JP2004117402A

JP2004117402A - camera

Info

Publication number: JP2004117402A
Application number: JP2002276370A
Authority: JP
Inventors: Yoshimi Ono; 大野　好美; Katsuhiko Funo; 布野　勝彦
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-09-20
Filing date: 2002-09-20
Publication date: 2004-04-15

Abstract

【課題】本発明は、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させる。
【解決手段】第１回転筒７、第２回転筒１０などが回転させられて、鏡胴３の長さが調整され、変倍光学系２が望遠撮影状態にされるとき、第１回転筒７、第２回転筒１０などと一体となって回転するカム溝筒１９によって、第１遮光枠３０をＣＣＷ方向に付勢させて、第１遮光枠３０に形成されている開口部２８を角度“０”〜“θａ”の範囲で、回転させるとともに、第２遮光枠３６をＣＷ方向に付勢させて、第２遮光枠３６に形成されている開口部２８を角度“０”〜“θｂ”の範囲で、回転させて、レンズ枠２４に形成されている開口部２２の四隅をカットさせる。
【選択図】　　　図１An object of the present invention is to reduce harmful light caused by reflection in a lens barrel or the like and prevent occurrence of flare or the like even when performing wide-angle shooting or telephoto shooting.
When a first rotary cylinder, a second rotary cylinder, and the like are rotated to adjust the length of a lens barrel and a zoom optical system is set to a telephoto shooting state, the first rotary cylinder is rotated. 7. The first light shielding frame 30 is urged in the CCW direction by the cam groove cylinder 19 that rotates integrally with the second rotary cylinder 10 and the like, and the opening 28 formed in the first light shielding frame 30 is angled. While rotating in the range of “0” to “θa”, the second light-shielding frame 36 is urged in the CW direction to open the opening 28 formed in the second light-shielding frame 36 at an angle of “0” to “θb”. Is rotated to cut the four corners of the opening 22 formed in the lens frame 24.
[Selection diagram] Fig. 1

