JP4231273B2 - Eye characteristics measuring device - Google Patents

Description

（ｆ：第１測定部２５Ａのハルトマン板とＣＣＤとの距離）
【００４３】
ここで、波面収差Ｗをゼルニケ多項式Ｚ_ｉ ^２ｊ−ｉを使った展開であらわすと、
【００４４】
【数２】

【００４５】
上の２つの式と、測定で求められた△ｘ、△ｙ（よって、Ｘ、Ｙも含む）に関する測定値を使って、ゼルニケ係数ｃ_ｉ ^２ｊ−ｉの各値を求めることができる。また、角膜収差を求める場合、前眼部観察部４０の前眼部像受光部４１からの信号に基づき、角膜の傾き及び角膜の高さを計算し、角膜を光学レンズと同様に扱うことにより光学特性が計算される。なお、図１８、図１９に、ゼルニケ多項式についての説明図（１）及び（２）を示す。
【００４６】
次に、演算部６００は、測定結果が得られたか判断する（Ｓ１０３）。演算部６００は、例えば、収差測定１において取得したハルトマン像の各点像の重心位置が所定の数以上（例えば３分の１以上）取れない、又は各点像のぼけが大きいとき（例えば、無収差時の２０倍以上など）、又は隣接するスポット像と分離できずに検出できない点が所定の数以上ある等の予め定められたひとつ又は複数の適宜の条件に従い判断することができる。ここで、演算部６００は、測定結果が得られた場合（Ｓ１０３）、ステップＳ１０５の処理へ移り、一方、測定結果が得られなかった場合（Ｓ１０３）、図６に示すステップＳ１５１の処理へ進む。
【００４７】
ステップＳ１０５では、演算部６００は、求められた収差を打ち消すような補償光学部６０における補償量Ｍを求め、制御部６１０及び第５駆動部９１４を介して、補償量Ｍに応じた信号（１５）を出力し、可変鏡等の補償光学部６０をゆがませる（Ｓ１０５）。また、補償光学部６０は、信号（１５）に従い適宜の変形手段により変形する。なお、補償光学部６０は、可変鏡以外に、液晶空間光変調器を用いても良い。以下、収差を打ち消すために必要な補償光学部６０における補償量Ｍの算出について説明する。
【００４８】
図７は、可変鏡上の座標（Ｘ_ｍ、Ｙ_ｍ）と光学系の座標（Ｘ、Ｙ）の関係の説明図である。補償する収差をＷｃとし、解析された収差の式が、
【００４９】
【数３】

【００５０】
であるとき、可変鏡上の座標（Ｘ_ｍ、Ｙ_ｍ）と光学系の座標（Ｘ、Ｙ）の関係は、可変鏡への入射角θを考慮して、
【００５１】
【数４】

【００５２】
となる。可変鏡の補償量Ｍは、反射であることから２倍効くことと、目の瞳孔と可変鏡での倍率を考慮する。可変鏡の瞳孔に対する倍率をｋとすると、補償量Ｍは、
【００５３】
【数５】

【００５４】
となる。ここで求められた補償量Ｍは、収差の高次成分を含むことができる。補償光学部６０は、演算部６００から出力された補償量Ｍに基づいて変形する。なお、倍率ｋ及び無補償状態での入射角θは予め設定された値であり、予めメモリ８００に記憶されている。なお、低次成分の球面度数成分は、移動部１５によって第１受光光学系２０Ａを移動させることにより補償することもできる。また、低次成分の乱視成分は、バリアブルクロスシリンダー１３ｂを回動することにより補償することもできる。例えば、求められた収差のうち、３次以上の高次収差が所定以上でない場合に、演算部６００は、求められた収差に従い第１受光光学系２０Ａを移動及び／又はバリアブルクロスシリンダー１３ｂを回動させることができる。この場合、例えば演算部６００は、求められた収差のうち球面度数成分ｃ_２ ^０に従い第２受光光学系２０Ａを移動させ、及び／又は、乱視成分ｃ_２ ^−２並びにｃ_２ ^２に従いバリアブルクロスシリンダー１３ｂを回動させる。さらに、演算部６００は、ｃ_２ ^０及び／又はｃ_２ ^−２並びにｃ_２ ^２以外の収差に従い補償量Ｍを求め、補償量Ｍに基づいて補償光学部６０を変形させる。このとき、補償量Ｍは、ｃ_２ ^０＝０及び／又はｃ_２ ^−２＝０並びにｃ_２ ^２＝０として算出すればよい。なお、補償量Ｍは、球面度数成分及び／又は乱視成分の補償後に再度収差を測定し、この収差に基づき算出してもよい。
【００５５】
ゆがませた可変鏡をさらにゆがませる場合、補償後に測定された収差に対して上記の解析と同様に補償量Ｍを求め、補償後の可変鏡にさらにその分を付加すればよい。また、補償光学部６０により完全に収差をなくすのではなく、若干ハルトマン板への入射光を発散方向にする又は傾けるようにしてもよい。これにより第１測定部２５Ａにおいて、補償後の収差を高い感度で測定することができる。演算部６００は、収差測定１の測定結果が得られなかった場合（Ｓ１０３）、図６の収差補償の処理へ移る。
【００５６】
図６は、ハルトマン像から被検眼１００の光学特性が求められない場合の収差測定のフローチャートである。以下、図６に示す処理について説明する。
【００５７】
まず、演算部６００は、おおよその収差量が分かる、もしくは適当に収差補正をしてみるか判断する（Ｓ１５１）。例えば、角膜収差，過去の収差データ等を参考に測定を続けるかどうか判断する。判断方法としては、演算部６００は、自動的に表示したダイアログボックス、もしくはメニューから立ち上げた入力部６５０等から測定を続ける又は終了する信号を入力しても良い。また、演算部６００は、メモリ８００に角膜収差データ又は過去の収差データがあるかを検索し、データの有無によって測定を続けるか終了するかを判断しても良い。
【００５８】
演算部６００は、測定を続けない場合、表示部７００に解析不可能通知表示を行い（Ｓ１５３）、測定を終了する。一方、演算部６００は、測定を続ける場合、角膜収差データ、過去の収差データ等のゼルニケ係数、収差データ等を、装置内のメモリ８００、もしくは入力部６５０から入力し、可変鏡等の補償光学部６０の補償量Ｍを求め、制御部６１０及び第５駆動部９１４を介して可変鏡をゆがませる（Ｓ１５５）。また、演算部６００は、前眼部観察部４０の前眼部像受光部４１からの信号を入力して角膜波面収差を求め、求めた収差に基づいて補償量Ｍを算出してもよい。補償量Ｍの算出についてはステップＳ１０５と同様である。演算部６００は、制御部６１０及び第５駆動部９１４を介して、補償量Ｍに応じた信号（１５）を出力し、補償光学部６０をゆがませる。
【００５９】
次に、演算部６００は、補償後に光学特性の測定が可能か判断する（Ｓ１５７）。演算部６００は、例えば、第１受光部２１Ａからハルトマン像を入力し、入力したハルトマン像の重心位置が所定の数以上（例えば３分の１）取れない、もしくは各点像のぼけが大きい（例えば、無収差時の２０倍以上など）、もしくは隣接するスポット像と分離できずに検出できない点が所定の数以上ある等の予め定められたひとつ又は複数の適宜の条件に従い判断することができる。演算部６００は、測定不可能な場合、さらに補償するか判断する（Ｓ１５９）。例えば、演算部６００は、自動的に表示したダイアログボックス、もしくはメニューから立ち上げた入力部６５０等から測定を続ける又は終了する信号を入力しても良い。また、演算部６００は、メモリ８００に別の収差データがあるかを検索しても良い。演算部６００は、補償する場合はステップＳ１５５へ戻り、一方、補償しない場合は、表示部７００に解析不可能通知を表示し（Ｓ１６１）、測定を終了する。
【００６０】
一方、演算部６００は、測定可能な場合（Ｓ１５７）、図５のステップＳ１０６へ進む。
図５に戻り、演算部６００は、第２受光部２１Ｂから第２信号を取得し、補償光学部６０で補償されている収差（補償収差）を測定する（Ｓ１０６）。第２受光部２１Ｂで受光される光束は、第２光源部１６から発した無収差の光束が補償光学部６０で反射することで、補償光学部６０での補償収差を有した光束である。この光束を受光し、収差を測定することで、補償光学部６０での補償収差を正確に得ることができる。例えば、補償光学部６０による収差を打ち消すための入力値と、実際に打ち消している収差にずれがある場合、このずれにより生ずる測定誤差を除去することができる。
【００６１】
次に、演算部６００は、収差測定２として、第１受光部２１Ａから第１信号を取得し、収差を求める（Ｓ１０７）。ここで求められる収差は、補償後の収差であり、第１測定部２５Ａによって、微小な収差を高精度に測定可能である。また、ステップＳ１０６及びＳ１０７の処理は、逆の順序で行っても良いし、並行して行うこともできる。
【００６２】
演算部６００は、ステップＳ１０７で得られた収差が、予め定められた許容値以下であるか判断する（Ｓ１０９）。例えば、演算部６００は、高次収差のＲＭＳ値が０．１以下であるかを判断しても良い。収差のＲＭＳ値は、ゼルニケ係数ｃ_ｉ ^２ｊ−ｉを用いて次式で算出される。
【００６３】
【数６】

【００６４】
演算部６００は、これら収差のＲＭＳ値の予め定められた一つ又は複数が許容値以下であるか判断する。
【００６５】
演算部６００は、収差が許容値より大きい場合（Ｓ１０９）、ステップＳ１０５へ戻り、さらに補償光学部６０をゆがませる。一方、演算部６００は、許容値より小さい場合（Ｓ１０９）、ステップＳ１０７で測定された収差Ｗ２に、ステップＳ１０６で測定された補償収差Ｗ１を加えて、実際の被検眼１００の収差Ｗ（ゼルニケ係数ｃ_ｉ ^２ｊ−ｉを含む）を求める（Ｓ１１１）。また、演算部６００は、求められたゼルニケ係数ｃ_ｉ ^２ｊ−ｉと光学系の配置（例、移動位置が初期条件でどこに来ているかなどの情報）により、既知の方法をつかって、球面度数Ｓ、乱視度数Ｃ、乱視軸Ａ、高次球面収差等の光学特性を得ることができる。演算部６００は、次式のようにゼルニケ係数の２次項から球面度数Ｓ、乱視度数Ｃ、乱視軸Ａを求めることができる。
【００６６】
【数７】

