JP4705252B2

JP4705252B2 - Fundus camera

Info

Publication number: JP4705252B2
Application number: JP2001029632A
Authority: JP
Inventors: 和彦弓掛
Original assignee: Topcon Corp
Current assignee: Topcon Corp
Priority date: 2001-02-06
Filing date: 2001-02-06
Publication date: 2011-06-22
Anticipated expiration: 2021-02-06
Also published as: JP2002224039A

Description

【０００１】
【発明の属する技術分野】
この発明は、被検眼の前眼部からフレア（有害光）を除去するための遮光手段が設けられた眼底カメラに関するものである。
【０００２】
【従来の技術】
従来の眼底カメラには、例えば特公昭６１−５７２９号のように、照明光学系から被検眼に照明光を投影して眼底を照明して、この眼底からの反射光を撮影光学系により撮影手段に導いて眼底像を撮影手段で撮像すると共に、被検眼の角膜，水晶体等からのフレアが撮影光学系に入射するのを防止するために、角膜及び水晶体後面と共役な遮光板を照明光学系に設けたものがある。
【０００３】
【発明が解決しようとする課題】
この様な眼底カメラで撮影される被検眼は、人によって角膜や水晶体の厚さが異なるために、角膜−水晶体後面の間隔が異なる。
【０００４】
しかしながら、この眼底カメラでは、遮光板が固定されていたため、フレアを完全に除去できないものであった。
【０００５】
また、固視標を用いて被検眼を回旋（旋回）させて、被検眼の光軸の向きを撮影光学系の光軸に対して傾斜させることにより、照明光学系からの照明光束が眼底の周縁部側に投影されるようにして、より広範囲の眼底の撮影を行うことも行われている。
【０００６】
しかし、この場合には、水晶体の曲率中心と眼球の回旋中心が一致しないため、角膜及び水晶体の位置移動が起こり、角膜や水晶体の周辺部からのフレアが撮影光学系に入りやすくなる傾向にある。
【０００７】
更に、最近は白内障手術等に用いるＩＯＬ（intraocular lens)の普及により、ＩＬＯを装着した被検眼も増加しており、本来の水晶体とは形状及び屈折率が異なるため、従来の絞り位置ではフレア除去が困難な場合も増加する傾向にある。
【０００８】
そこで、この発明の第１の目的は、被検眼の角膜及び水晶体の厚さが異なっても、角膜や水晶体の周辺部からのフレアを除去できる眼底カメラを提供することを目的とするものである。
【０００９】
この発明の第２の目的は、被検眼の回旋により角膜及び水晶体の位置移動が起こっても、角膜や水晶体の周辺部からのフレアを除去できる眼底カメラを提供することを目的とするものである。
【００１０】
【課題を解決するための手段】
この第１の目的を達成するため、請求項１の発明は、被検眼の角膜，虹彩，水晶体後面の少なくとも一つと共役にさせるフレア除去用の遮光手段を介して前記被検眼の眼底を照明する照明光学系と、前記被検眼を撮影する撮影光学系と、前記遮光手段を前記照明光学系の光軸方向に移動調整させる駆動手段と、を有する眼底カメラにおいて、
前記被検眼に固視標を視認させて該被検眼の光軸を所定の方向に誘導させる固視標提示手段を更に備えると共に、前記固視標の提示位置に応じて前記駆動手段を作動制御することにより前記遮光手段を前記光軸方向に移動させて、前記遮光手段を角膜，水晶体後面の少なくとも一つと共役にさせる制御回路を備えることを特徴とする。
【００１１】
また、第２の目的を達成するため、請求項２の発明は、被検眼の角膜，虹彩，水晶体後面の少なくとも一つと共役にさせるフレア除去用の遮光手段を介して前記被検眼の眼底を照明する照明光学系と、前記被検眼を撮影する撮影光学系と、前記遮光手段を前記照明光学系の光軸方向に移動調整させる駆動手段と、を有する眼底カメラにおいて、
角膜，虹彩，水晶体後面の少なくとも一つのフレア状態を検出するフレア検出装置を更に備えると共に、
前記フレア検出装置からの検出信号を基に前記駆動手段を作動制御することにより前記遮光手段を前記光軸方向に移動させて、前記遮光手段を角膜，水晶体後面の少なくとも一つと共役にさせる制御回路を備えることを特徴とする。
【００１２】
請求項３に記載の発明は、被検眼の角膜，虹彩，水晶体後面の少なくとも一つと共役にさせるフレア除去用の遮光手段を介して前記被検眼の眼底を照明する照明光学系と、前記被検眼を撮影する撮影光学系とを有すると共に、前記遮光手段は、前記照明光学系の光軸と同心の同心遮光手段と、前記被検眼が回旋したときに前記同心遮光手段と切り換えて用いられ且つ前記被検眼の回旋方向に偏心した遮光部を有する偏心遮光手段である眼底カメラにおいて、
前記被検眼に固視標を視認させて該被検眼の光軸を所定の方向に誘導させる固視標提示手段を更に備えると共に、前記固視標の提示位置に応じて前記駆動手段を作動制御することにより前記遮光手段を前記光軸方向に移動させて、前記遮光手段を角膜，水晶体後面の少なくとも一つと共役にさせる制御回路を備えることを特徴とする。
【００１３】
請求項４に記載の発明は、被検眼の角膜，虹彩，水晶体後面の少なくとも一つと共役にさせるフレア除去用の遮光手段を介して前記被検眼の眼底を照明する照明光学系と、前記被検眼を撮影する撮影光学系とを有すると共に、前記遮光手段は、前記照明光学系の光軸と同心の同心遮光手段と、前記被検眼が回旋したときに前記同心遮光手段と切り換えて用いられ且つ前記被検眼の回旋方向に偏心した遮光部を有する偏心遮光手段である眼底カメラにおいて、
角膜，虹彩，水晶体後面の少なくとも一つのフレア状態を検出するフレア検出装置を更に備えると共に、前記フレア検出装置からの検出信号を基に前記駆動手段を作動制御することにより前記遮光手段を前記光軸方向に移動させて、前記遮光手段を角膜，水晶体後面の少なくとも一つと共役にさせる制御回路を備えることを特徴とする。
【００１４】
【発明の実施の形態】
以下、この発明の実施の形態を図面に基づいて説明する。
[構成]
図１（ａ）において眼底カメラは、被検眼Ｅを照明する照明光学系１と、照明された被検眼Ｅを撮影する撮影光学系１０を有する。
＜照明光学系１＞
照明光学系１は、観察用照明光学系と、撮影用照明光学系を有する。
（観察用照明光学系）
