JP4503716B2 - Microscope transmission illumination device - Google Patents

Description

【００６８】
そこで、前記コンデンサレンズの照明可能な最大の開口数をＮＡ１、前記コンデンサレンズの最大の照明範囲を観察可能な対物レンズの開口数をＮＡ２とした場合、
ＮＡ２／ＮＡ１＜０．６（条件２）
を満足するコンデンサレンズを備えた透過照明光学系とすることが好ましい。
【００６９】
以上のような条件２を満足することで、最も広い照明範囲を観察可能な対物レンズにおいて、照明角度が大きく対物レンズに直接入射しない照明光を充分に確保することができる。照明光の成分としては、暗視野照明を含む偏斜照明光の領域が充分に確保されるので、２つ以上の遮光体を各々移動して偏斜照明から暗視野照明までの照明の自由度が増える。この結果、低倍率の対物レンズの観察から、透明な位相標本のコントラストを連続して変化させることができる。また、対物レンズの倍率が高くなると開口数も大きくなるので、対物レンズの倍率が高くなるにつれて暗視野照明を含む偏斜照明の領域が少なくなる。このため、低倍率での観察だけでなく、それ以外の倍率の観察においても、条件２を満足することは重要である。
【００７０】
上述した遮光体は、図６に示したように、コンデンサレンズの前側焦点位置、もしくはその近傍に配置した構成としたが、顕微鏡の光学系のデザインによって、様々な位置に配置することが可能である。そのような光学系の一例を図２９を参照して説明する。
【００７１】
図２９は、図６に示した光学系の内、透過照明光学系のデザインを変更した構成を示す（図６と同一の部材については同一の参照符号が付してある）。この透過照明光学系は、図６に示した拡散板２２と偏向ミラー２４との間に、リレーレンズ６０及び６１を配設している。この構成によれば、光源２０から射出した光は、コレクタレンズ２１によって平行光とされた後、リレーレンズ６０によって一次光源像（結像位置を符号Ｐ３で示す）をつくる。そして、この一次光源像は、リレーレンズ６１、偏向ミラー２４、投影レンズ２５を介して、コンデンサレンズ２６の前側焦点位置に投影される（２次光源像）。絞り２３は視野絞りであり、絞り４１は開口絞りとして機能する。
【００７２】
このような光学系によれば、対物レンズ３１の瞳と共役位置である１次光源像の位置Ｐ３もしくはその近傍位置に、上述したような構成の遮光体４０ａ，４０ｂ（上述した他の構成の遮光体であっても良い）を配置することが可能となる。また、このような構成においても、上述した条件１が満足されるように、各遮光体を移動させることで、偏斜照明又は暗視野照明の効果が得られる。また、低倍や極低倍領域を照明する場合、コンデンサレンズを照明光路から取り外すか、あるいは１倍以下の照明に使用されるコンデンサレンズをアフォーカル系として構成する。この場合、対物レンズ３１の瞳位置と共役になる位置は、投影レンズ２５の前側焦点位置である視野絞り２３と対応するため、この視野絞り２３の位置、もしくはその近傍に上述した構成の遮光体を移動可能に配置することで同様の効果が得られる。
【００７３】
また、上述した透過照明光学系において、偏向ミラー２４を回動可能に構成しても良い。偏向ミラー２４の回動は、図５に示した実体顕微鏡の場合、ミラー傾き調整レバー２０４を操作することで行うことができる。このように、偏向ミラー２４を回動可能に構成したことにより、偏斜照明時や暗視野照明時において、標本に対する照明光の角度を任意に調節することが可能となる。
【００７４】
上述した構成において、透過照明光学系に用いられるコンデンサレンズは、対物レンズの倍率に応じて切り換え可能に構成されている。すなわち、コンデンサレンズの開口絞りと標本との間にある少なくとも１つのレンズ群が、低倍率の対物レンズと高倍率の対物レンズに応じて、着脱または他のレンズ群に切換えて使用するように構成されている。そして、このように構成されるコンデンサレンズにおいては、上述したような遮光体は、低倍率時のコンデンサレンズの瞳位置、またはその近傍に配置するのが良い。
【００７５】
このように、低倍率時のコンデンサレンズの瞳位置、またはその近傍に遮光体を配置するのは以下の理由による。すなわち、本発明による照明法は、大きい開口数を有する高倍率時の観察において得られる標本について、正しい情報になるとは限らないが、低倍率時においては、回折現象というよりは照明による散乱現象に近い。しかも、低倍率時の観察では、解像を重視するのではなく、コントラストを連続的に変化させて可視化することが重要である。
【００７６】
低倍率時のコンデンサレンズの瞳位置に、前記対物レンズの瞳内に形成される開口を制御する遮光体を配置することで、位相標本を可視化する低倍率時においても、前述したように、明視野照明から偏斜照明、さらには暗視野照明へと連続的に照明を変えることが可能となり、位相標本のコントラストを連続して変化させることができる。さらに、高倍率時に、位相差観察や微分干渉観察が可能なコンデンサレンズであるユニバーサルコンデンサと併用することで、それぞれの照明を切換えて使用することも可能となる。すなわち、低倍率での観察には、上述したような照明法を使用して位相標本全体の構造や分布をコントラスト良く可視化し、高倍率での観察では、従来の観察法である位相差や微分干渉を使用して微細構造の観察が行えるように構成することもできる。
【００７７】
上述したように、透過照明光学系において、開口絞りと標本の間にある少なくとも１つのレンズ群が、低倍率、高倍率に応じて着脱、または他のレンズ群に切換えられるコンデンサレンズを使用する場合において、高倍率時のコンデンサレンズの焦点距離をＦ１、低倍率時のコンデンサレンズの焦点距離をＦ２としたとき、
Ｆ１／Ｆ２＜０．４５（条件３）
を満足するように構成するのが好ましい。
【００７８】
このような条件３を満足するように、コンデンサレンズを設計することで、高倍率から低倍率、さらには極低倍率領域まで、２つのコンデンサレンズを切換えることで良好な照明が可能となる。特に、低倍率から極低倍率領域において、対物レンズの瞳内に形成される開口形状を制御する上述した遮光体によって、照明を自由に変化させて透明な位相標本をコントラスト良く可視化することができる。
【００７９】
次に、本発明の顕微鏡透過照明装置に用いられるコンデンサレンズの好ましい構成例を具体的に説明する。
【００８０】
（構成例１）
図３０は、高倍率に用いられるコンデンサレンズを示しており、レンズ系は、レンズ群Ｌ１、Ｌ２及びＬ３で構成されている。また、開口絞り７０、および、コンデンサレンズの瞳位置Ｐ１において、図示しない位相差用リングスリット、微分干渉用プリズム、暗視野用リングスリット等の特殊観察用ターレットディスクを備えている。標本はスライドガラス７２上に載置され、ステージ面に配置されている。上述したように構成された遮光体７４ａ，７４ｂは、瞳位置Ｐ１の近傍に、移動可能に配置されている。以下にコンデンサレンズの構成を示す。
【００８１】
【表２】

【００８２】
上記したようなコンデンサレンズによれば、低倍側の対物レンズの瞳径に対して、コンデンサレンズの瞳径が十分大きく、標本を照射する暗視野照明を含む偏斜照明成分を確保できる。この結果、開口絞り位置近傍に、対物レンズの瞳内に形成される開口の形状を制御する遮光体を移動可能に配置することで、透明な位相標本等を可視化し、連続的にコントラストを変化させることができる。また、本発明における照明装置に加えて、前記コンデンサレンズによれば、位相差観察、微分干渉観察および暗視野観察等を行うことができ、多様な観察法に対応できる照明光学系となる。なお、ターレットディスク内に、遮光体７４ａ，７４ｂを配置し、移動させる構成でも同様な効果が得られる。
【００８３】
（構成例２）
図３１は、高倍率に用いられるコンデンサレンズを示しており、レンズ系は、レンズ群Ｌ１、Ｌ２及びＬ３で構成されている。また、開口絞り７０、および、コンデンサレンズの瞳位置Ｐ１において、図示しない位相差用リングスリット、微分干渉用プリズム、暗視野用リングスリット等の特殊観察用ターレットディスクを備えている。標本はスライドガラス７２上に載置され、ステージ面に配置されている。この場合、レンズＬ３とステージとの間は、油浸用のオイルが満たされている。また、上述したように構成された遮光体７４ａ，７４ｂは、瞳位置Ｐ１の近傍に、移動可能に配置されている。以下にコンデンサレンズの構成を示す。
【００８４】
【表３】

【００８５】
上記したようなコンデンサレンズによれば、低倍側の対物レンズの瞳径に対して、コンデンサレンズの瞳径が十分大きく、標本を照射する暗視野照明を含む偏斜照明成分を確保できる。この結果、開口絞り位置近傍に、対物レンズの瞳内に形成される開口の形状を制御する遮光体を移動可能に配置することで、透明な位相標本等を可視化し、連続的にコントラストを変化させることができる。また、本発明における照明装置に加えて、前記コンデンサレンズによれば、位相差観察、微分干渉観察および暗視野観察等を行うことができ、多様な観察法に対応できる照明光学系となる。なお、ターレットディスク内に、遮光体７４ａ，７４ｂを配置し、移動させる構成でも同様な効果が得られる。
【００８６】
（構成例３）
図３２は、低倍率に用いられるコンデンサレンズを示しており、対物レンズの瞳内に形成される開口の形状を制御する遮光体７４ａ，７４ｂが移動可能に設けられている。このコンデンサレンズは、レンズ系内に、開口絞り７０と、接合を含む５枚のレンズで構成されている。標本はスライドガラス７２上に載置され、ステージ面に配置されている。上記遮光体７４ａ，７４ｂは、瞳位置近傍である開口絞り７０の近傍に配置されている。以下にコンデンサレンズの構成を示す。
【００８７】
【表４】

【００８８】
上記したようなコンデンサレンズによれば、極低倍の対物レンズの瞳径に対して、コンデンサレンズの瞳径が十分大きく、標本を照射する暗視野照明を含む偏斜照明成分を確保できる。この結果、開口絞り位置近傍に、対物レンズの瞳内に形成される開口の形状を制御する遮光体を移動可能に配置することで、透明な位相標本等を可視化し、連続的にコントラストを変化させることができる。しかも、従来の技術で述べたように、この倍率領域では、位相標本を可視化してコントラストを変化させるような照明が無いので、この構成例によれば、従来にはなかった照明が実現できる。
【００８９】
（構成例４）
図３３は、開口絞りと標本の間にある少なくとも１つのレンズ群が、高倍率と低倍率に応じて切換えて使用されるコンデンサレンズの構成を示している。図（ａ）が高倍率時に用いられる構成であり、図（ｂ）が低倍率時に用いられる構成である。
【００９０】
高倍率時に用いられるコンデンサレンズは、図３０に示した構成と同一である。そして、低倍率時には、レンズ群Ｌ２，Ｌ３が照明光路より移動し、代わりにレンズ群Ｌ４が照明光路に挿入される。低倍率時における瞳位置Ｐ１近傍に、対物レンズの瞳内に形成される開口を制御する遮光体７４ａ，７４ｂが移動可能に配置される。
【００９１】
高倍率時における照明範囲は、１０倍〜１００倍に対応しており、低倍率時における照明範囲は、１．２５倍〜４倍に対応する。以下にコンデンサレンズの構成を示す。
【００９２】
【表５】