（ここに、ＳＥ：等価球面度数、Ｓ_ｍｏｖｅ：固視移動分の球面度数、ｒ：瞳径）
【００６７】
次に、演算部６００は、求められた収差マップ、収差係数、ハルトマン像等の測定結果を表示部７００に表示し、メモリ８００に記憶する（Ｓ１１３）。また、演算部６００は、メモリ８００から角膜形状データ等を読み出し、表示部７００にさらに表示しても良い。
【００６８】
さらに、演算部６００は、測定を終了するか判断し（Ｓ１１５）、測定を続ける場合はステップＳ１０１に戻り、終了の場合は測定を終了する。測定終了の判断は、例えば、演算部６００は、自動的に表示したダイアログボックス、もしくはメニューから立ち上げた入力部６５０等から測定を続ける又は終了する信号を入力しても良い。
【００６９】
図８は、第１の実施の形態の光学系における収差測定のフローチャートの第１の変形例である。本変形例は、補償収差の測定と補償後の収差測定を並行して行う例である。各処理の詳細については、図５と同様であるので、同じ符号を付し説明を省略する。
【００７０】
図９は、第１の実施の形態の光学系における収差測定のフローチャートの第２の変形例である。本変形例は、補償後の収差測定毎に、被検眼１００の収差演算及び演算結果の出力を行う例である。
【００７１】
まず、演算部６００は、ステップＳ１０１〜Ｓ１０７及びステップＳ１１１の処理を実行する。処理の詳細については上述と同様であるので省略する。
【００７２】
演算部６００は、求められた波面収差マップ、収差係数、ハルトマン像等の測定結果を表示部７００に表示し、メモリ８００に記憶する（Ｓ２０１）。なお、表示部７００への表示は必ずしも毎回行う必要はない。例えば、表示部７００への表示処理に時間がかかる等、測定に影響を及ぼす場合、一定の測定回数毎に結果を表示するようにしても良い。
【００７３】
演算部６００は、ステップＳ１１１で得られた収差２が、予め定められた許容値以下であるか判断する（Ｓ１０９）。判断基準は、上述と同様とすることができる。演算部６００は、収差が許容値より大きい場合、ステップＳ１０５へ戻り、許容値より小さい場合、求められた波面収差マップ、収差係数等の測定結果を表示部７００に表示し、メモリ８００に記憶する（Ｓ２０３）。なお、ステップＳ２０１において、既に当該測定結果の表示、記憶を行っている場合は、ステップＳ２０３の処理を省略しても良い。なお、演算部６００は、収差が許容値以下であるかを判断する代わりに、さらに補償光学部６０をゆがませるかの入力を指示する表示を表示部７００に出力し、入力部６５０から信号を入力するようにしてもよい。次に、演算部６００は、ステップＳ１１５の処理を実行する。処理の詳細は上述と同様である。
【００７４】
（第２の実施の形態の光学系のフローチャート）
図１０は、第２の実施の形態の光学系における収差測定のフローチャートである。図１０は、図２又は図３に示すような長焦点又は高感度の第１測定部２５Ａと、短焦点または低感度の第３測定部２５Ｃを備える光学系を用いた形態におけるフローチャートである。演算部６００は、短焦点または低感度の第３測定部２５Ｃの信号に基づき補償光学部６０での補償量Ｍを高速に求め、補償光学部６０をゆがませる。また、演算部６００は、第２受光部２１Ｂで受光された第２信号に基づく補償光学部６０での補償収差と、長焦点又は高感度の第１測定部２５Ａの信号に基づく補償後の収差から被検眼１００の光学特性を求める。
【００７５】
まず、演算部６００は、短焦点又は低感度の第３測定部２５Ｃでの信号に基づいて収差測定１を行う（Ｓ２５１）。演算部６００は、第３測定部２５Ｃの第３受光部２１Ｃからハルトマン像を取得し、取得した画像に基づき、スポット像の重心点を検出する。無収差での重心点を中心とする矩形エリア内でそのスポットと対応する重心位置を探すことで高速可能となるように対応付けする。演算部６００は、得られたスポット像の重心点に基づいて、被検眼１００の粗い収差を求める。
次に、演算部６００は、ステップＳ１０３、Ｓ１０５、１０６の処理を実行する。処理の詳細は上述と同様であるので省略する。
【００７６】
演算部６００は、長焦点又は高感度の第１測定部２５Ａからの信号に基づいて収差測定２を行う（Ｓ２５７）。演算部６００は、第１測定部２５Ａの第１受光部２１Ａから、ハルトマン像の第１信号を入力する。次に、演算部６００は、入力した第１信号から、ハルトマン像の点像移動量を求め、点像移動量に基づき被検眼１００の光学特性を求める。従来の長焦点又は高感度の測定部を用いる収差測定では、スポット像のずれが大きくなることがあり、スポット像の対応付けに時間がかかる、又は、対応が取れず測定ができない場合がある。本実施の形態では、入力したハルトマン像の第１信号は、被検眼１００の収差がある程度打ち消されているハルトマン像であるため、長焦点又は高感度であってもスポットの位置ずれは小さくなっており、精密かつ高速な収差演算が可能である。また、ステップＳ１０６及びＳ２５７の処理は、逆の順序で行っても良いし、並行して行っても良い。
【００７７】
次に、演算部６００は、ステップＳ１０９〜Ｓ１１５の処理を実行する。処理の詳細は上述と同様であるので省略する。なお、第２の実施の形態において、図９に示す変形例のように、補償後の収差測定毎に、被検眼１００の収差演算及び演算結果の出力を行う変形も可能である。
【００７８】
（第３の実施の形態の光学系のフローチャート）
第３の実施の形態の光学系におけるフローチャートは、図１０に示すフローチャートを用いることができる。なお、図３に示す光学系を用いた場合、ステップＳ１０６における補償収差の測定は、第２受光光学系２０Ｂを用いる代わりに、第３受光光学系２０Ｃを用いることも可能である。また、演算部６００は、ステップＳ２５７の第１測定部２５Ａでの収差測定２よりも前に、第３受光部２１Ｃの出力に基づく収差が、予め定められた許容値以下となるように補償光学部６０を変形させても良い。
【００７９】
図１１は、第３の実施の形態の光学系における収差測定のフローチャートの変形例である。本変形例は、図３に示す光学系を用いて収差が補償された光束を第３受光部２１Ｃで受光し、第３受光部２１Ｃからの信号に基づき求められる収差が、予め定められた許容値以下になるように補償を行う例である。
【００８０】
まず、演算部６００は、ステップＳ２５１、Ｓ１０３、Ｓ１０５の各処理を実行する。処理の詳細については上述と同様であるので省略する。次に、演算部６００は、第３測定部２５Ｃでの信号に基づいて、補償後の収差の測定を行う（Ｓ２５３）。処理の詳細は、上述のステップＳ２５１と同様であるので省略する。演算部６００は、ステップＳ２５３で求められた収差が、予め定められた第１許容値以下であるか判断する（Ｓ２５５）。例えば、演算部６００は、高次収差のＲＭＳ値が０．１以下であるかを判断しても良い。演算部６００は、収差が第１許容値より大きい場合、ステップＳ１０５へ戻り、さらに補償光学部６０をゆがませる。一方、演算部６００は、収差が第１許容値より小さい場合、ステップＳ１０６の処理へ移る。
【００８１】
また、演算部６００は、収差が第１許容値以下であるかを判断する代わりに、第１受光部２１Ａから第１信号を入力し、第１信号に基づく測定が可能かを判断しても良い。演算部６００は、例えば、入力した第１信号に基づく各点像の重心位置が所定の数以上（例えば３分の１以上）取れない、又は各点像のぼけが大きい（例えば、無収差時の２０倍以上など）、又は隣接するスポット像と分離できずに検出できない点が所定の数以上ある等の予め定められたひとつ又は複数の条件により、第１信号に基づく測定が不可能と判断することができる。また、判断条件は、適宜の条件を用いてよい。ここで、演算部６００は、測定不可能と判断した場合、ステップＳ１０５の処理へ移り、一方、測定可能と判断した場合ステップＳ１０６の処理へ移る。
【００８２】
演算部６００は、ステップＳ１０６、Ｓ２５７の処理を実行する。処理の詳細については上述と同様であるので省略する。次に、演算部６００は、ステップＳ２５７で求められた収差２が、予め定められた第２許容値以下であるか判断する（Ｓ２５９）。例えば、演算部６００は、高次収差のＲＭＳ値が０．１以下であるかを判断しても良い。また、第１許容値と第２許容値は、異なる値を取ることができる。例えば、測定の感度を考慮して、第１許容値≧第２許容値としてもよい。演算部６００は、収差２が第２許容値より大きい場合（Ｓ２５９）、収差２に従い、補償光学部６０をさらにゆがませ（Ｓ２６１）、ステップＳ２５７へ戻る。補償光学部６０をゆがませる処理の詳細は、ステップＳ１０５と同様である。一方、演算部６００は、収差２が第２許容値より小さい場合、ステップＳ１１１の処理へ移る。
次に、演算部６００は、ステップＳ１１１〜Ｓ１１５の処理を実行する。処理の詳細は上述と同様であるので省略する。
【００８３】
４．変形例
（第１の実施の形態の変形例）
図１２は、眼特性測定装置の光学系の第４の構成図である。図１２は、図１における収差測定用の第１測定部２５Ａと、補償収差測定用の第２測定部２５Ｂを共用する変形例である。例えば、第１光源部１１と第２光源部１６を交互に点灯することで、第１受光光学系２０Ａには、被検眼１００から反射して戻ってくる光束と、第２光源部１６から発した光束が切り替えられて入射する。また、第１光源部１１と第２光源部１６の前にチョッパーを設け、第１受光光学系２０Ａに入射する光束を制御するようにしてもよい。なお、チョッパー以外にも、光束を遮断する適宜の手段を用いてもよい。その他各部の詳細な説明については、図１と同様であるので同じ符号を付し省略する。また、図１２には、図１の点線枠にあたる部分のみを示しているが、それ以外の部分については図１と同様である。
【００８４】
図１３は、第１の実施の形態の変形例における第１のフローチャートである。図１３は、図１２に示す測定部を共用した光学系を用いて、１つの測定部を切り替えることにより、補償収差の測定と、補償後の収差の測定を行うフローチャートである。
【００８５】
まず、演算部６００は、第１測定部２５Ａからの出力に基づく被検眼１００の収差測定１を行う（Ｓ３０１）。演算部６００は、例えば、第１光源部１１を点灯、第２光源部１６を消灯することで、被検眼１００で反射した光束が第１受光光学系２０Ａに入射するようにし、第１受光部２１Ａから第１信号を入力する。次に、演算部６００は、入力した第１信号に基づき被検眼１００の収差を求める。収差の演算については、上述と同様である。さらに、演算部６００は、前眼部観察部４０の前眼部像受光部４１からの信号に基づき角膜形状、角膜収差等を求めてもよい。また、演算部６００は、これら計算結果をメモリ８００に記憶する。
演算部６００は、ステップＳ１０３、Ｓ１０５の処理を実行する。処理の詳細は上述と同様であるので省略する。
【００８６】
演算部６００は、第１測定部２５Ａからの信号に基づき、補償収差を測定する（Ｓ３０６）。演算部６００は、例えば、第１光源部１１を消灯、第２光源部１６を点灯することで、第２光源部１６から発し、補償光学部６０で反射した光束が第１受光光学系２０Ａに入射するようにする。さらに、演算部６００は、第１受光部２１Ａから第１信号を入力し、入力した第１信号に基づいて、補償光学部６０での補償収差を測定する。収差の演算については、上述と同様である。また、演算部６００は、求めた収差をメモリ８００に記憶する。
【００８７】
次に、演算部６００は、第１測定部２５Ａからの出力に基づく被検眼１００の収差測定２を行う（Ｓ３０７）。処理の詳細は、ステップＳ３０１と同様である。
【００８８】
なお、上述の処理では、演算部６００は、第１受光光学系２０Ａへ入射する光束を、第１及び第２光源部１１及び１６の点灯・消灯によって切り替えているが、第１及び第２光源部１１及び１６の前にチョッパー等の光束を遮断する手段を設け、これを制御することにより第１受光光学系２０Ａへ入射する光束を切り替えるようにしてもよい。また、ステップＳ３０６とＳ３０７の処理は、順序を逆にしてもよい。
演算部６００は、ステップＳ１０９〜Ｓ１１５の処理を実行する。処理の詳細については上述と同様であるので省略する。
【００８９】
図１４は、第１の実施の形態の変形例における第２のフローチャートである。図１４は、補償後の収差測定毎に、被検眼１００の収差演算及び演算結果の出力を行う変形例である。各処理の詳細については図９及び図１３と同様であるので、同じ符号を付しその説明は省略する。
【００９０】
（第２の実施の形態の変形例）
図１５は、眼特性測定装置の光学系の第５の構成図である。図１５は、図２における収差測定用の第１測定部２５Ａと、補償収差測定用の第２測定部２５Ｂを共用する変形例である。例えば、第１光源部１１と第２光源部１６を交互に点灯することで、第１受光部２１Ａは、被検眼１００から反射して戻ってくる光束と、第２光源部１６から発した光束を切り替えて受光する。また、第１光源部１１と第２光源部１６の前にチョッパー等の適宜の光束遮断手段を設け、第１受光光学系２０Ａ及び第３受光光学系２０Ｃに入射する光束を制御するようにしてもよい。その他各部の詳細な説明については、図２と同様であるので同じ符号を付し省略する。図１５には、図１の点線枠にあたる部分のみを示しているが、それ以外の部分については図１と同様である。
【００９１】
図１６は、第２の実施の形態の変形例におけるフローチャートである。図１６は、図１５に示す短焦点又は低感度の第３受光光学系２０Ｃを備える光学系に対するフローチャートである。この例では、１つの測定部を切り替えることにより、補償収差の測定と、眼特性測定用の測定を行う。各処理の詳細については図１０、図１３と同様であるので、同じ符号を付しその説明は省略する。また、図１１に示す変形例と同様に、第３測定部２５Ｃからの出力により測定された収差が予め定められた許容値以下になるまで、補償光学部６０を変形することも可能である。
【００９２】
（第３の実施の形態の変形例）
図１７は、眼特性測定装置の光学系の第６の構成図である。図１７は、図３における収差測定用の第１測定部２５Ａと、補償収差測定用の第２測定部２５Ｂを共用する変形例である。第１の実施の形態の変形例と同様に、第１受光光学２０Ａに入射する光束を切り替えて測定する。また、その他各部の詳細な説明については、図３と同様であるので同じ符号を付し省略する。図１７には、図１の点線枠にあたる部分のみを示しているが、それ以外の部分については図１と同様である。
また、第３の実施の形態の変形例におけるフローチャートは、図１６に示すフローチャートを用いることができる。
【００９３】
【発明の効果】
本発明によると、被検眼１００の光学特性を測定する場合に、測定光の収差を打ち消すような補正をし、さらに補正されていない小さな収差量を測定し、精密な測定を行う眼特性測定装置が提供できる。また、本発明によると、収差を打ち消すための入力値と、実際に補償されている収差にずれの影響を除去し、より正確な測定を行うことができる。本発明によると、低感度と高感度の光学系の特性を生かし、精密かつ高速な測定ができる。さらに、本発明によると、測定光の収差を打ち消すことにより、収差量が多い場合においても測定が可能な測定レンジの広い眼特性測定装置が提供できる。
【図面の簡単な説明】
【図１】眼特性測定装置の光学系の第１の構成図。
【図２】眼特性測定装置の光学系の第２の構成図。
【図３】眼特性測定装置の光学系の第３の構成図。
【図４】眼特性測定装置の電気系の構成図。
【図５】第１の実施の形態の光学系における収差測定のフローチャート。
【図６】ハルトマン像から被検眼の光学特性が求められない場合の収差測定のフローチャート。
【図７】可変鏡上の座標と光学系の座標の関係の説明図。
【図８】第１の実施の形態の光学系における収差測定のフローチャートの第１の変形例。
【図９】第１の実施の形態の光学系における収差測定のフローチャートの第２の変形例。
【図１０】第２の実施の形態の光学系における収差測定のフローチャート。
【図１１】第３の実施の形態の光学系における収差測定のフローチャートの変形例。
【図１２】眼特性測定装置の光学系の第４の構成図。
【図１３】第１の実施の形態の変形例における第１のフローチャート。
【図１４】第１の実施の形態の変形例における第２のフローチャート。
【図１５】眼特性測定装置の光学系の第５の構成図。
【図１６】第２の実施の形態の変形例におけるフローチャート。
【図１７】眼特性測定装置の光学系の第６の構成図。
【図１８】ゼルニケ多項式（１）。
【図１９】ゼルニケ多項式（２）。
【符号の説明】
１０ 第１照明光学系
１１ 第１光源部
１６ 第２光源部
２０Ａ 第１受光光学系
２１Ａ 第１受光部
２５Ａ 第１測定部
２０Ｃ 第３受光光学系
２１Ｃ 第３受光部
２５Ｃ 第３測定部
２０Ｂ 第２受光光学系
２１Ｂ 第２受光部
２５Ｂ 第２測定部
３０ 前眼部観察部
４０ 前眼部照明部
５０ 第１調整光学部
６０ 補償光学部
７０ 第２調整光学部
９０ 視標光学部
６００ 演算部
６１０ 制御部
６５０ 入力部
７００ 表示部
８００ メモリ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an eye characteristic measuring apparatus, and more particularly to an eye characteristic measuring apparatus that accurately measures optical characteristics of an eye to be examined using a wavefront sensor.
[0002]
[Prior art]
2. Description of the Related Art In recent years, optical instruments used for medical use have become widespread as optical characteristic measuring apparatuses that perform eye functions such as eye refraction and adjustment, and examination of the inside of an eyeball, particularly in ophthalmology. For example, there is an apparatus called a photorefractometer that obtains the refractive power and corneal shape of the eye to be examined.
[0003]
Also disclosed is a retinal image resolution improving apparatus that corrects wave aberration by deforming a deformable optical member such as a deformable mirror, and has a half width but the same shape as the wave aberration. (For example, refer to Patent Document 1). In this device, the laser light reflected from the retina of the eye forms a wavefront on the Hartmann Shack wavefront sensor via a deformable mirror. The formed wavefront is digitized via a camera by a digital processor, and wave aberration is measured. The digital data processor transmits a correction signal that feeds back to the deformable mirror based on the measured wave aberration. The deformable mirror is deformed to correct the wave aberration of the eye and has the same shape although the width of the wave aberration is half.
[Patent Document 1]
JP-T-2001-507258
[0004]
[Problems to be solved by the invention]
However, in an apparatus for measuring the optical characteristics of an eye having an aberration, accurate measurement may be difficult when the amount of aberration is large.
[0005]
In view of the above points, the present invention performs correction so as to cancel the aberration of the measurement light when measuring the optical characteristics of the eye to be measured, and further measures a small amount of uncorrected aberration to perform precise measurement. An object of the present invention is to provide an eye characteristic measuring device. Another object of the present invention is to perform more accurate measurement in consideration of a case where there is a difference between an input value for canceling out aberration and an actually corrected aberration. An object of the present invention is to perform precise and high-speed measurement using an optical system with low sensitivity and high sensitivity. Furthermore, an object of the present invention is to provide an eye characteristic measuring device having a wide measurement range that can be measured even when the amount of aberration is large by canceling out the aberration of the measuring light.
[0006]
[Means for Solving the Problems]
According to the first solution of the present invention,
A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A first light receiving optical system for receiving a part of the reflected light beam reflected from the retina of the eye to be examined through the compensation optical unit and the first conversion member that converts the reflected light into at least substantially 17 beams; ,
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A second light receiving optical system for receiving the light beam from the second light source unit via the compensation optical unit and a second conversion member that converts at least substantially 17 beams;
A second light receiving portion for receiving a light flux of the second light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the first light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
The optical characteristics compensated by the compensating optical unit based on the output of the second light receiving unit and the optical characteristics based on the output of the first light receiving unit after compensation by the compensating optical unit are measured, and these measured opticals A measurement calculation unit for obtaining the optical characteristics of the eye to be examined based on the characteristics;
Is provided.
[0007]
According to the second solution of the present invention,
A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A part of the reflected light beam reflected from the retina of the eye to be examined and the light beam from the second light source unit are received through the adaptive optics unit and the first conversion member that converts at least substantially 17 beams. A first light receiving optical system for
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the first light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
Based on the output of the first light receiving unit by the light beam from the second light source unit, the optical characteristic compensated by the compensation optical unit is measured, while the first light receiving unit by the light beam from the first light source unit is measured. Based on the output, a measurement calculation unit that measures the optical characteristics after compensation by the adaptive optics unit, and obtains the optical characteristics of the eye to be inspected based on the measured optical characteristics;
Is provided.
[0008]
According to the third solution of the present invention,
A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
For receiving a part of the reflected light beam reflected from the retina of the eye to be examined through the adaptive optics and at least substantially the first conversion member having a long focus or high sensitivity for converting the beam into 17 beams. A first light receiving optical system;
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A second light receiving optical system for receiving the light beam from the second light source unit via the compensation optical unit and a second conversion member that converts at least substantially 17 beams;
A second light receiving portion for receiving a light flux of the second light receiving optical system;
Via a third conversion member having a short-focus or low-sensitivity lens unit that converts part of the reflected light beam reflected and returned from the retina of the eye to be converted into at least substantially 17 beams. A third light receiving optical system for receiving light;
A third light receiving portion for receiving a light flux of the third light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the third light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
The optical characteristics compensated by the compensating optical unit based on the output of the second light receiving unit and the optical characteristics based on the output of the first light receiving unit after compensation by the compensating optical unit are measured, and these measured opticals A measurement calculation unit for obtaining the optical characteristics of the eye to be examined based on the characteristics;
Is provided.
[0009]
According to the fourth solution of the present invention,
A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A long-focus or high-sensitivity first that converts part of the reflected light beam reflected from the retina of the eye to be examined and the light beam from the second light source unit into the adaptive optics unit and at least substantially 17 beams. A first light receiving optical system for receiving light through the conversion member;
