレンズ用露光部内に塗布されたマイクロレンズ形成用塗料は均一に広がっているため、このようなマイクロレンズ形成用塗料を硬化させてマイクロレンズを形成した場合、マイクロレンズの曲率が一定であり、位置精度も良好であるマイクロレンズ基板を形成することができる。
【０１３１】
Ｃ．液晶ディスプレイについて
本発明のマイクロレンズ基板は、目視者方向への輝度を高めるために、例えば液晶ディスプレイ等のディスプレイに隣接または密着する部品として用いることができる。この場合、室内照明や太陽光などの周囲の外光の影響を抑え、表示画質を向上させるために遮光部を設けてもよい。また、光の透過性を高めるため、もしくは光の干渉による発色を防止する等の目的から、濡れ性可変層、好ましくは光触媒含有層の肉厚を薄くすることが好ましい。具体的には、１μｍ以下、より好ましくは０．２μ以下である。
【０１３２】
図５は、本発明のマイクロレンズ基板を用いた液晶ディスプレイの一例を示すものである。この液晶ディスプレイは、アレイ側基板９と液晶部１０とカラーフィルタ１１とからなる液晶ディスプレイ部１２のカラーフィルタ１１側面に、マイクロレンズ基板１が配置されてなるものである。このマイクロレンズ基板１は、カラーフィルタ１１の画素部との位置が一致するように基板２上に各マイクロレンズ４が形成されたものであり、これらマイクロレンズ４がカラーフィルタ１１側となるように配置されている。このマイクロレンズ基板１には、上述したように外光の影響を抑え、表示画質を向上させるために遮光部６が形成されている。このような液晶ディスプレイにおいて、液晶ディスプレイ部１２で発生した光は、本発明のマイクロレンズ基板１を通過して外部に発光１３として発せられ、マイクロレンズの作用により目視者への輝度が高められる。
【０１３３】
本発明のマイクロレンズ基板を用いた液晶ディスプレイは、品質が良好でかつコスト的に有利なマイクロレンズ基板を用いているので、液晶ディスプレイとしての品質も良好でありかつ低コストの液晶ディスプレイとすることができるという利点を有するものである。
【０１３４】
Ｄ．撮像素子について
本発明のマイクロレンズ基板は、撮像装置の光感度を高めるために例えばＣＣＤといった撮像素子に隣接もしくは密着する部品として用いることができる。この場合、好ましくは迷光によるコントラストの低下等といった特性への悪影響を避ける等の理由により、遮光部を設けることが好ましい。また上記液晶ディスプレイの場合と同様に、濡れ性可変層、好ましくは光触媒含有層の肉厚を薄くすることが好ましく、具体的な肉厚としては、１μｍ以下、より好ましくは０．２μ以下である。
【０１３５】
図６は、本発明のマイクロレンズ基板を用いた撮像素子の一例を示すものである。この撮像素子は、有色フィルタ１４および光電変換素子１５からなる撮像素子部１６の有色フィルタ１４側面にマイクロレンズ基板１が配置されてなるものである。このマイクロレンズ基板１は、有色フィルタ１４側に遮光部６が配置され、この遮光部６が形成された基板２の反対側の面にマイクロレンズ４が形成されている。入射光１７は、マイクロレンズ基板１のマイクロレンズ４を経て撮像素子部１６に入るので、撮像素子の光感度を高めることができる。
【０１３６】
本発明のマイクロレンズ基板を用いた撮像素子は、品質が良好でかつコスト的に有利なマイクロレンズ基板を用いているので、撮像素子としての品質も良好でありかつ低コストの撮像素子とすることができる。
【０１３７】
なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
【０１３８】
【実施例】
以下、本発明について、実施例を通じてさらに詳述する。
【０１３９】
（実施例１／光触媒含有層の形成）
イソプロピルアルコール３ｇ、オルガノシラン（東芝シリコーンＴＳＬ８１１３）０．４ｇ、フルオロアルコキシシランＭＦ−１６０Ｅ（トーケムプロダクツ）０．３ｇ、光触媒無機コーティング剤ＳＴ−Ｋ０１（石原産業）２ｇを混合した。この溶液をスピンコーティング法により、石英ガラス製透明基板上に塗布した。そして１５０℃の温度で１０分間乾燥することにより、加水分解、重縮合反応を進行させ、光触媒がオルガノポリシロキサン中に強固に固定された膜厚０．２μｍの透明な層を得ることができた。この光触媒含有層上に水銀ランプにより７０ｍＷ／ｃｍ²の照度で５０秒問、マスクを介してパターン露光した。
【０１４０】
非露光部および露光部の液体との接触角を測定した結果、非露光部においては表面張力３０ｍＮ／ｍの液体（純正化学株式会社製、エチレングリコールモノエチルエーテル）との接触角を接触角測定器（協和界面科学株式会社製 ＣＡ−Ｚ型）を用いて測定（マイクロシリンジから液滴を滴下して３０秒後）した結果、３２度であり、露光部では表面張力５０ｍＮ／ｍの液体（純正化学株式会社製ぬれ標準試薬液Ｎｏ．５０）との接触角を同様に測定した結果、７度であった。
露光部、非露光部で濡れ性が異なるパターンが形成された。
【０１４１】
（実施例２／マイクロレンズのコーティングによる形成）
石英ガラス製の透明基板上に、実施例１に記載の光触媒含有層形成用材料を用い、スピンコーティング法にて光触媒含有層を形成した。これに開口部直径５０μｍの円形パターンが２μｍ間隔で複数個並んだ、ネガ型フォトマスクを介して、水銀ランプにより７０ｍＷ／ｃｍ²の照度で９０秒間露光し、表面に親液性領域からなる円形パターンが形成された透明基板を得た。
【０１４２】
紫外線硬化型モノマー（ＰＯ変性グリセリントリアクリレート：荒川化学工業社製、商品名：ビームセット７２０）１０００ｇ、硬化開始剤（チバスペシャリティケミカルズ社製、商品名：イルガキュア１８４）５０ｇを混合し、３分間攪拌した。得られた混合液（マイクロレンズ形成用塗料）をビードコーティング法（スライドコーティング法）にて、上記の濡れ性の異なる円形パターンが施された透明基板上に、膜厚１２μｍにて塗布したところ、露光部分（円形パターン部分）のみに混合液が付着した。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で５秒間露光することにより、直径５０μｍ、焦点距離１ｍｍのマイクロレンズアレイを有するマイクロレンズ基板を得ることができた。
【０１４３】
（実施例３／マイクロレンズの吐出法による形成）
石英ガラス製の透明基板上に、実施例１に記載の光触媒含有層形成用材料を用い、スピンコーティング法にて光触媒含有層を形成した。これに開口部直径２００μｍの円形パターンが１００μｍ間隔で複数個並んだ、ネガ型フォトマスクを介して、水銀ランプにより７０ｍＷ／ｃｍ²の照度で９０秒間露光し、表面に親液性領域の円形パターンが形成された透明基板を得た。
【０１４４】
紫外線硬化型モノマー（ＰＯ変性グリセリントリアクリレート：荒川化学工業社製、商品名：ビームセット７２０）１０００ｇ、硬化開始剤紫外線硬化型モノマー（ＰＯ変性グリセリントリアクリレート：荒川化学工業社製、商品名：ビームセット７２０）１０００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：イルガキュア１８４）５０ｇを混合し、３分間攪拌した。得られた混合液（マイクロレンズ形成用塗料）を液体精密定量吐出装置（ＥＦＤ社製ディスペンサー、１５００ＸＬ−１５）にて、上記の濡れ性の異なる円形パターンが施された透明基板上の円形パターン部分の中心に０．０００１ｍｌ吐出した。このとき吐出液（マイクロレンズ形成用塗料）は円形パターン部のみに広がり、それ以外の部分に広がることは無かった。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光することにより、直径２００μｍ、焦点距離５００μｍのマイクロレンズアレイを有するマイクロレンズ基板を得ることができた。
【０１４５】
（実施例４／有色マイクロレンズの吐出法による形成）
石英ガラス製の透明基板上に実施例１に記載の光触媒含有層形成用材料を用いスピンコーティング法にて光触媒含有層を形成した。これに開口部直径２００μｍの円形パターンが１００μｍ間隔で複数個並んだネガ型フォトマスクを介して水銀ランプにより７０ｍＷ／ｃｍ²の照度で９０秒間露光し、表面に親液性領域からなる円形パターンが形成された透明基板を得た。
【０１４６】
次いで、紫外線硬化型モノマー（２官能アクリレートモノマー、日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）５００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、赤色染料（東京化成社製、ローズベンガル）０．５ｇを混合し、３分間攪拌し、赤色用のマイクロレンズ形成用塗料を得た。
【０１４７】
また、紫外線硬化型モノマー（２官能アクリレートモノマー、日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）５００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、緑色染料（東京化成社製、ビリリアントグリーン）０．５ｇを混合し、３分間攪拌し、緑色用のマイクロレンズ形成用塗料を得た。
【０１４８】
さらに、紫外線硬化型モノマー（２官能アクリレートモノマー、日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）５００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、青色染料（東京化成社製、ヴィクトリアブルー）０．５ｇを混合し、３分間攪拌し、青色用のマイクロレンズ形成用塗料を得た。
【０１４９】
得られたマイクロレンズ形成用塗料を液体精密吐出装置（ＥＦＤ製ディスペンサー、１５００ＸＬ−１５）にて、上記の濡れ性の異なる円形パターンが施された透明基板上の円形パターン部分の中心に０．０００１ｍｌ吐出した。この時、吐出液（マイクロレンズ形成用塗料）は円形パターン部のみに広がり、それ以外の部分に広がることはなかった。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光することにより、直径２００μｍ、焦点距離５００μｍの有色マイクロレンズアレイを有するマイクロレンズ基板を得た。
【０１５０】
（実施例５／有色マイクロレンズのコーティングによる形成）
石英ガラス製透明基板上に実施例１記載の光触媒含有層形成用材料を用いてスピンコーティング法にて光触媒含有層を形成した。これに開口部直径２００μｍの円形パターンが縦方向に１００μｍ間隔、横方向に７００μｍ間隔で複数個並んだネガ型フォトマスクを介して、水銀ランプにより７０ｍＷ／ｃｍ²の照度で９０秒間露光し、表面に親液性領域である円形パターンが施された透明基板を得た。
【０１５１】
次いで、紫外線硬化型モノマー（２官能アクリレートモノマー：日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）４００ｇ、紫外線硬化型モノマー（１，６ヘキサンジオールジアクリレート、日本化薬社製、商品名：ＫＳ−ＨＤＤＡ）１００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、赤色染料（東京化成社製、ローズベンガル）０．５ｇを混合し、３分間攪拌し、赤色用マイクロレンズ形成用塗料を得た。
【０１５２】
また、紫外線硬化型モノマー（２官能アクリレートモノマー：日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）４００ｇ、紫外線硬化型モノマー（１，６ヘキサンジオールジアクリレート、日本化薬社製、商品名：ＫＳ−ＨＤＤＡ）１００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、緑色染科（東京化成社製ビリリアントグリーン）０．５ｇを混合し、３分間攪拌し、緑色用マイクロレンズ形成用塗料を得た。
【０１５３】
さらに、紫外線硬化型モノマー（２官能アクリレートモノマー：日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）４００ｇ、紫外線硬化型モノマー（１，６ヘキサンジオールジアクリレート、日本化薬社製、商品名：ＫＳ−ＨＤＤＡ）１００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇ、青色染料（東京化成社製、ヴィクトリアブルー）０．５ｇを混合し、３分間攪拌し、青色用マイクロレンズ形成用塗料を得た。
【０１５４】
得られた赤色用マイクロレンズ形成用塗料を、ディップコーティング法にて、上記の濡れ性の異なる円形パターンが施された透明基板上に１２μｍにて塗布したところ、露光部分（円形パターン部分、親液性領域）のみに塗料が付着した。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光することにより硬化させた。
【０１５５】
この赤色マイクロレンズを形成した透明基板上に上記と同様にして光触媒含有層を形成し、赤色レンズの縦方向の列から１００μｍの間隔をおいて上記と同様の条件で親液性領域の円形パターンを形成した。緑色用マイクロレンズ形成用塗料を用い、赤色と同様の操作を行なうことで緑色マイクロレンズを形成した。
【０１５６】
青色用マイクロレンズ形成用塗料を用いて同様の操作を行ない、赤と緑のマイクロレンズの縦の列の間に１００μｍの間隔をおいて青色マイクロレンズを形成し、直径２００μｍ、焦点距離１ｍｍの有色マイクロレンズアレイを有するマイクロレンズ基板を得た。
【０１５７】
（実施例６／遮光部のコーティングによる形成）
直径１００μｍであって、１０μｍ間隔に並んだマイクロレンズアレイを有する本発明のマイクロレンズ基板（基板：石英ガラス）の裏面に、実施例１記載の光触媒含有層形成用材料を用いて光触媒含有層を形成した。次いで、開口部直径１０μｍであって、１００μｍの間隔で並んだフォトマスクとレンズとの位置合わせを行った後、水銀ランプによりパターン露光を行った。
【０１５８】
次いで、紫外線硬化型モノマー（２官能アクリレートモノマー、日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）５００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇの混合液にカーボンブラックを１００ｇ分散し、遮光部形成用組成物を調製した。この遮光部形成用組成物を、ブレードコーターによりパターン露光された光触媒含有層上に全面塗布すると、非露光部はハジキ、露光部のみに選択的に付着した。次いで、１５０℃で３０分間加熱して、遮光部を形成し、遮光部を有するマイクロレンズ基板を得た。
【０１５９】
（実施例７／遮光部の吐出法による形成）
直径７００μｍであって１０μｍ間隔に並んだマイクロレンズアレイを有する本発明のマイクロレンズ基板（基板：石英ガラス）の裏面に、実施例１記載の光触媒含有層用材料を用いて光触媒含有層を形成した。次いで、開口部直径１０μｍであって７００μｍの間隔で並んだフォトマスクを介して、レンズとの位置合わせ後、水銀ランプによりパターン露光を行った。
【０１６０】
次いで、ディスペンサー（ＥＦＤ社製）により露光部へ実施例６記載の遮光部形成用組成物を吐出することにより、遮光部形成用組成物を露光部にのみ付着させた。次いで、１５０℃で３０分間加熱して、遮光部を有するマイクロレンズ基板を得た。
【０１６１】
（実施例８／マイクロレンズの吐出量による焦点距離の変化）
石英ガラス製透明基板上に実施例１に記載の光触媒含有層形成用材料を用い、スピンコーティング法にて光触媒含有層を形成した。これに開口部直径９ｍｍの円形パターンをもつマスクを介して水銀ランプにより７０ｍＷ／ｃｍ²の照度で９０秒間露光し、表面に親液性領域である円形パターンが施された透明基板を得た。
【０１６２】
紫外線硬化型モノマー（２官能アクリレートモノマー、日本化薬社製、商品名：ＫＡＹＡＲＡＤＰＥＧ４００ＤＡ）５００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：ダロキュア１１７３）２５ｇを混合し、３分間攪拌した。得られたマイクロレンズ形成用塗料をマイクロシリンジにて、上記の濡れ性の異なる円形パターンが施された透明基板上の円形パターン部分の中心に１５〜５５μＬ吐出した。このとき吐出液（マイクロレンズ形成用塗料）は円形パターン部のみに広がりそれ以外の部分に広がることは無く、また滴下量が多いほど基板との接触角が大きくなった。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光することにより、直径９ｍｍ、焦点距離２７〜９０ｍｍのレンズを、樹脂混合液（マイクロレンズ形成用塗料）の吐出量を制御することにより設計、作成することができた。結果を表１に示す。
【０１６３】
【表１】

【０１６４】
（比較例）
比較のために上記樹脂混合液を、光触媒含有層を持たない石英ガラス製透明基板（濡れ性のパターンを有していない基板）上に１５〜５５μＬ吐出した。このとき吐出液は吐出量が多くなるほど濡れ広がり、その形状も安定せず様々な形となった。基板との接触角も吐出量に従って変化することは無かった。これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光したが、得られたレンズ形状物は形状、直径、焦点距離が制御されたものではなかった。樹脂溶液（マイクロレンズ形成用塗料）滴下量と基板との接触角、生成されたレンズ形状物の直径および焦点距離の関係を表２に示す。
【０１６５】
【表２】

【０１６６】
表１および表２から明らかなように、実施例８のマイクロレンズはマイクロレンズ形成用塗料の滴下量によりマクロレンズの基材との接触角が変化し、焦点距離もこれにともなって変化したが、比較例のマイクロレンズにはそのような傾向がなく、マイクロレンズ形成用塗料の滴下量が増加すると形成されたレンズの半径が大きくなっていた。
【０１６７】
（実施例９）
石英ガラス透明基板上に、実施例１に記載の光触媒含有層形成用材料を用い、スピンコーティング法にて光触媒含有層を形成した。
【０１６８】