【００９３】
上記したようなコンデンサレンズによれば、低倍率時の瞳位置近傍に、遮光体を配置したことで、１．２５倍から４倍において、位相標本等を可視化し、コントラストを連続的に変化させることができる。この結果、極低倍から低倍の領域では、上記したような低倍型のコンデンサレンズで位相標本を可視化して観察することができ、高倍率時では、位相差や微分干渉、及び暗視野観察を行うことができる。
【００９４】
（構成例５）
図３４は、高倍率と低倍率に応じて切換えて使用されるコンデンサレンズの構成を示している。図（ａ）が高倍率時に用いられる構成であり、図（ｂ）が低倍率時に用いられる構成である。この場合、高倍率時に用いられるコンデンサレンズは、図３０に示した構成と同一であり、低倍率時に用いられるコンデンサレンズは、図３２に示した構成と同一である。以下にコンデンサレンズの構成を示す。
【００９５】
【表６】

【００９６】
上記したようなコンデンサレンズによれば、低倍率時の瞳位置近傍に、遮光体を配置したことで、１．２５倍から４倍において、位相標本等を可視化し、コントラストを連続的に変化させることができる。また、高倍率時のコンデンサレンズは、位相差観察、微分干渉観察をするための光学素子をコンデンサレンズの瞳位置に配置することで、そのような観察が可能となる。
【００９７】
この結果、極低倍から低倍の領域では、上記したような低倍型のコンデンサレンズで位相標本を可視化して観察することができ、高倍率時では、位相差観察、微分干渉観察、及び暗視野観察等を行うことができ、多様な観察法に対応できる照明光学系となる。また、低倍率時に配置される遮光体７４ａ，７４ｂの位置と、高倍率時のコンデンサレンズの瞳位置が近いため、高倍率時のコンデンサレンズでも、遮光体７４ａ，７４ｂを使用して、対物レンズの瞳内に形成される開口を制御することができる。
【００９８】
以上のような透過照明光学系は、図示しない落射蛍光顕微鏡と組み合わせて使用することも可能である。位相差観察用対物レンズのように、対物レンズの瞳位置に位相膜を配置する必要がないので、対物レンズにロスが無く、蛍光を明るく観察することができる。蛍光染色された透明な位相標本においては、上述したような透過照明系を用いて、コントラスト良く可視化し、落射蛍光照明によって蛍光染色された細胞等を観察することができる。
【００９９】
次に、図３５を参照して、本発明の別の実施の形態について説明する。図３５は、実体顕微鏡における透過照明光学系の概略構成を示す図である。
【０１００】
透過照明光学系は、ハロゲンランプ等の光源８０の光を略平行光束にするコレクターレンズ等の平行光束部材８２と、平行光束部材８２からの光束を拡散させる摺りガラス等の第１の拡散板８３と、第１の拡散板８３からの拡散光線を集光する凸レンズ等の第１の集光部材８５と、第１の集光部材８５からの光を拡散する摺りガラス等の第２の拡散板８６と、第２の拡散板８６からの光を上方向に偏向する偏向ミラー８７と、偏向ミラー８７からの光を集光して標本載置ガラス８９上の標本９０に照射する、凸レンズ等の第２の集光部材８８とを具備している。
【０１０１】
前記第２の拡散板８６と偏向ミラー８７との間には、第１の補助凸レンズ９１が光路から挿脱可能に配置され、ミラー８７と第２の集光部材８８との間には、第２の補助凸レンズ９２が挿脱可能に配置されている。第２の集光部材８８と第２の補助凸レンズ９２との間には、上述した実施の形態の遮光体と同様に構成された第１及び第２の遮光体９５ａ，９５ｂが移動可能に配置されている。さらに、第２の拡散部材８６と第２の補助凸レンズ９１との間には、同様な構成の遮光体９５ｃ，９５ｄが移動可能に配置されている。
【０１０２】
上記構成によれば、光源８０から出射した光は、平行光束部材８２で効率よく集光されて略平行光線にされ、第１の拡散板８３に入射する。第１の拡散板８３は照明視野を満たすために大きな面積の略均一な光源としての役割を持つ。第１の拡散板８３で拡散された光は、第１の集光部材８５によって集光される。第１の集光部材８５は第１の拡散板８５で発散方向に拡散された光を照明に有効な収束方向に集める役目を持つ。
【０１０３】
第２の拡散板８６に入射した光は、さらにその収束方向に沿って拡散される。第２の拡散板８６は開口数を満たすための光の拡散を行い、最終的な光源となる。第２の拡散板８６で拡散された光は、偏向ミラー８７によって上方に偏向され、第２の集光部材８８に入射し、標本載置透明部材８９を通して標本９０を照明する。
【０１０４】
第２の拡散板８６と偏向ミラー８７との間に挿入される第１の補助凸レンズ９１は、照明視野が狭く開口数が大きくなる高倍率対物レンズのために、光の収束を強め、光の利用効率を上げる役目を果たす。また、偏向ミラー８７と第２の集光部材８８との間に挿入される第２の補助凸レンズ９２は、第２の集光部材８８と併せて凸レンズのパワーを上げることで、照明視野を狭め角度の大きい光で標本９０を照明する役目を果たす。すなわち、照明光学系が、対物レンズの倍率に応じて切り換えられるため、最適な照明条件で観察できる。
【０１０５】
高倍率の対物レンズは焦点距離が短く、照明装置内の瞳共役位置は、第２の集光部材８８に限りなく近づき、また、低倍率の対物レンズの場合は、そこから離れ、偏向ミラー８７で光軸を折り返す位置の手前に瞳共役位置が存在することが通例である。従って、それらの位置に、遮光体９５ａ，９５ｂ、及び９５ｃ，９５ｄを各々配置し、各遮光体を独立して光軸に対して挿脱を行うことで明るさ絞りを形成でき、さらに、各遮光体を光軸から任意にずらすことで、偏斜照明が可能になる。
【０１０６】
なお、上述した遮光体９５ａ，９５ｂ（９５ｃ，９５ｄ）は、図１２乃至図１５に示した駆動機構によって移動可能となっており、遮光体によって、左右の対物レンズの瞳は、図１１、図２０〜図２５に示したように、共に上下方向から均等に絞られる。左右の瞳が均等に絞られるため、左右の像の見え方は均等となり、実体顕微鏡の特徴である左右の視差で自然に立体感が得られる。また、前記実施の形態と同様、遮光体を移動することで、対物レンズやの瞳に入射する直接光と、回折光の割合を制御することができ、コントラストを強調したり、連続的に変化させることができる。すなわち、微細構造を持つ標本に対して非常に細やかなコントラスト調整が可能になり、今まで観察不可能であったものが観察できるようになる。また、高倍率と低倍率に適した位置に絞りを配置したので、高倍率から低倍率まで、偏斜照明を行うことができる。また、低倍率から高倍率への切り換えは、レンズ９１，９２の付加によって実現できるため構造が簡単になり、安価に構成できる。さらに、拡散板を二つ配置し、各々の役割を明確にしたので、光学系の最適設計を行い易く、効率が良くなり、不必要に拡散効果が大きい拡散板を用いなくても済む。
【０１０７】
図３６は、図３５に示した構成の変形例を示す。この変形例において、図３５に示した構成との相違点は、偏向ミラー８７を回動可能に構成し、かつ、低倍率側の遮光体９５ｃ，９５ｄを取除いた点である。
【０１０８】
これは、微細構造を観察する場合、主に解像の関係から、高倍率で観察が行える、という要求が高いことに基づく。なお、低倍率での観察は、回動する偏向ミラー８７ａによって、十分な照明効果（偏斜照明）で大きい視野を従来通りのコントラストで得られる。このように、高倍率での偏斜照明を遮光体９５ａ，９５ｂで行い、低倍率での偏斜照明を偏向ミラー８７ａで行うことにより、コストの低下が図れる。また、瞳位置の共役関係が不十分な中倍率での偏斜照明も偏向ミラー８７ａで行えるため、使い勝手が良い。
【０１０９】
なお、図３５、図３６に示した実施の形態における照明系は、偏斜照明において、高倍率、低倍率で照明視野の充足と、開口数（瞳）の充足を行うための一例である。したがって、公知の明視野照明装置の瞳位置に、上記したような遮光体を配置しても、十分に偏斜照明が行える。但し、偏斜照明を行うにあたり、その汎用性、効果を十分に発揮するためには、上記の照明系もしくはそれ以上の広い照明視野と、大きな開口数を持った光学系と組み合わせることが好ましい。
【０１１０】
また、図に示した照明光学系において、第１，第２の拡散板８３，８６を一体化し、第１の集光部材８５をなくして第１，第２の拡散板各々にレンズ効果を分配することも可能である。また、第１，第２の補助凸レンズ９１，９２を挿入する代りに、第１，第２の集光部材８５，８８の焦点距離を変えることも可能であり、補助凸レンズを挿入する位置も変更することが可能である。
【０１１１】
また、図３５、図３６に示した実施の形態において、以下のように変形することが可能である。
【０１１２】
ズーム実体顕微鏡の高倍率の瞳位置、および低倍率の瞳位置と各々共役な２個所に、少なくとも２つの遮光体を移動可能に配置する。このような構成によれば、高倍率と低倍率で、最適な偏斜照明を実現できる。
【０１１３】
図に示す光学系に、光源からの出射光軸を上方に偏向する他の偏向部材を設け、この偏向部材を傾けて照明光線を偏斜させるように構成する。このように他の偏向部材の偏斜を組合わせることで、偏斜照明の範囲が広がる。
【０１１４】
【発明の効果】
以上、本発明によれば、次のような効果が得られる。
【０１１５】
顕微鏡の対物レンズの瞳内に形成される開口の形状を、遮光体の移動によって制御することで、標本を透過して対物レンズに入射する直接光と回折光の強度の割合を調節することが可能となる。この結果、位相標本のような透明な物体を可視化し、かつコントラストを連続的に変化させることが可能となり、様々な厚みや屈折率の差がある標本を最適に照明できる。しかも、顕微鏡に特別な対物レンズを設ける必要も無い。
【０１１６】
低倍領域や極低倍領域では、従来、明視野照明法しか存在しなかったが、本発明の照明法によって、低倍領域や極低倍領域から位相標本を可視化して、標本の全体的構造や分布を観察することができる。さらに、従来からの位相差観察法や、微分干渉観察法を併せて用いることにより、多様な照明を提供することができる。
【図面の簡単な説明】
【図１】（ａ）乃至（ｄ）は、一般的な偏斜照明法におけるコンデンサレンズの模式図、及び夫々の開口絞りによって形成される瞳の開口形状を示す図。
【図２】（ａ）は、一般的な暗視野照明法におけるコンデンサレンズの模式図であり、（ｂ）は、絞りの形状を示す図。
【図３】（ａ）は、従来の透過照明装置の概略構成を示す図であり、（ｂ）は、左右の対物レンズの瞳の開口形状を示す図。
【図４】（ａ）は、従来の別の透過照明装置の概略構成を示す図であり、（ｂ）は、左右の対物レンズの瞳とナイフエッジとの関係を示す図。
【図５】本発明の透過照明装置が適用可能な実体顕微鏡の外観を示す図。
【図６】図５に示した実体顕微鏡の光学系の構成を模式的に示す図。
【図７】（ａ）は、明視野照明状態におけるコンデンサレンズと対物レンズの部分を模式的に示す図であり、（ｂ）は、その時の瞳の状態を示す図。
【図８】（ａ）は、図６に示した光学系において、遮光体、コンデンサレンズ、対物レンズの部分を模式的に示す図であり、（ｂ）は、その時の瞳の状態を示す図。
【図９】（ａ）は、図８に示した構成において、遮光体を移動させた状態を示す図であり、（ｂ）は、その時の瞳の状態を示す図。
【図１０】（ａ）は、図８に示した構成において、遮光体を移動させた状態を示す図であり、（ｂ）は、その時の瞳の状態を示す図。
【図１１】（ａ）乃至（ｄ）は、夫々図７乃至図１０に対応する図であり、図６に示した光学系を、実体顕微鏡に適用した場合の瞳と遮光体との位置関係を示す図。
【図１２】顕微鏡本体内に設けられる遮光体の駆動機構の一例を示す図。
【図１３】遮光体の駆動機構の第２の構成例を示す図。
【図１４】遮光体の駆動機構の第３の構成例を示す図であり、（ａ）は平面図、（ｂ）は側面図。
【図１５】遮光体の駆動機構の第４の構成例を示す図であり、（ａ）は平面図、（ｂ）は、図（ａ）のＩ−Ｉ線に沿った断面図。
【図１６】対物レンズの瞳に形成される開口に対し、部分的に光の強度を制御する構成を示す図であり、（ａ）は光学系の概略を示す図、（ｂ）は、遮光体と瞳の関係を示す図、（ｃ）は、遮光体部分の別の構成例を示す図。
【図１７】（ａ）及び（ｂ）を含み、それぞれ、対物レンズの瞳に形成される開口に対し、部分的に光の強度を制御する別の構成例を示す図。
【図１８】対物レンズの瞳に形成される開口形状を制御する別の構成例を示す図であり、図（ａ）は光学系の概略を示す図、図（ｂ）は、遮光体と瞳の関係を示す図。
【図１９】対物レンズの瞳に形成される開口形状を制御する別の構成例を示す図であり、（ａ）は光学系の概略を示す図、（ｂ）は、遮光体と瞳の関係を示す図。
【図２０】実体顕微鏡において、対物レンズの瞳に形成される開口に対し、部分的に光の強度を制御する構成を示す、遮光体と瞳の関係を示す図。
【図２１】図２０において、遮光体部分の別の構成例を示す図。
【図２２】対物レンズの瞳に形成される開口に対し、部分的に光の強度を制御する別の構成例を示す図。
【図２３】対物レンズの瞳に形成される開口に対し、部分的に光の強度を制御する別の構成例を示す図
【図２４】実体顕微鏡における対物レンズの瞳に形成される開口形状を制御する別の構成例を示す図であり、図（ａ）は光学系の概略を示す図、図（ｂ）は、遮光体と瞳の関係を示す図。
【図２５】実体顕微鏡における対物レンズの瞳に形成される開口形状を制御する別の構成例を示す図であり、（ａ）は光学系の概略を示す図、（ｂ）は、遮光体と瞳の関係を示す図。
【図２６】遮光体の別の構成例を示す図であり、（ａ）乃至（ｅ）は、それぞれ、２つの遮光体が移動した際の位置関係の例を示す図。
【図２７】遮光体の別の構成例を示す図であり、（ａ）及び（ｂ）は、それぞれ、２つの遮光体が移動した際の位置関係の例を示す図。
【図２８】遮光体の別の構成例を示す図であり、（ａ）は、１枚の遮光体の構成を示す図、（ｂ）及び（ｃ）は、それぞれ、２つの遮光体が移動した際の位置関係の例を示す図。
【図２９】透過照明光学系の別の構成例を示す図。
【図３０】本発明の透過照明光学系に用いられる高倍率用コンデンサレンズの構成を示す図。
【図３１】高倍率用コンデンサレンズの第２の構成を示す図。
【図３２】本発明の透過照明光学系に用いられる低倍率用コンデンサレンズの構成を示す図。
【図３３】顕微鏡透過照明装置に用いられる切換可能なコンデンサレンズの構成を示しており、（ａ）は高倍率用コンデンサレンズの構成を示す図、（ｂ）は低倍率用のコンデンサレンズの構成を示す図。
【図３４】顕微鏡透過照明装置に用いられる切換可能なコンデンサレンズの第２の構成を示しており、（ａ）は高倍率用コンデンサレンズの構成を示す図、（ｂ）は低倍率用のコンデンサレンズの構成を示す図。
【図３５】本発明の別の実施の形態を示す図。
【図３６】図２９に示した実施の形態の変形例を示す図。
【符号の説明】
２０…光源
２６…コンデンサレンズ
３０…標本
３１…対物レンズ
４０，４０ｂ，４０ｃ，４０ｄ，４０ｅ，４０ｆ…遮光体
４５，４５ａ，４５ｂ…フィルタ
４６ａ，４６ｂ…偏光板
９５ａ，９５ｂ，９５ｃ，９５ｄ…遮光体。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission illumination device applicable to various microscopes.
[0002]
[Prior art]
Conventionally, a phase difference observation method, a differential interference observation method, a modulation contrast method, an oblique illumination method, and the like have been proposed so that various colorless and transparent phase samples can be visualized and observed.
[0003]
In the phase difference observation method, a ring slit is arranged at the pupil position of the illumination optical system of the microscope, and a phase film conjugate with the ring slit is arranged at the pupil of the imaging optical system at a position conjugate with the ring slit. Is. The advantage of this observation method is that an observation image with a high detection sensitivity and a clear contrast can be obtained even for a specimen having a small refractive index difference between structures, a granular microstructure of a cell, or the like. On the other hand, the disadvantage of this observation method is that it is difficult to confirm the outline of the structure due to a phenomenon called halo, in which the edge of the structure of the sample appears white. Furthermore, the ring slit arranged in the illumination optical system and the phase film arranged on the pupil plane of the observation optical system must be projected and matched, and the aberration performance of the pupil from the ring slit to the phase film plane is improved. There is a need. In the phase difference observation method, observation at high magnification is not a problem, but observation at low magnification or extremely low magnification cannot correct the aberration performance of the pupil well. Actually, the phase difference observation method is possible up to about 4 times the objective lens.
[0004]
In the differential interference observation method, two orthogonal polarized lights generated by a birefringent crystal are illuminated with a slight shift on the sample surface, and these are made to interfere with each other to observe the minute structure of the sample. The advantage of this observation method is that a three-dimensional observation can be performed with a very high contrast. On the other hand, the disadvantage of this observation method is that it is expensive because it uses a birefringent crystal, and because it is an observation using polarized light, if it is made of a substance that affects the polarization state, an accurate observation image can be obtained. I can't get it. For example, a plastic petri dish is not suitable for differential interference observation. This is because the polarization is disturbed by the birefringence of the plastic. Furthermore, since the polarization state is disturbed by distortion of the lens or objective lens in the illumination optical system, a dedicated objective lens or the like is required. In addition, since the two light beams interfere with each other, what can actually be observed is more than 4 times the objective lens, which is not suitable for observation at low magnification or extremely low magnification.
[0005]
In the modulation contrast observation method, as disclosed in JP-A-51-128548, a slit is arranged at the pupil position of the illumination optical system of the microscope, and a plurality of regions having different transmittances are arranged at the pupil position of the imaging optical system. Is to be placed. In general, an absorption film having an appropriate transmittance is disposed in a region conjugated with the slit, and one side adjacent to the absorption film is defined as a transmission region, and the other side is defined as an oblique light region. On the pupil plane, the area where light is transmitted varies depending on the size of refraction due to the structure in the specimen, and the transmittance changes accordingly, so that a three-dimensional image with black and white shading is obtained. The advantage of this observation method is that a three-dimensional image can be obtained by shading a phase object with a relatively inexpensive configuration. Moreover, since there is no halo seen by the above-mentioned phase difference observation method, it is easy to observe the outline of the structure, which is suitable for manipulation of cells and the like. On the other hand, the disadvantages of this observation method are that the detection sensitivity is inferior to that of the phase difference observation method and the microstructure is difficult to confirm. Further, every time the objective lens is replaced, a complicated operation for aligning the direction of the slit and the absorbing film is required. Furthermore, since the slit is projected onto the absorption film of the observation optical system, it is necessary to improve the aberration of the optical system that projects the pupil as in the phase difference observation method. For this reason, a low-magnification or extremely low-magnification objective lens cannot correct the pupil aberration well, and is not suitable for observation.
[0006]
Furthermore, there are a declination illumination method and a dark field illumination method as illumination methods for visualizing the phase specimen.
[0007]
1A to 1D are schematic views of condenser lenses in a general oblique illumination method. In these drawings, reference numeral 1 is an aperture stop, reference numerals 2a and 2b are lens groups, and Reference numeral 3 denotes a sample. The aperture stop 1 restricts the illumination aperture, has a variable circular aperture, and moves in a plane perpendicular to the illumination optical axis O, whereby the illumination angle with respect to the specimen 3 is controlled. . That is, the state of the pupil when the aperture stop 1 in the state shown in FIG. (A) is moved and reduced is shown in FIG. (B), and the state of the pupil when the aperture stop 1 is further reduced is shown in FIG. The state of the pupil when the aperture stop 1 is moved in the opened state is shown in FIG.
[0008]
FIG. 2A shows a schematic diagram of a condenser lens in a general dark field illumination method. In the conventional dark field illumination method, as shown in the figure, a diaphragm 1a is arranged in the vicinity where the aperture diaphragm is disposed, which is shielded on the inner side and has a slit in the outer ring zone. As shown in FIG. 2 (b), the diaphragm 1a is provided with a region 1b for shielding light at the central portion. By this region 1b, the illumination light is not directly incident on the objective lens, and the sample 3 Observing the scattered light emitted from the dark field enables dark field observation. In this case, dark field observation can be performed using various objective lenses by selecting the shape of the diaphragm 1a according to the numerical aperture of the objective lens.
[0009]
By the way, in the observation using a microscope, there is a need for observation not only in the micro region but also in the macro region, and there is a case where it is desired to use a 1 × objective lens or a very low magnification 0.5 × objective lens. . In general, such a macro region is observed using a stereomicroscope. Stereo microscopes have the advantage of being inexpensive, excellent in operability, and capable of three-dimensional observation, and the illumination method is also transparent like a phase specimen, such as dark field, bright field, and oblique illumination. There is a means of visualizing simple specimens.
[0010]
Japanese Patent Laid-Open No. 4-318804 discloses a transmission illumination device for a stereomicroscope that can perform oblique illumination. FIG. 3 is a diagram showing the transmission illumination device disclosed in this publication. As shown in FIG. 3A, this apparatus guides the light from the light source 5 to the mirror 8 through the collector lens 6 and the frosted glass 7, and mounts the light beam reflected by the mirror 8 through the condenser lens 9. The specimen 10 a on the transparent member 10 is irradiated and guided to the objective lens 12. By rotating the mirror 8 and changing the angle, the ratio of the dark portion 13a to the bright portion 13b of the pupil 13 of the left and right objective lenses shown in FIG. 3B can be adjusted.
[0011]