A first light receiving portion for receiving a light flux of the first light receiving optical system;
Via a third conversion member having a short-focus or low-sensitivity lens unit that converts part of the reflected light beam reflected and returned from the retina of the eye to be converted into at least substantially 17 beams. A third light receiving optical system for receiving light;
A third light receiving portion for receiving a light flux of the third light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the third light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
Based on the output of the first light receiving unit by the light beam from the second light source unit, the optical characteristic compensated by the compensation optical unit is measured, while the first light receiving unit by the light beam from the first light source unit is measured. Based on the output, a measurement calculation unit that measures the optical characteristics after compensation by the adaptive optics unit, and obtains the optical characteristics of the eye to be inspected based on the measured optical characteristics;
Is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1. Optical system configuration
(Optical system in the first embodiment)
FIG. 1 shows a first configuration diagram of an optical system of an eye characteristic measuring apparatus.
The eye characteristic measurement device includes a first illumination optical system 10, a first light source unit 11, a second light source unit 16, a first measurement unit 25A, a second measurement unit 25B, and an anterior eye unit illumination unit 30. The anterior eye observation unit 40, the first adjustment optical unit 50, the compensation optical unit 60, the second adjustment optical unit 70, and the target optical unit 90 are provided. The first measurement unit 25A includes a first light receiving optical system 20A and a first light receiving unit 21A. The second measuring unit 25B includes a second light receiving optical system 20B and a second light receiving unit 21B. For the eye 100, the retina (fundus) and cornea (anterior eye) are shown.
[0011]
Hereinafter, each part will be described in detail.
The first illumination optical system 10 is for illuminating a minute region on the fundus of the eye 100 to be examined with the light flux from the first light source unit 11. The first illumination optical system 10 includes, for example, a condenser lens, a pair of positive and negative cylinder lenses 13a (so-called variable cross cylinders), and a relay lens. The variable cross cylinder 13a may not be provided.
[0012]
The first light source unit 11 emits a light beam having a first wavelength. The first light source unit 11 preferably has high spatial coherence and not high temporal coherence. Here, as an example, the first light source unit 11 employs an SLD (super luminescence diode), and a point light source with high luminance can be obtained. Note that the first light source unit 11 is not limited to the SLD, and even the one having high coherence in both space and time, such as a laser, can be used by appropriately reducing the time coherence by inserting a rotating diffusion plate or the like. it can. And even if the LED does not have high coherence in space and time, it can be used by inserting a pinhole or the like at the position of the light source in the optical path as long as the amount of light is sufficient. Moreover, the wavelength of the 1st light source part 11 for illumination can use the wavelength (for example, 780 nm) of an infrared region, for example.
[0013]
The first light receiving optical system 20A is for receiving, for example, a light beam reflected and returned from the retina of the eye 100 to be guided to the first light receiving unit 21A. The first light receiving optical system 20A includes, for example, a first conversion member 22A (eg, a Hartmann plate), an afocal lens, a variable cross cylinder 13b, and a relay lens. The first conversion member 22A is a wavefront conversion member having a lens unit for converting the reflected light flux into at least 17 plural beams. The first conversion member 22A may be a wavefront conversion member having a long focal point or a highly sensitive lens unit. For the first conversion member 22A, a plurality of micro Fresnel lenses arranged in a plane orthogonal to the optical axis can be used. The reflected light from the fundus is condensed on the first light receiving part 21A via the first conversion member 22A. The first light receiving unit 21A is for receiving light from the first light receiving optical system 20A that has passed through the first conversion member 22A and generating a first signal. Further, the front focal point of the afocal lens 42 substantially coincides with the pupil of the eye 100 to be examined.
[0014]
The second light source unit 16 emits a light beam having a second wavelength. The light beam emitted from the second light source unit 16 is used to measure the aberration (compensation aberration) actually compensated by the adaptive optics unit 60. The light beam from the second light source unit 16 is reflected by the beam splitter 17 through the lens and irradiates the adaptive optics unit 60. The light beam having an aberration by being reflected by the compensation optical unit 60 is reflected by the beam splitter 18, received by the second light receiving optical system 20B, and the aberration is measured. The beam splitters 17 and 18 can use, for example, dichroic mirrors that pass the first wavelength light beam emitted from the first light source unit 11 and reflect the second wavelength light beam emitted from the second light source unit 16. In this case, the second wavelength emitted from the second light source unit 16 is different from the first wavelength emitted from the first light source unit 11. In addition, the light beam emitted from the second light source unit 16 may use polarized light having a reverse polarity to the polarization direction of the reflected light beam from the eye 100 to be examined. This can be realized by using the polarization beam splitter 17 that transmits the polarization direction of the reflected light beam from the retina of the eye 100 and reflects the opposite polarization direction. The beam splitter 18 can split the reflected light beam from the eye 100 and the light beam from the second light source unit 16 by using, for example, a polarization beam splitter. The beam splitter 17 can also be a half mirror.
[0015]
The second light receiving optical system 20B is for receiving the light beam emitted from the second light source unit 16 and reflected by the adaptive optics unit 60 and guiding it to the second light receiving unit 21B. The second light receiving optical system 20B includes, for example, a second conversion member 22B (for example, a Hartmann plate), an afocal lens shared with the first light receiving optical system 20A, a variable cross cylinder 13b, and a relay lens. The second conversion member 22B is a wavefront conversion member having a lens unit for converting the light beam reflected by the adaptive optics unit 60 into at least 17 plural beams. As the second conversion member 22B, a plurality of micro Fresnel lenses arranged in a plane orthogonal to the optical axis can be used. The light beam from the second light source unit 16 is condensed on the second light receiving unit 21B via the adaptive optics unit 60 and the second conversion member 22B. The second light receiving unit 21B is for receiving the light from the second light receiving optical system 20B that has passed through the second conversion member 22B and generating a second signal. The light beams of the first light receiving optical system 20A and the second light receiving optical system 20B are separated by, for example, a beam splitter 18. In the present embodiment, the reflected light beam from the retina of the eye 100 to be examined is transmitted and guided to the first light receiving unit 21A, the light beam from the second light source unit 16 is reflected and guided to the second light receiving unit 21B. However, the measurement may be performed by reversing the relationship between reflection and transmission and replacing the light receiving unit.
[0016]
The moving unit 15 integrally moves a portion surrounded by a dotted line in FIG. 1 including the first illumination optical system 10, the first light receiving optical system 20A, and the second light receiving optical system 20B. For example, assuming that the light beam from the first light source unit 11 is reflected at the point where the light is collected, the relationship in which the signal peak at the first light receiving unit 21A due to the reflected light is maximized is maintained, and the first light receiving unit 21A It moves to the direction where the signal peak becomes strong, and can stop at the position where the intensity becomes maximum. Moreover, the 1st illumination optical system 10 and the 1st light reception optical system 20A are moved separately, for example, suppose that the light beam from the 1st light source part 11 was reflected in the point which condenses, and the 1st light reception part by the reflected light is used. It is also possible to maintain the relationship in which the signal peak at 21A is maximized, move in the direction in which the signal peak at the first light receiving unit 21A becomes stronger, and stop at the position where the intensity is maximized.
[0017]
Incident light from the first light source unit 11 to the eye 100 can be depressed by decentering the diaphragm 12 to change the incident position of the light beam in a direction perpendicular to the optical axis, preventing the reflection of the apex of the lens and cornea. . The diaphragm 12 has a diameter smaller than the effective range of the Hartmann plate 22A, and can perform so-called single-pass aberration measurement in which the aberration of the eye affects only the light receiving side.
[0018]
Note that the incident light beam emitted from the first light source unit 11 follows the same way as the measurement light beam diffusely reflected from the fundus after paraxially after the measurement light beam diffusely reflected from the fundus occupies a common optical path. To do. However, in the single pass measurement, the diameters of the respective light beams are different, and the beam diameter of the incident light beam is set to be considerably smaller than the measurement light beam. Specifically, the beam diameter of the incident light beam may be, for example, about 1 mm at the pupil position of the eye 100 to be examined, and the beam diameter of the measurement light beam may be about 7 mm. Note that double-pass measurement can also be performed by appropriately arranging the optical system.
[0019]
The anterior ocular segment illumination unit 30 includes a third light source unit 31 that emits a light beam having a third wavelength. The anterior eye unit is patterned with the light beam from the third light source unit 31 using, for example, platid ring or kerat ring. Irradiate with. In the case of keratoling, a pattern only near the center of curvature of the cornea can be obtained from the kerato image. The third wavelength of the light beam emitted from the third light source unit 31 is different from, for example, the first wavelength (here, 780 nm), and a long wavelength can be selected (for example, 940 nm).
[0020]
The anterior ocular segment observation unit 40 includes, for example, an anterior ocular segment image light receiving unit 41 including a relay lens, a telecentric diaphragm, and a CCD. The light flux reflected and returned from the anterior segment of the eye 100 to be examined is observed. The telecentric diaphragm is a diaphragm for preventing the anterior segment image from being blurred. The signal from the anterior segment image light receiving unit 41 is used for calculations such as corneal shape, corneal wavefront aberration, alignment adjustment, and the like.
[0021]
For example, the first adjustment optical unit 50 mainly adjusts the working distance, and includes a light source unit, a condensing lens, and a light receiving unit. Here, the working distance adjustment is performed, for example, by irradiating a parallel light beam emitted from the light source unit in the vicinity of the optical axis toward the eye 100 and for reflecting the light reflected from the eye 100 using a condenser lens. Through the light receiving unit. Further, when the eye 100 to be examined is at an appropriate working distance, a spot image from the light source unit is formed on the optical axis of the light receiving unit. On the other hand, when the eye 100 to be examined deviates back and forth from an appropriate working distance, the spot image from the light source unit is formed above or below the optical axis of the light receiving unit. The light receiving unit only needs to be able to detect a change in the light beam position in the plane including the light source unit, the optical axis, and the light receiving unit. For example, a one-dimensional CCD, a position sensing device (PSD), etc. arranged in the plane. Can be applied.
[0022]
The compensation optical unit 60 is an adaptive optical system (adaptive optics) that compensates for the aberration of the measurement light by being deformed, and is disposed in the first light receiving optical system 20A and the second light receiving optical system 20B. As the compensation optical unit 60, for example, a variable mirror or a liquid crystal spatial light modulator can be used. In addition, an appropriate optical system that can compensate for the aberration of the measurement light may be used. The variable mirror changes the reflection direction of the light beam by deforming the mirror by an actuator provided inside the mirror. In addition, there are a method of deforming by electrostatic capacity, a method of deforming by using a piezo, and the like, but other appropriate methods can be used. The liquid crystal spatial light modulator modulates the phase by utilizing the light distribution of the liquid crystal, and is used after being reflected in the same manner as a mirror. Although a polarizer is required in the middle of the optical path, the beam splitter 63 plays a role in this embodiment. The beam splitter 63 is configured by a mirror (for example, a polarization beam splitter) that reflects the light beam from the first light source unit 11 and transmits the light beam reflected and returned by the retina of the eye 100 to be examined. The compensating optical system 60 may be a transmissive optical system other than the one used by reflecting. The adaptive optics unit 60 is not limited to this, but it is better to allow parallel light beams to enter. For example, when the eye 100 to be examined has no aberration, a reflected light beam from the retina of the eye 100 to be examined enters the adaptive optics 60 as parallel light. Further, for example, the light flux from the second light source unit 16 is always incident as parallel light.