上記光触媒含有層を、高圧水銀ランプにて２５ｍＷ／ｃｍ²（３６５ｎｍ）の照度にて４０秒間照射し、これを照射したまま照射波長８３０ｎｍの半導体レーザにてパターン状に照射した。半導体レーザのパターン照射は、マイクロレンズアレイ形成用ＣＡＤデータに基づき、ガルバノメータを用いて行われた。このとき、半導体レーザ照射面の温度は５０℃であった。照射表面における表面張力５０ｍＮ／ｍの液体（純正化学株式会社製、ぬれ標準試薬液Ｎｏ．５０）との接触角を接触角測定器（協和界面科学株式会社製、ＣＡ−Ｚ型）を用いて測定（マイクロシリンジから液滴を滴下して３０秒後）した結果、７度であった。
【０１６９】
紫外線硬化型モノマー（ＰＯ変成グリセリントリアクリレート、荒川化学工業社製、商品名：ビームセット７２０）１０００ｇ、光重合開始剤（チバスペシャリティケミカルズ社製、商品名：イルガキュア１８４）５０ｇ、を混合し、３分間攪拌し、マイクロレンズ形成用塗料を作製した。
【０１７０】
得られたマイクロレンズ形成用塗料を液体精密吐出装置（ＥＦＤ製ディスペンサー、１５００ＸＬ−１５）にて、上記のＣＡＤデータに基づき形成された濡れ性の異なる部分に、０．０００１ｍＬ吐出した。このとき、吐出液（マイクロレンズ形成用塗料）は、ＣＡＤデータに基づき形成された濡れ性の異なる部分にのみ広がり、それ以外の部分に広がることは無かった。
【０１７１】
これを水銀ランプにより７０ｍＷ／ｃｍ²の照度で１０秒間露光することにより、ＣＡＤデータにより設定された直径３０〜５０μｍの種々の底面形状を有するマイクロレンズアレイを有するマイクロレンズ基板を得た。
【０１７２】
【発明の効果】
本発明は、基板と、この基板の表面上に設けられ、濡れ性を変化させることができる濡れ性可変層と、この濡れ性可変層上に設けられた複数のマイクロレンズとを有することを特徴とするマイクロレンズ基板である。このように、本発明は、濡れ性可変層上に複数のマイクロレンズを形成する構成としたものであるので、予めマイクロレンズを設ける部分の濡れ性可変層の濡れ性を液体との接触角が小さい親液性領域とし、他の部分の濡れ性可変層を液体との接触角が大きい撥液性領域とすることができる。したがって、このマイクロレンズを設ける親液性領域の部分にマイクロレンズ形成用塗料を付着させることにより、液体との接触角の小さい親液性領域にのみマイクロレンズ形成用塗料が付着するため、基板上に精度良くマイクロレンズを形成することができる。また、マイクロレンズの焦点距離は、マイクロレンズ形成用塗料の量と、このマイクロレンズ形成用塗料が塗布される親液性領域の面積との関係で決定されるため、比較的容易に焦点距離を制御することが可能となるという効果を有する。
【図面の簡単な説明】
【図１】本発明のマイクロレンズ基板の一例を示す概略断面図である。
【図２】本発明のマイクロレンズ基板における焦点距離の調整を示す概略断面図である。
【図３】本発明のマイクロレンズ基板に遮光部を形成した例を示す概略断面図である。
【図４】図３に示すマイクロレンズ基板の遮光部が形成された面を示す概略平面図である。
【図５】本発明のマイクロレンズ基板を用いた液晶ディスプレイを示す概略断面図である。
【図６】本発明のマイクロレンズ基板を用いた撮像素子を示す概略断面図である。
【符号の説明】
１…マイクロレンズ基板
２…基板
３…濡れ性可変層
４…マイクロレンズ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microlens substrate in which a plurality of microlenses are arranged on a substrate, and particularly to a microlens substrate that is advantageous in terms of cost because it is manufactured by a simple manufacturing method, and a manufacturing method thereof. It is.
[0002]
[Prior art]
In recent years, a demand for a microlens substrate in which a microlens is disposed on a transparent substrate is increasing. For example, a color liquid crystal display (LCD) uses a color filter to make the constituent pixel portions three primary colors (R, G, B), and controls the transmission of each light of the three primary colors by electrical switching of the liquid crystal for color display. There is an advantage that power consumption is smaller than that of a plasma display or the like. In such a liquid crystal display, in order to make the display bright and clear, a so-called backlight system having an illumination light source behind has become popular in recent years. However, when an illumination light source is used, the power consumption increases, and the advantage of the liquid crystal display that the power consumption is small is impaired. For this reason, it is required to reduce the power required for the illumination light source by efficiently condensing the light from the illumination light source on the pixel portion of the color filter. A liquid crystal display using a microlens substrate is proposed (Japanese Patent Laid-Open No. 60-165623, etc.).
[0003]
In addition, color image sensors using a CCD or the like have been developed in which a microlens substrate having a microlens corresponding to each light receiving cell is disposed on the light receiving surface in order to increase the effective aperture ratio (Japanese Patent Laid-Open No. 61-61). -67003).
[0004]
Furthermore, in recent years, even in optical fibers that have been increasingly used for optical communication and the like, a microlens is used in combination when combining light (Japanese Patent Laid-Open No. 61-153602).
[0005]
As described above, the microlens substrate in which the microlens is arranged on one surface of the transparent substrate is used in various applications. The manufacturing method of this microlens is as follows: (1) A method of making a refractive index gradient type lens using the distribution of ion concentration diffused in glass (Electronics Letters Vol.17, No.13, PP452 (1981)) , (2) A method of molding the surface of plastic or glass into a lens-shaped irregularity with a mold, (3) Patterning into a planar shape of a lens using a thermoplastic resin, and then heating it above the softening point of the thermoplastic resin (4) Proximity exposure is performed on the photosensitive resin to cause blurring at the pattern edge. According to this blur, a method of obtaining a convex lens shape by giving a distribution to the amount of photoreaction products (Japanese Patent Laid-Open No. 61-153602), (5) exposure by irradiating light having a strength distribution on a photosensitive resin. Then, a method of forming a refractive index distribution pattern according to the light intensity to form a microlens (Japanese Patent Laid-Open No. 60-72927, etc.), (6) Shrinkage accompanying crystallization caused by light irradiation on the photosensitive glass is used. To form a convex lens (Applied Optics Vol.24, No.16, PP2520 (1985)), (7) When a photosensitive resin is exposed to a desired pattern using an aligner, the non-exposed area is exposed to the exposed area. Convex lens formation method using the phenomenon that unreacted monomer moves and the exposed area swells (Journal of the Japan Society of Applied Physics, Micro-Optics Research Group, Vol.5, No.2, PP118 (1987), Vol.6 , No. 2, PP87 (1988)) and the like have been proposed.
[0006]
However, in any of the manufacturing methods described above, a microlens having desired characteristics cannot be manufactured more easily, which causes a problem in terms of cost and a problem in terms of quality.
[0007]
The present invention has been made in view of the above circumstances, and since the manufacturing process is simple, it is advantageous in terms of cost, and is manufactured with high accuracy, so that the microlens substrate having good quality and such a microlens substrate can be obtained. The main object is to provide a method of manufacturing a lens substrate.
[0008]
[Means for Solving the Problems]
  To achieve the above object, the present invention provides a substrate according to claim 1, a wettability variable layer provided on the surface of the substrate and capable of changing wettability, and provided on the wettability variable layer. With multiple microlensesThe wettability variable layer is a photocatalyst-containing layer composed of at least a photocatalyst and a binder, and the wettability is changed so that the contact angle with the liquid is reduced by irradiation of energy.A microlens substrate is provided.
[0009]
  As described above, since the present invention is configured to have a plurality of microlenses on the wettability variable layer, the wettability of the wettability variable layer where the microlens is previously provided has a small contact angle with the liquid. The lyophilic region can be used, and the wettability variable layer in the other part can be a liquid repellent region having a large contact angle with the liquid. Therefore, by attaching the microlens forming paint to the portion of the lyophilic area where the microlens is provided, the microlens forming paint adheres only to the lyophilic area having a small contact angle with the liquid. The microlens can be formed with high accuracy. In addition, the focal length of the microlens is determined by the relationship between the amount of the microlens forming paint and the area of the lyophilic area (microlens forming portion) to which the microlens forming paint is applied. Thus, it becomes possible to control the focal length easily.
In addition, if a photocatalyst-containing layer whose wettability changes so that the contact angle with the liquid is reduced by energy irradiation, the wettability of this layer can be easily changed by performing energy pattern irradiation, etc. It is possible to form a lyophilic region having a small contact angle with the lyophilic region, and only a portion where the microlens is formed can be easily formed as a lyophilic region. Therefore, since the lyophilic region can be formed more easily and with higher accuracy, by forming a microlens in this lyophilic region, a more accurate microlens substrate can be obtained in a simpler process. it can.
