JP4700785B2

JP4700785B2 - Ophthalmic equipment

Info

Publication number: JP4700785B2
Application number: JP2000160304A
Authority: JP
Inventors: 知行岩永
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2000-05-30
Filing date: 2000-05-30
Publication date: 2011-06-15
Anticipated expiration: 2020-05-30
Also published as: JP2001340297A

Description

【０００１】
【発明の属する技術分野】
本発明は、被検眼を観察しながら検査部を被検眼に位置合わせして、眼屈折力、眼底像、眼底血流量等の被検眼の固有情報を得る眼科装置に関するものである。
【０００２】
【従来の技術】
従来、この種の眼科装置において検査部を被検眼に位置合わせする際には、操作者はテレビモニタ等の表示部に映った被検眼の前眼部像を観察し、操作手段を操作して検査部を被検眼に粗く位置合わせしている。また、被検眼の角膜に投影した指標光束の角膜反射像又は瞳孔像が表示部に現れた後には、角膜反射像又は瞳孔像を光軸周りに表示した位置合わせ用マークに一致させるように操作手段を操作して、検査部を被検眼に精密に位置合わせしている。
【０００３】
この眼科装置では、被検眼の基準位置と検査部の光軸との一致の許容範囲は、検査部の位置ずれによる測定値のずれがどの程度まで許容できるかに関係し、それによって位置合わせの許容範囲つまり測定可能領域を定めている。
【０００４】
近年、検査部を駆動手段により３軸方向に駆動して被検眼に自動的に位置合わせする眼科装置が提案されている。この眼科装置は被検眼からの反射指標像を光電的に検出し、検出した反射指標像と検査部の光軸とを一致させるように駆動手段を制御している。
【０００５】
この眼科装置では、被検眼の基準位置が測定可能領域に入った後も駆動手段の制御を続けるか、被検眼の基準位置が測定可能領域に入ったときに駆動手段の制御を停止し、被検眼の基準位置が測定可能領域から逸脱したときに駆動手段の制御を再開している。
【０００６】
【発明が解決しようとする課題】
しかしながら、被検眼の基準位置が測定可能領域に入った後も駆動手段の制御を続ける場合には、十分な精度の測定値が得られる状態になっているにも拘わらず駆動手段を必要以上に繰り返して制御するので、測定値を迅速に得ることができないという問題が生ずる。
【０００７】
また、被検眼の基準位置が測定可能領域に入ったときに駆動手段の制御を停止し、被検眼の基準位置が測定可能領域から逸脱したときに駆動手段の制御を再開する場合には、被検眼の基準位置が測定可能領域の端に位置するときに駆動手段の制御を停止したときに、被検眼の眼球の僅かな運動によって被検眼の基準位置が測定可能領域から逸脱し、安定した測定値を得られないという問題が生ずる。
【０００８】
本発明の目的は、上述の問題点を解消し、駆動手段を不必要に制御することなく安定した測定値を迅速に得ることができる眼科装置を提供することにある。
【０００９】
本発明の他の目的は、簡素化と小型化が可能な眼科装置を提供することにある。
【００１０】
【課題を解決するための手段】
上記目的を達成するための本発明に係る眼科装置は、被検眼を測定する測定手段と、被検眼の基準位置を検出する検出手段と、前記測定手段を駆動する駆動手段と、被検眼の前記基準位置と前記測定手段との位置のずれ量に応じて、前記測定手段及び前記駆動手段のうちの少なくとも一方を制御する制御手段とを有することを特徴とする。
【００１１】
【発明の実施の形態】
本発明を図示の実施の形態に基づいて詳細に説明する。
図１は第１の実施の形態の光学的な構成図であり、被検眼Ｅの前方の光路Ｏ１上にダイクロイックミラー１が被検眼Ｅに対向して配置されている。被検眼Ｅの前眼部を照明するための近赤外光を発する発光ダイオード等の前眼部照明光源２が、被検眼Ｅとダイクロイックミラー１の間の光軸外に配置されている。ダイクロイックミラー１の反射方向には対物レンズ３とダイクロイックミラー４が配置され、ダイクロイックミラー４の反射方向の光路Ｏ２上にはダイクロイックミラー５、結像レンズ６、ＣＣＤカメラ等の撮像素子７が配置されている。撮像素子７は被検眼Ｅの前眼部近傍と略共役な位置に配置されており、対物レンズ３〜撮像素子７によって前眼部観察光学系が構成されている。
【００１２】
また、ダイクロイックミラー５の反射方向には、結像レンズ８と撮像素子９が配置され、対物レンズ３〜撮像素子９によって角膜反射指標像撮像光学系が構成されている。撮像素子９はＣＣＤカメラ等とされ、被検眼Ｅの前眼部近傍と略共役な位置に配列されている。そして、ダイクロイックミラー４の透過方向にはミラー１０が配置され、ミラー１０の反射方向の光路Ｏ３上には被検眼Ｅを固視させるための図示しない固視標投影光学系が配置されている。
【００１３】
一方、ダイクロイックミラー１の透過方向の光路Ｏ４上には、対物レンズ１１、ハーフミラー等のビームスプリッタ１２、孔あきミラー１３、投影絞り１４、投影レンズ１５、指標板１６、眼屈折力測定光源１７が配置されている。眼屈折力測定光源１７は前眼部照明光源２よりも波長が数１０ｎｍ長い近赤外光を発する光源とされ、対物レンズ１１〜眼屈折力測定光源１７により眼屈折力測定光投影光学系が構成されている。
【００１４】
孔あきミラー１３の反射方向には、光軸外に６つの開口を有する６孔絞り１８、６分割プリズム１９、リレーレンズ２０、ＣＣＤカメラ等の撮像素子２１が配置され、対物レンズ１１〜撮像素子２１により眼屈折力測定受光光学系が構成されている。
【００１５】
また、ビームスプリッタ１２の反射方向には、角膜指標投影レンズ２２、角膜指標板２３、近赤外光を発する発光ダイオード等の角膜指標用光源２４が配置され、対物レンズ１１〜角膜指標用光源２４により角膜指標投影光学系が構成されている。
【００１６】
ダイクロイックミラー１は眼屈折力測定光源１７と角膜指標用光源２４から発した波長の光の大部分を透過して一部を反射すると共に、前眼部照明光源２から発した波長の光を反射する特性を有している。また、ダイクロイックミラー４は可視光を透過し、近赤外光を反射する特性を有している。更に、ダイクロイックミラー５は、眼屈折力測定光源１７と角膜指標用光源２４から発した波長の光を反射し、前眼部照明光源２から発した波長の光を透過する特性を有している。
【００１７】
撮像素子７、９、２１の出力はＡ／Ｄコンバータ２５、２６、２７をそれぞれ介して共通の演算処理部２８に接続されていると共に、画像メモリ２９、３０、３１にそれぞれ接続されている。そして、演算処理部２８には眼屈折力測定光源１７、角膜指標用光源２４、画像メモリ２９、３０、３１、Ｄ／Ａコンバータ３２を介したテレビモニタ３３、駆動モータ等の駆動手段３４、各種のスイッチ等が配置された信号入力手段３５が接続されている。信号入力手段３５のスイッチは、駆動手段３４を操作するためのスイッチ、測定を開始するためのスイッチ、測定回数を設定するためのスイッチ等とされている。
【００１８】
前述の前眼部観察光学系、固視標投影光学系、眼屈折力測定光投影光学系、眼屈折力測定受光光学系、角膜指標投影光学系、角膜反射指標像撮像光学系等により検査部が構成されている。この検査部は３軸方向に移動可能な架台に搭載され、光軸方向のＺ軸方向と、このＺ軸方向に垂直で相互に垂直なＸ軸方向とＹ軸方向の双方向とに駆動手段３４により電動駆動されるようになっている。
【００１９】
図２は演算処理部２８の演算処理手順を示すフローチャート図であり、検者が信号入力手段３５の測定開始スイッチをオンにすると、測定動作が開始し、前眼部照明光源２が点灯して被検眼Ｅを照明する。前眼部照明光源２による前眼部周辺からの反射散乱光はダイクロイックミラー１で反射し、対物レンズ３で略平行光となってダイクロイックミラー４で反射し、ダイクロイックミラー５と結像レンズ６を透過して撮像素子７上に被検眼Ｅの前眼部像を形成する。
【００２０】
撮像素子７からの出力信号はＡ／Ｄコンバータ２５を介してデジタル信号に変換され、演算処理部２８とＤ／Ａコンバータ３２を介してテレビモニタ３３上に前眼部像Ｅ’として映出される。同時に、デジタル信号は画像メモリ２９に記憶され、演算処理部２８は画像メモリ２９に記憶された前眼部像データから被検眼Ｅの瞳孔を抽出し、瞳孔の中心位置を検出する。
【００２１】
例えば、瞳孔の中心位置を検出する際には、被検眼Ｅの前眼部を十分に照明すると、前眼部像の明るさは瞳孔で最も暗くなり虹彩と強膜では順次に明るくなるので、瞳孔の明るさの境界を適当な閾値で２値化処理することにより瞳孔の中心位置を検出することができる。
【００２２】
演算処理部２８は瞳孔の中心位置を検出した後に、瞳孔の中心位置と検査部の光軸との光軸と垂直な面内つまりＸＹ平面内でのずれ量を算出し、このずれ量をなくすように駆動手段３４を制御する。瞳孔の中心位置を検出して駆動手段３４を制御すると、瞳孔の中心位置を再び検出し、ずれ量が予め設定してある許容範囲内にあるか否かを判断する。そして、ずれ量が許容範囲内にないと判断した場合には、ずれ量をなくすように駆動手段３４のＸＹ方向の制御を行い、ずれ量が許容範囲内にあるか否かを再び判断する。
【００２３】
ずれ量が許容範囲内にあると判断したときには、直ちに角膜指標用光源２４を点灯し、角膜反射指標像の位置、強度、及びコントラストを算出する。この際に、角膜指標用光源２４から発した光束は角膜指標板２３を照明し、角膜指標板２３の透光部を透過した角膜指標光束は角膜指標投影レンズ２２を透過し、ビームスプリッタ１２により対物レンズ１１の手前で角膜指標板２３の像を一旦形成し、対物レンズ１１により略平行光とされ、その大部分がダイクロイックミラー１を透過して被検眼Ｅに入射する。
【００２４】
被検眼Ｅの角膜Ｅｃで反射した光束は、角膜曲率中心と角膜頂点の中点の位置に反射光束の反射像を形成し、その光束の一部はダイクロイックミラー１で反射し、対物レンズ３で略平行光となり、ダイクロイックミラー４で光路Ｏ２に偏向し、ダイクロイックミラー５で反射し、結像レンズ８を介して撮像素子９に角膜反射指標像を含む画像として撮像される。
【００２５】
撮像素子９からの信号はＡ／Ｄコンバータ２６によりデジタル化され、画像メモリ３０に記憶されると同時に演算処理部２８に入力する。演算処理部２８は画像メモリ３０に記憶された角膜反射指標像を含む画像データから角膜反射指標像を抽出し、角膜反射指標像の位置、強度、及びコントラストを算出する。そして、角膜反射指標像の相対位置からＸＹ方向のずれ量を検出し、角膜反射指標像の強度とコントラストからＺ方向の相対位置を検出する。
【００２６】
角膜反射視標像は次の方法で抽出することができる。即ち、角膜反射視標像は通常瞳孔内に存在するので、角膜反射指標像を含む画像データのうち、瞳孔像が最も暗く角膜反射視標像が最も明るい。従って、瞳孔の中心位置は既に検出しているので、瞳孔の中心位置に近い所定レベル以上の輝点を画像データから探せば、角膜反射指標像を容易に特定でき、その位置、強度、及びコントラストを算出することができる。
【００２７】
角膜反射指標像を算出すると、その強度とコントラストが所定レベルを満たしているか否かを判断する。それらが所定レベルを満たしていないと判断した場合には、それらが所定レベルを満たすように駆動手段３４のＺ方向の制御を行う。そして、１回目の強度とコントラストの算出と駆動手段３４のＺ方向の制御を行った後に、それらが所定レベルを満たすまで強度とコントラストの算出と駆動手段３４の制御を繰り返す。これにより、検査部と被検眼Ｅとの距離を測定するために必要な作動距離にすることができる。
【００２８】
ここで、図３は被検眼Ｅの位置基準と検査部との位置合わせの許容領域Ａ１〜Ａ３を同心円状に分割して示しており、これらの許容領域Ａ１〜Ａ３は被検眼Ｅが適正な位置にきたときの被検眼Ｅの角膜の頂点に接する測定光軸Ｏに垂直な平面内に設けられている。領域Ａ１は測定を許容すると共に被検眼Ｅの位置基準と検査部の光軸Ｏとを一致させるように駆動手段３４を制御する測定許容駆動制御領域とされている。領域Ａ２は領域Ａ１内に設けられて測定を許容する測定許容領域とされている。そして、領域Ａ３は領域Ａ１、Ａ２の外に設けられて被検眼Ｅの位置基準と検査部の光軸Ｏとを一致させるように駆動手段３４を制御する駆動制御領域とされている。
【００２９】
なお、被検眼Ｅの位置基準と検査部の光軸Ｏとの相対位置に応じて測定値は或る程度変動するので、領域Ａ１は測定値を所定の精度で得ることのできる範囲に設定する必要がある。また、領域Ａ１、Ａ２の範囲をテレビモニタ３３に表示することが好ましい。更には、領域Ａ１、Ａ２を同心円状に分割したが、同心円状に限定することなく例えば矩形状に分割しても支障はない。
【００３０】
次に、演算処理部２８は検出した角膜反射指標像の位置を被検眼Ｅの位置基準とし、被検眼Ｅの位置基準が領域Ａ１〜Ａ３のどの領域に存在するかを判断する。被検眼Ｅの位置基準が領域Ａ１に存在すると判断した場合には、被検眼Ｅの位置基準が所望の測定精度を得ることのできる範囲の端に位置しているので、眼球の僅かな運動等によって領域Ａ１から外れる虞れがある。従って、演算処理部２８は直ちに既知の方法による眼屈折力の測定を開始し、同時に検出した被検眼Ｅの位置基準と検査部の光軸Ｏとのずれ量を求め、ずれ量がなくなるように駆動手段３４のＸＹ方向の制御を行う。
【００３１】
信号入力手段３５の測定回数設定スイッチにより、任意の測定回数を設定することができるが、例えば測定回数を予め設定するか又は検者がＮ回と設定すれば、１回目の測定が終了した時点で演算処理部２８は測定回数がＮ回に達しているか否かを判断し、Ｎ回に達していない場合には角膜反射指標像の強度とコントラストから駆動手段３４のＺ方向の制御を再び行い、角膜反射指標像の位置から被検眼Ｅの位置基準がどの領域Ａ１〜Ａ３に存在するかを判断する。
【００３２】