[0023]
The beam splitter 61 is constituted by, for example, a dichroic mirror that reflects a light beam having a first wavelength and transmits a light beam having a third wavelength. In addition, a rotary prism 62 is provided for uniformizing light caused by uneven reflection from the fundus.
[0024]
For example, the second adjustment optical unit 70 performs alignment adjustment in the XY directions, and includes an alignment light source unit, a lens, and a beam splitter in order to create a bright spot at the apex of the cornea.
[0025]
The target optical unit 90 includes, for example, a landscape chart of the eye 100 to be examined, an optical path for projecting a target for fixation or clouding, and includes a light source unit (for example, a lamp), a fixation target 92, A relay lens is provided. The fixation target 92 can be irradiated to the fundus with the light flux from the light source unit, and the image to be examined 100 is observed.
[0026]
(Conjugate relationship)
The fundus of the eye 100 to be examined, the fixation target 92 of the target optical unit 90, the first light source unit 11, the second light source unit 16, and the first light receiving unit 21A are conjugate. Further, the pupil (iris) of the eye 100 to be examined, the rotary prism 62, the first conversion member (Hartmann plate) 22A, the stop 12 on the measurement light incident side of the first illumination optical system 10, and the compensation optical unit 60 such as a variable mirror. Is conjugate.
[0027]
Although the above-described embodiment has been described mainly as a single path with a thin incident light beam, the present invention can also be applied to an eye-specific measuring device as a double path with a large incident light beam. At this time, the optical system is arranged in a double-pass configuration, but the measurement / calculation processing by the calculation unit is the same.
[0028]
(Optical system in the second embodiment)
FIG. 2 is a second configuration diagram of the optical system of the eye characteristic measuring apparatus. FIG. 2 shows only the portion corresponding to the dotted line frame in FIG. 1, but the other portions are the same as those in FIG. The eye characteristic measuring apparatus in FIG. 2 further includes a third measuring unit 25C having a short focus or low sensitivity and a half mirror 24. In the optical system of FIG. 2, the first conversion member 22A is a wavefront conversion member having a long focal point or a highly sensitive lens unit.
[0029]
The third measuring unit 25C includes a third light receiving optical system 20C and a third light receiving unit 21C. Similar to the first light receiving optical system 20A, the third light receiving optical system 20C receives the light beam reflected and returned from the retina of the eye 100 and guides it to the third light receiving unit 21C. The third light receiving optical system 20C includes, for example, a third conversion member 22C (for example, a Hartmann plate), an afocal lens shared with the first light receiving optical system 20A, a variable cross cylinder 13b, and a relay lens. The third conversion member 22C is a wavefront conversion member having a short focal point or low-sensitivity lens unit for converting the reflected light beam into at least 17 plural beams. The variable cross cylinder 13b may not be provided. The third conversion member 22C is conjugate with the pupil (iris) of the eye 100 to be examined. For the third conversion member 22C, a plurality of micro Fresnel lenses arranged in a plane orthogonal to the optical axis can be used. The reflected light from the fundus is condensed on the third light receiving unit 21C via the third conversion member 22C. The third light receiving unit 21C is for receiving the light from the third light receiving optical system 20C that has passed through the third conversion member 22C and generating a third signal. The third light receiving unit 21C is conjugate with the fundus and the like of the eye 100 to be examined. The light beams of the first measurement unit 25A and the third measurement unit 25C are separated by the half mirror 24. Alternatively, a mirror unit may be used instead of the half mirror 24, and the mirror unit may be switched to the first or third measurement unit 25A or 25C by being inserted into the optical path by moving.
[0030]
In the present embodiment, the short focus and the low sensitivity are such that the change in the beam converted by the third conversion member 22C over the measurable range is set smaller than the conversion pitch of the third conversion member 22C. As a result, it is easy to associate each spot obtained by the third light receiving unit 21C with a lattice point, and signal processing can be facilitated and speeded up. On the other hand, in the measurement with long focus or high sensitivity, the spot position may be greatly displaced, and spots may exist outside the range of the Hartmann grating. Therefore, if the spot position is too shifted due to a large amount of aberration, it may be difficult to associate each spot with a lattice point, and signal processing may take time. Therefore, as one of the embodiments, the compensation amount of the compensation optical unit 60 is determined based on the signal of the third measuring unit 25C having short focus or low sensitivity, and the compensated light beam is measured with long focus or high sensitivity. This enables high-speed and accurate measurement.
[0031]
(Optical system in the third embodiment)
FIG. 3 is a third configuration diagram of the optical system of the eye characteristic measuring apparatus. FIG. 3 shows only a portion corresponding to the dotted line frame in FIG. 1, but the other portions are the same as those in FIG. In the optical system of FIG. 3, the compensation optical unit 60 is inserted in common with the first, second, and third light receiving optical systems 20A, 20B, and 20C. The light beam reflected and returned from the retina of the eye 100 to be examined passes through the beam splitter 18 through the adaptive optics unit 60, is divided by the half mirror 24, and is guided to the first and third measurement units 25A and 25C. Alternatively, a mirror unit may be used instead of the half mirror 24, and the mirror unit may be switched to the first or third measurement unit 25A or 25C by being inserted into the optical path by moving. Further, the light beam from the second light source unit 16 is reflected by the beam splitter 18 through the adaptive optics unit 60 and guided to the second measurement unit 25B. By guiding the light beam through the compensation optical unit 60 to the third measurement unit 25C, the compensated aberration and the compensation aberration can be measured by the third measurement unit 25C. It is also possible to modify the adaptive optics unit 60 until the aberration measured by the output from the third measuring unit 25C is equal to or less than a predetermined tolerance. Moreover, although the optical system shown in FIGS. 2 and 3 has been described mainly as a single path with a thin incident light beam, it can be appropriately changed for double path measurement.
[0032]
2. Electrical system configuration
FIG. 4 is a configuration diagram of an electrical system of the eye characteristic measuring apparatus.
The configuration of the electrical system of the eye characteristic measurement device includes a calculation unit 600, a control unit 610, an input unit 650, a display unit 700, a memory 800, a first drive unit 910, a third drive unit 911, 2 drive part 912, the 3rd drive part 913, and the 5th drive part 914 are provided. The calculation unit 600 includes, for example, a compensation amount calculation unit 601 and a measurement calculation unit 602 that performs various eye characteristic measurements. Furthermore, the input unit 650 includes a pointing device for designating appropriate buttons, icons, positions, regions, and the like displayed on the display unit 700, a keyboard for inputting various data, and the like.
[0033]
In addition, the calculation unit 600 includes a first signal (4) from the first light receiving unit 21A, a third signal (14) from the third light receiving unit 21C, and a signal (7) from the anterior ocular segment observation unit 40. Then, the signal (10) from the first adjustment optical unit 50 and the second signal (17) from the second light receiving unit 21B are input.
[0034]
The measurement calculation unit 602 inputs the first signal (4) from the first light receiving unit 21A, the third signal (14) from the third light receiving unit 21C, and the second signal (17) from the second light receiving unit 21B. For example, the optical characteristics of the eye 100 to be examined are obtained based on the tilt angle of the luminous flux. Further, the compensation amount calculation unit 601 obtains the compensation amount in the compensation optical unit 60 based on the optical characteristics obtained from the output of the first measurement unit 25A or the third measurement unit 25C, for example. Further, the compensation amount calculation unit 601 may perform the aberration measurement by performing compensation based on the corneal aberration calculated from the corneal shape based on the anterior segment image light receiving unit 41. The calculation unit 600 appropriately outputs signals or other signals / data corresponding to the calculation results to the control unit 610 that controls the electric drive system, the display unit 700, and the memory 800, respectively.
[0035]
The control unit 610 controls turning on and off of the first light source unit 11 and the second light source unit 16 and controls the first driving unit 910 to the fifth driving unit 914 based on a control signal from the calculation unit 600. Is for. For example, the control unit 610 outputs a signal (1) to the first light source unit 11 and a signal (5) to the second adjustment optical unit 70 based on a signal according to the calculation result in the calculation unit 600. Is output to the anterior segment illumination unit 30, and signals 8 and 9 are output to the first adjustment optical unit 50 to the target optical unit 90. The signal (11) is output, the signal (16) is output to the second light source unit 16, and the signal is output to the first drive unit 910 to the fifth drive unit 914.
[0036]
The first drive unit 910 outputs the signal (2) based on the signal (4) or (14) from the first or third light receiving unit 21A or 21C input to the arithmetic unit 600, and the first illumination The variable cross cylinder 13a of the optical system 10 and the variable cross cylinder 13b of the first light receiving optical system 20A (or the third light receiving optical system 20C) are rotated by driving an appropriate lens moving means, so that the eye 100 to be examined is rotated. This is for correcting the astigmatism component. This correction need not be performed.
[0037]
For example, the second drive unit 911 generates the first illumination based on the received light signals (4) and / or (14) from the first and / or third light receiving units 21A and / or 21C input to the calculation unit 600. The optical system 10 and the first and third light receiving optical systems 20A and 20C are moved in the optical axis direction, and a signal (3) is output to the moving unit 15 and the lens moving means of the moving unit 15 is driven. To do. By moving the first and third light receiving optical systems 20A and 20C in the optical axis direction, the spherical power component of the low-order aberration can be compensated.
[0038]
For example, the third drive unit 912 moves the target optical unit 90 and outputs a signal (12) to an appropriate moving unit (not shown) and drives the moving unit. The third driving unit 913 rotates the rotary prism 62 and outputs a signal (13) to an appropriate lens moving unit (not shown) and drives the lens moving unit. The fifth drive unit 914 drives the adaptive optics unit 60, and outputs a signal (15) based on the compensation amount obtained by the compensation amount computing unit 602 to the deformation means of the adaptive optics unit 60, and This deformation means is driven.
[0039]
3. Action
(Flowchart of the optical system of the first embodiment)
5 and 6 are flowcharts of aberration measurement in the optical system according to the first embodiment. The aberration measurement in the flowcharts of FIGS. 5 and 6 is a form using the optical system shown in FIG. The calculation unit 600 determines the compensation amount based on the output from the first measurement unit 25A in the aberration measurement 1, distorts the compensation optical unit 60, and further converts the first signal received by the first light receiving unit 21A into the first signal. The optical characteristics of the eye 100 to be examined are obtained from the aberration after compensation based on the aberration and the aberration (compensation aberration) compensated by the compensation optical unit 60 based on the second signal received by the second light receiving unit 21B.
[0040]
First, as the aberration measurement 1, the calculation unit 600 obtains the aberration of the eye 100 based on the first signal from the first light receiving unit 21A (S101). The calculation unit 600 receives the first signal of the Hartmann image from the first light receiving unit 21A of the first measurement unit 25A. Next, the calculation unit 600 calculates the point image movement amounts Δx and Δy of the Hartmann image from the input first signal, calculates the Zernike coefficient based on the point image movement amounts, and calculates the aberration of the eye 100 to be examined. . Further, the calculation unit 600 may obtain a corneal shape, a corneal aberration, and the like based on a signal from the anterior ocular segment image light receiving unit 41 of the anterior ocular segment observation unit 40. In addition, the calculation unit 600 stores these calculation results in the memory 800.
[0041]
The aberration calculation will be described below. The calculation unit 600 calculates the movement amounts Δx and Δy of each point image from the image of the first measurement unit 25A. The amount of movement and the wavefront aberration W are related by the following partial differential equation.
[0042]
[Expression 1]