[0010]
In the present invention, as described in claim 2, the substrate is preferably a transparent substrate. As a use of microlenses, light that is used to increase the brightness in the viewer direction in liquid crystal displays, etc., or used to increase the photosensitivity of image sensors such as CCD elements, is transmitted through the microlens substrate. There are many cases that need to be configured. Therefore, the substrate used for the microlens substrate is preferably a transparent substrate.
[0013]
  the aboveClaim 1 or claim 2In the microlens substrate described inClaim 3As described above, when the photocatalyst-containing layer contains fluorine and the photocatalyst-containing layer is irradiated with energy, the photocatalyst-containing layer has a fluorine content on the surface of the photocatalyst-containing layer as compared with that before energy irradiation. The photocatalyst-containing layer is preferably formed so as to decrease.
[0014]
As described above, the microlens substrate of the present invention is configured such that the fluorine content of the energy irradiation portion on the photocatalyst containing layer formed on the substrate is reduced. A pattern composed of a portion having a reduced content can be formed. When the fluorine content decreases, the portion becomes a region having higher lyophilicity than other portions, so that only the portion where the microlens is formed can be easily made a lyophilic region. A microlens substrate can be manufactured.
[0015]
  the aboveAny one of claims 1 to 3In the microlens substrate described inClaim 4The photocatalyst is a titanium oxide (TiO₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)_Three), Tungsten oxide (WO_Three), Bismuth oxide (Bi₂O_Three), And iron oxide (Fe₂O_ThreeIt is preferable that it is 1 type, or 2 or more types of substances selected from these. Above allClaim 5The photocatalyst is titanium oxide (TiO₂) Is preferable. This is because titanium oxide is effective as a photocatalyst because of its high band gap energy, is chemically stable, has no toxicity, and is readily available.
[0016]
  the aboveClaims 1 to 5In the microlens substrate according to any one of the preceding claims, the binder which is another component constituting the photocatalyst-containing layer isClaim 6Y as described in_nSiX_(4-n)Wherein Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group or a halogen, and n is an integer from 0 to 3. It is preferable that it is the organopolysiloxane which is a 1 type, or 2 or more types of hydrolyzed condensate or cohydrolyzed condensate of the silicon compound. This is because it is easy to introduce a fluoroalkyl group or the like that has binding energy against the catalytic action of the photocatalyst and exhibits liquid repellency, and the lyophilicity when irradiated with energy can be increased.
[0017]
  the aboveClaim 6In the microlens substrate described inClaim 7As described above, it is preferable that 0.01 mol% or more of a silicon compound containing a fluoroalkyl group is contained in the silicon compound constituting the organopolysiloxane.
[0018]
Thus, if the silicon compound containing a fluoroalkyl group is contained in an amount of 0.01 mol% or more, the surface of the photocatalyst containing layer will contain sufficient fluorine element, and energy will be irradiated to contain the fluorine element. Since the difference in wettability between the lyophilic region on the photocatalyst-containing layer whose amount has been reduced and the liquid repellent region on the surface of the photocatalyst-containing layer that has not been irradiated with energy can be increased, a microlens can be added This is because the microlens-forming paint can be accurately adhered without protruding into the liquid-repellent region, and a microlens substrate with good quality can be manufactured.
[0019]
  the aboveClaims 1 to 7In the invention described in any of the claims up to here,Claim 8(See below)Claim 9OrClaim 10In the invention described inClaim 11The contact angle with the liquid having a surface tension of 40 mN / m on the photocatalyst-containing layer is 10 degrees or more in the portion where the energy is not irradiated and less than 10 degrees in the portion where the energy is irradiated It is preferable that
[0020]
Since the portion not irradiated with energy is a portion that requires liquid repellency, when the contact angle with a liquid having a surface tension of 40 mN / m is less than 10 degrees, the liquid repellency is not sufficient, Since there is a possibility that the coating material for forming the microlens remains, it is not preferable. In addition, when the contact angle with the liquid with the surface tension of 40 mN / m in the portion irradiated with energy is 10 degrees or more, the spread of the microlens forming paint in this portion may be inferior, and the uniform curvature This is because there is a possibility that problems such as inability to form can occur.
[0021]
  From such claim 1Claim 8A liquid crystal display using the microlens substrate according to any one of the preceding claims (Claim 12) Or image sensor (Claim 13) Uses a high-quality microlens substrate obtained by a simple process, and is advantageous in terms of cost and good quality.
[0022]
  Furthermore, the present invention aims to achieve the above object.Claim 9(1) a step of providing a photocatalyst-containing layer on the substrate that changes the wettability of the irradiated portion in the direction in which the contact angle with the liquid decreases due to energy irradiation; and (2) provided on the substrate. Forming a microlens exposure part by irradiating energy to the microlens formation part, which is a part for forming a microlens on the photocatalyst-containing layer, and (3) forming a microlens on the microlens exposure part. A method for producing a microlens substrate, comprising the steps of: applying a coating material and forming a microlens.
[0023]
As described above, in the method for producing a microlens substrate of the present invention, a photocatalyst containing layer is provided on the substrate, and the photocatalyst containing layer is irradiated with a pattern of energy to reduce the contact angle with the liquid. An exposed portion can be formed. A microlens can be easily formed by adhering a microlens-forming paint to the microlens exposure portion. Therefore, it is possible to manufacture a microlens substrate that is a simple manufacturing method and the microlens position accuracy is accurate.
[0024]
  In addition, the aboveClaim 9In the manufacturing method of the microlens described inClaim 10As described above, it is preferable that the step of applying the microlens-forming coating material on the microlens exposure portion is applied by an inkjet method. By applying the ink jet method, it becomes possible to efficiently apply the microlens forming paint, and the application position of the microlens forming paint is accurate, and the amount of the microlens paint remaining in the liquid-repellent region. This is because a microlens substrate with higher quality can be efficiently manufactured.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. First, a microlens substrate will be described, and then a method for manufacturing the microlens substrate will be described.
[0026]
A. About microlens substrate
First, the microlens substrate of the present invention will be described in detail. The microlens substrate of the present invention includes a substrate, a wettability variable layer provided on the surface of the substrate and capable of changing wettability, and a plurality of microlenses provided on the wettability variable layer. It is characterized by having.
[0027]
Thus, in the microlens substrate of the present invention, the microlens is provided on the wettability variable layer capable of changing the wettability. Therefore, the wettability of the portion where the microlens is previously provided can be a lyophilic region having a small contact angle with the liquid, and the other portion can be a liquid repellent region having a large contact angle with the liquid. By applying and adhering the microlens forming paint to the microlens forming portion where the microlens is provided, the microlens forming paint adheres only to the lyophilic region having a small contact angle with the liquid. The microlens-forming coating material is uniformly distributed over the entire lens forming portion, and a microlens having a predetermined angle with respect to the substrate and a predetermined curvature can be formed. Here, the microlens substrate is composed of at least a substrate and a plurality of microlenses arranged thereon, and is a microlens array in which microlenses are arranged at a predetermined interval. Also good.
[0028]
An example of such a microlens substrate of the present invention will be described with reference to the drawings.
[0029]
FIG. 1 shows an example of the microlens substrate of the present invention. The microlens substrate 1 includes a substrate 2, a wettability variable layer 3 provided on the substrate 2, and the wettability variable layer. 3 and a plurality of microlenses 4 formed on the substrate 3. The microlens 4 is formed on a microlens forming portion 5 having the wettability variable layer 3 as a lyophilic region, and the portion other than the microlens forming portion 5 is liquid repellent. It is. The microlens 4 is formed on the substrate using this wettability difference.
[0030]
Hereafter, each part which comprises the microlens substrate of this invention is each demonstrated.
[0031]
(Wettability variable layer)
The wettability variable layer 3 is not particularly limited as long as the wettability of the surface can be changed by an external stimulus such as a physical stimulus or a chemical stimulus. For example, it may be a layer whose surface roughness changes due to acid or alkali and the like, and the wettability changes, or the substance in the wettability variable layer changes due to ultraviolet light or visible light, etc. It may be a layer whose properties change.
[0032]
Regarding the change in wettability, the wettability variable layer may be such that the contact angle with the liquid is large before the stimulus is applied, and the contact angle with the liquid is changed small after the stimulus is applied, Conversely, the wettability variable layer may be such that the contact angle with the liquid is small before the stimulus is applied and the contact angle with the liquid changes greatly after the stimulus is applied.
[0033]
(Photocatalyst containing layer)
In the present invention, the wettability variable layer is preferably a photocatalyst-containing layer whose wettability changes so that the contact angle with the liquid is reduced by energy irradiation. In this way, the wettability is reduced so that the contact angle with the liquid is reduced by exposure (in the present invention, not only light is irradiated but also energy is applied). By providing a photocatalyst containing layer that changes, wettability can be easily changed by performing pattern irradiation of energy, etc., and a pattern of a lyophilic region having a small contact angle with the liquid can be formed, for example, a microlens It is possible to easily make only the region forming the lyophilic region. Therefore, the microlens substrate can be efficiently manufactured, which is advantageous in terms of cost. In this case, light containing ultraviolet light is usually used as energy.
[0034]
Here, the lyophilic region is a region having a small contact angle with the liquid, and refers to a region having good wettability with respect to a microlens-forming paint or the like. Further, the liquid repellent region is a region having a large contact angle with the liquid, and refers to a region having poor wettability with respect to a microlens-forming paint or the like.
[0035]
In the unexposed portion, the photocatalyst-containing layer has a contact angle with a liquid with a surface tension of 40 mN / m of 10 degrees or more, preferably a contact angle with a liquid with a surface tension of 30 mN / m of 10 degrees or more, particularly a surface The contact angle with a liquid having a tension of 20 mN / m is preferably 10 degrees or more. This is because the unexposed part is a part that requires liquid repellency in the present invention, and therefore, when the contact angle with the liquid is small, the liquid repellency is not sufficient, and the microlens-forming paint This is because there is a possibility that it may remain in the liquid repellent region, or it may be difficult to increase the angle of the microlens with respect to the substrate.
[0036]
In addition, the photocatalyst-containing layer has a contact angle with a liquid that decreases when exposed to light, and a contact angle with a liquid with a surface tension of 40 mN / m is less than 10 degrees, preferably a liquid with a surface tension of 50 mN / m. It is preferable that the layer has a contact angle with a liquid of 10 degrees or less, particularly a surface tension of 60 mN / m, of 10 degrees or less. This is because if the contact angle between the exposed portion and the liquid is high, the ink spread in this portion may be inferior, and problems such as a microlens having an accurate curvature may not be obtained.
[0037]
In addition, the contact angle with the liquid here is measured using a contact angle measuring instrument (Kyowa Interface Science Co., Ltd. CA-Z type) with a liquid having various surface tensions (from the microsyringe to the liquid. 30 seconds after dropping), and the result was obtained or the result was graphed. In this measurement, as a liquid having various surface tensions, a wetness index standard solution manufactured by Junsei Chemical Co., Ltd. can be used.
[0038]
The photocatalyst-containing layer of the present invention is preferably composed of at least a photocatalyst and a binder. By using such a layer, the critical surface tension can be increased by the action of the photocatalyst by energy irradiation, and the contact angle with the liquid can be decreased.
[0039]
In such a photocatalyst-containing layer, the action mechanism of a photocatalyst represented by titanium oxide as described later is not necessarily clear, but a carrier generated by irradiation with light or the like directly reacts with a nearby compound, Alternatively, it is considered that the active oxygen species generated in the presence of oxygen and water change the chemical structure of the organic matter.
[0040]
Using the action of such a photocatalyst, oily soil is decomposed by light irradiation to be hydrophilic and washable with water, or a hydrophilic film is formed on the surface of glass or the like to impart antifogging properties, Or what is called an antibacterial tile etc. which form the content layer of a photocatalyst on the surface of a tile etc. and reduce the number of airborne microbes in the air is proposed.
[0041]
When a photocatalyst-containing layer is used as the wettability variable layer in the present invention, the photocatalyst is used to change the wettability of the exposed portion by using an action such as oxidation or decomposition of an organic group or additive that is part of the binder. It can be made lyophilic and a large difference in wettability with the non-exposed part can be produced. Therefore, by improving the acceptability (lyophilicity) and repellent property (liquid repellency) with the microlens-forming coating material, it is possible to obtain a microlens substrate with good quality and advantageous in terms of cost.
[0042]
Further, when such a photocatalyst containing layer is used in the present invention, the photocatalyst containing layer contains at least a photocatalyst and fluorine, and the fluorine content on the surface of the photocatalyst containing layer irradiates the photocatalyst containing layer with energy. In this case, the photocatalyst-containing layer may be formed so as to be lower than that before energy irradiation due to the action of the photocatalyst.