観察用照明光学系は、観察用赤外光源２，コンデンサレンズ３，第１のリレーレンズ５，遮光手段６，第２のリレーレンズ７，穴あきミラー８，対物レンズ９をこの順に有する。この観察用赤外光源２には、タングステンランプと赤外フィルター又は近赤外フィルターを組み合わせた赤外光源を用いることもできる。
【００１５】
遮光手段６は、図１（ｂ）に示したようなリングスリットＲｓが形成されたリングスリット板を遮光板（遮光物）６ａ，６ｂ，６ｃとして有する。尚、遮光板６ａ〜６ｃは、内側の遮光部Ｒａと外側のリング状の遮光部Ｒｂ間にリングスリットＲｓが形成されていると共に、遮光部Ｒａ，Ｒｂ及びリングスリットＲｓは照明光学系１の光軸Ｏと同心に形成されていて、同心遮光手段となっている。
【００１６】
この遮光板６ａ，６ｃは、遮光板６ｂを虹彩と共役にしたときに、標準的な人の角膜，水晶体後面とそれぞれ略共役となる位置に配設されている。また、遮光板６ａ，６ｃは、観察用照明光学系１の光軸Ｏの方向に移動操作可能に設けられていて、人によって異なる角膜や水晶体の厚さの相違、或いは角膜と水晶体後面との間隔の相違があっても、角膜，虹彩，水晶体後面と共役に調整できる様になっている。
【００１７】
この調整は、手動で行うこともできるし、駆動モータ（電動手段）で行うこともできる。本実施例では、パルスモータ等の駆動モータＭ１，Ｍ２で遮光板６ａ，６ｂ，６ｃが観察用照明光学系１の光軸Ｏの方向に移動操作可能に設けられている。
【００１８】
尚、遮光板６ａ，６ｃは、リングスリット板である必要はなく、内側の遮光部Ｒａのみを有する構成の遮光板に代えてもよい。
（撮影用照明光学系）
撮影用照明光学系は、撮影用光源４，第１のリレーレンズ５，遮光手段６，第２のリレーレンズ７，穴あきミラー８，対物レンズ９をこの順に有する。この撮影用光源４には、可視光にて撮影を行うため、例えばキセノンランプの様な可視光源を用いる。
＜撮影光学系１０＞
撮影光学系１０は、撮影光学系１１ａと、観察光学系１１ｂを有する。
【００１９】
撮影光学系１１ａは、対物レンズ９，穴あきミラー８の中央の開口８ａ，結像レンズ１２，クイックリターンミラー１３，ダハプリズム１４，フィールドレンズ１４ａ，第１の撮影レンズ１５，撮影用ＴＶカメラ（撮像装置）１６を有する。
【００２０】
また、観察光学系１１ｂは、対物レンズ９，穴あきミラー８の中央の開口８ａ，結像レンズ１２，クイックリターンミラー１３，フィールドレンズ１７ａ，ミラー１７，第２の撮影レンズ１８，観察用ＴＶカメラ（撮像装置）１９を有する。観察用ＴＶカメラ１９は赤外観察を行うため、赤外又は近赤外に感度のあるＴＶカメラを用いる。
＜制御回路＞
上述したＴＶカメラ１６，１９からの映像信号は、図２に示した演算制御回路２０に入力される。この演算制御回路（演算制御手段）２０は、ＴＶカメラ１６，１９からの映像信号をカラーＣＲＴや液晶カラーモニター等の表示装置２１に入力して、被検眼像を表示させる。
【００２１】
また、演算制御回路２０には、スイッチ２２，２３，２４，２５からのオン・オフ信号が入力されると共に、撮影スイッチ２６のＯＮ信号が入力されるようになっている。また、演算制御回路２０は、撮影スイッチ２６がオン操作されたとき、ソレノイドＳでクイックリターンミラー１３を撮影光学系１１ａの結像レンズ１２とフィールドレンズ１４ａとの間に挿入する様になっている。
[作用]
次に、この様な構成の眼底カメラの作用を説明する。
（１）赤外観察
この様な構成において、通常、実線で示した如くクイックリターンミラー１３は観察光学系１１ａの結像レンズ１２とフィールドレンズ１４ａとの間に挿入されている。この状態において眼底カメラの図示しない電源を投入すると、演算制御回路２０により観察用赤外照明光源２が点灯させられる。
【００２２】
この点灯により観察用赤外光源２から出射した赤外光は、コンデンサレンズ３，第１のリレーレンズ５，遮光手段６，第２のリレーレンズ７，穴あきミラー８及び対物レンズ９を介して被検眼Ｅの前眼部に投影され、被検眼Ｅの眼底Ｅｆを照明する。
【００２３】
この際、観察用赤外光源２は、コンデンサレンズ３，第１のリレーレンズ５，遮光手段６，撮影用光源４した撮影光は、第１のリレーレンズ５，遮光手段６，第２のリレーレンズ７を介して穴あきミラー８に結像された後に、対物レンズ９を介して被検眼Ｅの虹彩上に結像される。
【００２４】
一方、被検眼Ｅで反射した反射光は、対物レンズ９，穴あきミラー８の中央の開口８ａ，結像レンズ１２，クイックリターンミラー１３，ダハプリズム１４，クイックリターンミラー１３，フィールドレンズ１７ａ，第２の撮影レンズ１８を介して観察用ＴＶカメラ１９に投影されて、観察用ＴＶカメラ１９に被検眼Ｅの像を結像させる。このとき結像レンズ１２を移動することにより眼底共役位置を移動させて被検眼の視度に対応することが可能である。
【００２５】
そして、観察用ＴＶカメラ１９からの映像信号が演算制御回路２０に入力される。この演算制御回路２０は、入力された映像信号を表示装置２１に転送して、表示装置２１に被検眼Ｅの像をリアルタイムで白黒表示させる。
（２）撮影
この状態において演算制御回路２０は、撮影スイッチ２６がオン操作されると、ソレノイドＳを作動させてクイックリターンミラー１３を観察光学系１１ａの結像レンズ１２とフィールドレンズ１４ａとの間から退出させると共に、観察用光源２を消灯させ、撮影光源４を点灯させる。
【００２６】
この点灯状態において、撮影光源４から出射した可視光（可視撮影光）は、第１のリレーレンズ５，遮光手段６，第２のリレーレンズ７，穴あきミラー８及び対物レンズ９を介して被検眼Ｅの眼底（被検眼眼底）Ｅｆに投影され、眼底Ｅｆを照明する。
【００２７】
一方、眼底Ｅｆで反射した反射光は、対物レンズ９，穴あきミラー８の中央の開口８ａ，結像レンズ１２，クイックリターンミラー１３，ダハプリズム１４，フィールドレンズ１４ａ，第１の撮影レンズ１５を介して撮影用ＴＶカメラ１６に投影されて、撮影用ＴＶカメラ１６に被検眼Ｅの眼底Ｅｆの像（眼底像）を結像させる。
【００２８】
この撮影用ＴＶカメラ１６からの映像信号は演算制御回路２０に入力される。そして、演算制御回路２０は、入力された映像信号を表示装置２１に転送して、表示装置２１に被検眼Ｅの眼底像をカラー表示させる。
【００２９】
尚、撮影用ＴＶカメラ１５は、撮像手段として３５ミリフィルム及びインスタントカメラ等の撮像装置（撮影手段）を用いる構成としてもかまわない。
（３）フレア除去
＜遮光像６ｂ′，６ａ′，６ｃ′が虹彩ｉ，角膜ｃ，水晶体後面Ｌｂと一致＞
図３はリングスリットにて照明された被検眼前眼部の様子を示している。
【００３０】