(F: Distance between the Hartmann plate of the first measuring unit 25A and the CCD)
[0043]
Here, wavefront aberration W is expressed by Zernike polynomial Z_i ^2j-iExpressing with deployment,
[0044]
[Expression 2]

[0045]
Using the above two equations and the measured values for Δx and Δy (and thus including X and Y) obtained by measurement, the Zernike coefficient c_i ^2j-iEach value of can be obtained. Further, when determining corneal aberration, the cornea tilt and cornea height are calculated based on the signal from the anterior segment image light receiving unit 41 of the anterior segment observation unit 40, and the cornea is handled in the same manner as the optical lens. Optical properties are calculated. 18 and 19 are explanatory diagrams (1) and (2) for the Zernike polynomial.
[0046]
Next, the calculation unit 600 determines whether a measurement result is obtained (S103). For example, when the center of gravity of each point image of the Hartmann image acquired in the aberration measurement 1 cannot be obtained by a predetermined number or more (for example, one third or more), or the blur of each point image is large (for example, It can be determined according to one or a plurality of appropriate conditions such as 20 times or more when there is no aberration) or a predetermined number or more of points that cannot be detected without being separated from the adjacent spot images. Here, when the measurement result is obtained (S103), the calculation unit 600 proceeds to the process of step S105. On the other hand, when the measurement result is not obtained (S103), the calculation unit 600 proceeds to the process of step S151 shown in FIG. .
[0047]
In step S105, the calculation unit 600 obtains the compensation amount M in the compensation optical unit 60 that cancels the obtained aberration, and sends a signal (15) corresponding to the compensation amount M via the control unit 610 and the fifth drive unit 914. ) And the adaptive optics unit 60 such as a variable mirror is distorted (S105). In addition, the adaptive optics unit 60 is deformed by appropriate deformation means according to the signal (15). The adaptive optics unit 60 may use a liquid crystal spatial light modulator other than the variable mirror. Hereinafter, calculation of the compensation amount M in the adaptive optics unit 60 necessary for canceling out aberration will be described.
[0048]
FIG. 7 shows coordinates (X_m, Y_m) And the coordinates (X, Y) of the optical system. The aberration to be compensated is Wc, and the analyzed aberration equation is
[0049]
[Equation 3]