Japanese Utility Model Publication No. 41-5808 discloses a transmission illumination device of a stereomicroscope that can selectively perform oblique illumination and dark field illumination. FIG. 4 is a diagram for explaining this. As shown in FIG. 4A, this apparatus guides the light from the light source 5 to the mirror 8 through the collector lens 6 and the frosted glass 7, and reflects the light reflected by the mirror 8 through the condenser lens 9. 10a is configured to be guided to the objective lens 12. A knife edge 15 that cuts the luminous flux is provided in the vicinity of the frosted glass 7 disposed at a position conjugate with the pupil of the objective lens 12.
[0012]
As shown in FIG. 4B, oblique oblique illumination and dark field illumination can be selectively performed by moving the knife edge 15 up and down with respect to the conjugate image 17 of the pupils of the two objective lenses arranged side by side. it can. Japanese Patent Laid-Open No. 4-318804 proposes disposing a stop instead of the knife edge 15 of FIG.
[0013]
[Problems to be solved by the invention]
Each of the above-described phase difference observation method, differential interference observation method, and modulation contrast observation method capable of observing a transparent object such as a phase sample requires a dedicated observation optical system. Further, there is a need to satisfactorily correct the optical performance of the pupil projection optical system of the illumination optical system and the observation optical system, which is not suitable for observation at low magnification or extremely low magnification.
[0014]
Further, in the oblique illumination method shown in FIG. 1 (a) described above, if the aperture stop 1 is moved and narrowed as shown in FIG. 1 (c), the resolution and brightness of the illumination light are insufficient. In addition, when it is moved as shown in FIG. 1D, it is difficult to adjust the degree of freedom of oblique illumination, that is, the ratio of illumination light that is directly incident on the objective lens and illumination light that is not incident. This is because the aperture stop is configured to form a circular aperture.
[0015]
Further, even in the case of the dark field illumination shown in FIG. 2 described above, since the angle of the dark field illumination light changes depending on the width of the annular slit and the opening position, it cannot be visualized with good contrast if the thickness of the specimen changes. Sometimes. That is, in order to freely adjust the angle of the illumination light, it is necessary to prepare a large number of ring-shaped slits having different configurations, which is not practical.
[0016]
Further, even in the oblique illumination method proposed in the above-described stereomicroscope, since only one side of the pupil of the objective lens is illuminated, only one contrast can be obtained. In addition, by arranging a slit in the pupil of the illumination optical system, the effect of declination illumination can be obtained by limiting the aperture of the pupil of the objective lens, but in the conventional example, the shape of the slit or the arrangement of the slit is fixed. Therefore, the intensity and angle of illumination light cannot be freely finely adjusted according to changes in the thickness and refractive index of various specimens.
[0017]
As described above, the conventional microscope illumination device is not sufficient as an illumination method for visualizing the phase sample with good contrast when observing in the low to very low magnification region.
[0018]
An object of the present invention is to visualize a phase sample with good contrast without specifying a dedicated optical element or the like in an observation optical system, particularly in a low to extremely constant magnification region, and to make it possible to specify the structure and distribution. The object is to provide an illumination device for a microscope. That is, an object of the present invention is to provide an illuminating device that continuously changes the contrast of specimens having various thicknesses and refractive indexes and provides optimum illumination to the specimen.
[0019]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a transmission illumination optical system including a light source, a condenser lens for condensing light emitted from the light source and illuminating the sample, and an objective lens for observing the sample In a transmission illumination device used for a microscope having an observation optical system,
In the transmission illumination optical system, disposed in a conjugate position or a conjugate vicinity with the pupil position of the objective lens, By moving each independently Control the shape of the aperture formed in the pupil of the objective lens Open The mouth side shape has at least two light-shielding bodies having straight portions.
The present invention also provides a transmission illumination optical system comprising a light source, a condenser lens for condensing light emitted from the light source and illuminating the sample, and an observation optical system including an objective lens for observing the sample In a transmission illumination device used for a microscope having:
In the transmission illumination optical system, disposed in a conjugate position or a conjugate vicinity with the pupil position of the objective lens, By moving each independently The linear part which controls the shape of the opening formed in the pupil of the objective lens has two light shields parallel to each other.
[0020]
As described above, the shape of the aperture formed in the pupil of the objective lens is continuously changed by independently moving at least two light shielding bodies to a position conjugate to or near the pupil position of the objective lens. It becomes possible to control. That is, the angle of the illumination light that illuminates the specimen is continuously changed by the movement of each light shield, and the ratio of the intensity of the illumination light incident on the objective lens and the diffracted light emitted from the specimen is continuously controlled.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described using a normal microscope as an example.
[0022]
FIG. 6 is a diagram schematically showing a configuration of an optical system of a microscope, and the optical system includes a transmission illumination optical system that irradiates the specimen and an observation optical system that observes the specimen.
[0023]
The transmission illumination optical system includes a light source 20 such as a halogen lamp, a collector lens 21 that converts light from the light source 20 into a substantially parallel light beam, a diffusion plate 22 that diffuses light from the collector lens, and a diffusion plate. A field stop 23 that restricts the light beam from the light source, a deflection mirror 24 that deflects the light beam that has passed through the field stop upward, a projection lens 25 that projects a light source image from the deflection mirror, and light from the projection lens. The condenser lens 26 irradiates the specimen 30 as a parallel light beam. In this case, the light source image from the projection lens 25 is projected onto the pupil position P1 of the transmission illumination optical system, which is the front focal position of the condenser lens 26, and illuminates the specimen 30.
[0024]
The observation optical system includes an objective lens 31, an imaging lens 32, and an eyepiece lens 33. The focal position P2 of the objective lens 31 serving as the pupil position of the observation optical system is as described above. This is a conjugate relationship with the pupil position P1, which is the focal position of the condenser lens. The light transmitted through the specimen 30 passes through the objective lens 31 and the imaging lens 32 and is observed by the eyepiece 33.
[0025]
In the transmission illumination optical system configured as described above, at least two light shields 40a and 40b at a position conjugate with the pupil position P2 of the objective lens 31 (that is, the pupil position P1) or in the vicinity of the conjugate position. Are arranged so that they can move independently. By moving these light shields 40a and 40b, the shape of the opening formed in the pupil of the objective lens 31 is controlled as will be described in detail below. That is, by changing the angle of the illumination light that illuminates the specimen 30, it is possible to adjust the ratio of the intensity of the illumination light that directly enters the objective lens 31 and the diffracted light emitted from the specimen 30.
[0026]
This will be specifically described with reference to FIGS. In these drawings, FIG. (A) is a diagram schematically showing the optical system, and FIG. (B) is a diagram showing the positional relationship between the pupil and the light shield in the microscope. A circle indicated by symbol A indicates the pupil with the maximum numerical aperture that can be illuminated by the condenser lens 26, and a circle indicated by symbol C indicates the aperture of the objective lens 31 of the microscope at the pupil position P1 of the condenser lens 26. The pupils corresponding to the numbers are shown, and the circle indicated by the symbol B indicates the incident state of light at the pupil position of the objective lens 31 (aperture shape; black portions are portions shielded by the light shielding bodies 40a and 40b). .
[0027]
FIG. 7 shows a state where there is no light blocking body, which is a so-called bright field illumination state. In such a configuration, as shown in FIG. 6, at least two light shielding bodies 40a and 40b are located at the pupil position P1 of the condenser lens 26 or in the vicinity thereof (about ± several mm from the pupil position P1 in the optical axis direction). Are arranged so that they can move independently. In this case, the aperture stop 41 may be disposed adjacent to the light shield.
[0028]
There are at least two light shields, and the shape, number, and movement method of each light shield can be variously configured. For example, as shown in FIG. 8, it is possible to configure each to have a rectangular shape, independently move as indicated by an arrow, and shield the above-described pupil C from light. That is, when the light shields 40a and 40b are positioned as shown in FIG. 8, an opening shape (illumination state) as shown by the pupil B is obtained. In this figure, the area shielded by the light shield 40a (shown by diagonal lines) corresponds to the black area on the left side of the pupil B described above, and the area shielded by the light shield 40b is the black area on the right side of the pupil B. Correspond.
[0029]
FIG. 9 shows a state in which the light shielding body 40b is further moved to the light shielding body 40a side from the state shown in FIG. As shown in the opening shape of the pupil B in this state, the illumination light directly incident on the specimen 30 is only the narrow and narrow region on the left side of the pupil B in the drawing. As described above, by moving the light shields 40a and 40b independently, an effect as oblique illumination can be obtained, and by changing the interval between the light shields 40a and 40b, an effect as an aperture stop can be obtained. . Further, by arbitrarily moving the light shielding bodies 40a and 40b, the shape of the aperture formed in the pupil of the objective lens can be controlled. That is, by continuously changing the angle and amount of illumination light that irradiates the specimen 30, the ratio of the intensity of the illumination light directly incident on the objective lens and the intensity of diffracted light emitted from the specimen can be continuously adjusted. Optimal observation can be performed according to the specimen.
[0030]
Further, as shown in FIG. 10, the dark field illumination for moving the light shields 40a and 40b to shield the pupil C to cut off the direct light incident on the objective lens and observe the scattered light from the specimen. It is also possible to do. In this case, the illumination light quantity and angle of the dark field illumination light can be adjusted by changing the interval and the position of the light shields 40a and 40b while the pupil C is shielded.
[0031]
The optical system as described above can be applied to a stereomicroscope. FIGS. 11A to 11D are diagrams corresponding to FIGS. 7 to 10, respectively, showing the positional relationship between the pupil and the light shielding member when the above-described optical system is applied to a stereomicroscope. In FIG. 11, circles denoted by reference characters C1 and C2 indicate pupils corresponding to the apertures of the left and right objective lenses of the stereomicroscope, and circles indicated by reference characters B1 and B2 are at the pupil positions of the left and right objective lenses. The incident state of light is shown.
[0032]
Here, a configuration example in which the transmission illumination device according to the present invention is incorporated in a stereomicroscope will be described. FIG. 5 is a side view showing the overall configuration of the stereomicroscope. This stereomicroscope 200 includes a light-shielding member switching lever 210a (210b), a filter lever 202, a volume knob 203, a mirror tilt adjustment lever 204 provided as necessary, and a lamp house LH. The focusing unit F, the focusing handle FH, the lens barrel K, the mirror body KB, the objective lens housing T, and the eyepiece EO are provided. Note that the sample S is placed on the surface of the transmissive illumination stand and observed through two eyepieces EO on the left and right.
[0033]
The drive mechanism of the above-described light shielding bodies 40a and 40b will be described with reference to FIGS.
[0034]
As shown in FIG. 12, each of the light shields 40a and 40b is independently pierced through the wall surface of the casing body 205a constituting the transmission illumination base 205 shown in FIG. It is attached to the inside of the tip of 210a, 210b. Each lever 210a, 210b can be operated independently in the direction of the arrow, and as a result, as shown in FIGS. 8 to 10, the light shields 40a, 40b are planes including the optical axes of the left and right observation optical systems. Can be moved in a direction perpendicular to the direction parallel to the direction (front-rear direction with respect to the observer). It should be noted that a translation mechanism (not shown) may be provided at the rear end of each lever 210a, 210b so that both light shields are interlocked.
[0035]
FIG. 13 is a diagram illustrating a second configuration example of the light shielding body and its driving mechanism.
[0036]