図中、６ｂ′，６ａ′，６ｃ′は、それぞれ虹彩ｉ，角膜ｃ，水晶体Ｌの後面Ｌｂ（以下、水晶体後面Ｌｂと略）と略共役位置となる様に照明光学系１に配置した遮光板６ｂ，６ａ，６ｃによる遮光像である。そして、照明光学系１による眼底Ｅｆの照明時に、遮光像６ｂ′と遮光線３２，３２及び遮光像６ｃ′と遮光線３２，３２で囲まれた部分が遮光部３４，３４となる。従って、照明光束３１が遮光部３４，３４の外を通って被検眼Ｅの眼底Ｅｆを照明する。一方、眼底Ｅｆからの反射光は、撮影光束３３として遮光部３４，３４の部分を通過した後、撮影光学系１０の撮影光学系１１ａや観察光学系１１ｂに入射することになる。この様にして、被検眼Ｅの虹彩ｉ，角膜ｃ，水晶体後面１ｂの各面での有害反射光が撮影光束３３中に入ることを防いでいる。尚、この撮影光束３３は、撮影光学系１０の穴あきミラー８の開口８ａ等によって決まる。
＜遮光像６ｃ′が水晶体後面Ｌｂと不一致＞
しかし、図４に示すように被検眼によっては、例えば水晶体Ｌの厚さ及び後面の曲率半径が異なるために、遮光像６ｃ′が水晶体後面Ｌｂから離れて、遮光像６ｃ′による遮光が不完全になり、有害反射光を除去することが困難になる。
【００３１】
そこで、遮光像６ｂ′，６ａ′がそれぞれ虹彩ｉ，角膜ｃと略共役位置にした状態で、スイッチ２２，２３を操作することにより演算制御回路２０により駆動モータＭ２を正転又は逆転操作させながら、照明光学系１の遮光板６ｃを光軸Ｏ方向に前後に移動させることにより、遮光像６ｃ′の縁部が図３に示したように水晶体後面Ｌｂに一致するように、水晶体後面Ｌｂ側に移動させ、有害反射光を除去させる。Ｌａは水晶体前面である。
【００３２】
尚、遮光像６ａ′が角膜ｃから離れて、遮光像６ａ′による遮光が不完全になり、有害反射光を除去することが困難になる場合には、スイッチ２４，２５を操作することにより演算制御回路２０により駆動モータＭ２を正転又は逆転操作させながら、照明光学系１の遮光板６ａを光軸Ｏ方向に前後に移動させることにより、遮光像６ａ′の縁部が角膜ｃに一致するように、角膜ｃ側に移動させ、有害反射光を除去させる様にする。
【００３３】
また、水晶体Ｌの厚さ及び後面の曲率半径が異なるために、遮光像６ａ′，６ｃ′が角膜ｃ及び水晶体後面Ｌｂからそれぞれ離れて、遮光像６ａ′，６ｃ′による遮光が不完全になり、有害反射光を除去することが困難になる場合には、遮光板６ａ，６ｃをそれぞれ上述したように光軸方向に移動させる。
（その他１）
また、より広範囲の眼底を撮影するために、被検眼Ｅを図示しない固視標により視線誘導する場合がある。図５はこの場合の被検眼Ｅの前眼部の様子を示したものであり、図５中実線３５は視軸を表す。
【００３４】
この場合、角膜ｃ及び水晶体後面Ｌｂの曲率半径が眼球（被検眼Ｅ）の回旋中心４０と異なるため、前述の水晶体Ｌの形状が異なる場合と同様に有害反射光の除去が困難となる。即ち、遮光像６ａ′，６ｃ′が角膜ｃ及び水晶体後面Ｌｂから離反する。ここで、上述したように遮光板６ａ及び６ｂは、内側の遮光部Ｒａと外側のリング状の遮光部Ｒｂ間にリングスリットＲｓが形成されている。尚、有害反射光の発する方向は被検眼の回旋方向と対応している。
【００３５】
この結果、図６（ａ）に示すように遮光部Ｒａに円弧状突部ａを有害反射光の発生する方向に突出させた遮光板６′ａを設けるか、図６（ｂ）に示すように遮光部Ｒａを有害反射光の発生する方向に偏心させた遮光板６′ｃを設けることにより、遮光板６′ａ，６′ｃの径をなるべく小さくすることが可能であり、被検眼Ｅが小瞳孔である場合に有効である。この様に遮光部Ｒａの一部に光軸Ｏに対して偏心した突部ａを設けるか又は遮光部Ｒａの全体を光軸Ｏに対して偏心させることにより、図６（ａ），図６（ｂ）の遮光板６′ａ，６′ｃは偏心遮光板（偏心遮光手段）となる。
【００３６】
また、被検眼Ｅの誘導方向は任意の方向となるので、円弧状突部ａや遮光部Ｒａの偏心方向が被検眼Ｅの回旋方向と一致するように、遮光板Ｅを照明光学系１の光軸回りに図示しないパルスモータ等の駆動モータで回転させる様にする。この際の制御は演算制御回路２０により行わせる。
【００３７】
従って、図１（ｂ）に示した遮光板６ａ，６ｃと図６（ａ）又は図６（ｂ）に示した構成を有する遮光板６′ａ，６′ｃを用意しておいて、被検眼Ｅを上述したように回旋させない場合には、図１（ｂ）に示した遮光板６ａ，６ｃを用いる。また、被検眼Ｅを回旋させる場合には、図１（ｂ）に示した遮光板６ａを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板６′ａに切り替え、図１（ｂ）に示した遮光板６ｃを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板６′ｃに切り替える様にすると良い。
【００３８】
尚、補足すると、遮光部Ｒａの径を単純に大きくした場合、被検眼Ｅの有効反射光の除去は可能であるが、照明光束の外側を被検眼瞳孔、内側を遮光物により制限されるため、被検眼眼底が充分に照明されない場合が存在する。
（その他２）
また、被検眼の角膜ｃ、虹彩ｉ、水晶体後面Ｌｂからの有害反射光が撮影光束３３に入った場合、撮影像にフレアーが生じる。フレアーは眼底像の周辺に表れるため、検者は表示装置（観察モニター）２１のフレアー像を観察しながら、フレアーが無くなるようにスイッチ２２，２３及び２４，２５をオン操作して、駆動モータＭ１，Ｍ２をそれぞれ正転又は逆転させることにより、遮光板６ａ，６ｃを駆動モータＭ１，Ｍ２によりそれぞれ光軸Ｏ方向に移動操作するとよい。
【００３９】
この様な検者による遮光板６ａ，６ｃの移動操作により、検者は表示装置（観察モニター）２１上のフレアー像が消えたことを確認し、撮影スイッチ２６をオン操作して撮影を行う。
【００４０】
被検眼Ｅを上述したように回旋させる場合には、図１（ｂ）に示した遮光板６ａを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板６′ａに切り替え、図１（ｂ）に示した遮光板６ｃを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板６′ｃに切り替える様にする。しかも、この状態で、検者は表示装置（観察モニター）２１のフレアー像を観察しながら、フレアーが無くなるようにスイッチ２２，２３及び２４，２５をオン操作して、駆動モータＭ１，Ｍ２をそれぞれ正転又は逆転させることにより、遮光板６′ａ，６′ｃを駆動モータＭ１，Ｍ２によりそれぞれ光軸Ｏ方向に移動操作するとよい。尚、この場合もその他１で示すように遮光板６′ａ，６′ｃを光軸回りに回転させる。