[0043]
In the microlens substrate having such a feature, a pattern composed of a portion having a small fluorine content can be easily formed by pattern irradiation with energy. Here, fluorine has an extremely low surface energy. Therefore, the surface of a substance containing a large amount of fluorine has a smaller critical surface tension. Therefore, the critical surface tension of the portion having a small fluorine content is larger than the critical surface tension of the surface of the portion having a large fluorine content. This means that the portion with a low fluorine content is a lyophilic region compared to the portion with a high fluorine content. Therefore, forming a pattern composed of a portion having a lower fluorine content than the surrounding surface forms a pattern of a lyophilic region in the liquid repellent region.
[0044]
Therefore, when such a photocatalyst-containing layer is used, the pattern of the lyophilic region can be easily formed in the lyophobic region by irradiating the pattern with energy. Therefore, it is possible to easily form a microlens, and a microlens substrate with good quality can be obtained.
[0045]
As described above, the fluorine content contained in the fluorine-containing photocatalyst containing layer is a portion where the fluorine content in the lyophilic region having a low fluorine content formed by energy irradiation is not irradiated with energy. When the fluorine content is 100, it is preferably 10 or less, preferably 5 or less, particularly preferably 1 or less.
[0046]
By setting it within such a range, it is possible to make a large difference in lyophilicity between the energy-irradiated portion and the unirradiated portion. Therefore, by forming a microlens in such a photocatalyst-containing layer, it becomes possible to form a microlens accurately only in a lyophilic region where the fluorine content is reduced, and a predetermined angle with respect to the substrate. This is because a microlens having a predetermined curvature can be formed, and a microlens substrate can be obtained with high accuracy. This rate of decrease is based on weight.
[0047]
For the measurement of the fluorine content in the photocatalyst-containing layer, various commonly used methods can be used. For example, X-ray photoelectron spectroscopy (ES-ray photoelectron spectroscopy, ESCA) for Chemical Analysis)), and any method that can quantitatively measure the amount of fluorine on the surface, such as X-ray fluorescence analysis and mass spectrometry, is not particularly limited.
[0048]
Examples of the photocatalyst used in the present invention include titanium oxide (TiO 2), which is known as an optical semiconductor.₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)_Three), Tungsten oxide (WO_Three), Bismuth oxide (Bi₂O_Three), And iron oxide (Fe₂O_Three1) or a mixture of two or more selected from these.
[0049]
In the present invention, titanium oxide is particularly preferably used because it has a high band gap energy, is chemically stable, has no toxicity, and is easily available. Titanium oxide includes anatase type and rutile type, and both can be used in the present invention, but anatase type titanium oxide is preferable. Anatase type titanium oxide has an excitation wavelength of 380 nm or less.
[0050]
Examples of such anatase-type titanium oxide include hydrochloric acid peptizer-type anatase-type titania sol (STS-02 manufactured by Ishihara Sangyo Co., Ltd. (average particle size 7 nm), ST-K01 manufactured by Ishihara Sangyo Co., Ltd.), nitric acid solution An anatase type titania sol (TA-15 manufactured by Nissan Chemical Co., Ltd. (average particle size 12 nm)) and the like can be mentioned.
[0051]
The smaller the particle size of the photocatalyst, the more effective the photocatalytic reaction occurs. The average particle size is preferably 50 nm or less, and it is particularly preferable to use a photocatalyst of 20 nm or less. Further, the smaller the particle size of the photocatalyst, the smaller the surface roughness of the formed photocatalyst-containing layer, which is preferable. When the particle size of the photocatalyst exceeds 100 nm, the centerline average surface roughness of the photocatalyst-containing layer becomes coarse, and the photocatalyst The liquid repellency of the non-exposed part of the containing layer is lowered, and the lyophilic expression of the exposed part becomes insufficient.
[0052]
The microlens substrate of the present invention contains fluorine on the surface of the photocatalyst containing layer as described above, and reduces the fluorine content on the surface of the photocatalyst containing layer by irradiating the surface of the photocatalyst containing layer with energy, thereby repelling it. A microlens substrate obtained by forming a pattern of a lyophilic region in a liquid region and forming a microlens there may be used. Even in this case, it is preferable to use the titanium dioxide as described above as the photocatalyst. However, the content of fluorine contained in the photocatalyst containing layer in the case of using titanium dioxide in this way is X-ray photoelectron. When analyzed and quantified by spectroscopy, when the titanium (Ti) element is defined as 100, the fluorine (F) element is in a ratio of 500 or more, preferably 800 or more, particularly preferably 1200 or more. It is preferable that the element is contained on the surface of the photocatalyst containing layer.
[0053]
Fluorine (F) is included in the photocatalyst-containing layer to such an extent that the critical surface tension on the photocatalyst-containing layer can be sufficiently lowered, so that the liquid repellency on the surface can be secured, thereby irradiating energy with the pattern This is because the difference in wettability with the lyophilic region on the surface of the pattern portion where the fluorine content is reduced can be increased, and the quality of the finally obtained microlens substrate can be improved. .
[0054]
Further, in such a microlens substrate, the fluorine content in the lyophilic region formed by pattern irradiation with energy is 50 or less when the titanium (Ti) element is 100, It is preferably contained in a ratio of 20 or less, particularly preferably 10 or less.
[0055]
If the fluorine content in the photocatalyst-containing layer can be reduced to this extent, sufficient lyophilicity can be obtained for forming a microlens and the like, and the liquid repellency of the portion where the energy is not irradiated is obtained. Due to the difference in wettability, it is possible to form microlenses and the like with high accuracy, and a microlens substrate with good quality can be obtained.
[0056]
In the present invention, the binder used in the photocatalyst-containing layer preferably has a high binding energy such that the main skeleton is not decomposed by the photoexcitation of the photocatalyst. For example, (1) chloro or alkoxysilane or the like by sol-gel reaction or the like. Examples include organopolysiloxanes that exhibit high strength by hydrolysis and polycondensation, and (2) organopolysiloxanes crosslinked with reactive silicones that are excellent in water repellency and oil repellency.
[0057]
In the case of (1) above, the general formula:
Y_nSiX_(4-n)
(Here, Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group, an acetyl group or a halogen. N is an integer from 0 to 3. )
It is preferable that it is the organopolysiloxane which is a 1 type, or 2 or more types of hydrolysis condensate or cohydrolysis condensate of the silicon compound shown by these. Here, the number of carbon atoms of the group represented by Y is preferably in the range of 1 to 20, and the alkoxy group represented by X is a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. preferable.
[0058]
Specifically, methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltrit-butoxysilane; ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, Ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane; n-propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltriisopropoxy Silane, n-propyltri-t-butoxysilane; n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyl Lutriisopropoxysilane, n-hexyltri-t-butoxysilane; n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n-decyltriisopropoxysilane, n -Decyltri-t-butoxysilane; n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane Phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltri-t-butoxysilane; tetrachlorosilane Tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane; dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane; diphenyldichlorosilane, diphenyldibromosilane, Diphenyldimethoxysilane, diphenyldiethoxysilane;
Phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane; trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane, tri-t-butoxyhydrosilane; vinyl Trichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrit-butoxysilane; trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, Trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropro Lutri-t-butoxysilane; γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycyl Sidoxypropyltriisopropoxysilane, γ-glycidoxypropyltri-t-butoxysilane; γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane , Γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltrit-butoxysilane; γ-aminopropylmethyldimethoxysilane, γ-aminopropyl Tildiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltrit-butoxysilane; γ-mercaptopropylmethyldimethoxysilane, γ- Mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane; β- (3,4-epoxy Cyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; and partial hydrolysates thereof; and mixtures thereof.
[0059]
In addition, a polysiloxane containing a fluoroalkyl group can be preferably used as the binder. Specifically, one or two or more hydrocondensation condensates or cohydrolysis condensates of fluoroalkylsilanes shown below can be used. In general, those known as fluorine-based silane coupling agents can be used.
[0060]
CF_Three(CF₂)_ThreeCH₂CH₂Si (OCH_Three)_Three;
CF_Three(CF₂)_FiveCH₂CH₂Si (OCH_Three)_Three;
CF_Three(CF₂)₇CH₂CH₂Si (OCH_Three)_Three;
CF_Three(CF₂)₉CH₂CH₂Si (OCH_Three)_Three;
(CF_Three)₂CF (CF₂)_FourCH₂CH₂Si (OCH_Three)_Three;
(CF_Three)₂CF (CF₂)₆CH₂CH₂Si (OCH_Three)_Three;
(CF_Three)₂CF (CF₂)₈CH₂CH₂Si (OCH_Three)_Three;
CF_Three(C₆H_Four) C₂H_FourSi (OCH_Three)_Three;
CF_Three(CF₂)_Three(C₆H_Four) C₂H_FourSi (OCH_Three)_Three;
CF_Three(CF₂)_Five(C₆H_Four) C₂H_FourSi (OCH_Three)_Three;
CF_Three(CF₂)₇(C₆H_Four) C₂H_FourSi (OCH_Three)_Three;
CF_Three(CF₂)_ThreeCH₂CH₂SiCH_Three(OCH_Three)₂;
CF_Three(CF₂)_FiveCH₂CH₂SiCH_Three(OCH_Three)₂;
CF_Three(CF₂)₇CH₂CH₂SiCH_Three(OCH_Three)₂;
CF_Three(CF₂)₉CH₂CH₂SiCH_Three(OCH_Three)₂;
(CF_Three)₂CF (CF₂)_FourCH₂CH₂SiCH_Three(OCH_Three)₂;
(CF_Three)₂CF (CF₂)₆CH₂CH₂SiCH_Three(OCH_Three)₂;
(CF_Three)₂CF (CF₂)₈CH₂CH₂SiCH_Three(OCH_Three)₂;
CF_Three(C₆H_Four) C₂H_FourSiCH_Three(OCH_Three)₂;
CF_Three(CF₂)_Three(C₆H_Four) C₂H_FourSiCH_Three(OCH_Three)₂;
CF_Three(CF₂)_Five(C₆H_Four) C₂H_FourSiCH_Three(OCH_Three)₂;
CF_Three(CF₂)₇(C₆H_Four) C₂H_FourSiCH_Three(OCH_Three)₂;
CF_Three(CF₂)_ThreeCH₂CH₂Si (OCH₂CH_Three)_Three;
CF_Three(CF₂)_FiveCH₂CH₂Si (OCH₂CH_Three)_Three;
CF_Three(CF₂)₇CH₂CH₂Si (OCH₂CH_Three)_Three;
CF_Three(CF₂)₉CH₂CH₂Si (OCH₂CH_Three)_Three;and
CF_Three(CF₂)₇SO₂N (C₂H_Five) C₂H_FourCH₂Si (OCH_Three)_Three
[0061]
By using a polysiloxane containing a fluoroalkyl group as described above as a binder, the liquid repellency of the non-exposed portion of the photocatalyst containing layer is greatly improved, and the function of preventing the adhesion of the microlens forming paint, the microlens substrate The function etc. which make the angle with respect to more than a predetermined angle can be expressed.
[0062]
Examples of the reactive silicone (2) include compounds having a skeleton represented by the following general formula.
[0063]
[Chemical 1]

[0064]
However, n is an integer greater than or equal to 2, R¹, R²Each represents a substituted or unsubstituted alkyl, alkenyl, aryl or cyanoalkyl group having 1 to 10 carbon atoms, and 40% or less of the total is vinyl, phenyl or phenyl halide in a molar ratio. R¹, R²Is preferably a methyl group because the surface energy becomes the smallest, and the methyl group is preferably 60% or more by molar ratio. In addition, the chain end or side chain has at least one reactive group such as a hydroxyl group in the molecular chain.
[0065]
In addition to the above organopolysiloxane, a stable organosilicon compound that does not undergo a crosslinking reaction, such as dimethylpolysiloxane, may be mixed in the binder.
[0066]
In the microlens substrate of the present invention, various binders such as organopolysiloxane can be used in the photocatalyst-containing layer. In the present invention, as described above, fluorine is contained in the photocatalyst containing layer containing such a binder and photocatalyst, and the fluorine on the surface of the photocatalyst containing layer is reduced by irradiating energy in a pattern, thereby reducing the liquid repellent region. A lyophilic region may be formed inside. At this time, it is necessary to contain fluorine in the photocatalyst-containing layer. As a method of incorporating fluorine into the photocatalyst-containing layer containing such a binder, a fluorine compound is relatively used for a binder having a high binding energy. Examples thereof include a method of bonding with weak binding energy and a method of mixing a fluorine compound bonded with relatively weak binding energy into the photocatalyst containing layer. By introducing fluorine by such a method, when energy is irradiated, a fluorine bonding site having a relatively low binding energy is first decomposed, and thus fluorine can be removed from the photocatalyst containing layer. is there.
[0067]
Examples of the first method, that is, a method of bonding a fluorine compound with a relatively weak binding energy to a binder having a high binding energy include a method of introducing a fluoroalkyl group as a substituent into the organopolysiloxane. be able to.