The respective light shielding bodies 40a and 40b are penetrated independently in an oblique direction with respect to the side wall of the housing body 205a, and the tip portions of the two levers 211a and 211b are slidable independently in the arrow direction. It is attached inside. As described above, the operation lever that performs the movement of each light shielding body can be attached to any position on the side wall of the housing body 205a, and the shape of each light shielding body is also arbitrarily changed according to the attachment position. (The configuration shown in the figure is a pentagonal shape). In this modification as well, a translation mechanism may be provided at the rear end of each lever 211a, 211b so that both light shielding members are interlocked.
[0037]
14A and 14B are diagrams showing a third configuration example of the light shielding body and its driving mechanism, in which FIG. 14A is a plan view and FIG. 14B is a side view.
[0038]
As shown in the drawing, each of the light shielding bodies 40a and 40b is formed with elongated holes 40a1, 40a2 and 40b1, 40b2 extending along the oblique directions (Y1, Y2 directions) and along the left-right direction. Extending long holes 40a3 and 40b3 are formed.
[0039]
The side wall of the housing body 205a is provided with two levers 212a and 212b that are pierced independently and slidable. The light shielding bodies 40a and 40b are formed at the tips of the levers. Pins 213a and 213b that engage with the long holes 40a3 and 40b3 are formed. Further, links 215a, 215b, 215c, and 215d that engage with the long holes 40a1, 40a2, and 40b1, 40b2 formed in the light shielding bodies 40a, 40b are provided on the bottom surface of the housing body 205a.
[0040]
As a result, by moving the levers 212a and 212b in and out of the X1 and X2 directions, respectively, the light shielding bodies 40a and 40b move in the Y1 and Y2 directions along the respective long holes and relatively in the left and right directions. Moving.
[0041]
15A and 15B are diagrams showing a fourth configuration example of the light shielding body and its driving mechanism, in which FIG. 15A is a plan view and FIG. 15B is a side view. This drive mechanism includes a cam mechanism in addition to the link mechanism as described above.
[0042]
A cam shaft 220 that is movable in the axial direction and rotatable is provided in a side wall of the housing body 205a. Cam followers 221a and 221b to which light shields 40a and 40b are attached are arranged on the cam shaft 220, respectively. The cam followers 221a and 221b are provided with rotation fixed shafts 222a and 222b, respectively, and one end portions of the cam followers 221a and 221b are engaged with a long hole 225a formed in a holding portion 225 formed in the housing body 205a. The rotation of the cam followers 221a and 221b is restricted. Further, the other end portions of the rotation fixed shafts 222a and 222b are engaged with spiral grooves 220a and 220b formed in the cam shaft 220. When the cam shaft 220 is rotated by the knob 220c, each cam follower 221a, 221b is moved along the axial direction.
[0043]
As a result, by moving the cam shaft 220 in the axial direction (arrow X direction), the light shielding bodies 40a and 40b can be moved integrally in the axial direction, and the cam shaft 220 is rotated by the knob 220c. Thus, the light shielding bodies 40a and 40b can be moved closer to and away from each other, and the interval can be changed.
[0044]
According to the light shielding body and its driving mechanism as described above, the pupils of the left and right objective lenses in the stereomicroscope can be uniformly narrowed in the front-rear direction. Since the left and right pupils are evenly narrowed, the left and right images are viewed in a uniform manner, and a stereoscopic effect can be obtained with the left and right parallax that is a feature of the stereomicroscope. In this case, by moving each of the light shields 40a and 40b, the ratio of direct light and diffracted light with respect to the sample can be arbitrarily adjusted, and observation can be performed while continuously changing the contrast. Furthermore, the light can be directly cut by bringing the light shielding bodies 40a and 40b closer, and observation as a dark field is also possible. As described above, since the amount of light incident on the pupil of each objective lens can be freely changed, the contrast can be freely controlled, and the contrast can be further enhanced by adding oblique light, thereby supporting a wide range of specimens. Of course, the drive mechanism described above can also be applied to a normal microscope.
[0045]
Next, a case where another configuration for controlling the shape of the aperture formed in the pupil of the objective lens is applied to a normal microscope will be described.
[0046]
FIG. 16 shows a configuration in which the light intensity is partially controlled with respect to the opening formed in the pupil of the objective lens. As shown in FIG. 1A, an optical member for controlling the intensity of light, for example, an ND (Neutral Density) filter 45, is movably disposed in the vicinity of one light shield 40a. As shown in FIG. 4B, the filter 45 is movable in the direction of the arrow, and is configured to be movable independently of the movement of the light shield 40a.
[0047]
In FIG. 5B, the area where the pupil C is shielded by the light shields 40a and 40b is indicated by diagonal lines, and the area where light passes through the filter 45 is indicated by grid lines. With this configuration, as indicated by the pupil B, regions having different amounts of light can be formed in the pupil of the objective lens (in the pupil B, the portion indicated by the symbol D is an opening, and the lattice indicated by the symbol E) A line part shows the area | region where the light quantity was suppressed by the filter 45 in the opening part). As a result, the amount of illumination light directly incident on the sample is suppressed, and it becomes easy to observe a fine region of the sample with good contrast. Further, by arbitrarily moving the light blocking bodies 40a and 40b and the filter 45, the angle of the illumination light that illuminates the sample is changed, and the ratio of the illumination light directly incident on the objective lens and the diffracted light emitted from the sample is made finer. Can be adjusted.
[0048]
Although the above-described filter 45 is arranged so as to overlap the light shielding body 40a, the degree of freedom of illumination is further increased by separately arranging the light shielding body 40b as shown in FIG. Can do.
[0049]
FIG. 17 shows another configuration example in which the intensity of light is partially controlled with respect to the opening formed in the pupil of the objective lens. In the configuration shown in FIG. 17A, two ND filters 45a and 45b having different dimming ratios are stacked in the vicinity of one light shield 40a, can be moved independently of each other, and can move relative to the light shields 40a and 40b. However, they are arranged so that they can move independently.
[0050]
With this configuration, it is possible to adjust the intensity of light with respect to the opening of the same size, increase the degree of freedom of illumination, and visualize the phase sample and the like, so that the contrast can be adjusted more finely. . Of course, in this configuration as well, the filters 45a and 45b having the same configuration may be disposed on the light shielding body 40b side.
[0051]
In the above configuration, the ND filter is used as a member for adjusting the light intensity. However, the intensity at the opening can be arbitrarily adjusted even by using a polarizing element. For example, as shown in FIG. 17B, a rotatable polarizing plate 46a covering the entire area of the pupil A of the capacitor is disposed adjacent to the light shielding bodies 40a and 40b, and in the vicinity of the light shielding body 40a. The polarizing plate 46b is disposed so as to be movable in the direction of the arrow. As a result, by overlapping the polarizing plate 46b on the polarizing plate 46a and rotating the polarizing plate 46a, the light intensity can be continuously adjusted in the overlapping region, and the contrast of the phase sample can be continuously changed. Can do.
[0052]
Alternatively, the same effect can be obtained by using a liquid crystal panel other than the ND filter and the polarizing plate as described above. That is, by controlling the applied voltage applied to the liquid crystal panel, the shape of the opening formed in the pupil of the objective lens can be changed, and regions with different brightness can be arbitrarily formed in the opening. Further, the above-described ND filter, polarizing element, and liquid crystal element may be arbitrarily combined.
[0053]
In the configuration described above, the condenser lens is configured to include an aperture stop 41 as shown in FIG. Here, when the condenser lens includes the aperture stop 41, control of the aperture formed in the pupil of the objective lens will be described with reference to FIG.
[0054]
The aperture stop 41 is configured to stop the pupil A having the maximum numerical aperture that can be illuminated by the condenser lens 26. For this reason, by adjusting the aperture stop 41 together with the light shields 40a and 40b, the light in the regions G and H can be cut as shown in the figure. That is, by narrowing down the aperture stop 41, the aperture region of the objective lens pupil B can be limited in the longitudinal direction. It is also possible to adjust dark field illumination light that does not directly enter the objective lens. The arrangement of the aperture stop 41 can be applied to all the configuration examples described above.
[0055]
The moving direction of the light shielding bodies 40a and 40b described above is not limited as long as the aperture shape of the pupil of the objective lens can be controlled effectively. For example, as shown in FIGS. 19 (a) and 19 (b), even if each light shielding member is configured to rotate and move with the shafts 40p and 40q extending in the left-right direction as supporting axes, the pupils of the respective objective lenses It is possible to effectively control the opening shape.
[0056]
16 to 19 have been described using a normal microscope as an example, but the optical system shown in each drawing can be similarly applied to a stereomicroscope. The positional relationship between the pupil and the light shielding body in the stereomicroscope is the same as the configuration shown in FIG. 11, and as shown in FIGS. 20 to 25, respectively.
[0057]
26 to 28 are diagrams showing modifications of the light shielding body. These modified examples are applied to a normal microscope.
[0058]
In the configuration shown in FIG. 26, one light shield 40c has an L shape, and the other light shield 40d has a rectangular shape. The light shielding bodies 40c and 40d having such a shape are configured to be movable back and forth and to the left and right, and the light shielding body 40d is further configured to be rotatable in a plane perpendicular to the optical axis. ) To (d), the aperture shape of the pupil of the objective lens, that is, the illumination light directly incident on the objective lens can be continuously adjusted (in each figure, the hatched portion of the pupil C is This is a portion shielded by the respective light shields 40c and 40d). Furthermore, as shown in FIG. 4E, dark field illumination can be performed by shielding only the pupil C. In this case, by partially shielding the pupil A, the amount of light during dark field illumination is also reduced. It can be adjusted continuously and the degree of freedom of observation of the phase sample is improved.
[0059]
FIG. 27 shows a configuration example in which four square light shields 40e are arranged at a position conjugate with (or in the vicinity of) the pupil position of the objective lens. As shown in FIGS. 4A and 4B, each light-shielding body is moved in the front-rear and left-right directions to switch from bright field illumination to oblique illumination and further to dark field illumination while changing the incident angle of illumination light. Further, by configuring each light blocking body 40e to be rotatable or arranging an aperture stop separately, the degree of freedom of illumination is increased and the degree of freedom of observation of the phase sample is improved.
[0060]
Further, in FIG. 28, as shown in FIG. 28A, a rectangular light shielding body 40f in which a quarter circular cutout 40h is formed is arranged at a position conjugate with (or in the vicinity of) the pupil position of the objective lens. A configuration example is shown. As shown in FIG. 5A, when the respective light shields are brought into contact with each other, a light shield having a circular opening formed in the center as a whole is formed, and oblique illumination of the circular opening can be performed. Also, by moving each light shield in the arrow direction, for example, various opening shapes can be realized as shown in FIG.
[0061]
As described above, even if there are two or more light shields or the shape is not rectangular, the aperture shape of the pupil of the objective lens can be arbitrarily controlled, and a transparent phase sample can be visualized. It is possible to adjust the contrast continuously.
[0062]
In the configuration described above, when the area of the pupil of the objective lens is D1, and the area of the opening formed in the pupil of the objective lens by the various light shielding elements is D2, the ratio of D1 and D2 (D2 / D1)
D2 / D1 <0.5 (condition 1)
It is preferable to move each light shield so as to satisfy the above.
[0063]
By satisfying this condition 1, a transparent phase sample or the like can be visualized with good contrast.
[0064]
That is, the ratio (D2 / D1) between D1 and D2 is a ratio of direct light that passes through the specimen and directly enters the objective lens and diffracted light by the specimen, and is a numerical value that indicates the degree of oblique illumination. By satisfying the above conditions, oblique illumination or dark field illumination that captures diffracted light from the sample and suppresses the ratio of direct light can be visualized with high contrast.
[0065]
Further, in the above-described configuration, in order to visualize a transparent phase sample with good contrast, an illumination optical system including a condenser lens that can take a large illumination angle is required, such as oblique illumination and dark field illumination. Furthermore, it is important that the phase specimen can be visualized as the illumination range of the condenser lens is wider, that is, at a low magnification, and the observation efficiency can be improved by widening the observation range.
[0066]
In general, there is a certain relationship between the magnification and numerical aperture of the objective lens, and the magnification and numerical aperture of the objective lens have values as shown in the following table.
[0067]
[Table 1]