（その他３）
上述した実施例では、検者が表示装置（モニター）２１の状態を観察しながら、遮光板（絞り）６ａ，６ｃを移動させる構成として説明したが、装置に周辺部のフレアが検出できるように検出器を設けたり、表示装置２１の映像信号を基にフレアーの状態を観察するような既知のフレアー検出機構を設け、その出力結果を演算制御回路２０に入力させる。そして、演算制御回路２０が、フレアー検出機構からの出力結果を基に、表示装置２１の画面上にフレア検出状態の表示を補助的に行ったり、或いはフレアー検出機構による出力結果がフレアを検出しない状態となるように、フレアー検出機構からの出力結果を基に遮光板（絞り）６ａ，６ｃを自動的に光軸方向に移動制御してもよい。
【００４１】
また、被検眼Ｅを上述したように回旋させる場合には、演算制御回路２０により図１（ｂ）に示した遮光板（同心遮光手段）６ａを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板（偏心遮光手段）６′ａに切り替え、図１（ｂ）に示した遮光板（同心遮光手段）６ｃを図６（ａ）又は図６（ｂ）に示した構成を有する遮光板（偏心遮光手段）６′ｃに切り替える様にする。
【００４２】
しかも、演算制御回路２０は、フレアー検出機構の出力結果を基に表示装置２１の画面上にフレア検出状態の表示を補助的に行ったり、或いはフレアー検出機構による出力結果がフレアを検出しない状態となるように、フレアー検出機構からの出力結果を基に遮光板（絞り）６′ａ，６′ｃを自動的に光軸方向に移動制御してもよい。尚、この場合もその他１で示すように遮光板６′ａ，６′ｃを光軸回りに回転させる。
（その他４）
また、実施例においては形状の異なる絞りを入れ替えることとして説明したが、機械的な機構により形状を変化させるようにしてもかまわない。
（その他５）
また、例えば液晶のような位置及び透過率を制御できるような素子を用いることにより、単純な構成で自由な位置及び大きさ、形状の絞りが提示可能となる。
【００４３】
【発明の効果】
以上説明した請求項１の発明は、被検眼の角膜及び水晶体の厚さが異なっても、角膜や水晶体の周辺部からのフレアを除去できると共に、フレア除去のための遮光手段の駆動操作が簡易となる。
【００４４】
また、請求項２の発明は、被検眼の角膜及び水晶体の厚さが異なっても、角膜や水晶体の周辺部からのフレアを除去できると共に、少なくとも角膜又は水晶体後面におけるフレアを除去できる。
【００４５】
更に、請求項３に記載の発明は、被検眼の回旋により角膜及び水晶体の位置移動が起こっても、角膜や水晶体の周辺部からのフレアを除去できると共に、フレア除去のための遮光手段の駆動操作が簡易となる。
【００４６】
また、請求項４に記載の発明は、被検眼の回旋により角膜及び水晶体の位置移動が起こっても、角膜や水晶体の周辺部からのフレアを除去できると共に、少なくとも角膜又は水晶体後面におけるフレアを除去できる。
【図面の簡単な説明】
【図１】（ａ）はこの発明にかかる眼底カメラの光学系の説明図、（ｂ）は（ａ）の遮光板の説明図である。
【図２】図１（ａ）に示した眼底カメラの制御回路である。
【図３】図１に示した被検眼の前眼部の拡大説明図である。
【図４】図３に示した前眼部の角膜−水晶体後面の間隔が大きい場合の作用説明図である。
【図５】図１に示した被検眼を固視標により回旋させたときの前眼部の拡大説明図である。
【図６】（ａ），（ｂ）は図１に示した遮光板の他の例を示す説明図である。
【符号の説明】
１・・・照明光学系
６ａ，６ｂ，６ｃ・・・（遮光手段，同心遮光手段）
６′ａ,６′ｃ・・・遮光板（偏心遮光手段）
１０・・・撮影光学系
２０・・・演算制御回路（制御回路）
ｃ・・・角膜
Ｅ・・・被検眼
ｉ・・・虹彩
Ｌａ・・・水晶体前面
Ｌｂ・・・水晶体後面
Ｍ１，Ｍ２・・・駆動モータ（駆動手段）
Ｒａ，Ｒｓ・・・遮光部
ａ・・・突部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fundus camera provided with a light shielding means for removing flare (harmful light) from an anterior eye portion of an eye to be examined.
[0002]
[Prior art]
A conventional fundus camera, for example, as disclosed in Japanese Patent Publication No. 61-5729, illuminates the fundus by projecting illumination light from an illumination optical system onto an eye to be examined, and the reflected light from the fundus is photographed by a photographing optical system. In order to capture the fundus image with the photographing means and prevent flare from the cornea, the crystalline lens, etc. of the subject's eye from entering the photographing optical system, a light shielding plate conjugate with the cornea and the rear surface of the crystalline lens is used as the illumination optical system. There is something that was provided.
[0003]
[Problems to be solved by the invention]
Since the eye to be examined photographed with such a fundus camera has a different cornea or lens thickness depending on the person, the distance between the cornea and the posterior surface of the lens differs.