[0068]
For example, as described in (1) above, as a method for obtaining an organopolysiloxane, an organopolysiloxane exhibiting high strength can be obtained by hydrolyzing and polycondensing chloro or alkoxysilane or the like by a sol-gel reaction or the like. . Here, in this method, as described above, the above general formula:
Y_nSiX_(4-n)
(Here, Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group, an acetyl group or a halogen. N is an integer from 0 to 3. )
An organopolysiloxane is obtained by hydrolyzing or co-hydrolyzing and condensing one or two or more of the silicon compounds represented by formula (1). In this general formula, silicon having a fluoroalkyl group as the substituent Y is obtained. By synthesizing using a compound, an organopolysiloxane having a fluoroalkyl group as a substituent can be obtained. When an organopolysiloxane having such a fluoroalkyl group as a substituent is used as a binder, the carbon bond portion of the fluoroalkyl group is decomposed by the action of the photocatalyst in the photocatalyst-containing layer when irradiated with energy. Therefore, the fluorine content in the portion where the photocatalyst-containing layer surface is irradiated with energy can be reduced.
[0069]
The silicon compound having a fluoroalkyl group used at this time is not particularly limited as long as it has a fluoroalkyl group, but has at least one fluoroalkyl group, and the carbon number of the fluoroalkyl group A silicon compound in which is 4 to 30, preferably 6 to 20, particularly preferably 6 to 16, is preferably used. Specific examples of such a silicon compound are as described above, and among these, the above silicon compound having a fluoroalkyl group having 6 to 8 carbon atoms, that is, a fluoroalkylsilane is preferable.
[0070]
In the present invention, such a silicon compound having a fluoroalkyl group may be used in combination with the above-mentioned silicon compound having no fluoroalkyl group, and these cohydrolyzed condensates may be used as the organopolysiloxane. In addition, one or two or more silicon compounds having such a fluoroalkyl group may be used, and these hydrolyzed condensates and cohydrolyzed condensates may be used as the organopolysiloxane.
[0071]
In the organopolysiloxane having a fluoroalkyl group thus obtained, among the silicon compounds constituting the organopolysiloxane, the silicon compound having the fluoroalkyl group is 0.01 mol% or more, preferably 0.1%. It is preferable that it is contained in mol% or more.
[0072]
By including this degree of fluoroalkyl group, the liquid repellency on the photocatalyst-containing layer can be increased, and the difference in wettability with the portion that has been made lyophilic by irradiation with energy can be increased. Because.
[0073]
In the method shown in (2) above, organopolysiloxane is obtained by crosslinking reactive silicone having excellent water repellency and oil repellency. In this case as well, R in the above general formula is similarly used.¹, R²By making either or both of them a fluorine-containing substituent such as a fluoroalkyl group, it is possible to include fluorine in the photocatalyst-containing layer, and when it is irradiated with energy, it is bonded from a siloxane bond. Since the portion of the fluoroalkyl group having a small energy is decomposed, the content of fluorine on the surface of the photocatalyst-containing layer can be reduced by energy irradiation.
[0074]
On the other hand, as a method for introducing a fluorine compound bonded with energy lower than the binding energy of the binder, for example, when introducing a low molecular weight fluorine compound, for example, a fluorine-based surfactant is mixed. Examples of the method of introducing a high molecular weight fluorine compound include a method of mixing a fluorine resin having high compatibility with the binder resin.
[0075]
In the present invention, the photocatalyst-containing layer can contain a surfactant in addition to the above-mentioned photocatalyst and binder. Specifically, hydrocarbons such as NIKKOLBL, BC, BO, BB series manufactured by Nikko Chemicals Co., Ltd., ZONYL FSN, FSO manufactured by DuPont, Surflon S-141, 145 manufactured by Asahi Glass Co., Ltd., Dainippon Ink Chemical industry Co., Ltd. MegaFuck F-141, 144, Neos Co., Ltd., Fategent F-200, F251, Daikin Industries Co., Ltd. Unidyne DS-401, 402, 3M Co., Ltd. Fluorado FC-170, Fluorine-based or silicone-based nonionic surfactants such as 176 can be mentioned, and cationic surfactants, anionic surfactants, and amphoteric surfactants can also be used.
[0076]
In addition to the above surfactants, the photocatalyst-containing layer includes polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin, polycarbonate, Polyvinyl chloride, polyamide, polyimide, styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, epichlorohydrin, polysulfide, polyisoprene, oligomers, polymers, etc. It can be included.
[0077]
The content of the photocatalyst in the photocatalyst containing layer can be set in the range of 5 to 60% by weight, preferably 20 to 40% by weight. The thickness of the photocatalyst-containing layer is preferably in the range of 0.05 to 10 μm, particularly preferably 0.1 to 0.2 μm.
[0078]
The photocatalyst-containing layer can be formed by dispersing a photocatalyst and a binder in a solvent together with other additives as necessary to prepare a coating solution, and applying the coating solution. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropanol are preferable. The application can be performed by a known application method such as spin coating, spray coating, dip coating, roll coating, or bead coating. When an ultraviolet curable component is contained as the binder, the photocatalyst-containing layer can be formed by irradiating ultraviolet rays and performing a curing treatment.
[0079]
(Micro lens)
The present invention is characterized in that a plurality of microlenses 4 are provided on the wettability variable layer 3, especially the photocatalyst-containing layer described above, as shown in FIG. In the present invention, microlenses are formed in a predetermined pattern by the microlens-forming paint in the lyophilic region exposed in the photocatalyst-containing layer and having a low contact angle with the liquid.
[0080]
In the present invention, the microlens formed on the substrate is preferably a microlens array in which microlenses are regularly arranged. This is because, in a liquid crystal display, an imaging device, and the like, which are main uses of microlenses, they are often used as microlens arrays. This regular arrangement pattern is determined by the mode of the elements used.
[0081]
Further, the shape of the bottom surface of each microlens, that is, the shape of the contact surface with the substrate is not particularly limited, and may be not only circular but also polygonal. In this case, by making the shape of the bottom surface of the microlens polygonal, the area of the region where the microlens is not formed can be reduced compared to a circular one, so that a microlens having a high aperture ratio can be easily obtained. Obtainable.
[0082]
On the microlens substrate of the present invention, the area ratio between the part where the microlens is arranged and the part where the microlens is not arranged varies greatly depending on the functional element used and the required characteristics. Can be in the range of 10,000: 1 to 1: 10000. Although the focal length of the microlens is generally in the range of 100 to 2500 μm, and the formation pitch of the microlens is in the range of 10 to 1000 μm, although it varies greatly depending on the use of the microlens substrate.
[0083]
Furthermore, the microlens substrate of the present invention can be a microlens substrate in which the focal length of the microlens is variously changed. That is, in the microlens substrate of the present invention, by adjusting the amount of the microlens-forming coating material attached to the substrate, a microlens with the focal length easily changed can be obtained, and the microlens having various focal lengths can be obtained. A lens can be easily formed. Hereinafter, this point will be specifically described with reference to FIG.
[0084]
FIG. 2A shows a case where a small amount of microlens-forming paint is applied. That is, in the wettability variable layer 3 formed on the substrate 2, a small amount of microlens forming paint was applied on the microlens forming portion 5 that was a lyophilic region, thereby forming a microlens 4 having a small curvature. Is. In the microlens substrate of the present invention, since the microlens 4 is formed on the microlens forming part 5 which is made lyophilic, a small amount of microlens forming paint as shown in FIG. Even if it is applied, the applied microlens forming coating spreads over the entire microlens forming portion 5. Therefore, microlenses having a small focal length and a small curvature can be easily formed by reducing the amount of coating.
[0085]
FIG. 2B shows the microlens 4 having a larger curvature and a shorter focal length than those in FIG. In the present invention, since the area of the microlens forming portion 5 that becomes the bottom surface of the microlens 4 is determined, the curvature of the microlens 4 is varied depending on the amount of the microlens forming paint applied in the microlens forming portion 5. And the focal length can be determined. FIG. 2 (b) shows an example in which a larger amount of microlens-forming coating material is applied than (a). Thus, in the present invention, by adjusting the amount of the microlens-forming coating material, Microlenses having various curvatures and focal lengths can be easily obtained.
[0086]
FIG. 2C shows a microlens 4 having a larger curvature and a shorter focal length. In this case, if there is a large difference in wettability between the microlens forming portion 5 that is a lyophilic region and the wettability variable layer 3 that is a liquid repellent region, even if a microlens forming paint is applied to a certain amount, The microlens can be formed without the microlens-forming paint protruding outside the microlens forming portion 5. Thus, in the present invention, the lyophilic region and the liquid repellent region of the wettability variable layer, that is, in FIG. 2C, the microlens forming portion 5 that has been made the lyophilic region and other wettability variable. By increasing the difference in wettability with the layer 3, a microlens having a large curvature and a short focal length can be easily formed.
[0087]
The microlens on the microlens substrate of the present invention can be a colored microlens. By making the microlens colored as described above, it is possible to have both a function as a color filter and a function as a microlens that are usually used for a color liquid crystal display or the like. Therefore, there is an advantage that the obtained functional element can be reduced in size and cost.
[0088]
The material constituting the microlens used in the present invention is liquid at the time of formation, can be applied on the wettability variable layer and can be cured thereafter, and further has a function as a lens after curing. The material is not particularly limited as long as it is a material that is permeable to energy rays such as electromagnetic waves to be obtained. Examples of such resins include various resins such as those obtained by applying a solution obtained by dissolving the above-described permeable resin in a solvent and then removing the solvent, thermoplastic resins, thermosetting resins, and photocurable resins. A photocurable resin is preferable because it is easy and quick to cure, and further, the lens molding material and the base material are not heated at the time of curing.
[0089]
Such a photocurable resin usually has at least one functional group, and performs ion polymerization or radical polymerization with ions or radicals generated by irradiating the photopolymerization initiator with curing energy rays, and has a molecular weight. A resin composition having at least a monomer or oligomer for forming a cross-linked structure and a photopolymerization initiator, if necessary, is cured. The functional group here refers to an atomic group or bonding mode that causes a reaction such as a vinyl group, a carboxyl group, or a hydroxyl group.
[0090]
Examples of such monomers and oligomers include unsaturated polyester type, enethiol type, and acrylic type. Among these, acrylic type is preferable because of its wide range of curing speed and physical property selection. Among such acrylic monomers and oligomers, those having a monofunctional group include 2-ethylhexyl acrylate, 2-ethylhexyl EO adduct acrylate, ethoxydiethylene glycol acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2 -Caprolactone adduct of hydroxyethyl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, nonylphenol EO adduct acrylate, acrylate obtained by adding caprolactone to nonylphenol EO adduct, 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, Furfuryl alcohol caprolactone adduct acrylate, acryloylmorpholine, di Clopentenyl acrylate, dicyclopentanyl acrylate, dicyclopentenyloxyethyl acrylate, isobornyl acrylate, acrylate of 4,4-dimethyl-1,3-dioxolane caprolactone adduct, 3-methyl-5,5-dimethyl-1 An acrylate of a caprolactone adduct of 3-dioxolane can be used.
[0091]
Among the acrylic monomers and oligomers, polyfunctional ones include hexanediol acrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, hydroxypivalate neopentyl glycol ester diacrylate, hydroxy Caprolactone adduct diacrylate of pivalic acid neopentylglycol ester, acrylic acid adduct of diglycidyl ether of 1,6-hexanediol, diacrylate of acetal compound of hydroxypivalaldehyde and trimethylolpropane, 2,2-bis [ 4- (acryloyloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloyloxydiethoxy) phenyl] methane, hydrogenated bisphenol Diacrylate of triethylene oxide adduct, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane propylene oxide adduct triacrylate, glycerin propylene oxide adduct triacrylate, dipentaerythritol hexa Examples thereof include acrylate pentaacrylate mixture, dipentaerythritol caprolactone adduct acrylate, tris (acryloyloxyethyl) isocyanurate, 2-acryloyloxyethyl phosphate, and the like.
[0092]
Further, the photopolymerization initiators include acetophenone, benzophenone, Michler ketone, benzyl, benzoin, benzoin ether, benzyldimethyl ketal, benzoin benzoate, α-acyloxime ester and other carbonyl compounds, tetra Examples thereof include sulfur compounds such as methylthiuram monosulfide and thioxanthones, and phosphorus compounds such as 2,4,6-trimethylbenzoyldiphenylphosphinoxide.
[0093]
In addition, photoinitiators such as aliphatic amines and aromatic amines and photosensitizers such as thioxanthone may be added as necessary.
[0094]
Further, as the thermoplastic resin, those having high transparency particularly in the visible light region and excellent optical characteristics such as refractive index, dispersion characteristics, and birefringence are preferable. Specifically, polycarbonate, polymethyl methacrylate, methyl phthalate homopolymer or copolymer, polyethylene terephthalate, polystyrene, diethylene glycol, bisallyl carbonate, acrylonitrile / styrene copolymer, methyl methacrylate / styrene copolymer, poly (− 4-methylpentene-1) and the like.