[0050]
The coordinates on the deformable mirror (X_m, Y_m) And the coordinates (X, Y) of the optical system in consideration of the incident angle θ to the deformable mirror,
[0051]
[Expression 4]

[0052]
It becomes. The compensation amount M of the variable mirror takes into account the double effect due to reflection and the magnification of the pupil of the eye and the variable mirror. If the magnification of the deformable mirror with respect to the pupil is k, the compensation amount M is
[0053]
[Equation 5]

[0054]
It becomes. The compensation amount M obtained here can include higher-order components of aberration. The adaptive optics unit 60 is deformed based on the compensation amount M output from the calculation unit 600. Note that the magnification k and the incident angle θ in the uncompensated state are preset values and are stored in the memory 800 in advance. Note that the spherical power component of the low order component can be compensated by moving the first light receiving optical system 20A by the moving unit 15. Further, the low-order astigmatism component can be compensated by rotating the variable cross cylinder 13b. For example, when the third-order or higher-order aberration among the obtained aberrations is not a predetermined value or more, the calculation unit 600 moves the first light receiving optical system 20A according to the obtained aberration and / or rotates the variable cross cylinder 13b. Can be moved. In this case, for example, the calculation unit 600 includes the spherical power component c among the obtained aberrations.₂ ⁰The second light receiving optical system 20A is moved according to₂ ^-2And c₂ ²Accordingly, the variable cross cylinder 13b is rotated. Furthermore, the calculation part 600 is c₂ ⁰And / or c₂ ^-2And c₂ ²The compensation amount M is obtained according to the aberration other than the above, and the adaptive optics unit 60 is deformed based on the compensation amount M. At this time, the compensation amount M is c₂ ⁰= 0 and / or c₂ ^-2= 0 and c₂ ²What is necessary is just to calculate as = 0. The compensation amount M may be calculated on the basis of this aberration after measuring the aberration again after compensating for the spherical power component and / or the astigmatism component.
[0055]
When the distorted deformable mirror is further distorted, a compensation amount M is obtained for the aberration measured after compensation in the same manner as in the above analysis, and that amount is further added to the compensated deformable mirror. In addition, the aberration may not be completely eliminated by the adaptive optics unit 60, but the incident light on the Hartmann plate may be slightly diverged or inclined. Thereby, in the first measurement unit 25A, the compensated aberration can be measured with high sensitivity. If the measurement result of the aberration measurement 1 is not obtained (S103), the calculation unit 600 proceeds to the aberration compensation process in FIG.
[0056]
FIG. 6 is a flowchart of aberration measurement when the optical characteristics of the eye 100 to be examined are not obtained from the Hartmann image. Hereinafter, the process illustrated in FIG. 6 will be described.
[0057]
First, the calculation unit 600 determines whether an approximate amount of aberration is known or whether to correct the aberration appropriately (S151). For example, it is determined whether or not to continue the measurement with reference to corneal aberration, past aberration data, and the like. As a determination method, the calculation unit 600 may input a signal for continuing or ending the measurement from an automatically displayed dialog box or an input unit 650 launched from a menu. In addition, the calculation unit 600 may search the memory 800 for corneal aberration data or past aberration data, and determine whether to continue or end the measurement depending on the presence / absence of the data.
[0058]
When the measurement unit 600 does not continue the measurement, the calculation unit 600 displays an analysis impossible notification on the display unit 700 (S153), and ends the measurement. On the other hand, when the measurement unit 600 continues measurement, Zernike coefficients such as corneal aberration data and past aberration data, aberration data, and the like are input from the memory 800 in the apparatus or the input unit 650, and adaptive optics such as a variable mirror is input. The compensation amount M of the unit 60 is obtained, and the deformable mirror is distorted through the control unit 610 and the fifth drive unit 914 (S155). Further, the calculation unit 600 may obtain a corneal wavefront aberration by inputting a signal from the anterior ocular segment image light receiving unit 41 of the anterior ocular segment observation unit 40, and may calculate the compensation amount M based on the obtained aberration. The calculation of the compensation amount M is the same as that in step S105. The calculation unit 600 outputs a signal (15) corresponding to the compensation amount M via the control unit 610 and the fifth drive unit 914, and distorts the adaptive optics unit 60.
[0059]
Next, the calculation unit 600 determines whether the optical characteristics can be measured after compensation (S157). The calculation unit 600 receives, for example, a Hartmann image from the first light receiving unit 21A, and the center of gravity position of the input Hartman image cannot be taken more than a predetermined number (for example, one third), or the blur of each point image is large ( For example, it can be determined according to one or a plurality of appropriate conditions, such as 20 times or more when there is no aberration), or a predetermined number or more of points that cannot be detected without being separated from adjacent spot images. . If the measurement is impossible, the calculation unit 600 determines whether to further compensate (S159). For example, the calculation unit 600 may input a signal to continue or end the measurement from an automatically displayed dialog box or an input unit 650 launched from a menu. The calculation unit 600 may search for another aberration data in the memory 800. If the compensation is made, the calculation unit 600 returns to step S155. On the other hand, if not compensated, the calculation unit 600 displays an analysis impossible notification on the display unit 700 (S161) and ends the measurement.
[0060]
On the other hand, if measurement is possible (S157), operation unit 600 proceeds to step S106 in FIG.
Returning to FIG. 5, the arithmetic unit 600 acquires the second signal from the second light receiving unit 21 </ b> B and measures the aberration (compensation aberration) compensated by the adaptive optics unit 60 (S <b> 106). The light beam received by the second light receiving unit 21 </ b> B is a light beam having the compensation aberration at the compensation optical unit 60 by the non-aberration light beam emitted from the second light source unit 16 being reflected by the compensation optical unit 60. By receiving this light beam and measuring the aberration, the compensation aberration in the compensation optical unit 60 can be obtained accurately. For example, when there is a difference between the input value for canceling out the aberration by the adaptive optics unit 60 and the aberration actually canceling out, the measurement error caused by this shift can be removed.
[0061]
Next, as the aberration measurement 2, the calculation unit 600 acquires the first signal from the first light receiving unit 21A and obtains the aberration (S107). The aberration obtained here is an aberration after compensation, and a minute aberration can be measured with high accuracy by the first measuring unit 25A. Further, the processes in steps S106 and S107 may be performed in the reverse order or in parallel.
[0062]
The calculation unit 600 determines whether the aberration obtained in step S107 is equal to or less than a predetermined allowable value (S109). For example, the calculation unit 600 may determine whether the RMS value of high-order aberration is 0.1 or less. The RMS value of the aberration is the Zernike coefficient c_i ^2j-iIs calculated by the following equation.
[0063]
[Formula 6]

[0064]
The calculation unit 600 determines whether one or more of the RMS values of these aberrations are equal to or less than an allowable value.
[0065]
If the aberration is larger than the allowable value (S109), the calculation unit 600 returns to step S105 and further distorts the adaptive optics unit 60. On the other hand, when the calculation unit 600 is smaller than the allowable value (S109), the arithmetic unit 600 adds the compensation aberration W1 measured in step S106 to the aberration W2 measured in step S107, and actually calculates the aberration W (Zernike coefficient) of the eye 100 to be examined. c_i ^2j-i(S111). In addition, the calculation unit 600 calculates the obtained Zernike coefficient c_i ^2j-iAnd optical system such as spherical power S, astigmatic power C, astigmatic axis A, higher order spherical aberration, etc., using known methods, depending on the arrangement of the optical system (eg, information on where the moving position is in the initial condition). Characteristics can be obtained. The calculation unit 600 can obtain the spherical power S, the astigmatism power C, and the astigmatism axis A from the quadratic term of the Zernike coefficient as in the following equation.
[0066]
[Expression 7]