被検眼Ｅの位置基準が領域Ａ２に存在すると判断した場合には、被検眼Ｅの位置基準が所望の測定精度を得ることのできる範囲の中心近傍に位置しているので、眼球の僅かな運動等によって領域Ａ２を出る虞れがなく、被検眼Ｅの位置基準と検査部の光軸Ｏとを一致させるために駆動手段３４を無駄に制御する必要はない。従って、演算処理部２８は直ちに既知の方法による眼屈折力の測定を開始し、１回目の測定が終了した後に領域Ａ１に存在する場合と同様に駆動手段３４を制御し、２回目の測定を行う。
【００３３】
また、被検眼Ｅの位置基準が領域Ａ３に存在すると判断した場合には、演算処理部２８は被検眼Ｅの位置基準と検査部の光軸Ｏとのずれ量を求め、ずれ量をなくすように駆動手段３４のＸＹ方向の制御を行う。その後に、角膜反射指標像の強度とコントラストから駆動手段３４のＺ方向の制御を再び行い、角膜反射指標像の位置から被検眼Ｅの位置基準がどの領域Ａ１〜Ａ３に存在するかを判断し、その領域Ａ１〜Ａ３に応じて駆動手段３４の制御を行う。
【００３４】
そして、Ｎ回目の測定が終了すると、他眼の測定が未だ終了していない場合には他眼の測定動作に自動的に移行し、所定回数の測定を行う。他眼の測定が既に終了している場合には、測定結果をテレビモニタ３３に表示するか、図示しないプリンタ等の印刷手段に出力して、全測定動作を終了する。
【００３５】
このように、第１の実施の形態では被検眼Ｅの位置基準を検出し、被検眼Ｅの位置基準と検査部との位置合わせの測定許容領域を複数の領域Ａ１〜Ａ３に分割し、検出した被検眼Ｅの位置基準が領域Ａ１〜Ａ３の内のどの領域に存在するかを判断して、測定や位置合わせの制御方法を変化させるので、駆動手段３４を不必要に制御することがなく、最小限に制御して安定した測定を迅速に行うことができる。
【００３６】
なお、第１の実施の形態では被検眼Ｅの位置基準を角膜反射指標像に基づいて算出したが、角膜反射指標像の代りに被検眼Ｅの瞳孔像に基づいて被検眼Ｅの瞳孔の中心位置を算出し、その位置を被検眼Ｅの位置基準としてもよい。
【００３７】
また、眼屈折力測定光源１７と角膜指標用光源２４を別個に設けたが、ビームスプリッタ１２、角膜指標投影レンズ２２、角膜指標板２３、角膜指標用光源２４を取り除き、眼屈折力測定光源１７を角膜指標用光源としてもよい。更に、角膜反射指標像撮像光学系のダイクロイックミラー５、結像レンズ８、撮像素子９の代りに、前眼部観察光学系の対物レンズ３〜撮像素子７を共用して角膜反射指標像を検出すれば、装置の簡素化と小型化が可能となる。
【００３８】
そして、角膜指標板２３を光軸上に配置したが、複数の角膜指標を光軸外に光軸と対称に配置し、これらの複数の角膜指標によって複数の角膜反射指標像を検出し、これらの複数の角膜反射指標像の中心位置を被検眼Ｅの位置基準としてもよい。
【００３９】
図４は第２の実施の形態の光学的な構成図であり、第１の実施の形態におけるダイクロイックミラー５、結像レンズ８、撮像素子９が取り除かれ、光路Ｏ２には偏向プリズム３６ａ、３６ｂを備えた絞り板３７が配置されている。また、第１の実施の形態のビームスプリッタ１２、角膜視標投影レンズ２２、角膜視標板２３、角膜視標用光源２４の代りに、発光ダイオード等の角膜視標用光源３８、３９が光路Ｏ４に対象に配置され、対物レンズ１１と共働する角膜視標投影光学系が構成されている。
【００４０】
図５に示すように、絞り板３７には光軸外に対称に位置する２つの開口３７ａ、３７ｂと、光軸上に位置する開口３７ｃとが形成され、偏向プリズム３６ａ、３６ｂが開口３７ａ、３７ｂにそれぞれ密着されている。また、角膜指標用光源３８、３９は前眼部照明光源２が発する光の波長と異なり、眼屈折力測定光源１７が発する光の波長と同様とされている。そして、絞り板３７の開口３７ａ、３７ｂは眼屈折力測定光源１７と角膜指標用光源３８、３９からの波長の光のみを透過するようになっており、偏向プリズム３６ａは光束を紙面に対する奥の方に偏向し、偏向プリズム３６ｂは光束を紙面に対する手前の方に偏向するようになっている。
【００４１】
例えば、一方の角膜指標用光源３９から発した光束は対物レンズ１１を介して被検眼Ｅの角膜Ｅｃに投影され、角膜Ｅｃで反射した光束はダイクロイックミラー１、対物レンズ３、ダイクロイックミラー４を介して偏向プリズム３６ａ、３６ｂと絞り板３７により分割偏向され、結像レンズ６を介して撮像素子７に導かれる。
【００４２】
ここで、図６〜図８は角膜視標光源３９から発した光束が偏向プリズム３６ａ、３６ｂ、絞り板３７、結像レンズ６を介して撮像素子７に導かれる状態を示し、図６被検眼Ｅに対する検査部の位置が適正である場合を示し、図７は被検眼Ｅに対する検査部の位置が近過ぎる場合を示し、図８は被検眼Ｅに対する検査部の位置が遠過ぎる場合を示している。光束Ｌａは絞り板３７の開口３７ａにより制限され、偏向プリズム３６ａにより紙面に対する奥の方に偏向される。光束Ｌｂは開口３７ｂにより制限され、偏向プリズム３６ｂにより紙面に対する手前の方に偏向される。そして、光束Ｌｃは開口３７ｃにより制限される。
【００４３】
図９〜図１１は検査部を瞳孔の中心位置に位置合わせした後にテレビモニタ３３に映出された被検眼Ｅの前眼部像Ｅ’を示し、像３８ａ、３８ｂ、３８ｃは角膜指標用光源３８からの光束が絞り板３７の開口３７ａ、３７ｂ、３７ｃによりそれぞれ分割された角膜指標用光源像を示し、像３９ａ、３９ｂ、３９ｃは角膜指標用光源３９からの光束が絞り板３７の開口３７ａ、３７ｂ、３７ｃによりそれぞれ分割された角膜指標用光源像を示している。そして、図９は被検眼Ｅに対する検査部の位置が適正である場合を示し、図１０は被検眼Ｅに対する検査部の位置が近過ぎる場合を示し、図１１は被検眼Ｅに対する検査部の位置が遠過ぎる場合を示している。
【００４４】
このように第２の実施の形態では、角膜指標用光源３８、３９から被検眼Ｅの角膜Ｅｃに指標光束を投影し、被検眼Ｅの角膜Ｅｃで反射した光束Ｌａ、Ｌｂ、Ｌｃを偏向プリズム３６ａ、３６ｂと絞り板３７により分割し、角膜指標用光源像３８ａ、３８ｂ、３８ｃ、３９ａ、３９ｂ、３９ｃの位置を検出して、被検眼Ｅと検査部との相対位置を三次元で検出することができる。従って、駆動手段３４を制御することにより、検査部を被検眼Ｅに適正に位置合わせすることができる。また、角膜指標用光源３８、３９は光路Ｏ４に対称に配置したので、被検眼Ｅの角膜Ｅｃで反射した中央の角膜指標用光源像３８ｃ、３９ｃの位置を検出し、それらの中点から角膜Ｅｃの中心を求めて被検眼Ｅの位置基準とすることができる。
【００４５】
なお、この第２の実施の形態では、角膜指標用光源３８、３９から被検眼Ｅの角膜Ｅｃに指標光束を投影し、偏向プリズム３６ａ、３６ｂと絞り板３７とにより角膜反射指標像を分割したので、被検眼Ｅの基準位置と検査部との３軸の相対位置を検出することができ、被検眼Ｅの位置基準と検眼部との位置合わせの領域を図１２に示すような測定許容領域Ａ１〜Ａ３に分割することができる。これらの領域Ａ１〜Ａ３は、検査部の光軸ＯであるＺ軸とそれに垂直なＹ軸とを含むＹＺ平面上の検査部が被検眼Ｅに対して適正な位置にきたときの領域としている。
【００４６】
この場合に、光軸Ｏは被検眼Ｅの位置基準と検査部とを位置合わせするための基準とし、領域Ａ１と領域Ａ２はＺ軸を回転軸とする回転対称形をした三次元の領域としている。領域Ａ１は測定を許容しかつ被検眼Ｅの位置基準が光軸Ｏと一致するように駆動手段３４を制御する測定許容駆動制御領域とし、領域Ａ２は領域Ａ１内にあって測定を許容する測定許容領域とし、領域Ａ３は領域Ａ１、Ａ２の外にあって被検眼Ｅの位置基準が光軸Ｏと一致するように駆動手段３４を制御する駆動制御領域としている。
【００４７】
そして、演算処理部２８は上述した方法に基づいて検査部に対する被検眼Ｅの位置基準の相対位置を検出し、被検眼Ｅの位置基準が領域Ａ１〜Ａ３のどの領域に存在するかを判断して、駆動手段３４の制御方法を第１の実施の形態と同様に変化させている。
【００４８】
従って、被検眼Ｅの位置基準と検査部の相対位置を三次元で検出し、被検眼Ｅの位置基準と検査部との位置合わせの測定許容領域を立体的に複数の領域Ａ１〜Ａ３に分割し、検出した被検眼Ｅの位置基準が領域Ａ１〜Ａ３の内のどの領域に存在するかを判断し、その領域Ａ１〜Ａ３により測定や位置合わせの制御方法を変化させるので、駆動手段３４を不必要に制御することがなく、最小限に制御して安定した測定を迅速に行うことができる。
【００４９】
【発明の効果】
以上説明したように本発明に係る眼科装置は、被検眼の位置基準と測定手段との位置ずれ量に応じて、測定手段と駆動手段の少なくとも一方を制御するので、駆動手段を不必要に制御することがなく、安定した測定値を迅速に得ることができる。
【図面の簡単な説明】
【図１】第１の実施の形態の光学的な構成図である。
【図２】演算処理部の演算処理手順を説明するフローチャート図である。
【図３】位置合わせの測定許容領域の説明図である。
【図４】第２の実施の形態の光学的な構成図である。
【図５】偏向プリズムを備えた絞り板の正面図である。
【図６】検査部が適正な場合の角膜反射指標光束の説明図である。
【図７】検査部が近過ぎる場合の角膜反射指標光束の説明図である。
【図８】検査部が遠過ぎる場合の角膜反射指標光束の説明図である。
【図９】検査部が適正な場合の被検眼の前眼部像の正面図である。
【図１０】検査部が近過ぎる場合の被検眼の前眼部像の正面図である。
【図１１】検査部が遠過ぎる場合の被検眼の前眼部像の正面図である。
【図１２】立体的な位置合わせの測定許容領域の説明図である。
【符号の説明】
１、４、５ダイクロイックミラー
２前眼部照明光源
３、１１対物レンズ
６、８結像レンズ
１０ミラー
１２ビームスプリッタ
１３孔あきミラー
１４投影絞り
１５、２２投影レンズ
１６、２３指標板
１７眼屈折力測定光源
１８６孔絞り
１９６分割プリズム
２０リレーレンズ
２１撮像素子
２４、３８、３９角膜指標用光源
２５〜２７Ａ／Ｄコンバータ
２８演算処理部
２９〜３１画像メモリ
３２Ｄ／Ａコンバータ
３３テレビモニタ
３４駆動手段
３５信号入力手段
３６ａ、３６ｂ偏向プリズム
３７絞り板
Ａ１測定許容駆動制御領域
Ａ２測定許容領域
Ａ３駆動制御領域[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ophthalmologic apparatus that obtains specific information of an eye to be examined, such as eye refractive power, fundus image, and fundus blood flow, by aligning an examination part with the eye to be examined while observing the eye to be examined.
[0002]
[Prior art]
Conventionally, in this type of ophthalmologic apparatus, when aligning the examination part with the eye to be examined, the operator observes the anterior eye part image of the eye to be examined shown on the display part such as a television monitor and operates the operation means. The examination part is roughly aligned with the eye to be examined. In addition, after the corneal reflection image or pupil image of the index light beam projected on the cornea of the eye to be examined appears on the display unit, the operation is performed so that the corneal reflection image or pupil image matches the alignment mark displayed around the optical axis. By operating the means, the examination part is precisely aligned with the eye to be examined.
[0003]
In this ophthalmologic apparatus, the allowable range of coincidence between the reference position of the eye to be examined and the optical axis of the examination part is related to the extent to which the deviation of the measurement value due to the deviation of the examination part is allowable, thereby adjusting the alignment. An allowable range, that is, a measurable area is defined.
[0004]
In recent years, an ophthalmologic apparatus has been proposed in which an examination unit is driven in three axial directions by a driving unit to automatically align with an eye to be examined. This ophthalmologic apparatus photoelectrically detects a reflection index image from the eye to be examined, and controls the driving means so that the detected reflection index image and the optical axis of the examination unit coincide.