[0095]
Furthermore, as described above, it is possible to colorize the microlens on the microlens substrate of the present invention. Examples of the colorant used for the coloration include dyes, inorganic pigments, and organic pigments. The colorant is not particularly limited as long as it is a colorant usually used in a colored filter. In the present invention, among them, a material that can give a high concentration and is hard to cause fading when the lens is cured or used as a microlens substrate is preferable.
[0096]
Specific dyes include azo dyes, anthraquinone dyes, indigoid dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, quinoline dyes, nitro dyes, and benzoquinone dyes. And dyes, naphthoquinone dyes, naphthalimide dyes, perinone dyes, pyrylium dyes, thiapyrylium dyes, azurenium dyes, squarylium salt dyes, and the like. Examples of the pigment include dianthraquinone, halogenated copper phthalocyanine, copper phthalocyanine, other phthalocyanine pigments, perylene pigments, pyranthrone pigments and other polycyclic quinone pigments, indigo pigments, quinacridone pigments, pyrrole pigments, pyrrolo pigments, and the like. Examples thereof include organic pigments such as pyrrole pigments and azo pigments.
[0097]
(substrate)
The material of the substrate used in the microlens substrate of the present invention varies greatly depending on the use of the microlens substrate. For example, when it is used for a liquid crystal display, an imaging device, or the like, the substrate is required to be a transparent substrate because it is required to be transparent with respect to visible light or the like like the microphone lens. On the other hand, in the case of using a microlens substrate as a mold, or in the case of using the microlens substrate by reflecting it instead of transmitting light or the like, it is not necessary to be a transparent substrate.
[0098]
As described above, various substrates such as a metal material, a semiconductor material, and an organic material can be used for the substrate used in the present invention depending on the application. However, at present, since the most common use of the microlens substrate is to transmit light to the microlens substrate such as a liquid crystal display and an image sensor, the substrate is a transparent substrate in the present invention. Preferably there is.
[0099]
Such a transparent substrate is not particularly limited, and may be an inorganic material or an organic material as long as the material can transmit visible light. Among them, preferable materials include soda glass, quartz glass, optical glass (for example, BSC7 (trade name) manufactured by HOYA Co., Ltd.), glass for electronics (non-alkali glass, etc.), translucent ceramics, polycarbonate, methyl A methacrylate monopolymer or copolymer, a polyethylene terephthalate, a plastic film such as polystyrene, a plastic sheet, and the like can be given.
[0100]
The thickness of the substrate in the present invention is not particularly limited, and can be set to a thickness according to the application for which the microlens substrate is used.
[0101]
(Shading part)
The microlens substrate of the present invention may be provided with a light shielding portion as necessary. This light shielding portion is usually provided so that unnecessary light around the lens does not enter the lens. This light shielding portion will be described with reference to FIGS.
[0102]
FIG. 3 shows an example in which a light shielding portion is provided on the surface opposite to the surface on which the microlens of the microlens substrate of the present invention is provided. A microlens substrate 1 shown in FIG. 3 is provided with a wettability variable layer 3 on a substrate 2 in the same manner as the microlens substrate shown in FIG. And a microlens 4 is provided here. In the microlens substrate 1 shown in FIG. 3, a light shielding portion 6 is further formed on the surface opposite to the surface on which the microlenses 4 are formed. In the example shown in FIG. 3, the light-shielding part 6 is provided with the wettability variable layer 3 in the same manner as the surface on which the microlenses 4 are formed, and the light-shielding part forming part 7 as a lyophilic region in the wettability variable layer 3. And a light shielding portion 6 is provided here.
[0103]
As shown in FIG. 4, such a light shielding portion 4 may be formed so that only a light transmission portion converged by the microlens 4 is an opening. In this example, the light shielding portion 4 corresponds to the central portion of the microlens 4. The part is an opening 8.
[0104]
In the microlens substrate of the present invention, the position where the light shielding portion is formed is not particularly limited. However, as shown in FIGS. 3 and 4, it is formed on the surface opposite to the surface on which the microlens is formed. It is preferred that
[0105]
The light-shielding portion in the present invention may be provided by a conventional method such as a method of forming a metal thin film such as chromium by sputtering or the like and patterning it, but for example on a transparent substrate as shown in FIG. A wettability variable layer, preferably a photocatalyst-containing layer, may be provided, and the change in wettability may be used to form.
[0106]
As a material for forming the light shielding part of the present invention, a metal such as chromium as described above, an organic material containing light shielding particles such as carbon fine particles, metal oxides, inorganic pigments, organic pigments in a resin binder, etc. Can be mentioned. As such a resin binder, polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, or a mixture of one or more kinds, photosensitive resin, and O A / W emulsion type resin composition, for example, an emulsion of reactive silicone can be used.
[0107]
B. About manufacturing method of microlens substrate
Next, the manufacturing method of the microlens substrate of the present invention will be described in detail. The manufacturing method of the microlens substrate of the present invention includes:
(1) providing a photocatalyst-containing layer on the substrate that changes the wettability of the irradiated portion in the direction in which the contact angle with the liquid decreases due to energy irradiation;
(2) forming a microlens exposure part by pattern irradiation with energy on a microlens formation part which is a part for forming a microlens on the photocatalyst-containing layer provided on the substrate;
(3) A step of applying a microlens forming paint to the microlens exposure part to form a microlens;
It is what has.
[0108]
First, the process of providing the photocatalyst containing layer that is the first process will be described. The photocatalyst-containing layer is formed by dispersing a photocatalyst and a binder as described above in a solvent together with other additives as necessary to prepare a coating solution. It is formed by advancing the condensation reaction to firmly fix the photocatalyst in the binder. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropylol are preferable, and the coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating, and bead coating. Further, in the case where an ultraviolet curable component is contained as a binder, the photocatalyst-containing layer can be formed on the substrate by performing a curing treatment by irradiating with ultraviolet rays.
[0109]
Next, a process for forming a microlens exposure unit, which is a second process, will be described. The photocatalyst containing layer is formed on the substrate by the first step, and the photocatalyst containing layer is irradiated with energy to form the microlens exposure part. The shape of the formation part of the microlens exposure part, Since the arrangement and the like are the same as those of the above-described part / arrangement where the microlens is formed, the description thereof is omitted here.
[0110]
As energy irradiated in the present invention, light including ultraviolet light can be used. Examples of such a light source including ultraviolet light include a mercury lamp, a metal halide lamp, and a xenon lamp. The wavelength of the light used for this exposure can be set in the range of 400 nm or less, preferably in the range of 380 nm or less, and the amount of light irradiation during the exposure is made lyophilic by the action of the photocatalyst. The irradiation dose required for expression can be obtained.
[0111]
If pattern irradiation is required for energy irradiation, it can be performed by pattern irradiation through a photomask using a light source as described above. As another method, a pattern is formed using a laser such as excimer or YAG. It is also possible to use a drawing irradiation method. However, such a method may have problems such as an expensive apparatus, difficult handling, and inability to perform continuous output.
[0112]
Therefore, in the present invention, the photocatalytic reaction initiation energy is added to the photocatalyst containing layer, and the pattern of the lyophilic region is formed by adding the reaction rate increasing energy in a pattern to the region where the photocatalytic reaction initiation energy is added. You may make it form. By forming a pattern using such an energy irradiation method, it is possible to use a reaction rate increasing energy that is relatively inexpensive and easy to handle, such as an infrared laser, during pattern formation. This is because no problem occurs.
[0113]
The reason why the pattern of the lyophilic region having changed wettability can be formed by applying such energy is as follows. That is, the photocatalytic reaction initiation energy is first applied to the region where the pattern is formed, thereby starting the catalytic reaction of the photocatalyst with respect to the photocatalyst containing layer. And reaction rate increase energy is added in the area | region where this photocatalytic reaction start energy was added. By adding the reaction rate increasing energy in this way, the photocatalytic reaction initiation energy is already added, and the reaction in the photocatalyst containing layer in which the reaction is initiated by the catalytic action of the photocatalyst is rapidly accelerated. Then, by adding the reaction rate increasing energy for a predetermined time, the change of the property in the property changing layer is changed to a desired range, and the pattern to which the reaction rate increasing energy is added is changed to the lyophilic region where the wettability is changed. It can be a pattern.
[0114]
Here, first, the photocatalytic reaction initiation energy will be described. The photocatalytic reaction initiation energy used in this energy irradiation method refers to the energy with which the photocatalyst initiates a catalytic reaction for changing the characteristics of the compound in the photocatalyst-containing layer.
[0115]
The amount of photocatalytic reaction initiation energy added here is an amount that does not cause a sudden change in wettability in the photocatalyst-containing layer. When the amount of photocatalytic reaction initiation energy added is small, it is not preferable because the sensitivity at the time of forming a pattern by adding reaction rate increasing energy is lowered, and when this amount is too large, the photocatalyst added with photocatalytic reaction initiation energy is not preferable. It is not preferable because the degree of change in the characteristics of the containing layer becomes too large and the difference from the region to which the reaction rate increasing energy is added becomes unclear. The amount of energy to be added is determined by conducting preliminary experiments on the amount of energy to be added and the amount of change in wettability in the photocatalyst containing layer in advance.
[0116]
The photocatalytic reaction initiation energy in this method is not particularly limited as long as it is an energy capable of initiating the photocatalytic reaction, but light is particularly preferable.
[0117]
The photocatalyst used in the present invention has a different wavelength of light for initiating a catalytic reaction depending on its band gap. For example, cadmium sulfide has a visible light of 496 nm and iron oxide has a light of 539 nm, and titanium dioxide has an ultraviolet light of 388 nm. Therefore, any light, whether visible light or ultraviolet light, can be used in the present invention. However, as described above, titanium dioxide is preferably used as the photocatalyst because it is effective as a photocatalyst because of its high band gap energy, is chemically stable, has no toxicity, and is easily available. Light including ultraviolet light that initiates the catalytic reaction of titanium is preferable. Specifically, it is preferable that ultraviolet light in a range of 400 nm or less, preferably 380 nm or less is included.
[0118]
Examples of light sources including such ultraviolet light include various ultraviolet light sources such as mercury lamps, metal halide lamps, xenon lamps, and excimer lamps.
[0119]
In the present invention, this photocatalytic reaction initiation energy may be added to a part of the photocatalyst-containing layer. For example, this photocatalytic reaction initiation energy is added in a pattern, and the reaction rate increase energy described later is also patterned. In addition, it is possible to form a pattern of a lyophilic region having changed wettability. However, for reasons such as simplification and simplification of the process, this photocatalytic reaction initiation energy is spread over the entire region where the pattern is formed. Preferably, the reaction rate increasing energy is applied in a pattern to the region where the photocatalytic reaction initiation energy is applied over the entire surface, thereby forming a pattern of the lyophilic region on the photocatalyst-containing layer. Is preferred.
[0120]
Next, the reaction rate increasing energy used in this method will be described. The reaction rate increasing energy used in this method refers to energy for increasing the reaction rate of the reaction for changing the wettability of the photocatalyst containing layer initiated by the photocatalytic reaction initiation energy. In the present invention, any energy having such an action can be used, but thermal energy is preferably used.
[0121]
The method of applying such thermal energy to the photocatalyst containing layer in a pattern is not particularly limited as long as it can form a heat pattern on the photocatalyst containing layer, but it is not limited to a method using an infrared laser or a thermal head. The method etc. can be mentioned. As such an infrared laser, for example, an infrared YAG laser (1064 nm) having an advantage of strong directivity and a long irradiation distance, and a diode laser (LED; 830 nm, 1064 nm, 1100 nm) having an advantage of being relatively inexpensive. In addition to the above, a semiconductor laser, a He—Ne laser, a carbon dioxide laser, and the like can be given.
[0122]
In this method, by adding the photocatalytic reaction initiation energy described above, the photocatalyst is activated to initiate a change in wettability due to the catalytic reaction in the photocatalyst-containing layer, and the reaction rate at the portion where the change in wettability occurs. By adding the increased energy to promote the catalytic reaction of the part, the pattern of the lyophilic region is formed by the difference in the reaction rate between the region where the reaction rate increasing energy is added and the region where it is not added. Can do.
[0123]
Finally, the third step of forming the microlens on the substrate will be described. The microlens-forming paint used in this step is a paint containing the above-mentioned microlens material, and can be applied to the microlens exposure part (microlens formation part) and then cured. Thus, there is no particular limitation as long as it has a function as a microlens. When the microlens is made of a photo-curing resin, the form of the microlens forming paint includes a liquid in which a monomer and a photopolymerization initiator are dissolved or dispersed, and an oligomer and a photopolymerization initiator that are dissolved. Alternatively, a dispersed liquid, a liquid in which a monomer or oligomer and a photopolymerization initiator are dissolved or dispersed can be used. When the microlens is a colored microlens as described above, a material obtained by mixing the above-described colorant with the microlens-forming coating material is used.