[0004]
However, in this fundus camera, since the light shielding plate is fixed, flare cannot be completely removed.
[0005]
Further, by rotating (turning) the eye to be examined using a fixation target and tilting the direction of the optical axis of the eye to be examined with respect to the optical axis of the imaging optical system, the illumination light beam from the illumination optical system is reflected on the fundus. A wider range of fundus photography is also performed by projecting to the peripheral edge side.
[0006]
However, in this case, since the center of curvature of the lens and the center of rotation of the eyeball do not coincide with each other, the position of the cornea and the lens is moved, and flare from the cornea and the periphery of the lens tends to easily enter the imaging optical system. .
[0007]
Furthermore, due to the widespread use of IOL (intraocular lens) used for cataract surgery, etc., the number of eyes to be examined is increasing, and the shape and refractive index are different from the original lens. There is also a tendency to increase even if it is difficult.
[0008]
Accordingly, a first object of the present invention is to provide a fundus camera capable of removing flare from the cornea and the peripheral portion of the crystalline lens even when the cornea and crystalline lens of the eye to be examined are different. .
[0009]
A second object of the present invention is to provide a fundus camera capable of removing flare from the cornea and the peripheral portion of the lens even if the cornea and the lens are moved due to the rotation of the eye to be examined. .
[0010]
[Means for Solving the Problems]
In order to achieve the first object, the invention of claim 1 illuminates the fundus of the eye to be examined through a flare-removing shading means that is conjugated with at least one of the cornea, iris, and lens rear surface of the eye to be examined. In a fundus camera comprising: an illumination optical system; an imaging optical system that images the eye to be examined; and a drive unit that moves and adjusts the light shielding unit in the optical axis direction of the illumination optical system .
The apparatus further comprises fixation target presenting means for causing the subject's eye to visually recognize the fixation target and guiding the optical axis of the eye to be examined in a predetermined direction, and controlling the operation of the drive means according to the presentation position of the fixation target. Thus, a control circuit is provided which moves the light shielding means in the optical axis direction to conjugate the light shielding means with at least one of the cornea and the rear surface of the crystalline lens .
[0011]
In order to achieve the second object, the invention of claim 2 illuminates the fundus of the eye to be examined through a flare-removing shading means that is conjugated with at least one of the cornea, iris, and posterior surface of the lens of the eye. A fundus camera comprising: an illuminating optical system; an imaging optical system that images the eye to be examined; and a driving unit that moves and adjusts the light shielding unit in an optical axis direction of the illumination optical system .
A flare detection device for detecting at least one flare state of the cornea, the iris, and the back surface of the lens;
A control circuit that controls the driving means based on a detection signal from the flare detection device to move the light shielding means in the optical axis direction so that the light shielding means is conjugated with at least one of the cornea and the rear surface of the crystalline lens. It is characterized by providing .
[0012]
According to a third aspect of the present invention, there is provided an illumination optical system that illuminates the fundus of the subject eye via a flare-removing shading means that is conjugated with at least one of the cornea, iris, and lens rear surface of the subject eye, and the subject eye The light shielding means is used by switching between the concentric light shielding means concentric with the optical axis of the illumination optical system and the concentric light shielding means when the eye to be examined is rotated and In a fundus camera that is an eccentric light-shielding means having a light-shielding part that is eccentric in the direction of rotation of the eye to be examined ,
The apparatus further comprises fixation target presenting means for causing the subject's eye to visually recognize the fixation target and guiding the optical axis of the eye to be examined in a predetermined direction, and controlling the operation of the drive means according to the presentation position of the fixation target. Thus, a control circuit is provided which moves the light shielding means in the optical axis direction to conjugate the light shielding means with at least one of the cornea and the rear surface of the crystalline lens.
[0013]
According to a fourth aspect of the present invention, there is provided an illumination optical system that illuminates the fundus of the subject eye via a flare-removing shading means that is conjugated with at least one of the cornea, iris, and lens rear surface of the subject eye, and the subject eye The light shielding means is used by switching between the concentric light shielding means concentric with the optical axis of the illumination optical system and the concentric light shielding means when the eye to be examined is rotated and In a fundus camera that is an eccentric light-shielding means having a light-shielding part that is eccentric in the direction of rotation of the eye to be examined ,
A flare detection device for detecting at least one flare state of the cornea, the iris, and the back surface of the crystalline lens is further provided, and the driving means is controlled based on a detection signal from the flare detection device to thereby control the light shielding means to the optical axis. And a control circuit for moving the light shielding means in a conjugate manner with at least one of the cornea and the rear surface of the crystalline lens.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Constitution]
In FIG. 1A, the fundus camera includes an illumination optical system 1 that illuminates the eye E and a photographing optical system 10 that captures the illuminated eye E.
<Illumination optical system 1>
The illumination optical system 1 includes an observation illumination optical system and a photographing illumination optical system.
(Observation illumination optics)
The observation illumination optical system includes an observation infrared light source 2, a condenser lens 3, a first relay lens 5, a light shielding unit 6, a second relay lens 7, a perforated mirror 8, and an objective lens 9. As the infrared light source 2 for observation, an infrared light source in which a tungsten lamp and an infrared filter or a near infrared filter are combined can be used.
[0015]
The light shielding means 6 includes ring slit plates formed with ring slits Rs as shown in FIG. 1B as light shielding plates (light shielding materials) 6a, 6b, 6c. In the light shielding plates 6a to 6c, a ring slit Rs is formed between the inner light shielding portion Ra and the outer ring-shaped light shielding portion Rb, and the light shielding portions Ra and Rb and the ring slit Rs are provided in the illumination optical system 1. It is formed concentrically with the optical axis O and serves as a concentric light shielding means.
[0016]
The light shielding plates 6a and 6c are disposed at positions which are substantially conjugate with the standard human cornea and the back surface of the crystalline lens when the light shielding plate 6b is conjugated with the iris. The light shielding plates 6a and 6c are provided so as to be movable in the direction of the optical axis O of the observation illumination optical system 1. The light shielding plates 6a and 6c are different in thickness between the cornea and the lens, or between the cornea and the back surface of the lens. Even if there is a difference in spacing, it can be adjusted to be conjugate with the cornea, iris, and posterior surface of the lens.
[0017]
This adjustment can be performed manually or by a drive motor (electric means). In the present embodiment, the light shielding plates 6a, 6b, 6c are provided so as to be movable in the direction of the optical axis O of the observation illumination optical system 1 by drive motors M1, M2 such as pulse motors.
[0018]
The light shielding plates 6a and 6c do not need to be ring slit plates, and may be replaced by a light shielding plate having a configuration having only the inner light shielding portion Ra.