[0005]
In this ophthalmologic apparatus, the control of the driving means is continued even after the reference position of the subject's eye enters the measurable region, or the control of the driving means is stopped when the reference position of the subject's eye enters the measurable region. When the reference position of the optometry deviates from the measurable area, the control of the driving means is resumed.
[0006]
[Problems to be solved by the invention]
However, if the control of the driving means is continued even after the reference position of the subject's eye enters the measurable region, the driving means is more than necessary even though the measurement value is sufficiently accurate. Since the control is repeated, there arises a problem that the measured value cannot be obtained quickly.
[0007]
In addition, when the control of the driving means is stopped when the reference position of the eye to be examined enters the measurable area and the control of the driving means is resumed when the reference position of the eye to be examined deviates from the measurable area, When the control of the driving means is stopped when the reference position of the optometry is located at the end of the measurable region, the reference position of the subject's eye deviates from the measurable region by a slight movement of the eyeball of the subject's eye, and stable measurement is performed. The problem arises that the value cannot be obtained.
[0008]
An object of the present invention is to provide an ophthalmic apparatus that can solve the above-described problems and can quickly obtain a stable measurement value without unnecessarily controlling a driving unit.
[0009]
Another object of the present invention is to provide an ophthalmic apparatus that can be simplified and miniaturized.
[0010]
[Means for Solving the Problems]
To achieve the above object, an ophthalmologic apparatus according to the present invention comprises a measuring means for measuring an eye to be examined, a detecting means for detecting a reference position of the eye to be examined, a driving means for driving the measuring means , and the above-mentioned eye of the eye to be examined. depending on the amount of positional deviation between the reference position and the measurement means, and having a control means for controlling at least one of said measuring means and said driving means.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the illustrated embodiment.
FIG. 1 is an optical configuration diagram of the first embodiment, in which a dichroic mirror 1 is disposed on an optical path O1 in front of the eye E to face the eye E. An anterior ocular segment illumination light source 2 such as a light emitting diode that emits near-infrared light for illuminating the anterior segment of the eye E is arranged outside the optical axis between the eye E and the dichroic mirror 1. An objective lens 3 and a dichroic mirror 4 are disposed in the reflection direction of the dichroic mirror 1, and an imaging device 7 such as a dichroic mirror 5, an imaging lens 6, and a CCD camera is disposed on the optical path O 2 in the reflection direction of the dichroic mirror 4. ing. The imaging element 7 is disposed at a position substantially conjugate with the vicinity of the anterior eye part of the eye E to be examined, and the anterior eye part observation optical system is configured by the objective lens 3 to the imaging element 7.
[0012]
An imaging lens 8 and an image sensor 9 are arranged in the reflection direction of the dichroic mirror 5, and the corneal reflection index image imaging optical system is configured by the objective lenses 3 to 9. The image sensor 9 is a CCD camera or the like, and is arranged at a position substantially conjugate with the vicinity of the anterior eye portion of the eye E to be examined. A mirror 10 is arranged in the transmission direction of the dichroic mirror 4, and a fixation target projection optical system (not shown) for fixing the eye E is fixed on the optical path O <b> 3 in the reflection direction of the mirror 10.
[0013]
On the other hand, on the optical path O 4 in the transmission direction of the dichroic mirror 1, the objective lens 11, a beam splitter 12 such as a half mirror, a perforated mirror 13, a projection aperture 14, a projection lens 15, an index plate 16, and an eye refractive power measurement light source 17. Is arranged. The eye refractive power measurement light source 17 is a light source that emits near-infrared light whose wavelength is several tens of nanometers longer than the anterior segment illumination light source 2, and the eye refractive power measurement light projection optical system is configured by the objective lens 11 to the eye refractive power measurement light source 17. It is configured.
[0014]
In the reflection direction of the perforated mirror 13, an imaging element 21 such as a six-hole aperture 18 having six openings outside the optical axis, a six-divided prism 19, a relay lens 20, and a CCD camera is disposed. 21 constitutes an eye refractive power measurement light receiving optical system.
[0015]
Further, a corneal index projection lens 22, a corneal index plate 23, and a corneal index light source 24 such as a light emitting diode that emits near-infrared light are arranged in the reflection direction of the beam splitter 12, and the objective lens 11 to the corneal index light source 24. Thus, the corneal index projection optical system is configured.
[0016]
The dichroic mirror 1 transmits most of the light having a wavelength emitted from the eye refractive power measurement light source 17 and the corneal marker light source 24 and reflects a part of the light, and reflects the light having a wavelength emitted from the anterior segment illumination light source 2. It has the characteristic to do. The dichroic mirror 4 has a characteristic of transmitting visible light and reflecting near infrared light. Further, the dichroic mirror 5 has a characteristic of reflecting light having a wavelength emitted from the eye refractive power measurement light source 17 and the corneal marker light source 24 and transmitting light having a wavelength emitted from the anterior segment illumination light source 2. .