[0124]
The method for applying such a microlens-forming coating material to the microlens exposure part (microlens formation part) is not particularly limited, but specifically, dip coating, roll coating, bead coating, spin coating Coating, air doctor coating, blade coating, knife coating, rod coating, gravure coating, rotary screen coating, kiss coating, slot orifice coating, spray coating, cast coating, extrusion coating, etc. can be used, these are short time It is preferable in that a large amount of microlenses can be formed.
[0125]
In the present invention, when applying the microlens-forming coating material to the microlens exposure part, a method by nozzle discharge may be used. As such a nozzle discharge method, for example, a microsyringe, a dispenser, an ink jet, a method in which a microlens-forming coating material is blown from the needle tip by an external stimulus such as an electric field, or a vibration element such as a piezo element that vibrates by an external stimulus is used. For example, a method of flying the microlens forming paint, a method of attaching the microlens forming paint attached to the needle tip to the surface of the base material, or the like can be used. These are suitable for forming a lens-shaped product having a large contact angle and a high height.
[0126]
In the present invention, among the above-described application methods, it is preferable that the microlens coating material is applied by an inkjet method from the viewpoint of application accuracy and rapidity. The ink jet device used in this case is not particularly limited, however, a method in which charged ink is continuously ejected and controlled by a magnetic field, a method in which ink is ejected intermittently using a piezoelectric element, and ink is heated. Ink jet devices using various methods such as a method of intermittently jetting using the foam can be used.
[0127]
The application of the microlens forming paint by the inkjet method is also effective in the case of a colored microlens forming paint in which a colorant is mixed with the microlens forming paint.
[0128]
In this way, the microlens forming coating applied in the microlens exposure unit is cured to form the microlens on the substrate, thereby forming the microlens substrate. In the present invention, the microlens-forming coating is cured by various methods depending on the type of raw material used. For example, in the case of a paint dissolved in a solvent, the solvent is removed by heating or the like to solidify.
[0129]
Considering the curing process of the microlens forming paint, the type of material of the microlens used in the present invention is preferably a photocurable resin. If this is a microlens forming paint using a photocurable resin, the microlens forming paint can be quickly cured by irradiating light, so the manufacturing time of the microlens substrate can be shortened. Because you can.
[0130]
As described above, since the microlens forming paint applied in the microlens exposure part spreads uniformly, the curvature of the microlens is reduced when the microlens forming paint is cured to form the microlens. Can be formed, and a microlens substrate with good positional accuracy can be formed.
[0131]
C. About LCD
The microlens substrate of the present invention can be used as a component adjacent to or in close contact with a display such as a liquid crystal display in order to increase the luminance in the viewer direction. In this case, a light-shielding portion may be provided in order to suppress the influence of ambient light such as room lighting or sunlight and improve display image quality. In addition, for the purpose of enhancing light transmission or preventing color development due to light interference, it is preferable to reduce the thickness of the wettability variable layer, preferably the photocatalyst-containing layer. Specifically, it is 1 μm or less, more preferably 0.2 μm or less.
[0132]
FIG. 5 shows an example of a liquid crystal display using the microlens substrate of the present invention. In this liquid crystal display, the microlens substrate 1 is disposed on the side surface of the color filter 11 of the liquid crystal display unit 12 including the array side substrate 9, the liquid crystal unit 10, and the color filter 11. The microlens substrate 1 is such that each microlens 4 is formed on the substrate 2 so that the position of the microlens substrate 1 coincides with the pixel portion of the color filter 11, and the microlens 4 is on the color filter 11 side. Has been placed. As described above, the microlens substrate 1 is provided with the light shielding portion 6 in order to suppress the influence of external light and improve the display image quality. In such a liquid crystal display, light generated in the liquid crystal display unit 12 passes through the microlens substrate 1 of the present invention and is emitted to the outside as light emission 13, and the brightness to the viewer is increased by the action of the microlens.
[0133]
Since the liquid crystal display using the microlens substrate of the present invention uses a microlens substrate that has good quality and is advantageous in terms of cost, the liquid crystal display has good quality as a liquid crystal display and a low-cost liquid crystal display. It has the advantage of being able to.
[0134]
D. About image sensor
The microlens substrate of the present invention can be used as a component that is adjacent to or in close contact with an imaging element such as a CCD, for example, in order to increase the optical sensitivity of the imaging apparatus. In this case, it is preferable to provide a light-shielding part for the reason of avoiding adverse effects on characteristics such as a decrease in contrast due to stray light. As in the case of the liquid crystal display, the wettability variable layer, preferably the photocatalyst-containing layer, is preferably thinned. The specific thickness is 1 μm or less, more preferably 0.2 μm or less. .
[0135]
FIG. 6 shows an example of an image sensor using the microlens substrate of the present invention. This image pickup device is obtained by arranging the microlens substrate 1 on the side surface of the color filter 14 of the image pickup device portion 16 including the color filter 14 and the photoelectric conversion element 15. In the microlens substrate 1, the light shielding portion 6 is disposed on the colored filter 14 side, and the microlens 4 is formed on the surface opposite to the substrate 2 on which the light shielding portion 6 is formed. Since the incident light 17 enters the image sensor section 16 through the microlens 4 of the microlens substrate 1, the light sensitivity of the image sensor can be increased.
[0136]
The imaging device using the microlens substrate of the present invention uses a microlens substrate that has good quality and is advantageous in terms of cost, so that the imaging device has good quality as an imaging device and is low in cost. Can do.
[0137]
The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
[0138]
【Example】
Hereinafter, the present invention will be described in more detail through examples.
[0139]
Example 1 Formation of Photocatalyst Containing Layer
3 g of isopropyl alcohol, 0.4 g of organosilane (Toshiba Silicone TSL8113), 0.3 g of fluoroalkoxysilane MF-160E (Tochem Products) and 2 g of photocatalytic inorganic coating agent ST-K01 (Ishihara Sangyo) were mixed. This solution was applied onto a quartz glass transparent substrate by spin coating. Then, by drying for 10 minutes at a temperature of 150 ° C., hydrolysis and polycondensation reaction proceeded, and a transparent layer having a thickness of 0.2 μm in which the photocatalyst was firmly fixed in the organopolysiloxane could be obtained. . 70 mW / cm by mercury lamp on this photocatalyst containing layer²The pattern was exposed through a mask at an illuminance of 50 seconds.
[0140]
As a result of measuring the contact angle with the liquid in the non-exposed part and the exposed part, the contact angle is measured in the non-exposed part with a liquid having a surface tension of 30 mN / m (manufactured by Junsei Chemical Co., Ltd., ethylene glycol monoethyl ether). As a result of measurement using a vessel (CA-Z type manufactured by Kyowa Interface Science Co., Ltd., 30 seconds after dropping a droplet from a microsyringe), the exposed portion is a liquid (surface tension 50 mN / m) The contact angle with Wet Standard Reagent Solution No. 50) manufactured by Pure Chemical Co., Ltd. was measured in the same manner, and as a result, it was 7 degrees.
Patterns with different wettability were formed between the exposed and non-exposed areas.
[0141]
Example 2 Formation by Coating Microlens
A photocatalyst-containing layer was formed on a transparent substrate made of quartz glass by the spin coating method using the photocatalyst-containing layer forming material described in Example 1. 70 mW / cm by a mercury lamp through a negative photomask in which a plurality of circular patterns having an opening diameter of 50 μm are arranged at intervals of 2 μm.²The substrate was exposed for 90 seconds at an illuminance of 1 to obtain a transparent substrate having a circular pattern composed of a lyophilic region formed on the surface.
[0142]
1000 g of UV curable monomer (PO-modified glycerin triacrylate: Arakawa Chemical Industries, trade name: Beam Set 720) and 50 g of curing initiator (Ciba Specialty Chemicals, trade name: Irgacure 184) are mixed and stirred for 3 minutes. did. When the obtained liquid mixture (microlens forming paint) was applied by a bead coating method (slide coating method) on the transparent substrate on which the circular pattern with different wettability was applied, the film thickness was 12 μm. The liquid mixture adhered only to the exposed portion (circular pattern portion). This is 70 mW / cm with a mercury lamp.²A microlens substrate having a microlens array with a diameter of 50 μm and a focal length of 1 mm could be obtained by exposing at an illuminance of 5 seconds.
[0143]
(Example 3 / Formation by microlens ejection method)
A photocatalyst-containing layer was formed on a transparent substrate made of quartz glass by the spin coating method using the photocatalyst-containing layer forming material described in Example 1. 70 mW / cm by a mercury lamp through a negative photomask in which a plurality of circular patterns having an opening diameter of 200 μm are arranged at intervals of 100 μm.²The substrate was exposed for 90 seconds at an illuminance of 1 to obtain a transparent substrate having a circular pattern of lyophilic regions formed on the surface.
[0144]
1000 g of UV curable monomer (PO-modified glycerin triacrylate: Arakawa Chemical Industries, trade name: beam set 720), curing initiator UV curable monomer (PO-modified glycerin triacrylate: Arakawa Chemical Industries, trade name: beam) Set 720) 1000 g and photopolymerization initiator (Ciba Specialty Chemicals, trade name: Irgacure 184) 50 g were mixed and stirred for 3 minutes. A circular pattern portion on a transparent substrate on which the circular pattern having different wettability is applied with the liquid mixture (microlens forming coating material) obtained using a liquid precise quantitative discharge device (EFD dispenser 1500XL-15) 0.0001 ml was discharged at the center of the tube. At this time, the discharge liquid (microlens forming paint) spread only in the circular pattern portion, and did not spread in other portions. This is 70 mW / cm with a mercury lamp.²A microlens substrate having a microlens array having a diameter of 200 μm and a focal length of 500 μm could be obtained by exposing at an illuminance of 10 seconds.
[0145]
Example 4 Formation by Colored Microlens Discharge Method
A photocatalyst-containing layer was formed on a transparent substrate made of quartz glass by the spin coating method using the photocatalyst-containing layer forming material described in Example 1. 70 mW / cm by a mercury lamp through a negative photomask in which a plurality of circular patterns with an opening diameter of 200 μm are arranged at intervals of 100 μm.²The substrate was exposed for 90 seconds at an illuminance of 1 to obtain a transparent substrate having a circular pattern composed of a lyophilic region formed on the surface.
[0146]
Next, 500 g of an ultraviolet curable monomer (bifunctional acrylate monomer, Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), 25 g of a photopolymerization initiator (Ciba Specialty Chemicals, trade name: Darocur 1173), red dye (Tokyo Kasei Co., Ltd.) Manufactured by Rose Bengal) and stirred for 3 minutes to obtain a red microlens-forming coating material.
[0147]
In addition, 500 g of an ultraviolet curable monomer (bifunctional acrylate monomer, Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), 25 g of photopolymerization initiator (Ciba Specialty Chemicals, trade name: Darocur 1173), green dye (Tokyo Kasei Co., Ltd.) (Manufactured by Virilliant Green) 0.5 g was mixed and stirred for 3 minutes to obtain a green microlens-forming paint.
[0148]
Furthermore, 500 g of an ultraviolet curable monomer (bifunctional acrylate monomer, Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), 25 g of a photopolymerization initiator (Ciba Specialty Chemicals, trade name: Darocur 1173), blue dye (Tokyo Kasei Co., Ltd.) Manufactured by Victoria Blue) and mixed for 3 minutes to obtain a blue microlens-forming paint.
[0149]
0.0001 ml of the obtained microlens-forming coating material is placed in the center of the circular pattern portion on the transparent substrate on which the circular pattern having different wettability is applied with a liquid precision discharge device (EFD dispenser, 1500XL-15). Discharged. At this time, the discharge liquid (microlens forming paint) spread only in the circular pattern portion, and did not spread in other portions. This is 70 mW / cm with a mercury lamp.²The microlens substrate having a colored microlens array having a diameter of 200 μm and a focal length of 500 μm was obtained by exposing at an illuminance of 10 seconds.
[0150]
(Example 5 / Formation by coating of colored microlenses)
A photocatalyst-containing layer was formed by spin coating using the photocatalyst-containing layer forming material described in Example 1 on a quartz glass transparent substrate. 70 mW / cm by a mercury lamp through a negative photomask in which circular patterns with an opening diameter of 200 μm are arranged at intervals of 100 μm in the vertical direction and at intervals of 700 μm in the horizontal direction.²The substrate was exposed for 90 seconds at an illuminance of 1 to obtain a transparent substrate having a circular pattern as a lyophilic region on the surface.
[0151]
Next, 400 g of an ultraviolet curable monomer (bifunctional acrylate monomer: Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), an ultraviolet curable monomer (1,6 hexanediol diacrylate, Nihon Kayaku Co., Ltd., trade name: KS-HDDA) ) 100 g, 25 g of photopolymerization initiator (manufactured by Ciba Specialty Chemicals, trade name: Darocur 1173) and 0.5 g of red dye (Tokyo Kasei Co., Ltd., Rose Bengal) are mixed and stirred for 3 minutes to form a red microlens A paint was obtained.