(Where SE: equivalent spherical power, S_move: Spherical power for fixation movement, r: pupil diameter)
[0067]
Next, the arithmetic unit 600 displays the obtained aberration map, aberration coefficient, Hartmann image, and other measurement results on the display unit 700 and stores them in the memory 800 (S113). In addition, the calculation unit 600 may read corneal shape data and the like from the memory 800 and further display them on the display unit 700.
[0068]
Further, the calculation unit 600 determines whether or not to end the measurement (S115). When the measurement is continued, the process returns to step S101, and when the measurement is ended, the measurement is ended. For example, the calculation unit 600 may input a signal for continuing or ending the measurement from an automatically displayed dialog box or an input unit 650 launched from a menu.
[0069]
FIG. 8 is a first modification of the flowchart of aberration measurement in the optical system according to the first embodiment. This modification is an example in which the measurement of compensation aberration and the measurement of aberration after compensation are performed in parallel. The details of each process are the same as those in FIG.
[0070]
FIG. 9 is a second modification of the flowchart of aberration measurement in the optical system according to the first embodiment. This modification is an example in which the aberration calculation of the eye to be examined 100 and the calculation result are output every time the aberration measurement after compensation is performed.
[0071]
First, the calculation unit 600 executes the processes of steps S101 to S107 and step S111. The details of the processing are the same as described above, and will be omitted.
[0072]
The calculation unit 600 displays the measurement results such as the obtained wavefront aberration map, aberration coefficient, Hartmann image, etc. on the display unit 700 and stores them in the memory 800 (S201). Note that the display on the display unit 700 is not necessarily performed every time. For example, when the measurement is affected, for example, it takes a long time for the display process on the display unit 700, the result may be displayed every certain number of measurements.
[0073]
The calculation unit 600 determines whether the aberration 2 obtained in step S111 is equal to or less than a predetermined allowable value (S109). The determination criteria can be the same as described above. If the aberration is larger than the allowable value, the calculation unit 600 returns to step S105. If the aberration is smaller than the allowable value, the calculation unit 600 displays the obtained wavefront aberration map, aberration coefficient, and other measurement results on the display unit 700 and stores them in the memory 800. (S203). In step S201, if the measurement result is already displayed and stored, the process in step S203 may be omitted. Note that, instead of determining whether the aberration is less than or equal to the allowable value, the calculation unit 600 outputs a display instructing input to further distort the adaptive optics unit 60 to the display unit 700, and receives a signal from the input unit 650. May be input. Next, the calculating part 600 performs the process of step S115. Details of the processing are the same as described above.
[0074]
(Flowchart of optical system of second embodiment)
FIG. 10 is a flowchart of aberration measurement in the optical system according to the second embodiment. FIG. 10 is a flowchart in a form using an optical system including the long focus or high sensitivity first measurement unit 25A and the short focus or low sensitivity third measurement unit 25C as shown in FIG. 2 or FIG. The calculation unit 600 obtains the compensation amount M in the compensation optical unit 60 at high speed based on the signal of the third measurement unit 25C having short focus or low sensitivity, and distorts the compensation optical unit 60. The calculation unit 600 also compensates the compensation aberration in the compensation optical unit 60 based on the second signal received by the second light receiving unit 21B, and the aberration after compensation based on the signal from the long focus or high sensitivity first measurement unit 25A. From this, the optical characteristics of the eye 100 to be examined are obtained.
[0075]
First, the calculation unit 600 performs the aberration measurement 1 based on the signal from the short focus or low sensitivity third measurement unit 25C (S251). The calculation unit 600 acquires a Hartmann image from the third light receiving unit 21C of the third measurement unit 25C, and detects the barycentric point of the spot image based on the acquired image. Corresponding so as to enable high speed by searching for the center of gravity position corresponding to the spot in the rectangular area centered on the center of gravity with no aberration. The calculation unit 600 obtains a rough aberration of the eye 100 based on the center of gravity of the obtained spot image.
Next, the calculating part 600 performs the process of step S103, S105, 106. The details of the processing are the same as described above, and will be omitted.
[0076]
The calculation unit 600 performs the aberration measurement 2 based on the signal from the long-focus or high-sensitivity first measurement unit 25A (S257). The calculation unit 600 receives the first signal of the Hartmann image from the first light receiving unit 21A of the first measurement unit 25A. Next, the arithmetic unit 600 obtains the point image movement amount of the Hartmann image from the input first signal, and obtains the optical characteristics of the eye 100 to be examined based on the point image movement amount. In the aberration measurement using the conventional long focal point or high sensitivity measurement unit, the deviation of the spot image may be large, and it may take time to associate the spot image, or the measurement cannot be performed because the correspondence cannot be taken. In the present embodiment, since the input first signal of the Hartmann image is a Hartmann image in which the aberration of the eye 100 to be examined is canceled to some extent, even if the focal point or the sensitivity is long, the positional deviation of the spot becomes small. Therefore, precise and high-speed aberration calculation is possible. Further, the processes in steps S106 and S257 may be performed in the reverse order or in parallel.
[0077]
Next, the calculating part 600 performs the process of step S109-S115. The details of the processing are the same as described above, and will be omitted. In the second embodiment, as in the modification shown in FIG. 9, it is possible to perform a modification for calculating the aberration of the eye 100 and outputting the calculation result every time the compensated aberration is measured.
[0078]
(Flowchart of optical system according to the third embodiment)
As the flowchart in the optical system of the third embodiment, the flowchart shown in FIG. 10 can be used. When the optical system shown in FIG. 3 is used, the compensation aberration measurement in step S106 can use the third light receiving optical system 20C instead of using the second light receiving optical system 20B. In addition, the arithmetic unit 600 performs adaptive optics so that the aberration based on the output of the third light receiving unit 21C is equal to or less than a predetermined allowable value before the aberration measurement 2 in the first measurement unit 25A in step S257. The part 60 may be deformed.
[0079]
FIG. 11 is a modification of the flowchart of aberration measurement in the optical system according to the third embodiment. In this modification, a light beam whose aberration has been compensated using the optical system shown in FIG. 3 is received by the third light receiving unit 21C, and the aberration obtained based on the signal from the third light receiving unit 21C has a predetermined tolerance. This is an example in which compensation is performed so as to be equal to or less than the value.
[0080]
First, the calculation unit 600 executes each process of steps S251, S103, and S105. The details of the processing are the same as described above, and will be omitted. Next, the computing unit 600 measures the compensated aberration based on the signal from the third measuring unit 25C (S253). Details of the process are the same as in step S251 described above, and are therefore omitted. The calculation unit 600 determines whether the aberration obtained in step S253 is equal to or less than a predetermined first tolerance (S255). For example, the calculation unit 600 may determine whether the RMS value of high-order aberration is 0.1 or less. If the aberration is larger than the first allowable value, the calculation unit 600 returns to step S105 and further distorts the adaptive optics unit 60. On the other hand, when the aberration is smaller than the first allowable value, the arithmetic unit 600 proceeds to the process of step S106.
[0081]
Further, instead of determining whether the aberration is equal to or less than the first allowable value, the calculation unit 600 receives the first signal from the first light receiving unit 21A and determines whether the measurement based on the first signal is possible. good. For example, the arithmetic unit 600 cannot obtain a predetermined number or more (for example, one third or more) of the center of gravity of each point image based on the input first signal, or the blur of each point image is large (for example, when there is no aberration). It is determined that measurement based on the first signal is impossible due to one or more predetermined conditions such as a predetermined number or more of points that cannot be detected without being separated from adjacent spot images. can do. Moreover, an appropriate condition may be used as the determination condition. Here, when it is determined that the measurement is impossible, the calculation unit 600 proceeds to the process of step S105, and when it is determined that the measurement is possible, the process proceeds to the process of step S106.
[0082]
The calculation unit 600 executes the processes of steps S106 and S257. The details of the processing are the same as described above, and will be omitted. Next, the calculation unit 600 determines whether or not the aberration 2 obtained in step S257 is equal to or smaller than a predetermined second tolerance (S259). For example, the calculation unit 600 may determine whether the RMS value of high-order aberration is 0.1 or less. Further, the first tolerance value and the second tolerance value can take different values. For example, the first tolerance value ≧ the second tolerance value may be set in consideration of measurement sensitivity. When the aberration 2 is larger than the second allowable value (S259), the calculation unit 600 further distorts the adaptive optics unit 60 according to the aberration 2 (S261), and returns to step S257. The details of the process of distorting the adaptive optics unit 60 are the same as in step S105. On the other hand, when the aberration 2 is smaller than the second allowable value, the calculation unit 600 proceeds to the process of step S111.
Next, the calculating part 600 performs the process of step S111-S115. The details of the processing are the same as described above, and will be omitted.
[0083]
4). Modified example
(Modification of the first embodiment)
FIG. 12 is a fourth block diagram of the optical system of the eye characteristic measuring apparatus. FIG. 12 shows a modification in which the first measurement unit 25A for measuring aberration and the second measurement unit 25B for measuring compensation aberration in FIG. 1 are shared. For example, by alternately turning on the first light source unit 11 and the second light source unit 16, the first light receiving optical system 20 </ b> A has a light beam reflected and returned from the eye 100 and a light emitted from the second light source unit 16. Incident light is switched. Further, a chopper may be provided in front of the first light source unit 11 and the second light source unit 16 to control the light beam incident on the first light receiving optical system 20A. In addition to the chopper, an appropriate means for blocking the light beam may be used. The detailed description of the other parts is the same as in FIG. FIG. 12 shows only the portion corresponding to the dotted line frame in FIG. 1, but the other portions are the same as those in FIG.
[0084]
FIG. 13 is a first flowchart in the modification of the first embodiment. FIG. 13 is a flowchart for measuring the compensation aberration and measuring the compensated aberration by switching one measurement unit using the optical system sharing the measurement unit shown in FIG.
[0085]
First, the calculation unit 600 performs the aberration measurement 1 of the eye 100 based on the output from the first measurement unit 25A (S301). For example, the calculation unit 600 turns on the first light source unit 11 and turns off the second light source unit 16 so that the light beam reflected by the eye 100 is incident on the first light receiving optical system 20A. The first signal is input from 21A. Next, the calculation unit 600 obtains the aberration of the eye 100 based on the input first signal. The calculation of aberration is the same as described above. Further, the calculation unit 600 may obtain a corneal shape, a corneal aberration, and the like based on a signal from the anterior ocular segment image light receiving unit 41 of the anterior ocular segment observation unit 40. In addition, the calculation unit 600 stores these calculation results in the memory 800.
The calculation unit 600 executes the processes of steps S103 and S105. The details of the processing are the same as described above, and will be omitted.
[0086]
The calculation unit 600 measures the compensation aberration based on the signal from the first measurement unit 25A (S306). For example, the calculation unit 600 turns off the first light source unit 11 and turns on the second light source unit 16 so that the light beam emitted from the second light source unit 16 and reflected by the compensation optical unit 60 is applied to the first light receiving optical system 20A. Make it incident. Further, the calculation unit 600 receives the first signal from the first light receiving unit 21A, and measures the compensation aberration in the adaptive optics unit 60 based on the input first signal. The calculation of aberration is the same as described above. In addition, the calculation unit 600 stores the obtained aberration in the memory 800.
[0087]
Next, the calculation unit 600 performs the aberration measurement 2 of the eye 100 based on the output from the first measurement unit 25A (S307). Details of the processing are the same as in step S301.
[0088]
In the above-described processing, the arithmetic unit 600 switches the light beam incident on the first light receiving optical system 20A by turning on and off the first and second light source units 11 and 16, but the first and second light sources. Means for blocking the light beam such as a chopper may be provided in front of the units 11 and 16, and the light beam incident on the first light receiving optical system 20A may be switched by controlling the means. Further, the order of the processes in steps S306 and S307 may be reversed.
The calculation unit 600 executes the processes of steps S109 to S115. The details of the processing are the same as described above, and will be omitted.
[0089]
FIG. 14 is a second flowchart in the modification of the first embodiment. FIG. 14 is a modified example in which the aberration calculation of the eye 100 to be examined and the calculation result output are performed every time the compensated aberration is measured. Since the details of each process are the same as those in FIGS. 9 and 13, the same reference numerals are given and description thereof is omitted.
[0090]
(Modification of the second embodiment)
FIG. 15 is a fifth block diagram of the optical system of the eye characteristic measuring apparatus. FIG. 15 shows a modification in which the first measurement unit 25A for aberration measurement and the second measurement unit 25B for measurement of compensation aberration in FIG. 2 are shared. For example, by alternately lighting the first light source unit 11 and the second light source unit 16, the first light receiving unit 21 </ b> A reflects the light beam reflected from the subject eye 100 and the light beam emitted from the second light source unit 16. Switch to receive light. Also, an appropriate light beam blocking means such as a chopper is provided in front of the first light source unit 11 and the second light source unit 16 so as to control the light beam incident on the first light receiving optical system 20A and the third light receiving optical system 20C. Also good. The detailed description of the other parts is the same as in FIG. FIG. 15 shows only a portion corresponding to the dotted line frame in FIG. 1, but the other portions are the same as those in FIG.
[0091]
FIG. 16 is a flowchart in the modification of the second embodiment. FIG. 16 is a flowchart for an optical system including the short-focus or low-sensitivity third light receiving optical system 20C shown in FIG. In this example, measurement of compensation aberration and measurement for measuring eye characteristics are performed by switching one measurement unit. Since the details of each process are the same as those in FIGS. 10 and 13, the same reference numerals are given and description thereof is omitted. Similarly to the modification shown in FIG. 11, the adaptive optics unit 60 can be modified until the aberration measured by the output from the third measurement unit 25C is equal to or less than a predetermined tolerance.
[0092]
(Modification of the third embodiment)
FIG. 17 is a sixth configuration diagram of the optical system of the eye characteristic measuring apparatus. FIG. 17 shows a modification in which the first measurement unit 25A for measuring aberration and the second measurement unit 25B for measuring compensation aberration in FIG. 3 are shared. As in the modification of the first embodiment, measurement is performed by switching the light beam incident on the first light receiving optical unit 20A. The detailed description of the other parts is the same as in FIG. FIG. 17 shows only the portion corresponding to the dotted line frame in FIG. 1, but the other portions are the same as in FIG.
Moreover, the flowchart shown in FIG. 16 can be used for the flowchart in the modification of 3rd Embodiment.
[0093]
【The invention's effect】
According to the present invention, when measuring the optical characteristics of the eye 100 to be examined, an ophthalmic characteristic measuring apparatus that performs correction so as to cancel out the aberration of the measurement light, further measures a small amount of uncorrected aberration, and performs precise measurement. Can be provided. Further, according to the present invention, it is possible to remove the influence of the shift in the input value for canceling out the aberration and the aberration that is actually compensated, and perform more accurate measurement. According to the present invention, accurate and high-speed measurement can be performed by taking advantage of the characteristics of low-sensitivity and high-sensitivity optical systems. Furthermore, according to the present invention, it is possible to provide an eye characteristic measuring device with a wide measurement range that can be measured even when the amount of aberration is large by canceling the aberration of the measurement light.
[Brief description of the drawings]
FIG. 1 is a first configuration diagram of an optical system of an eye characteristic measuring apparatus.
FIG. 2 is a second configuration diagram of an optical system of the eye characteristic measuring apparatus.
FIG. 3 is a third configuration diagram of an optical system of the eye characteristic measuring apparatus.
FIG. 4 is a configuration diagram of an electrical system of the eye characteristic measurement device.
FIG. 5 is a flowchart of aberration measurement in the optical system according to the first embodiment.
FIG. 6 is a flowchart of aberration measurement when the optical characteristics of the eye to be examined cannot be obtained from the Hartmann image.
FIG. 7 is an explanatory diagram of a relationship between coordinates on a variable mirror and coordinates of an optical system.
FIG. 8 is a first modified example of a flowchart of aberration measurement in the optical system according to the first embodiment.
FIG. 9 shows a second modification of the flowchart of aberration measurement in the optical system according to the first embodiment.
FIG. 10 is a flowchart of aberration measurement in the optical system according to the second embodiment.
FIG. 11 is a modified example of a flowchart of aberration measurement in the optical system according to the third embodiment.
FIG. 12 is a fourth block diagram of an optical system of the eye characteristic measuring device.
FIG. 13 is a first flowchart in a modification of the first embodiment.
FIG. 14 is a second flowchart in a modification of the first embodiment.
FIG. 15 is a fifth block diagram of an optical system of the eye characteristic measuring device.
FIG. 16 is a flowchart in a modification of the second embodiment.
FIG. 17 is a sixth block diagram of an optical system of the eye characteristic measuring device.
FIG. 18 is a Zernike polynomial (1).
FIG. 19 is a Zernike polynomial (2).
[Explanation of symbols]
10 First illumination optical system
11 1st light source part
16 2nd light source part
20A First light receiving optical system
21A 1st light-receiving part
25A 1st measurement part
20C Third light receiving optical system
21C 3rd light-receiving part
25C 3rd measurement part
20B Second light receiving optical system
21B 2nd light-receiving part
25B 2nd measurement part
30 Anterior segment observation unit
40 Anterior illumination unit
50 1st adjustment optical part
60 Adaptive optics
70 Second adjustment optical unit
90 Target optical part
600 Calculation unit
610 control unit
650 input section
700 Display unit
800 memory