[0068]
Therefore, when NA1 is the maximum numerical aperture that can be illuminated by the condenser lens, and NA2 is the numerical aperture of the objective lens that can observe the maximum illumination range of the condenser lens,
NA2 / NA1 <0.6 (condition 2)
It is preferable to provide a transmission illumination optical system including a condenser lens that satisfies
[0069]
By satisfying the condition 2 as described above, in the objective lens capable of observing the widest illumination range, it is possible to sufficiently secure illumination light that has a large illumination angle and does not directly enter the objective lens. As a component of illumination light, an area of oblique illumination light including dark field illumination is sufficiently ensured, and therefore, the degree of freedom of illumination from oblique illumination to dark field illumination by moving each of two or more light shields. Will increase. As a result, the contrast of the transparent phase sample can be continuously changed from the observation of the low magnification objective lens. Further, since the numerical aperture increases as the magnification of the objective lens increases, the area of oblique illumination including dark field illumination decreases as the magnification of the objective lens increases. For this reason, it is important to satisfy Condition 2 not only for observation at a low magnification but also for observation at other magnifications.
[0070]
As shown in FIG. 6, the above-described light shielding body is configured to be disposed at or near the front focal position of the condenser lens, but can be disposed at various positions depending on the design of the optical system of the microscope. is there. An example of such an optical system will be described with reference to FIG.
[0071]
FIG. 29 shows a configuration in which the design of the transmission illumination optical system is changed in the optical system shown in FIG. 6 (the same members as those in FIG. 6 are denoted by the same reference numerals). In this transmission illumination optical system, relay lenses 60 and 61 are disposed between the diffusion plate 22 and the deflection mirror 24 shown in FIG. According to this configuration, the light emitted from the light source 20 is collimated by the collector lens 21 and then forms a primary light source image (image formation position is indicated by the symbol P3) by the relay lens 60. The primary light source image is projected on the front focal position of the condenser lens 26 via the relay lens 61, the deflection mirror 24, and the projection lens 25 (secondary light source image). The stop 23 is a field stop, and the stop 41 functions as an aperture stop.
[0072]
According to such an optical system, the light shielding bodies 40a and 40b having the above-described configuration (the other configurations described above) are disposed at the position P3 of the primary light source image that is a conjugate position with the pupil of the objective lens 31 or in the vicinity thereof. It may be possible to arrange a light shielding body. Also in such a configuration, the effect of oblique illumination or dark field illumination can be obtained by moving each light shield so that the above-described condition 1 is satisfied. When illuminating a low magnification or extremely low magnification region, the condenser lens is removed from the illumination optical path, or the condenser lens used for illumination of 1x or less is configured as an afocal system. In this case, since the position conjugate with the pupil position of the objective lens 31 corresponds to the field stop 23 which is the front focal position of the projection lens 25, the light shielding body having the above-described structure is located at or near the position of the field stop 23. The same effect can be obtained by arranging the movably.
[0073]
Further, in the above-described transmission illumination optical system, the deflection mirror 24 may be configured to be rotatable. The deflection mirror 24 can be rotated by operating the mirror tilt adjustment lever 204 in the case of the stereomicroscope shown in FIG. Thus, by configuring the deflection mirror 24 to be rotatable, the angle of the illumination light with respect to the specimen can be arbitrarily adjusted during oblique illumination or dark field illumination.
[0074]
In the configuration described above, the condenser lens used in the transmission illumination optical system is configured to be switchable according to the magnification of the objective lens. In other words, at least one lens group between the aperture stop of the condenser lens and the sample is configured to be attached or detached or used by switching to another lens group according to the low magnification objective lens and the high magnification objective lens. Has been. In the condenser lens configured as described above, the light shielding member as described above is preferably arranged at or near the pupil position of the condenser lens at the time of low magnification.
[0075]
Thus, the reason why the light shielding body is arranged at or near the pupil position of the condenser lens at the time of low magnification is as follows. That is, the illumination method according to the present invention does not always provide correct information on a sample obtained at high magnification observation with a large numerical aperture, but at low magnification, it is more likely to be a scattering phenomenon due to illumination than a diffraction phenomenon. close. Moreover, in observation at a low magnification, it is important not to focus on resolution but to visualize by changing the contrast continuously.
[0076]
As described above, a light shielding body that controls the aperture formed in the pupil of the objective lens is arranged at the pupil position of the condenser lens at low magnification, so that the phase sample can be visualized at low magnification as described above. The illumination can be continuously changed from the field illumination to the oblique illumination, and further to the dark field illumination, and the contrast of the phase sample can be continuously changed. Furthermore, by using together with a universal condenser which is a condenser lens capable of phase difference observation and differential interference observation at high magnification, it becomes possible to switch each illumination. That is, for observation at low magnification, the illumination method as described above is used to visualize the structure and distribution of the entire phase specimen with good contrast, and for observation at high magnification, the phase difference and differentiation that are conventional observation methods are used. It can also be configured such that the microstructure can be observed using interference.
[0077]
As described above, in the transmission illumination optical system, when using a condenser lens in which at least one lens group between the aperture stop and the specimen is attached or detached according to low magnification or high magnification, or switched to another lens group , When the focal length of the condenser lens at high magnification is F1, and the focal length of the condenser lens at low magnification is F2,
F1 / F2 <0.45 (condition 3)
It is preferable to satisfy the above requirement.
[0078]
By designing the condenser lens so as to satisfy such condition 3, it is possible to perform satisfactory illumination by switching the two condenser lenses from a high magnification to a low magnification, and further to an extremely low magnification region. In particular, in the low-magnification to ultra-low-magnification region, the above-described light-shielding body that controls the aperture shape formed in the pupil of the objective lens can freely change illumination and visualize a transparent phase sample with good contrast. .
[0079]
Next, a preferred configuration example of the condenser lens used in the microscope transmission illumination device of the present invention will be specifically described.
[0080]
(Configuration example 1)
FIG. 30 shows a condenser lens used for high magnification, and the lens system includes lens groups L1, L2, and L3. Further, a special observation turret disk such as a phase difference ring slit, a differential interference prism, a dark field ring slit (not shown) is provided at the aperture stop 70 and the pupil position P1 of the condenser lens. The specimen is placed on the slide glass 72 and placed on the stage surface. The light shielding bodies 74a and 74b configured as described above are movably disposed in the vicinity of the pupil position P1. The configuration of the condenser lens is shown below.
[0081]
[Table 2]