(Illumination optics for photography)
The photographing illumination optical system has a photographing light source 4, a first relay lens 5, a light shielding means 6, a second relay lens 7, a perforated mirror 8, and an objective lens 9 in this order. For the photographing light source 4, a visible light source such as a xenon lamp is used for photographing with visible light.
<Photographing optical system 10>
The photographing optical system 10 includes a photographing optical system 11a and an observation optical system 11b.
[0019]
The photographing optical system 11a includes an objective lens 9, a central aperture 8a of a perforated mirror 8, an imaging lens 12, a quick return mirror 13, a roof prism 14, a field lens 14a, a first photographing lens 15, a photographing TV camera (imaging). Device) 16.
[0020]
The observation optical system 11b includes an objective lens 9, a central opening 8a of the perforated mirror 8, an imaging lens 12, a quick return mirror 13, a field lens 17a, a mirror 17, a second photographing lens 18, and an observation TV camera. (Imaging device) 19 is provided. Since the observation TV camera 19 performs infrared observation, a TV camera sensitive to infrared or near infrared is used.
<Control circuit>
Video signals from the TV cameras 16 and 19 described above are input to the arithmetic control circuit 20 shown in FIG. The arithmetic control circuit (arithmetic control means) 20 inputs video signals from the TV cameras 16 and 19 to a display device 21 such as a color CRT or a liquid crystal color monitor and displays an eye image to be examined.
[0021]
In addition, an ON / OFF signal from switches 22, 23, 24, and 25 and an ON signal of shooting switch 26 are input to arithmetic control circuit 20. The arithmetic control circuit 20 is configured to insert the quick return mirror 13 between the imaging lens 12 and the field lens 14a of the photographing optical system 11a by the solenoid S when the photographing switch 26 is turned on. .
[Action]
Next, the operation of the fundus camera having such a configuration will be described.
(1) Infrared observation In such a configuration, the quick return mirror 13 is normally inserted between the imaging lens 12 and the field lens 14a of the observation optical system 11a as indicated by the solid line. In this state, when a power source (not shown) of the fundus camera is turned on, the observation infrared illumination light source 2 is turned on by the arithmetic control circuit 20.
[0022]
The infrared light emitted from the observation infrared light source 2 by this lighting is passed through the condenser lens 3, the first relay lens 5, the light shielding means 6, the second relay lens 7, the perforated mirror 8 and the objective lens 9. The light is projected onto the anterior segment of the eye E and illuminates the fundus oculi Ef of the eye E.
[0023]
At this time, the observation infrared light source 2 includes the condenser lens 3, the first relay lens 5, the light shielding means 6, and the photographing light emitted from the photographing light source 4 is the first relay lens 5, the light shielding means 6, the second relay. After forming an image on the perforated mirror 8 through the lens 7, the image is formed on the iris of the eye E through the objective lens 9.
[0024]
On the other hand, the reflected light reflected by the eye E is the objective lens 9, the central aperture 8a of the perforated mirror 8, the imaging lens 12, the quick return mirror 13, the roof prism 14, the quick return mirror 13, the field lens 17a, and the second lens. The image is projected onto the observation TV camera 19 through the photographing lens 18 and an image of the eye E is formed on the observation TV camera 19. At this time, by moving the imaging lens 12, the fundus conjugate position can be moved to correspond to the diopter of the eye to be examined.
[0025]
Then, a video signal from the observation TV camera 19 is input to the arithmetic control circuit 20. The arithmetic control circuit 20 transfers the input video signal to the display device 21 and causes the display device 21 to display the image of the eye E to be examined in real time in black and white.
(2) Shooting In this state, when the shooting switch 26 is turned on, the arithmetic control circuit 20 activates the solenoid S to move the quick return mirror 13 between the imaging lens 12 and the field lens 14a of the observation optical system 11a. The observation light source 2 is turned off and the photographing light source 4 is turned on.
[0026]
In this lighting state, visible light (visible photographing light) emitted from the photographing light source 4 is received through the first relay lens 5, the light shielding means 6, the second relay lens 7, the perforated mirror 8 and the objective lens 9. The image is projected onto the fundus oculi Ef (the fundus oculi to be examined) Ef to illuminate the fundus Ef.
[0027]
On the other hand, the reflected light reflected by the fundus oculi Ef passes through the objective lens 9, the central aperture 8a of the perforated mirror 8, the imaging lens 12, the quick return mirror 13, the roof prism 14, the field lens 14a, and the first photographing lens 15. Then, the image is projected onto the photographing TV camera 16 and an image of the fundus oculi Ef (fundus image) of the eye E to be examined is formed on the photographing TV camera 16.
[0028]
The video signal from the photographing TV camera 16 is input to the arithmetic control circuit 20. Then, the arithmetic control circuit 20 transfers the input video signal to the display device 21 so that the fundus image of the eye E to be examined is displayed in color on the display device 21.
[0029]
The photographing TV camera 15 may be configured to use an imaging device (imaging means) such as a 35 mm film and an instant camera as the imaging means.
(3) Flare removal <Shaded images 6b ', 6a', 6c 'coincide with iris i, cornea c, and lens rear surface Lb>
FIG. 3 shows a state of the anterior eye segment illuminated by the ring slit.
[0030]
In the figure, 6b ', 6a', 6c 'are light shielding elements arranged in the illumination optical system 1 so as to be substantially conjugate with the iris i, the cornea c, and the rear surface Lb of the lens L (hereinafter abbreviated as the lens rear surface Lb). It is the light-shielding image by board 6b, 6a, 6c. When the fundus oculi Ef is illuminated by the illumination optical system 1, the portions surrounded by the light shielding image 6 b ′ and the light shielding lines 32 and 32 and the light shielding image 6 c ′ and the light shielding lines 32 and 32 become the light shielding portions 34 and 34. Accordingly, the illumination light flux 31 illuminates the fundus oculi Ef of the eye E through the light shielding portions 34 and 34. On the other hand, the reflected light from the fundus oculi Ef passes through the portions of the light shielding portions 34 and 34 as the photographing light flux 33 and then enters the photographing optical system 11a and the observation optical system 11b of the photographing optical system 10. In this way, harmful reflected light from each of the iris i, the cornea c, and the lens rear surface 1b of the eye E is prevented from entering the imaging light flux 33. The photographic light flux 33 is determined by the aperture 8a of the perforated mirror 8 of the photographic optical system 10 and the like.
<Shaded image 6c 'does not coincide with lens rear surface Lb>
However, as shown in FIG. 4, depending on the eye to be examined, for example, the thickness of the lens L and the radius of curvature of the rear surface are different, so that the light-shielded image 6c ′ is separated from the lens rear surface Lb, and light-shielding by the light-shielded image 6c ′ is incomplete. It becomes difficult to remove harmful reflected light.