[0017]
Outputs of the image sensors 7, 9, and 21 are connected to a common arithmetic processing unit 28 via A / D converters 25, 26, and 27, and are connected to image memories 29, 30, and 31, respectively. The arithmetic processing unit 28 includes an eye refractive power measurement light source 17, a corneal index light source 24, image memories 29, 30 and 31, a television monitor 33 via a D / A converter 32, a drive unit 34 such as a drive motor, The signal input means 35 in which the switches are arranged is connected. The switch of the signal input means 35 is a switch for operating the drive means 34, a switch for starting measurement, a switch for setting the number of measurements, and the like.
[0018]
Inspection unit using the anterior ocular segment observation optical system, fixation target projection optical system, eye refractive power measurement light projection optical system, eye refractive power measurement light receiving optical system, corneal index projection optical system, corneal reflection index image imaging optical system, etc. Is configured. This inspection unit is mounted on a gantry movable in three axial directions, and is driven in the Z-axis direction in the optical axis direction and in both the X-axis direction and the Y-axis direction perpendicular to each other and perpendicular to the Z-axis direction. 34 is electrically driven.
[0019]
FIG. 2 is a flowchart showing the calculation processing procedure of the calculation processing unit 28. When the examiner turns on the measurement start switch of the signal input means 35, the measurement operation starts and the anterior segment illumination light source 2 is turned on. The eye E is illuminated. Reflected and scattered light from the vicinity of the anterior segment by the anterior segment illumination light source 2 is reflected by the dichroic mirror 1, becomes substantially parallel light by the objective lens 3 and is reflected by the dichroic mirror 4, and passes through the dichroic mirror 5 and the imaging lens 6. The anterior eye part image of the eye E to be examined is formed on the image sensor 7 through the transmission.
[0020]
An output signal from the image sensor 7 is converted into a digital signal via the A / D converter 25 and is displayed as an anterior segment image E ′ on the television monitor 33 via the arithmetic processing unit 28 and the D / A converter 32. . At the same time, the digital signal is stored in the image memory 29, and the arithmetic processing unit 28 extracts the pupil of the eye E from the anterior segment image data stored in the image memory 29, and detects the center position of the pupil.
[0021]
For example, when the center position of the pupil is detected, if the anterior segment of the eye E is sufficiently illuminated, the brightness of the anterior segment image is the darkest in the pupil and sequentially brightens in the iris and sclera. The center position of the pupil can be detected by binarizing the brightness boundary of the pupil with an appropriate threshold value.
[0022]
After detecting the center position of the pupil, the arithmetic processing unit 28 calculates a shift amount in a plane perpendicular to the optical axis between the center position of the pupil and the optical axis of the inspection unit, that is, in the XY plane, and eliminates the shift amount. Thus, the driving means 34 is controlled. When the center position of the pupil is detected and the driving means 34 is controlled, the center position of the pupil is detected again, and it is determined whether or not the deviation amount is within a preset allowable range. When it is determined that the deviation amount is not within the allowable range, the drive unit 34 is controlled in the X and Y directions so as to eliminate the deviation amount, and it is determined again whether the deviation amount is within the allowable range.
[0023]
When it is determined that the deviation amount is within the allowable range, the corneal index light source 24 is immediately turned on, and the position, intensity, and contrast of the corneal reflection index image are calculated. At this time, the light beam emitted from the corneal index light source 24 illuminates the corneal index plate 23, and the corneal index light beam transmitted through the light transmitting portion of the corneal index plate 23 is transmitted through the corneal index projection lens 22, and is transmitted by the beam splitter 12. An image of the corneal indicator plate 23 is once formed in front of the objective lens 11 and is made substantially parallel light by the objective lens 11, most of which passes through the dichroic mirror 1 and enters the eye E to be examined.
[0024]
The light beam reflected by the cornea Ec of the eye E forms a reflected image of the reflected light beam at the midpoint of the center of corneal curvature and the apex of the cornea, and a part of the light beam is reflected by the dichroic mirror 1 and is reflected by the objective lens 3. The light becomes substantially parallel light, is deflected to the optical path O2 by the dichroic mirror 4, is reflected by the dichroic mirror 5, and is imaged as an image including a corneal reflection index image via the imaging lens 8 on the imaging element 9.
[0025]
A signal from the image sensor 9 is digitized by the A / D converter 26 and stored in the image memory 30 and simultaneously input to the arithmetic processing unit 28. The arithmetic processing unit 28 extracts the corneal reflection index image from the image data including the corneal reflection index image stored in the image memory 30, and calculates the position, intensity, and contrast of the corneal reflection index image. Then, the amount of deviation in the XY direction is detected from the relative position of the corneal reflection index image, and the relative position in the Z direction is detected from the intensity and contrast of the corneal reflection index image.