[0082]
According to the condenser lens as described above, the pupil diameter of the condenser lens is sufficiently larger than the pupil diameter of the objective lens on the low magnification side, and a declination illumination component including dark field illumination for irradiating the sample can be secured. As a result, a transparent phase sample etc. can be visualized and the contrast continuously changed by movably placing a light-shielding body that controls the shape of the aperture formed in the pupil of the objective lens near the aperture stop position. Can be made. Further, in addition to the illumination device according to the present invention, the condenser lens can perform phase difference observation, differential interference observation, dark field observation, and the like, and becomes an illumination optical system that can cope with various observation methods. It should be noted that the same effect can be obtained with a configuration in which the light shields 74a and 74b are arranged and moved in the turret disk.
[0083]
(Configuration example 2)
FIG. 31 shows a condenser lens used for high magnification, and the lens system includes lens groups L1, L2, and L3. Further, a special observation turret disk such as a phase difference ring slit, a differential interference prism, a dark field ring slit (not shown) is provided at the aperture stop 70 and the pupil position P1 of the condenser lens. The specimen is placed on the slide glass 72 and placed on the stage surface. In this case, the oil for oil immersion is filled between the lens L3 and the stage. Further, the light shielding bodies 74a and 74b configured as described above are movably disposed in the vicinity of the pupil position P1. The configuration of the condenser lens is shown below.
[0084]
[Table 3]