[0031]
Therefore, the operation control circuit 20 operates the drive motor M2 in the normal or reverse direction by operating the switches 22 and 23 in a state where the light-shielded images 6b 'and 6a' are substantially in the conjugate positions with the iris i and the cornea c, respectively. By moving the light shielding plate 6c of the illumination optical system 1 back and forth in the direction of the optical axis O, the lens rear surface Lb side so that the edge of the light shielding image 6c 'coincides with the lens rear surface Lb as shown in FIG. To remove harmful reflections. La is the front surface of the crystalline lens.
[0032]
If the light-shielded image 6a 'is away from the cornea c and the light-shielded image 6a' is incompletely shielded and it is difficult to remove harmful reflected light, it is calculated by operating the switches 24 and 25. By moving the light shielding plate 6a of the illumination optical system 1 back and forth in the direction of the optical axis O while the drive motor M2 is rotated forward or backward by the control circuit 20, the edge of the light shielding image 6a 'coincides with the cornea c. As described above, it is moved to the cornea c side to remove harmful reflected light.
[0033]
Further, since the thickness of the crystalline lens L and the curvature radius of the rear surface are different, the light-shielded images 6a 'and 6c' are separated from the cornea c and the rear surface Lb of the crystalline lens, respectively, and the light shielding by the light-shielded images 6a 'and 6c' becomes incomplete. When it is difficult to remove harmful reflection light, the light shielding plates 6a and 6c are moved in the optical axis direction as described above.
(Other 1)
In addition, in order to photograph a wider range of the fundus, the eye E may be guided by a fixation target (not shown). FIG. 5 shows the state of the anterior segment of the eye E in this case, and the solid line 35 in FIG. 5 represents the visual axis.
[0034]
In this case, since the radii of curvature of the cornea c and the lens rear surface Lb are different from the rotation center 40 of the eyeball (eye E), it is difficult to remove harmful reflected light as in the case where the shape of the lens L is different. That is, the light-shielded images 6a ′ and 6c ′ are separated from the cornea c and the lens rear surface Lb. Here, as described above, in the light shielding plates 6a and 6b, the ring slit Rs is formed between the inner light shielding portion Ra and the outer ring-shaped light shielding portion Rb. The direction in which harmful reflected light is emitted corresponds to the direction of rotation of the eye to be examined.
[0035]
As a result, as shown in FIG. 6 (a), a light shielding plate 6'a having an arcuate protrusion a protruding in the direction in which harmful reflected light is generated is provided on the light shielding portion Ra, or as shown in FIG. 6 (b). By providing a light shielding plate 6'c in which the light shielding portion Ra is decentered in the direction in which harmful reflected light is generated, the diameter of the light shielding plates 6'a and 6'c can be made as small as possible. This is effective when is a small pupil. In this way, by providing a protrusion a decentered with respect to the optical axis O in a part of the light shielding portion Ra, or by decentering the entire light shielding portion Ra with respect to the optical axis O, FIGS. The light shielding plates 6'a and 6'c in (b) serve as eccentric light shielding plates (eccentric light shielding means).
[0036]
In addition, since the guiding direction of the eye E is an arbitrary direction, the light shielding plate E is placed on the illumination optical system 1 so that the eccentric direction of the arcuate protrusion a and the light shielding portion Ra matches the rotation direction of the eye E to be examined. The optical axis is rotated by a drive motor such as a pulse motor (not shown). The control at this time is performed by the arithmetic control circuit 20.
[0037]
Accordingly, the light shielding plates 6a and 6c shown in FIG. 1 (b) and the light shielding plates 6'a and 6'c having the configuration shown in FIG. 6 (a) or 6 (b) are prepared. When the optometry E is not rotated as described above, the light shielding plates 6a and 6c shown in FIG. 1B are used. When the eye E is rotated, the light shielding plate 6a shown in FIG. 1B is switched to the light shielding plate 6′a having the configuration shown in FIG. 6A or 6B. The light shielding plate 6c shown in FIG. 1 (b) may be switched to the light shielding plate 6'c having the configuration shown in FIG. 6 (a) or 6 (b).
[0038]
Supplementally, when the diameter of the light-shielding portion Ra is simply increased, the effective reflected light of the eye E can be removed, but the outside of the illumination light beam is restricted by the subject's eye pupil and the inside is restricted by the light-shielding object. There are cases where the fundus of the eye to be examined is not sufficiently illuminated.
(Other 2)
Further, when harmful reflected light from the cornea c, the iris i, and the lens rear surface Lb of the eye to be examined enters the photographing light flux 33, flare occurs in the photographed image. Since the flare appears around the fundus image, the examiner observes the flare image on the display device (observation monitor) 21 and turns on the switches 22, 23 and 24, 25 so that the flare disappears, thereby driving the motor M1. , M2 may be rotated forward or backward, respectively, to move the light shielding plates 6a, 6c in the direction of the optical axis O by the drive motors M1, M2.
[0039]
By such an operation of moving the light shielding plates 6a and 6c by the examiner, the examiner confirms that the flare image on the display device (observation monitor) 21 has disappeared, and operates the photographing switch 26 to perform photographing.
[0040]
When the eye E is rotated as described above, the light shielding plate 6a shown in FIG. 1 (b) is switched to the light shielding plate 6'a having the configuration shown in FIG. 6 (a) or 6 (b). The light shielding plate 6c shown in FIG. 1B is switched to the light shielding plate 6′c having the configuration shown in FIG. 6A or 6B. Moreover, in this state, the examiner observes the flare image of the display device (observation monitor) 21 and turns on the switches 22, 23, 24, and 25 so that the flare is eliminated, and turns on the drive motors M1 and M2, respectively. The light shielding plates 6'a and 6'c may be moved and operated in the direction of the optical axis O by the drive motors M1 and M2 by rotating in the forward or reverse direction. In this case as well, as indicated by 1, the light shielding plates 6 ′ a and 6 ′ c are rotated around the optical axis.
(Other 3)
In the above-described embodiment, the inspector has observed the state of the display device (monitor) 21 while moving the light shielding plates (apertures) 6a and 6c. However, the device can detect the flare in the peripheral portion. A detector or a known flare detection mechanism for observing the flare state based on the video signal of the display device 21 is provided, and the output result is input to the arithmetic control circuit 20. Then, the arithmetic control circuit 20 displays the flare detection state on the screen of the display device 21 on the basis of the output result from the flare detection mechanism, or the output result by the flare detection mechanism does not detect the flare. The light shielding plates (apertures) 6a and 6c may be automatically moved and controlled in the optical axis direction based on the output result from the flare detection mechanism so as to be in the state.