[0026]
The corneal reflection visual target image can be extracted by the following method. That is, since the corneal reflection target image normally exists in the pupil, the pupil image is the darkest and the corneal reflection target image is the brightest among the image data including the corneal reflection index image. Therefore, since the center position of the pupil has already been detected, the corneal reflection index image can be easily identified by searching the image data for a bright spot of a predetermined level or more close to the center position of the pupil, and its position, intensity, and contrast Can be calculated.
[0027]
When the corneal reflection index image is calculated, it is determined whether the intensity and contrast satisfy a predetermined level. If it is determined that they do not satisfy the predetermined level, the driving means 34 is controlled in the Z direction so that they satisfy the predetermined level. Then, after the first calculation of the intensity and contrast and the control of the driving means 34 in the Z direction, the calculation of the intensity and contrast and the control of the driving means 34 are repeated until they satisfy a predetermined level. Thereby, it can be set as the working distance required in order to measure the distance of a test | inspection part and the eye E to be examined.
[0028]
Here, FIG. 3 shows the permissible areas A1 to A3 for alignment between the position reference of the eye E to be examined and the examination part, which are concentrically divided, and these permissible areas A1 to A3 are appropriate for the eye E to be examined. It is provided in a plane perpendicular to the measurement optical axis O in contact with the apex of the cornea of the eye E when it comes to the position. The region A1 is a measurement-permitted drive control region in which the drive unit 34 is controlled so as to allow measurement and match the position reference of the eye E with the optical axis O of the examination unit. The region A2 is a measurement allowable region that is provided in the region A1 and allows measurement. The area A3 is a drive control area that is provided outside the areas A1 and A2 and controls the driving unit 34 so that the position reference of the eye E to be inspected and the optical axis O of the examination unit coincide.
[0029]
Since the measured value varies to some extent according to the relative position between the position reference of the eye E to be examined and the optical axis O of the examination unit, the area A1 is set in a range where the measured value can be obtained with a predetermined accuracy. There is a need. Further, it is preferable to display the range of the areas A1 and A2 on the television monitor 33. Furthermore, although the regions A1 and A2 are concentrically divided, the present invention is not limited to the concentric circles, and there is no problem even if they are divided into rectangular shapes, for example.
[0030]
Next, the arithmetic processing unit 28 uses the position of the detected corneal reflection index image as a position reference of the eye E to be examined, and determines in which of the areas A1 to A3 the position reference of the eye E is present. If it is determined that the position reference of the eye E is present in the area A1, the position reference of the eye E is located at the end of the range where desired measurement accuracy can be obtained. There is a possibility that the region A1 may be out of the region A1. Therefore, the arithmetic processing unit 28 immediately starts measuring the eye refractive power by a known method, obtains the amount of deviation between the detected position reference of the eye E and the optical axis O of the examination unit, and eliminates the amount of deviation. The drive means 34 is controlled in the X and Y directions.
[0031]
An arbitrary number of measurements can be set by the measurement number setting switch of the signal input means 35. For example, when the number of measurements is set in advance or the examiner sets N times, the first measurement is completed. Then, the arithmetic processing unit 28 determines whether or not the number of measurements has reached N times. If the number has not reached N times, the control unit 28 again controls the driving means 34 in the Z direction from the intensity and contrast of the corneal reflection index image. The region A1 to A3 in which the position reference of the eye E is present is determined from the position of the corneal reflection index image.
[0032]
If it is determined that the position reference of the eye E exists in the area A2, the position reference of the eye E is located near the center of the range where the desired measurement accuracy can be obtained. There is no risk of exiting the area A2 due to, for example, and it is not necessary to control the driving means 34 wastefully in order to match the position reference of the eye E to be examined and the optical axis O of the examination part. Accordingly, the arithmetic processing unit 28 immediately starts measuring the eye refractive power by a known method, and controls the driving means 34 in the same manner as in the case where it exists in the region A1 after the first measurement is completed, and performs the second measurement. Do.
[0033]
When it is determined that the position reference of the eye E is present in the area A3, the arithmetic processing unit 28 obtains a deviation amount between the position reference of the eye E and the optical axis O of the examination unit so as to eliminate the deviation amount. Then, the drive means 34 is controlled in the X and Y directions. Thereafter, control in the Z direction of the driving means 34 is performed again from the intensity and contrast of the corneal reflection index image, and it is determined in which region A1 to A3 the position reference of the eye E is present from the position of the corneal reflection index image. The drive means 34 is controlled according to the areas A1 to A3.
[0034]