[0152]
In addition, 400 g of an ultraviolet curable monomer (bifunctional acrylate monomer: Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), an ultraviolet curable monomer (1,6 hexanediol diacrylate, Nihon Kayaku Co., Ltd., trade name: KS-HDDA) ) 100 g, 25 g of photopolymerization initiator (manufactured by Ciba Specialty Chemicals, trade name: Darocur 1173) and 0.5 g of green dye (Tokyo Chemical Co., Ltd., virilliant green) are mixed, stirred for 3 minutes, and green microlens A forming paint was obtained.
[0153]
Furthermore, 400 g of ultraviolet curable monomer (bifunctional acrylate monomer: Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA), ultraviolet curable monomer (1,6 hexanediol diacrylate, Nippon Kayaku Co., Ltd., trade name: KS-HDDA) ) 100 g, 25 g of photopolymerization initiator (manufactured by Ciba Specialty Chemicals, trade name: Darocur 1173) and 0.5 g of a blue dye (Tokyo Kasei Co., Ltd., Victoria Blue) are mixed and stirred for 3 minutes to form a blue microlens A paint was obtained.
[0154]
When the obtained coating material for forming a micro lens for red was applied by a dip coating method onto a transparent substrate on which a circular pattern having different wettability was applied, the exposed portion (circular pattern portion, lyophilic liquid). The paint adhered only to the sex region). This is 70 mW / cm with a mercury lamp.²The film was cured by exposure for 10 seconds at an illuminance of.
[0155]
A photocatalyst containing layer is formed on the transparent substrate on which the red microlenses are formed in the same manner as described above, and a circular pattern of the lyophilic region is formed under the same conditions as described above at an interval of 100 μm from the vertical row of red lenses. Formed. A green microlens was formed by performing the same operation as that for red using a coating material for forming a microlens for green.
[0156]
The same operation is carried out using the blue microlens forming paint, and a blue microlens is formed with a space of 100 μm between the vertical rows of red and green microlenses, and has a diameter of 200 μm and a focal length of 1 mm. A microlens substrate having a microlens array was obtained.
[0157]
(Example 6 / Formation by coating of light shielding part)
A photocatalyst-containing layer is formed on the back surface of the microlens substrate (substrate: quartz glass) of the present invention having a microlens array having a diameter of 100 μm and arranged at intervals of 10 μm using the photocatalyst-containing layer forming material described in Example 1. Formed. Next, after aligning the photomask and the lens having an opening diameter of 10 μm and arranged at intervals of 100 μm, pattern exposure was performed with a mercury lamp.
[0158]
Next, carbon black was added to a mixed solution of 500 g of an ultraviolet curable monomer (bifunctional acrylate monomer, Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA) and 25 g of a photopolymerization initiator (Ciba Specialty Chemicals, trade name: Darocur 1173). Disperse 100 g to prepare a light shielding part forming composition. When this composition for forming a light-shielding part was applied onto the entire surface of the photocatalyst-containing layer that had been pattern-exposed with a blade coater, the non-exposed part was selectively attached only to the repellency and the exposed part. Subsequently, it heated at 150 degreeC for 30 minute (s), the light shielding part was formed, and the microlens substrate which has a light shielding part was obtained.
[0159]
(Example 7 / Formation of light shielding part by ejection method)
A photocatalyst-containing layer was formed using the photocatalyst-containing layer material described in Example 1 on the back surface of the microlens substrate (substrate: quartz glass) of the present invention having a microlens array having a diameter of 700 μm and arranged at intervals of 10 μm. . Next, pattern alignment was performed with a mercury lamp after alignment with the lens through a photomask having an opening diameter of 10 μm and arranged at intervals of 700 μm.
[0160]
Subsequently, the composition for light-shielding part formation of Example 6 was discharged to the exposure part with the dispenser (made by EFD), and the composition for light-shielding part formation was made to adhere only to the exposure part. Subsequently, it heated at 150 degreeC for 30 minute (s), and the microlens board | substrate which has a light-shielding part was obtained.
[0161]
(Embodiment 8 / Change of focal length depending on discharge amount of micro lens)
Using the photocatalyst-containing layer forming material described in Example 1 on a quartz glass transparent substrate, a photocatalyst-containing layer was formed by a spin coating method. 70 mW / cm by a mercury lamp through a mask having a circular pattern with an opening diameter of 9 mm.²The substrate was exposed for 90 seconds at an illuminance of 1 to obtain a transparent substrate having a circular pattern as a lyophilic region on the surface.
[0162]
500 g of an ultraviolet curable monomer (bifunctional acrylate monomer, Nippon Kayaku Co., Ltd., trade name: KAYARADPEG400DA) and 25 g of a photopolymerization initiator (Ciba Specialty Chemicals, trade name: Darocur 1173) were mixed and stirred for 3 minutes. The obtained microlens-forming paint was discharged by a microsyringe in the center of the circular pattern portion on the transparent substrate on which the circular patterns with different wettability were applied. At this time, the discharge liquid (microlens forming coating material) spreads only to the circular pattern portion and does not spread to other portions, and the contact angle with the substrate increases as the dropping amount increases. This is 70 mW / cm with a mercury lamp.²The lens having a diameter of 9 mm and a focal length of 27 to 90 mm can be designed and created by controlling the discharge amount of the resin mixed liquid (microlens forming paint). The results are shown in Table 1.
[0163]
[Table 1]

[0164]
(Comparative example)
For comparison, 15 to 55 μL of the resin mixed solution was discharged onto a quartz glass transparent substrate having no photocatalyst containing layer (substrate having no wettability pattern). At this time, the discharge liquid spreads as the discharge amount increased, and the shape of the discharge liquid became unstable and various shapes. The contact angle with the substrate also did not change according to the discharge amount. This is 70 mW / cm with a mercury lamp.²Although the lens was exposed for 10 seconds at an illuminance of 1, the shape, diameter, and focal length were not controlled. Table 2 shows the relationship between the amount of the resin solution (microlens-forming coating material) dropped and the contact angle with the substrate, the diameter of the formed lens and the focal length.
[0165]
[Table 2]

[0166]
As is clear from Tables 1 and 2, in the microlens of Example 8, the contact angle of the macrolens with the base material changed depending on the amount of the microlens forming paint dropped, and the focal length also changed accordingly. The microlens of the comparative example did not have such a tendency, and the radius of the formed lens was increased as the amount of the microlens-forming paint increased.
[0167]
Example 9
On the quartz glass transparent substrate, the photocatalyst-containing layer forming material described in Example 1 was used to form a photocatalyst-containing layer by a spin coating method.
[0168]
The photocatalyst-containing layer is 25 mW / cm with a high-pressure mercury lamp.²Irradiation was performed at an illuminance of (365 nm) for 40 seconds, and irradiation was carried out in a pattern with a semiconductor laser having an irradiation wavelength of 830 nm. Pattern irradiation of the semiconductor laser was performed using a galvanometer based on CAD data for forming a microlens array. At this time, the temperature of the semiconductor laser irradiation surface was 50 ° C. Using a contact angle measuring device (Kyowa Interface Science Co., Ltd., CA-Z type), the contact angle with a liquid with a surface tension of 50 mN / m on the irradiated surface (Pure Chemical Co., Ltd., Wetting Standard Reagent Solution No. 50) As a result of measurement (30 seconds after dropping a droplet from the microsyringe), it was 7 degrees.
[0169]
1000 g of UV curable monomer (PO-modified glycerin triacrylate, manufactured by Arakawa Chemical Industries, trade name: Beam Set 720) and 50 g of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) were mixed. The mixture was stirred for minutes to prepare a microlens-forming paint.
[0170]
0.0001 mL of the obtained microlens-forming coating material was discharged onto a portion having different wettability formed based on the CAD data with a liquid precision discharge device (EFD dispenser, 1500XL-15). At this time, the discharge liquid (microlens forming coating material) spreads only to the part having different wettability formed based on the CAD data, and did not spread to other parts.
[0171]
This is 70 mW / cm with a mercury lamp.²The microlens substrate having microlens arrays having various bottom shapes with a diameter of 30 to 50 μm set by CAD data was obtained by exposing at an illuminance of 10 seconds.
[0172]
【The invention's effect】
The present invention includes a substrate, a wettability variable layer provided on the surface of the substrate and capable of changing wettability, and a plurality of microlenses provided on the wettability variable layer. And a microlens substrate. As described above, since the present invention is configured to form a plurality of microlenses on the wettability variable layer, the wettability of the wettability variable layer where the microlens is provided in advance is determined by the contact angle with the liquid. The small lyophilic region can be used, and the wettability variable layer in the other part can be a liquid repellent region having a large contact angle with the liquid. Therefore, by attaching the microlens forming paint to the portion of the lyophilic area where the microlens is provided, the microlens forming paint adheres only to the lyophilic area having a small contact angle with the liquid. The microlens can be formed with high accuracy. Further, the focal length of the microlens is determined by the relationship between the amount of the microlens forming paint and the area of the lyophilic area to which the microlens forming paint is applied. It has the effect that it can be controlled.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of a microlens substrate of the present invention.
FIG. 2 is a schematic cross-sectional view showing adjustment of a focal length in the microlens substrate of the present invention.
FIG. 3 is a schematic cross-sectional view showing an example in which a light shielding portion is formed on a microlens substrate of the present invention.
4 is a schematic plan view showing a surface on which a light shielding portion of the microlens substrate shown in FIG. 3 is formed. FIG.
FIG. 5 is a schematic cross-sectional view showing a liquid crystal display using the microlens substrate of the present invention.
FIG. 6 is a schematic cross-sectional view showing an image sensor using the microlens substrate of the present invention.
[Explanation of symbols]
1 ... Microlens substrate
2 ... Board
3 ... wettability variable layer
4 ... Micro lens

Claims (13)

A substrate provided on the surface of the substrate, possess a wettability-variable layer capable of changing the wettability, and a plurality of microlenses provided on the wettability-variable layer,
The microlens characterized in that the wettability variable layer is a photocatalyst-containing layer composed of at least a photocatalyst and a binder, and the wettability changes so that the contact angle with a liquid is reduced by energy irradiation. substrate.   The microlens substrate according to claim 1, wherein the substrate is a transparent substrate. The photocatalyst-containing layer contains fluorine, and when the photocatalyst-containing layer is irradiated with energy, the photocatalyst-containing layer has a fluorine content on the surface of the photocatalyst-containing layer that is reduced by the action of the photocatalyst as compared with that before energy irradiation. microlens substrate according to claim 1 or claim 2, characterized in that the containing layer is formed. The photocatalyst is titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), bismuth oxide (Bi ₂ O ₃ ), and oxidation. The microlens substrate according to any one of claims 1 to 3 , wherein the microlens substrate is one or more substances selected from iron (Fe ₂ O ₃ ). The microlens substrate according to claim 4, wherein the photocatalyst is titanium oxide (TiO ₂ ). The binder is Y _n SiX _(4-n) (where Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group, or an epoxy group, X represents an alkoxyl group or a halogen, and n represents an integer from 0 to 3.) to be characterized is one or more of the hydrolysis condensate or organopolysiloxane is a cohydrolysis condensate of a silicon compound represented by the claims from claim 1 The microlens substrate according to claim 5 . The microlens substrate according to claim 6, wherein a silicon compound containing a fluoroalkyl group is contained in an amount of 0.01 mol% or more among the silicon compounds constituting the organopolysiloxane. A contact angle with a liquid having a surface tension of 40 mN / m on the photocatalyst-containing layer is 10 degrees or more in a portion not irradiated with energy and less than 10 degrees in a portion irradiated with energy. The microlens substrate according to any one of claims 1 to 7 . (1) providing a photocatalyst-containing layer on the substrate that changes the wettability of the irradiated portion in the direction in which the contact angle with the liquid decreases due to energy irradiation;
(2) forming a microlens exposure part by pattern irradiation with energy on a microlens formation part that is a part for forming a microlens on the photocatalyst-containing layer provided on the substrate;
(3) A method of manufacturing a microlens substrate, comprising: applying a microlens-forming coating material to the microlens exposure portion to form a microlens. 10. The method of manufacturing a microlens substrate according to claim 9 , wherein the step of applying the microlens forming paint to the microlens exposure unit is applied by an inkjet method. The contact angle with the liquid having a surface tension of 40 mN / m on the photocatalyst-containing layer is 10 degrees or more in a portion not irradiated with energy and less than 10 degrees in a portion irradiated with energy. A method for manufacturing a microlens substrate according to claim 9 or 10 . A liquid crystal display using the microlens substrate according to any one of claims 1 to 8 . An image sensor using the microlens substrate according to any one of claims 1 to 8 .

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