[0041]
When the eye E is rotated as described above, the light-shielding plate (concentric light-shielding means) 6a shown in FIG. 1 (b) is replaced by the arithmetic control circuit 20 in FIG. 6 (a) or FIG. 6 (b). The light-shielding plate (eccentric light-shielding means) 6′a having the configuration shown in FIG. 6B is switched to the light-shielding plate (concentric light-shielding means) 6c shown in FIG. 1B. Switching to a light shielding plate (eccentric light shielding means) 6'c having
[0042]
Moreover, the arithmetic control circuit 20 assists the display of the flare detection state on the screen of the display device 21 based on the output result of the flare detection mechanism, or the output result of the flare detection mechanism does not detect the flare. As described above, the light shielding plates (diaphragms) 6'a and 6'c may be automatically controlled to move in the optical axis direction based on the output result from the flare detection mechanism. In this case as well, as indicated by 1, the light shielding plates 6 ′ a and 6 ′ c are rotated around the optical axis.
(Other 4)
Further, in the embodiment, it has been described that the apertures having different shapes are replaced, but the shape may be changed by a mechanical mechanism.
(Other 5)
In addition, by using an element that can control the position and transmittance, such as liquid crystal, a diaphragm with a free position, size, and shape can be presented with a simple configuration.
[0043]
【The invention's effect】
According to the first aspect of the present invention, flare from the cornea and the peripheral portion of the crystalline lens can be removed even when the cornea and the crystalline lens of the eye to be examined are different, and the driving operation of the light shielding means for removing the flare is simple. It becomes.
[0044]
Further, the invention of claim 2 can remove flare from the peripheral part of the cornea or the crystalline lens, and at least remove flare from the cornea or the posterior surface of the crystalline lens, even if the cornea and crystalline lens of the eye to be examined are different.
[0045]
Furthermore, the invention described in claim 3 is capable of removing flare from the cornea and the peripheral portion of the lens even when the position of the cornea and the lens is moved due to rotation of the eye to be examined, and driving the light shielding means for removing flare. Operation is simplified.
[0046]
Further, the invention described in claim 4 can remove flare from the peripheral part of the cornea or the lens even if the cornea and the lens are moved due to rotation of the eye to be examined, and at least remove flare from the cornea or the back surface of the lens. it can.
[Brief description of the drawings]
FIG. 1A is an explanatory diagram of an optical system of a fundus camera according to the present invention, and FIG. 1B is an explanatory diagram of a light shielding plate of FIG.
FIG. 2 is a control circuit of the fundus camera shown in FIG.
FIG. 3 is an enlarged explanatory view of an anterior eye portion of the eye to be examined shown in FIG.
4 is an operation explanatory diagram when the distance between the cornea and the posterior surface of the crystalline lens of the anterior eye portion shown in FIG. 3 is large.
FIG. 5 is an enlarged explanatory view of an anterior eye part when the eye to be examined shown in FIG. 1 is rotated by a fixation target;
6A and 6B are explanatory views showing another example of the light shielding plate shown in FIG.
[Explanation of symbols]
1... Illumination optical systems 6a, 6b, 6c... (Light shielding means, concentric light shielding means)
6'a, 6'c ... light shielding plate (eccentric light shielding means)
10 ... Optical optical system 20 ... Operation control circuit (control circuit)
c ... Cornea E ... Eye to be examined i ... Iris La ... Lens front Lb ... Lens rear surface M1, M2 ... Drive motor (drive means)
Ra, Rs ... light-shielding part a ... projection

Claims

An illumination optical system for illuminating the fundus of the subject's eye via the light shielding means for the flare removal to the cornea, iris, at least one conjugate with the lens rear surface, an imaging optical system for imaging the subject's eye, the A fundus camera comprising: a driving unit configured to move and adjust a light shielding unit in an optical axis direction of the illumination optical system ;
The apparatus further comprises fixation target presenting means for causing the subject's eye to visually recognize the fixation target and guiding the optical axis of the eye to be examined in a predetermined direction, and controlling the operation of the drive means according to the presentation position of the fixation target. Accordingly , the fundus camera is provided with a control circuit that moves the light shielding means in the optical axis direction to conjugate the light shielding means with at least one of the cornea and the rear surface of the crystalline lens .

An illumination optical system that illuminates the fundus of the subject eye via a flare-removing shading means that is conjugated with at least one of the cornea, iris, and posterior surface of the crystalline lens of the subject eye; a photographing optical system that photographs the subject eye ; A fundus camera comprising: a driving unit configured to move and adjust a light shielding unit in an optical axis direction of the illumination optical system ;
A flare detection device for detecting at least one flare state of the cornea, the iris, and the back surface of the lens;
A control circuit that controls the driving means based on a detection signal from the flare detection device to move the light shielding means in the optical axis direction so that the light shielding means is conjugated with at least one of the cornea and the rear surface of the crystalline lens. fundus camera comprising: a.

An illumination optical system that illuminates the fundus of the eye to be examined through a flare-removing shading means that is conjugated with at least one of the cornea, iris, and posterior surface of the lens; and an imaging optical system that photographs the eye to be examined The light shielding means is concentric light shielding means concentric with the optical axis of the illumination optical system, and is used by switching to the concentric light shielding means when the subject's eye rotates, and is light-shielded decentered in the rotation direction of the eye to be examined. In a fundus camera that is an eccentric light shielding means having a portion ,
The apparatus further comprises fixation target presenting means for causing the subject's eye to visually recognize the fixation target and guiding the optical axis of the eye to be examined in a predetermined direction, and controlling the operation of the drive means according to the presentation position of the fixation target. Accordingly, the fundus camera is provided with a control circuit that moves the light shielding means in the optical axis direction to conjugate the light shielding means with at least one of the cornea and the rear surface of the crystalline lens.

An illumination optical system that illuminates the fundus of the eye to be examined through a flare-removing shading means that is conjugated with at least one of the cornea, iris, and posterior surface of the lens; and an imaging optical system that photographs the eye to be examined The light shielding means is concentric light shielding means concentric with the optical axis of the illumination optical system, and is used by switching to the concentric light shielding means when the subject's eye rotates, and is light-shielded decentered in the rotation direction of the eye to be examined. In a fundus camera that is an eccentric light shielding means having a portion ,
A flare detection device for detecting at least one flare state of the cornea, the iris, and the back surface of the crystalline lens is further provided, and the driving means is controlled based on a detection signal from the flare detection device to thereby control the light shielding means to the optical axis. A fundus camera comprising a control circuit that moves in a direction to conjugate the light shielding means with at least one of the cornea and the rear surface of the crystalline lens.