When the measurement for the Nth time is completed, if the measurement for the other eye is not yet completed, the measurement operation for the other eye is automatically performed, and a predetermined number of measurements are performed. If the measurement of the other eye has already been completed, the measurement result is displayed on the television monitor 33 or output to a printing means such as a printer (not shown), and the entire measurement operation is terminated.
[0035]
As described above, in the first embodiment, the position reference of the eye E is detected, and the measurement allowable area for alignment between the position reference of the eye E and the inspection unit is divided into a plurality of areas A1 to A3 and detected. Since it is determined in which of the regions A1 to A3 the position reference of the eye E to be examined is present and the control method for measurement and alignment is changed, the drive means 34 is not unnecessarily controlled. Stable measurements can be made quickly with minimal control.
[0036]
In the first embodiment, the position reference of the eye E is calculated based on the corneal reflection index image, but the center of the pupil of the eye E based on the pupil image of the eye E instead of the corneal reflection index image. The position may be calculated, and the position may be used as the position reference for the eye E.
[0037]
The eye refractive power measurement light source 17 and the corneal index light source 24 are provided separately, but the beam splitter 12, the corneal index projection lens 22, the cornea index plate 23, and the corneal index light source 24 are removed, and the eye refractive power measurement light source 17 is provided. May be used as the light source for the corneal index. Further, instead of the dichroic mirror 5, the imaging lens 8, and the image sensor 9 of the corneal reflection index image imaging optical system, the objective lens 3 to the image sensor 7 of the anterior ocular segment observation optical system are shared to detect the corneal reflection index image. Then, the device can be simplified and downsized.
[0038]
The corneal index plate 23 is arranged on the optical axis, but a plurality of corneal indices are arranged symmetrically with the optical axis outside the optical axis, and a plurality of corneal reflection index images are detected by the plurality of corneal indices. The center position of the plurality of corneal reflection index images may be used as the position reference of the eye E to be examined.
[0039]
FIG. 4 is an optical configuration diagram of the second embodiment, in which the dichroic mirror 5, the imaging lens 8, and the image sensor 9 in the first embodiment are removed, and deflection prisms 36a and 36b are disposed in the optical path O2. A diaphragm plate 37 provided with is arranged. Further, instead of the beam splitter 12, the corneal target projection lens 22, the corneal target plate 23, and the corneal target light source 24 of the first embodiment, corneal target light sources 38 and 39 such as light emitting diodes are provided in the optical path. A corneal target projection optical system which is disposed on the object at O4 and cooperates with the objective lens 11 is configured.
[0040]
As shown in FIG. 5, the aperture plate 37 is formed with two openings 37a and 37b that are positioned symmetrically outside the optical axis, and an opening 37c that is positioned on the optical axis, and the deflection prisms 36a and 36b are the openings 37a, 37b is in close contact with each other. The corneal marker light sources 38 and 39 are different from the wavelength of light emitted from the anterior segment illumination light source 2 and are the same as the wavelength of light emitted from the eye refractive power measurement light source 17. The apertures 37a and 37b of the diaphragm plate 37 transmit only light having wavelengths from the eye refractive power measurement light source 17 and the corneal index light sources 38 and 39, and the deflection prism 36a transmits the light beam to the back of the paper surface. The deflecting prism 36b deflects the light beam toward the front side of the paper surface.
[0041]
For example, a light beam emitted from one corneal marker light source 39 is projected onto the cornea Ec of the eye E through the objective lens 11, and a light beam reflected by the cornea Ec passes through the dichroic mirror 1, the objective lens 3, and the dichroic mirror 4. Thus, the light is divided and deflected by the deflecting prisms 36 a and 36 b and the diaphragm plate 37 and guided to the image sensor 7 through the imaging lens 6.
[0042]
6 to 8 show a state in which the light beam emitted from the corneal target light source 39 is guided to the image sensor 7 through the deflecting prisms 36a and 36b, the diaphragm plate 37, and the imaging lens 6, and FIG. FIG. 7 shows a case where the position of the inspection part with respect to the eye E is too close, and FIG. 8 shows a case where the position of the inspection part with respect to the eye E is too far. Yes. The light beam La is limited by the opening 37a of the diaphragm plate 37, and is deflected by the deflecting prism 36a toward the back with respect to the paper surface. The light beam Lb is limited by the opening 37b and is deflected by the deflecting prism 36b toward the front of the paper surface. The light beam Lc is limited by the opening 37c.
[0043]
9 to 11 show the anterior segment image E ′ of the eye E displayed on the television monitor 33 after aligning the examination unit with the center position of the pupil, and images 38a, 38b, and 38c are light sources for corneal markers. 38 shows the corneal marker light source images obtained by dividing the light beam from the aperture plate 37 by the openings 37a, 37b, and 37c of the diaphragm plate 37, and the images 39a, 39b, and 39c show the luminous flux from the corneal marker light source 39 and the aperture 37a of the diaphragm plate 37. , 37b, 37c, respectively, show corneal marker light source images. 9 shows a case where the position of the examination part with respect to the eye E is appropriate, FIG. 10 shows a case where the position of the examination part with respect to the eye E is too close, and FIG. 11 shows the position of the examination part with respect to the eye E. Indicates the case is too far away.