[0085]
According to the condenser lens as described above, the pupil diameter of the condenser lens is sufficiently larger than the pupil diameter of the objective lens on the low magnification side, and a declination illumination component including dark field illumination for irradiating the sample can be secured. As a result, a transparent phase sample etc. can be visualized and the contrast continuously changed by movably placing a light-shielding body that controls the shape of the aperture formed in the pupil of the objective lens near the aperture stop position. Can be made. Further, in addition to the illumination device according to the present invention, the condenser lens can perform phase difference observation, differential interference observation, dark field observation, and the like, and becomes an illumination optical system that can cope with various observation methods. It should be noted that the same effect can be obtained with a configuration in which the light shields 74a and 74b are arranged and moved in the turret disk.
[0086]
(Configuration example 3)
FIG. 32 shows a condenser lens used at a low magnification, and light-shielding bodies 74a and 74b for controlling the shape of the opening formed in the pupil of the objective lens are movably provided. This condenser lens includes an aperture stop 70 and five lenses including a cemented lens in the lens system. The specimen is placed on the slide glass 72 and placed on the stage surface. The light shields 74a and 74b are disposed in the vicinity of the aperture stop 70 in the vicinity of the pupil position. The configuration of the condenser lens is shown below.
[0087]
[Table 4]

[0088]
According to the condenser lens as described above, the pupil diameter of the condenser lens is sufficiently large with respect to the pupil diameter of the extremely low magnification objective lens, and a declination illumination component including dark field illumination for irradiating the sample can be secured. As a result, a transparent phase sample etc. can be visualized and the contrast continuously changed by movably placing a light-shielding body that controls the shape of the aperture formed in the pupil of the objective lens near the aperture stop position. Can be made. In addition, as described in the prior art, in this magnification region, there is no illumination that changes the contrast by visualizing the phase sample, and according to this configuration example, it is possible to realize illumination that has not existed in the past.
[0089]
(Configuration example 4)
FIG. 33 shows a configuration of a condenser lens in which at least one lens group between the aperture stop and the specimen is used by switching according to high magnification and low magnification. Fig. (A) is a configuration used at high magnification, and Fig. (B) is a configuration used at low magnification.
[0090]
The condenser lens used at the time of high magnification has the same configuration as that shown in FIG. When the magnification is low, the lens groups L2 and L3 move from the illumination optical path, and the lens group L4 is inserted into the illumination optical path instead. In the vicinity of the pupil position P1 at the time of low magnification, light shields 74a and 74b for controlling the opening formed in the pupil of the objective lens are movably disposed.
[0091]
The illumination range at high magnification corresponds to 10 to 100 times, and the illumination range at low magnification corresponds to 1.25 to 4 times. The configuration of the condenser lens is shown below.
[0092]
[Table 5]

[0093]
According to the condenser lens as described above, by arranging the light shielding body in the vicinity of the pupil position at the time of low magnification, the phase sample or the like is visualized and the contrast is continuously changed from 1.25 to 4 times. be able to. As a result, in the extremely low to low magnification region, the phase specimen can be visualized and observed with the low magnification type condenser lens as described above. At high magnification, the phase difference, differential interference, and dark field can be observed. Observations can be made.
[0094]
(Configuration example 5)
FIG. 34 shows a configuration of a condenser lens that is used by switching according to high magnification and low magnification. Fig. (A) is a configuration used at high magnification, and Fig. (B) is a configuration used at low magnification. In this case, the condenser lens used at high magnification is the same as that shown in FIG. 30, and the condenser lens used at low magnification is the same as that shown in FIG. The configuration of the condenser lens is shown below.
[0095]
[Table 6]