Claims (15)

A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A first light-receiving optical system for receiving a part of the reflected light beam reflected and returned from the retina of the eye to be examined through the compensation optical unit and the first conversion member that converts at least substantially 17 beams; ,
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A second light receiving optical system for receiving the light beam from the second light source unit via the compensation optical unit and a second conversion member that converts at least substantially 17 beams;
A second light receiving portion for receiving a light flux of the second light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the first light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
The optical characteristics compensated by the compensating optical unit based on the output of the second light receiving unit and the optical characteristics based on the output of the first light receiving unit after compensation by the compensating optical unit are measured, and these measured opticals An eye characteristic measuring device including a measurement calculation unit that obtains optical characteristics of an eye to be examined based on the characteristics. A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A part of the reflected light beam reflected from the retina of the eye to be examined and the light beam from the second light source unit are received through the adaptive optics unit and the first conversion member that converts at least substantially 17 beams. A first light receiving optical system for
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the first light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
Based on the output of the first light receiving unit by the light beam from the second light source unit, the optical characteristic compensated by the compensating optical unit is measured, while the first light receiving unit by the light beam from the first light source unit is measured. An eye characteristic measurement device comprising: a measurement calculation unit that measures optical characteristics after compensation by the above-described compensation optical unit based on an output, and obtains optical characteristics of the eye to be inspected based on the measured optical characteristics. A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
For receiving a part of the reflected light beam reflected from the retina of the eye to be examined through the adaptive optics and at least substantially the first conversion member having a long focus or high sensitivity for converting the beam into 17 beams. A first light receiving optical system;
A first light receiving portion for receiving a light flux of the first light receiving optical system;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A second light receiving optical system for receiving the light beam from the second light source unit via the compensation optical unit and a second conversion member that converts at least substantially 17 beams;
A second light receiving portion for receiving a light flux of the second light receiving optical system;
Via a third conversion member having a short-focus or low-sensitivity lens unit that converts a part of the reflected light beam reflected and returned from the retina of the eye to be converted into at least substantially 17 beams. A third light receiving optical system for receiving light;
A third light receiving portion for receiving a light flux of the third light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the third light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
The optical characteristics compensated by the compensating optical unit based on the output of the second light receiving unit and the optical characteristics based on the output of the first light receiving unit after compensation by the compensating optical unit are measured, and these measured opticals An eye characteristic measuring device including a measurement calculation unit that obtains optical characteristics of an eye to be examined based on the characteristics. A first light source that emits a light beam having a first wavelength;
A first illumination optical system for illuminating a minute region on the retina of the eye to be examined with a light beam from the first light source unit;
A compensation optical unit that compensates for aberration of the transmitted or reflected light beam according to the compensation amount given based on the optical characteristic of the reflected light beam reflected and returned from the eye retina;
A second light source unit for illuminating the adaptive optics unit with a light beam of a second wavelength;
A long-focus or high-sensitivity first that converts part of the reflected light beam reflected from the retina of the eye to be examined and the light beam from the second light source unit into the adaptive optics unit and at least substantially 17 beams. A first light receiving optical system for receiving light through the conversion member;
A first light receiving portion for receiving a light flux of the first light receiving optical system;
Via a third conversion member having a short-focus or low-sensitivity lens unit that converts a part of the reflected light beam reflected and returned from the retina of the eye to be converted into at least substantially 17 beams. A third light receiving optical system for receiving light;
A third light receiving portion for receiving a light flux of the third light receiving optical system;
A compensation amount calculation unit for obtaining an optical characteristic of the eye to be examined based on an output of the third light receiving unit, obtaining a compensation amount according to the optical characteristic, and outputting the compensation amount to the compensation optical unit;
Based on the output of the first light receiving unit by the light beam from the second light source unit, the optical characteristic compensated by the compensating optical unit is measured, while the first light receiving unit by the light beam from the first light source unit is measured. An eye characteristic measurement device comprising: a measurement calculation unit that measures optical characteristics after compensation by the above-described compensation optical unit based on an output, and obtains optical characteristics of the eye to be inspected based on the measured optical characteristics. The second wavelength of the second light source unit is different from the first wavelength of the first light source unit,
The measurement calculation unit measures the optical characteristics compensated by the compensating optical unit based on the output of the second light receiving unit, and measures the optical characteristics based on the output of the first light receiving unit after compensation by the compensating optical unit. The eye characteristic measuring device according to claim 1, wherein the eye characteristic measuring device is configured to perform the steps in parallel. The measurement calculation unit is configured to turn on and off the first and second light source units, or to insert a light beam blocking unit in an optical path from the first and second light source units, to thereby form the first light receiving optical unit. The eye characteristic measuring device according to claim 2 or 4, wherein a light beam incident on the system is switched or selected. In the third light receiving optical system, the change in the beam converted by the third conversion member over the measurable range is set to be smaller than the conversion pitch of the third conversion member. As a result, signal processing is easy and The ophthalmic characteristic measurement device according to claim 3 or 4, wherein the ophthalmic characteristic measurement device is configured to increase speed. 8. The eye characteristic measuring device according to claim 1, wherein the compensation amount calculation unit is configured to obtain a compensation amount so as not to completely cancel the obtained optical characteristic of the eye to be examined. 9. The eye characteristic measuring device according to claim 1, wherein the compensation optical unit is configured to perform compensation including at least a high-order component of the optical characteristics of the eye to be examined. The compensation amount calculation unit moves the first light receiving optical system and / or a part of the first light receiving optical system when the third-order or higher order aberration is not a predetermined value or more among the obtained optical characteristics. The ophthalmic characteristic measurement device according to claim 1, configured to compensate for a spherical power component and / or an astigmatism component, which is a low-order aberration, by changing the state of the element. The compensation amount calculation unit moves the first light receiving optical system and / or changes the state of some elements of the first light receiving optical system to thereby reduce the spherical power component and / or astigmatism, which are low-order aberrations. 9. The component according to claim 1, wherein the compensation optical unit is configured to perform compensation including at least a high-order component of other optical characteristics by the compensation optical unit. Eye characteristic measuring device. The optical characteristics of the eye to be examined are displayed on the display unit after compensation by the compensation optical unit, and the compensation is further compensated by the compensation amount calculation unit and the compensation optical unit in accordance with an instruction from the input unit. The eye characteristic measuring device according to any one of 1 to 11. 13. The ophthalmic characteristic measuring apparatus according to claim 1, wherein the compensation optical unit includes at least one of a liquid crystal spatial light modulator and a variable mirror. 14. The first illumination optical system is configured to illuminate a minute region on the eye retina with a light beam from the first light source unit with a thin beam. The eye characteristic measuring device according to claim 1. The first illumination optical system is configured to illuminate a minute region on the eye retina with a wide beam when passing through the eye cornea with the light flux from the first light source unit. The eye characteristic measuring device according to claim 1.

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