[0044]
Thus, in the second embodiment, the index light beam is projected from the corneal index light sources 38 and 39 onto the cornea Ec of the eye E, and the light beams La, Lb, and Lc reflected by the cornea Ec of the eye E are deflected by the prism. 36a and 36b and the diaphragm plate 37, and the positions of the corneal index light source images 38a, 38b, 38c, 39a, 39b, and 39c are detected, and the relative position between the eye E and the examination part is detected in three dimensions. be able to. Therefore, by controlling the drive means 34, the examination part can be properly aligned with the eye E to be examined. Further, since the corneal marker light sources 38 and 39 are arranged symmetrically with respect to the optical path O4, the positions of the central corneal marker light source images 38c and 39c reflected by the cornea Ec of the eye E are detected, and the cornea is detected from the midpoint thereof. The center of Ec can be obtained and used as a position reference for the eye E.
[0045]
In the second embodiment, the index light beam is projected from the corneal index light sources 38 and 39 onto the cornea Ec of the eye E, and the corneal reflection index image is divided by the deflecting prisms 36a and 36b and the diaphragm plate 37. Therefore, the relative position of the three axes of the reference position of the eye E to be inspected and the examination part can be detected, and the region of alignment between the position reference of the eye E to be examined and the eye examination part can be measured as shown in FIG. It can be divided into areas A1 to A3. These regions A1 to A3 are regions when the inspection unit on the YZ plane including the Z axis, which is the optical axis O of the inspection unit, and the Y axis perpendicular thereto, comes to an appropriate position with respect to the eye E. .
[0046]
In this case, the optical axis O is used as a reference for aligning the position reference of the eye E to be examined and the examination part, and the regions A1 and A2 are rotationally symmetric three-dimensional regions having the Z axis as the rotation axis. Yes. The region A1 is a measurement allowable drive control region that allows measurement and controls the driving means 34 so that the position reference of the eye E coincides with the optical axis O. The region A2 is in the region A1 and allows measurement. The area A3 is outside the areas A1 and A2, and is a drive control area that controls the drive unit 34 so that the position reference of the eye E matches the optical axis O.
[0047]
Then, the arithmetic processing unit 28 detects the relative position of the position reference of the eye E with respect to the inspection unit based on the above-described method, and determines in which area of the areas A1 to A3 the position reference of the eye E is present. Thus, the control method of the driving unit 34 is changed in the same manner as in the first embodiment.
[0048]
Therefore, the position reference of the eye E and the relative position of the examination part are detected in three dimensions, and the measurement allowable area for alignment between the position reference of the eye E and the examination part is three-dimensionally divided into a plurality of areas A1 to A3. Then, it is determined in which of the areas A1 to A3 the position reference of the detected eye E exists, and the control method for measurement and alignment is changed by the areas A1 to A3. Without unnecessary control, stable measurement can be performed quickly with minimal control.
[0049]
【The invention's effect】
As described above, the ophthalmologic apparatus according to the present invention controls at least one of the measurement unit and the drive unit in accordance with the positional deviation amount between the position reference of the eye to be examined and the measurement unit, so that the drive unit is unnecessarily controlled. And stable measurement values can be obtained quickly.
[Brief description of the drawings]
FIG. 1 is an optical configuration diagram of a first embodiment.
FIG. 2 is a flowchart for explaining an arithmetic processing procedure of an arithmetic processing unit.
FIG. 3 is an explanatory diagram of a measurement allowable region for alignment.
FIG. 4 is an optical configuration diagram of the second embodiment.
FIG. 5 is a front view of a diaphragm plate provided with a deflecting prism.
FIG. 6 is an explanatory diagram of a corneal reflection index light beam when an inspection unit is appropriate.
FIG. 7 is an explanatory diagram of a corneal reflection index light beam when an inspection unit is too close.
FIG. 8 is an explanatory diagram of a corneal reflection index light beam when an inspection unit is too far.
FIG. 9 is a front view of an anterior segment image of an eye to be examined when the examination unit is appropriate.
FIG. 10 is a front view of an anterior segment image of an eye to be examined when an examination unit is too close.
FIG. 11 is a front view of an anterior segment image of an eye to be examined when the examination unit is too far away.
FIG. 12 is an explanatory diagram of a measurement allowable region for three-dimensional alignment.
[Explanation of symbols]
1, 4, 5 Dichroic mirror 2 Anterior illumination light source 3, 11 Objective lens 6, 8 Imaging lens 10 Mirror 12 Beam splitter 13 Perforated mirror 14 Projection aperture 15, 22 Projection lens 16, 23 Indicator plate 17 Eye refractive power Measurement light source 18 6-hole aperture 19 6-divided prism 20 Relay lens 21 Image sensors 24, 38, 39 Cornea index light sources 25-27 A / D converter 28 Arithmetic processing units 29-31 Image memory 32 D / A converter 33 Television monitor 34 Drive means 35 Signal input means 36a, 36b Deflection prism 37 Diaphragm plate A1 Measurement allowable drive control area A2 Measurement allowable area A3 Drive control area