[0096]
According to the condenser lens as described above, by arranging the light shielding body in the vicinity of the pupil position at the time of low magnification, the phase sample or the like is visualized and the contrast is continuously changed from 1.25 to 4 times. be able to. Further, the condenser lens at high magnification can be observed by arranging an optical element for phase difference observation and differential interference observation at the pupil position of the condenser lens.
[0097]
As a result, in the extremely low to low magnification region, the phase sample can be visualized and observed with the low magnification type condenser lens as described above. At high magnification, phase difference observation, differential interference observation, and It becomes an illumination optical system that can perform dark field observation and the like and can cope with various observation methods. In addition, since the positions of the light shielding bodies 74a and 74b arranged at the time of low magnification and the pupil position of the condenser lens at the time of high magnification are close, the light shielding bodies 74a and 74b are used in the condenser lens at the time of high magnification, and the objective lens The aperture formed in the pupil can be controlled.
[0098]
The transmission illumination optical system as described above can be used in combination with an epifluorescence microscope (not shown). Unlike the phase difference observation objective lens, it is not necessary to arrange a phase film at the pupil position of the objective lens, so that there is no loss in the objective lens and fluorescence can be observed brightly. In a transparent phase specimen that has been fluorescently stained, the transmission illumination system as described above can be used to visualize with high contrast, and cells and the like that are fluorescently stained by epifluorescence illumination can be observed.
[0099]
Next, another embodiment of the present invention will be described with reference to FIG. FIG. 35 is a diagram showing a schematic configuration of a transmission illumination optical system in a stereomicroscope.
[0100]
The transmission illumination optical system includes a parallel light beam member 82 such as a collector lens that converts light from a light source 80 such as a halogen lamp into a substantially parallel light beam, and a first diffusion plate 83 such as frosted glass that diffuses the light beam from the parallel light beam member 82. A first condensing member 85 such as a convex lens that condenses the diffused light from the first diffusing plate 83, and a second diffusing plate such as ground glass that diffuses the light from the first condensing member 85 86, a deflecting mirror 87 that deflects light from the second diffusion plate 86 upward, and a light such as a convex lens that collects the light from the deflecting mirror 87 and irradiates the specimen 90 on the specimen placing glass 89. A second light collecting member 88.
[0101]
Between the second diffusing plate 86 and the deflecting mirror 87, a first auxiliary convex lens 91 is disposed so as to be detachable from the optical path, and between the mirror 87 and the second condensing member 88, the first auxiliary convex lens 91 is disposed. Two auxiliary convex lenses 92 are detachably arranged. Between the 2nd condensing member 88 and the 2nd auxiliary convex lens 92, the 1st and 2nd light-shielding bodies 95a and 95b comprised similarly to the light-shielding body of embodiment mentioned above are arrange | positioned so that a movement is possible. Has been. Furthermore, between the second diffusing member 86 and the second auxiliary convex lens 91, light shields 95c and 95d having the same configuration are movably disposed.
[0102]
According to the above configuration, the light emitted from the light source 80 is efficiently condensed by the parallel light flux member 82 to be converted into a substantially parallel light beam, and is incident on the first diffusion plate 83. The first diffusion plate 83 serves as a substantially uniform light source having a large area in order to satisfy the illumination field. The light diffused by the first diffusion plate 83 is collected by the first light collecting member 85. The first light collecting member 85 has a function of collecting the light diffused in the diverging direction by the first diffusion plate 85 in the convergence direction effective for illumination.
[0103]
The light incident on the second diffusion plate 86 is further diffused along the convergence direction. The second diffusion plate 86 diffuses light to satisfy the numerical aperture and becomes the final light source. The light diffused by the second diffusing plate 86 is deflected upward by the deflection mirror 87, enters the second light collecting member 88, and illuminates the specimen 90 through the specimen mounting transparent member 89.
[0104]
The first auxiliary convex lens 91 inserted between the second diffusing plate 86 and the deflecting mirror 87 is a high-magnification objective lens having a narrow illumination field of view and a large numerical aperture. Plays a role in increasing usage efficiency. The second auxiliary convex lens 92 inserted between the deflecting mirror 87 and the second condensing member 88 increases the power of the convex lens together with the second condensing member 88 to narrow the illumination field of view. It serves to illuminate the specimen 90 with light having a large angle. That is, since the illumination optical system is switched according to the magnification of the objective lens, observation can be performed under optimum illumination conditions.
[0105]
The high-magnification objective lens has a short focal length, and the pupil conjugate position in the illuminator approaches the second condensing member 88 as much as possible. In general, there is a pupil conjugate position before the position at which the optical axis is turned back. Therefore, the light-shielding bodies 95a, 95b, and 95c, 95d are respectively arranged at those positions, and the brightness stop can be formed by inserting and removing each light-shielding body independently from the optical axis. By obliquely shifting the light shield from the optical axis, oblique illumination is possible.
[0106]
The light shielding bodies 95a and 95b (95c and 95d) described above can be moved by the drive mechanism shown in FIGS. 12 to 15, and the pupils of the left and right objective lenses are moved by the light shielding bodies as shown in FIGS. As shown in FIGS. 20 to 25, both are equally squeezed from the vertical direction. Since the left and right pupils are evenly narrowed, the left and right images are viewed in a uniform manner, and a stereoscopic effect can be naturally obtained with the left and right parallax that is a feature of the stereomicroscope. As in the previous embodiment, by moving the light shield, the ratio of the direct light and the diffracted light incident on the pupil of the objective lens and the diffracted light can be controlled, and the contrast is enhanced or continuously changed. Can be made. That is, a very fine contrast adjustment can be performed on a specimen having a fine structure, and what has been impossible to observe until now can be observed. In addition, since the diaphragm is arranged at a position suitable for high magnification and low magnification, oblique illumination can be performed from high magnification to low magnification. Further, since switching from the low magnification to the high magnification can be realized by adding the lenses 91 and 92, the structure becomes simple and can be constructed at low cost. Furthermore, since two diffuser plates are arranged and their roles are clarified, it is easy to optimally design the optical system, the efficiency is improved, and it is not necessary to use a diffuser plate that has an unnecessarily large diffusion effect.
[0107]
FIG. 36 shows a modification of the configuration shown in FIG. In this modified example, the difference from the configuration shown in FIG. 35 is that the deflection mirror 87 is configured to be rotatable and the light-shielding bodies 95c and 95d on the low magnification side are removed.
[0108]
This is based on the fact that when a fine structure is observed, there is a high demand for observation at a high magnification mainly due to the resolution. Note that, for observation at a low magnification, a large field of view with a sufficient illumination effect (oblique illumination) and a conventional contrast can be obtained by the rotating deflection mirror 87a. As described above, the oblique illumination at a high magnification is performed by the light shields 95a and 95b, and the oblique illumination at a low magnification is performed by the deflection mirror 87a, thereby reducing the cost. In addition, since the deflecting mirror 87a can perform oblique illumination at a medium magnification with insufficient conjugate relation of the pupil position, it is easy to use.
[0109]
The illumination system in the embodiment shown in FIGS. 35 and 36 is an example for satisfying the illumination field of view and satisfying the numerical aperture (pupil) at high magnification and low magnification in the oblique illumination. Therefore, even if the above-described light shielding body is arranged at the pupil position of a known bright field illumination device, sufficient oblique illumination can be performed. However, when performing oblique illumination, in order to fully exhibit its versatility and effects, it is preferable to combine the above illumination system or an optical system having a large illumination field of view and a large numerical aperture.
[0110]
Further, in the illumination optical system shown in the drawing, the first and second diffusion plates 83 and 86 are integrated, the first light collecting member 85 is eliminated, and the lens effect is distributed to each of the first and second diffusion plates. It is also possible to do. Further, instead of inserting the first and second auxiliary convex lenses 91 and 92, the focal lengths of the first and second light condensing members 85 and 88 can be changed, and the position where the auxiliary convex lenses are inserted is also changed. Is possible.
[0111]
Further, the embodiment shown in FIGS. 35 and 36 can be modified as follows.
[0112]
At least two light-shielding bodies are movably disposed at two positions conjugate to the high-magnification pupil position and the low-magnification pupil position of the zoom stereomicroscope. According to such a configuration, optimum oblique illumination can be realized at high magnification and low magnification.
[0113]
The optical system shown in the figure is provided with another deflecting member that deflects the optical axis emitted from the light source upward, and this deflecting member is tilted to tilt the illumination light beam. Thus, the range of the oblique illumination is expanded by combining the obliqueness of the other deflection members.
[0114]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0115]
By controlling the shape of the opening formed in the pupil of the objective lens of the microscope by moving the light shield, the ratio of the intensity of direct light and diffracted light that passes through the sample and enters the objective lens can be adjusted. It becomes possible. As a result, a transparent object such as a phase sample can be visualized and the contrast can be continuously changed, and a sample having various thicknesses and refractive index differences can be optimally illuminated. Moreover, it is not necessary to provide a special objective lens for the microscope.
[0116]
Conventionally, only the bright field illumination method existed in the low magnification region and the extremely low magnification region. However, the illumination method of the present invention visualizes the phase specimen from the low magnification region and the extremely low magnification region, and thereby the entire specimen is visualized. The structure and distribution can be observed. Furthermore, various illuminations can be provided by using the conventional phase difference observation method and differential interference observation method together.
[Brief description of the drawings]
FIGS. 1A to 1D are schematic views of a condenser lens in a general oblique illumination method, and diagrams showing an aperture shape of a pupil formed by each aperture stop.
FIG. 2A is a schematic diagram of a condenser lens in a general dark field illumination method, and FIG. 2B is a diagram showing a shape of a diaphragm.
FIG. 3A is a diagram illustrating a schematic configuration of a conventional transmission illumination apparatus, and FIG. 3B is a diagram illustrating an aperture shape of a pupil of left and right objective lenses.
4A is a diagram showing a schematic configuration of another conventional transmission illumination device, and FIG. 4B is a diagram showing a relationship between pupils and knife edges of left and right objective lenses.
FIG. 5 is a diagram showing the external appearance of a stereomicroscope to which the transmission illumination device of the present invention is applicable.
6 is a diagram schematically showing a configuration of an optical system of the stereomicroscope shown in FIG. 5. FIG.
7A is a diagram schematically illustrating a condenser lens and an objective lens in a bright field illumination state, and FIG. 7B is a diagram illustrating a pupil state at that time.
8A is a diagram schematically showing a light shielding body, a condenser lens, and an objective lens in the optical system shown in FIG. 6, and FIG. 8B is a diagram showing the state of the pupil at that time. .
9A is a diagram showing a state in which the light shield is moved in the configuration shown in FIG. 8, and FIG. 9B is a diagram showing a pupil state at that time.
10A is a diagram showing a state in which the light shield is moved in the configuration shown in FIG. 8, and FIG. 10B is a diagram showing a pupil state at that time.
FIGS. 11A to 11D are diagrams corresponding to FIGS. 7 to 10, respectively, and the positional relationship between the pupil and the light shielding body when the optical system shown in FIG. 6 is applied to a stereomicroscope; FIG.
FIG. 12 is a view showing an example of a driving mechanism of a light shielding body provided in the microscope main body.
FIG. 13 is a diagram illustrating a second configuration example of the light-shielding body driving mechanism.
14A and 14B are diagrams illustrating a third configuration example of a light-shielding body driving mechanism, in which FIG. 14A is a plan view, and FIG.
FIGS. 15A and 15B are diagrams showing a fourth configuration example of a light-shielding body driving mechanism, in which FIG. 15A is a plan view and FIG. 15B is a cross-sectional view taken along line II in FIG.
FIGS. 16A and 16B are diagrams showing a configuration in which the intensity of light is partially controlled with respect to an aperture formed in the pupil of the objective lens, FIG. 16A is a diagram showing an outline of an optical system, and FIG. The figure which shows the relationship between a body and a pupil, (c) is a figure which shows another structural example of a light-shielding body part.
FIG. 17 is a diagram showing another configuration example including (a) and (b) and partially controlling the light intensity with respect to the aperture formed in the pupil of the objective lens.
18A and 18B are diagrams showing another configuration example for controlling the shape of the aperture formed in the pupil of the objective lens. FIG. 18A is a diagram showing an outline of the optical system, and FIG. FIG.
19A and 19B are diagrams showing another configuration example for controlling the shape of the aperture formed in the pupil of the objective lens, where FIG. 19A is a diagram showing an outline of the optical system, and FIG. 19B is a relationship between the light shielding body and the pupil. FIG.
FIG. 20 is a diagram showing a relationship between a light shielding body and a pupil, showing a configuration in which the intensity of light is partially controlled with respect to an opening formed in the pupil of an objective lens in a stereomicroscope.
FIG. 21 is a diagram showing another configuration example of the light shielding part in FIG. 20;
FIG. 22 is a diagram showing another configuration example for partially controlling the light intensity with respect to the opening formed in the pupil of the objective lens.
FIG. 23 is a diagram showing another configuration example for partially controlling the light intensity with respect to the aperture formed in the pupil of the objective lens.
FIGS. 24A and 24B are diagrams showing another configuration example for controlling the shape of the aperture formed in the pupil of the objective lens in the stereomicroscope, FIG. 24A is a diagram showing an outline of the optical system, and FIG. The figure which shows the relationship between a body and a pupil.
FIGS. 25A and 25B are diagrams showing another configuration example for controlling the shape of the aperture formed in the pupil of the objective lens in the stereomicroscope, FIG. 25A is a diagram illustrating an outline of the optical system, and FIG. The figure which shows the relationship of a pupil.
FIGS. 26A and 26B are diagrams showing another configuration example of the light shield, and FIGS. 26A to 28E are diagrams showing examples of positional relationships when two light shields move.
FIGS. 27A and 27B are diagrams illustrating another configuration example of the light shielding body, and FIGS. 27A and 27B are diagrams illustrating an example of a positional relationship when the two light shielding bodies move. FIGS.
FIGS. 28A and 28B are diagrams showing another configuration example of the light shielding body, in which FIG. 28A is a diagram illustrating the configuration of one light shielding body, and FIGS. The figure which shows the example of the positional relationship at the time of doing.
FIG. 29 is a diagram showing another configuration example of the transmission illumination optical system.
FIG. 30 is a diagram showing a configuration of a high-magnification condenser lens used in the transmission illumination optical system of the present invention.
FIG. 31 is a diagram showing a second configuration of the high-magnification condenser lens.
FIG. 32 is a diagram showing a configuration of a low-magnification condenser lens used in the transmission illumination optical system of the present invention.
FIG. 33 shows the configuration of a switchable condenser lens used in a microscope transmission illumination device, where (a) shows the configuration of a high-magnification condenser lens, and (b) shows the configuration of a low-magnification condenser lens. FIG.
FIGS. 34A and 34B show a second configuration of a switchable condenser lens used in a microscope transmission illumination device, in which FIG. 34A shows a configuration of a high-magnification condenser lens, and FIG. 34B shows a low-magnification condenser; The figure which shows the structure of a lens.
FIG. 35 is a diagram showing another embodiment of the present invention.
FIG. 36 is a diagram showing a modification of the embodiment shown in FIG. 29;
[Explanation of symbols]
20 ... Light source
26 ... condenser lens
30 ... Sample
31 ... Objective lens
40, 40b, 40c, 40d, 40e, 40f ... light shield
45, 45a, 45b ... filter
46a, 46b ... Polarizing plate
95a, 95b, 95c, 95d...

Claims (10)

A microscope having a light source, a transmission illumination optical system including a condenser lens for condensing light emitted from the light source and illuminating the sample, and an observation optical system including an objective lens for observing the sample In the transmitted illumination device used,
A shape of an aperture formed in the pupil of the objective lens by being moved in the transmission illumination optical system, being located at a conjugate position or a position near the conjugate with the pupil position of the objective lens. that controls the shape of the open mouth side microscope transmission-illumination apparatus characterized by comprising at least two shading body having a linear portion. A microscope having a light source, a transmission illumination optical system including a condenser lens for condensing light emitted from the light source and illuminating the sample, and an observation optical system including an objective lens for observing the sample In the transmitted illumination device used,
A shape of an aperture formed in the pupil of the objective lens by being moved in the transmission illumination optical system, being located at a conjugate position or a position near the conjugate with the pupil position of the objective lens. A microscope transmission illumination device characterized in that the linear portion has two light shielding bodies whose parallel portions are parallel to each other. The two light shielding members is movable in the same direction, according to claim 1 or 2, characterized in that adjustable distance of the parallel portion of the linear portion of each form, and the positions of the parallel portion Microscope transmission illumination device. At least one optical member that partially controls the light intensity of the aperture formed in the pupil of the objective lens is disposed so as to be movable in a position where the light shielding body is disposed or in a plane near this position. The microscope transmission illumination device according to any one of claims 1 to 3 . The microscope transmission illumination device according to any one of claims 1 to 4 , wherein the condenser lens has an aperture stop, and the light blocking body is disposed in the vicinity of the aperture stop position. When the area of the pupil of the objective lens is D1 and the area of the opening formed in the pupil of the objective lens formed by the light shielding body is D2, D2 / D1 ≦ 0.5 is satisfied. The microscope transmission illumination device according to any one of claims 1 to 5 . NA2 / NA1 <0.6 is satisfied, where NA1 is the maximum numerical aperture that can be illuminated by the condenser lens and NA2 is the numerical aperture of the objective lens that can observe the maximum illumination range of the condenser lens. The microscope transmission illumination device according to any one of claims 1 to 6 .   The condenser lens has an aperture stop, and at least one lens group between the aperture stop and the sample is configured to be attachable / detachable or switchable according to a low magnification and a high magnification. The microscope transmission illumination apparatus according to claim 1, wherein the condenser lens is disposed at or near a pupil position of a condenser lens at a low magnification. The microscope transmission illumination device according to claim 8 , wherein F1 / F2 <0.45 is satisfied, where F1 is a focal length on the high magnification side of the condenser lens and F2 is a focal length on the low magnification side. . The objective lens is used in a stereomicroscope having a pupil position of the objective lens on the left and right sides, and the at least two light shields are moved in a direction orthogonal to a direction parallel to a plane including the left and right optical axes. The microscope transmission illumination device according to any one of claims 1 to 9 , wherein control is performed so that the left and right pupils of the left and right eyes are evenly narrowed .

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