Claims

A measuring means for measuring specific information of the eye to be examined;
Moving means for moving the measurement means so that an area based on the eye to be examined is located in a measurement allowable area with reference to the optical axis of the measurement means;
Detecting means for detecting that an area based on the eye to be examined is within the measurement allowable area;
When the detection means detects, the measurement means is controlled to start the measurement by the measurement means, and when the measurement by the measurement means is started, the region based on the eye to be examined is directed to the optical axis of the measurement means. Control means for controlling the moving means ;
An ophthalmologic apparatus comprising:

When the control unit starts measurement by the measurement unit, the region based on the subject eye is directed to the optical axis of the measurement unit according to the distance between the optical axis and the region based on the subject eye. The ophthalmologic apparatus according to claim 1, wherein the moving means is controlled.

The measurement allowable region has a region divided in a substantially concentric shape with the optical axis as a center.
When the control unit starts measurement by the measurement unit, the control unit controls the moving unit so that a region based on the eye to be examined is directed to an optical axis of the measurement unit according to the divided region. The ophthalmic apparatus according to claim 1.

The measurement allowable region has a region divided into a first region substantially centered on the optical axis and a second region outside the first region substantially centered on the optical axis,
When the control unit has a region based on the eye to be examined in the second region, the region based on the eye to be examined is directed toward the optical axis of the measurement unit when measurement by the measurement unit is started. the ophthalmic apparatus according to any one of claims 1 to 3, wherein the controller controls the moving means.

The control means controls the moving means to stop the movement of the measuring means when the measuring means starts when the area based on the eye to be examined exists in the first area; The ophthalmologic apparatus according to claim 4 .

A measuring means for measuring specific information of the eye to be examined;
Moving means for moving the measuring means;
When the region based on the eye to be examined exists in a second region outside the first region substantially centered on the optical axis of the measuring unit, the measurement unit and the moving unit are controlled to start measurement and Control means for aligning the eye to be examined and the measuring means;
An ophthalmologic apparatus comprising:

The control means is
When the region based on the eye to be examined exists in the first region, the measurement by the measurement unit is started,
When the area based on the eye to be examined exists in an area outside the second area, the eye to be examined is controlled so that the area based on the eye to be examined falls within the second area by controlling the driving means. The ophthalmic apparatus according to claim 6 , wherein alignment between the measuring unit and the measuring unit is performed.

The measuring means has an imaging means for taking an area based on the eye to be examined as an index image based on the eye to be examined;
The moving means moves the measuring means so that a position of the index image acquired from an image including the index image picked up by the imaging means is located in the measurement allowable region. Item 8. The ophthalmologic apparatus according to any one of Items 1 to 7 .

A corneal reflection index image obtained by using a light beam reflected by the cornea of the eye to be examined, a plurality of corneal reflection index images obtained by using a light beam reflected near the cornea of the eye to be examined, The ophthalmologic according to any one of claims 1 to 8 , wherein the ophthalmologic is one of a substantially center of a plurality of corneal reflection index images, a pupil image of the eye to be examined, and a substantially center of the pupil image. apparatus.

After the moving means moves the measuring means in the optical axis direction of the measuring means using at least one of the intensity and contrast of the area based on the eye to be examined, the area based on the eye to be examined is the measurement The ophthalmologic apparatus according to any one of claims 1 to 9 , wherein the measuring unit is moved in a direction intersecting the optical axis so as to be located in an allowable region.

An imaging means for taking an index image based on the eye to be examined, and a measuring means for measuring unique information of the eye to be examined;
Moving means for moving the measurement means so that the position of the index image acquired from the image including the index image is located within a measurement allowable region with reference to the optical axis of the measurement means;
Detecting means for detecting that the position of the index image is located within the measurement allowable region;
When the detection means detects, the measurement means is controlled to start the measurement by the measurement means, and when the measurement by the measurement means is started, the region based on the eye to be examined is directed to the optical axis of the measurement means. Control means for controlling the moving means ;
An ophthalmologic apparatus comprising:

The index image is a corneal reflection index image obtained using a light beam reflected by the cornea of the eye to be examined, a plurality of corneal reflection index images obtained by using a light beam reflected near the cornea of the eye to be examined, ophthalmologic apparatus according to claim 1 1, characterized in that any one of a pupil image.

An imaging means for taking a plurality of corneal reflection index images by a light beam reflected near the cornea of the eye to be examined, and a measuring means for measuring unique information of the eye to be examined;
The measuring means is arranged such that the position of the approximate center of the plurality of corneal reflection index images acquired from the image including the plurality of corneal reflection index images is located in a measurement allowable region with reference to the optical axis of the measuring means. Moving means for moving;
Detecting means for detecting that the position of the substantially center is located in the measurement allowable region; and when the detecting means detects, the measuring means is controlled to start measurement by the measuring means, and the measuring means Control means for controlling the moving means so that an area based on the eye to be examined is directed to the optical axis of the measuring means when starting measurement ;
An ophthalmologic apparatus comprising:

Wherein the plurality of cornea reflection index image, the ophthalmologic apparatus according to claims 1 to 3, characterized in that it is obtained by a plurality of corneal indices arranged symmetrically with respect to the optical axis to the outside of the optical axis.

Wherein the unique information, the eye refractive power, a fundus image, the ophthalmologic apparatus according to any one of claims 1 to 1 4, characterized in that at least one of a fundus blood flow.

Wherein the plurality of cornea reflection index image, claim 9, characterized in that at least six of the cornea reflection index images, 1 2, 1 3, 1 4 ophthalmologic apparatus according to any one of.

A moving step of moving the measuring means so that the area based on the eye to be examined is located within a measurement allowable area based on the optical axis of the measuring means for measuring the unique information of the eye to be examined;
A detection step of detecting that an area based on the eye to be examined is within the measurement allowable area;
A step of starting measurement by the measurement means upon detection in the detection step and moving the measurement means so that an area based on the eye to be examined is directed toward the optical axis of the measurement means when measurement by the measurement means is started When,
A method for controlling an ophthalmic apparatus, comprising:

When starting measurement by the measurement means, the measurement means is moved so that the region based on the eye to be examined is directed to the optical axis of the measurement means according to the distance between the optical axis and the region based on the eye to be examined. The method for controlling an ophthalmic apparatus according to claim 17 .