Description

【０００１】
【発明の属する技術分野】
本発明は、変倍光学系を持つカメラに係わり、特に広角撮影を行うときにもまた望遠撮影を行うときにも、フレアが発生しないようにしたカメラに関する。
【０００２】
【従来の技術】
カメラに取り付けられる変倍光学系として、従来、図１２に示すものが知られている。
この図に示す変倍光学系１００は、６枚のレンズ１０１〜１０６によって構成される６群６枚構成の光学系であり、図１３、図１４に示す如くレンズ１０１〜１０４からなる第１群レンズ１０７と、レンズ１０５と１０６からなる第２群レンズ１０８との間隔を変化させて倍率を変更させることにより、広角撮影でも、望遠撮影でも行えるようになっている。
そして、このような変倍光学系１００では、広角撮影時、望遠撮影時に、光軸に入射する光線束（中心光束）、３５ｍｍフィルムに対応するアパーチャサイズが２４×３６のとき、短辺（＝２４）に入射する光線束（短辺光束）、アパーチャサイズが２４×３６のとき、長辺（＝３６）に入射する光線束（長辺光束）、アパーチャサイズが２４×３６のとき、対角に入射する光線束（対角光束）など、撮影に必要な光束（以下、これらを必要光束と呼ぶ）の内側に、各レンズ１０１〜１０６を支持する部材、変倍させるための部材などが入らないように、これら各部材を配置しなければならない。
【０００３】
【発明が解決しようとする課題】
ところで、近年、各レンズ１０１〜１０６などを支持している鏡胴などを小型化させてカメラ全体を小型化させることが多く、鏡胴の先端部分にフードなどを取り付けることが難しい。
このため、変倍光学系１００を望遠にさせて、太陽光などのような強烈な光源側にある被写体を撮影しているとき、強烈な光がファインダ内に入らないようにしているときでも、太陽光がレンズ端面、鏡胴内壁などに反射して、その反射光がフィルムに到達し、フレアが発生してしまうという問題があった。
そこで、このような変倍光学系１００では、図１５に示す如く鏡胴１０９内部のうち、対角光束の外側となる各部分（フレア発生源部分１１０）に凹凸を付けさせるとともに、無反射塗料を塗布させて、反射率を低減させることにより、反射光を拡散させたり、望遠撮影時における短辺光束の外側に有害光カットシート１１１を配置させて有害光束をカットさせたりさせて、フレアの発生を防止させている。
しかしながら、このような変倍光学系１００を使用するときには、図１６に示す如く広角撮影を行うときにも、第１群レンズ１０８と有害光カットシート１１１とがぶつからないように、有害光カットシート１１１を配置させなければならないことから、変倍光学系１００の移動行程が大きいとき、端部１１２に有害光カットシート１１１を配置させることができないのみならず、端部１１３に取り付けた有害光カットシート１１１によって、短辺光束などがカットされないよう、有害光カットシート１１１を小さくしなければならない。
このため、このような変倍光学系１００では、有害光カットシート１１１を使用して、フレアを防止させるようにしても、望遠撮影を行うとき、対角方向からの有害光をカットさせることが難しく、フレアを防止させることができないというという問題があった。
本発明は上記の事情に鑑み、請求項１では、倍率などが変更されたとき、倍率などに対応させて、出射開口形状を変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができるカメラを提供することを目的としている。
【０００４】
また、請求項２では、倍率などが変更されて、望遠撮影状態にされたとき、入射開口の四隅部分をカットさせて、鏡胴内等の反射に起因する有害光を減少させ、フレアなどの発生を防止させることができるカメラを提供することを目的としている。
また、請求項３では、第１回転筒、第２回転筒などが回転させられて、第１直進筒と第２直進筒との位置関係が調整され、変倍光学系の倍率などが変更されたとき、倍率などに対応させて、出射開口形状を機械的に変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができるカメラを提供することを目的としている。
また、請求項４では、第１直進筒と第２直進筒との位置関係が調整されて、変倍光学系の倍率などが変更されたとき、倍率などに対応させて、出射開口形状を機械的に変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができるカメラを提供することを目的としている。
【０００５】
【課題を解決するための手段】
上記の目的を達成するために本発明は、請求項１では、複数のレンズ群によって構成された変倍光学系を持つカメラにおいて、前記変倍光学系を収納する可変長型の鏡胴と、前記変倍光学系を構成している後群レンズの射出面側に配置され、前記変倍光学系の倍率に応じて開口形状を変化させる有害光カット手段とを備えたことを特徴としている。
また、請求項２では、請求項１に記載のカメラにおいて、前記有害光カット手段は、略広角時の開口を持つ二枚の有害光カット部材を持ち、これら各有害光カット部材を相異なる方向へ回転させて、望遠撮影時の有害光をカットさせることを特徴としている。
また、請求項３では、請求項２に記載のカメラにおいて、前記鏡胴は、同心状に配置される複数の回転筒と、同心状に配置され、前記各回転筒が回転させられたとき、光軸方向に移動する複数の直進筒とを有し、前記変倍光学系を変倍させるとき、前記各回転筒のいずれかが回転させられたとき、前記各直進筒によって、前記変倍光学系の各レンズ群の少なくとも、いずれか１つ以上を光軸方向に移動させながら、前記各回転筒のいずれかによって、前記各有害光カット部材を相異なる方向へ回転させることを特徴としている。
また、請求項４では、請求項２に記載のカメラにおいて、前記鏡胴は、同心状に配置された複数の直進筒を有し、前記変倍光学系を変倍させるとき、各直進筒によって、前記変倍光学系の各レンズ群の少なくとも、いずれか１つ以上を光軸方向に移動させながら、各直進筒の移動差によって、前記各有害光カット部材を相異なる方向へ回転させることを特徴としている。
【０００６】
【発明の実施の形態】
以下、本発明を図面に示した実施の形態により詳細に説明する。
図１は本発明によるカメラの一形態で使用される変倍光学系、鏡胴部分の詳細な構成例を示す要部断面図ある。
この図に示すカメラ（鏡胴）１は、指定された倍率で被写体からの光束を集光させる変倍光学系２と、シャッタが押されたとき被写体からの光束を透過させるシャッタ機構などが収納される鏡胴３と、変倍光学系２の出射面側に配置されこの変倍光学系２が変倍されたとき出射面側の開口形状を調整する遮光手段４とを備えており、鏡胴３の長さが調整されて変倍光学系２が望遠撮影状態にされるとき遮光手段４によって出射面側の開口形状を調整して撮影に不要な有害光をカットさせながら、撮影を行わせる。
前記鏡胴３は、筒部材によって構成され、変倍光学系２を構成している第１群レンズ５、被写体からの光束を透過させるシャッタ機構などが取り付けられる第１直進筒６と、この第１直進筒６に回転自在に挿通される第１回転筒７と、変倍光学系２を構成している第２群レンズ１２などが収納され、直線案内部８などによって第１直進筒７にスライド自在に挿入され、第１回転筒７が回転したとき変倍光学系２の出射面側に繰り出される第２直進筒９と、第１回転筒７に回転自在に挿通される第２回転筒１０と、直線案内部１１などによって第２直進筒９にスライド自在に挿入され、第２回転筒１０が回転したとき変倍光学系２の出射面側に繰り出される第３直進筒１３と、第２回転筒１０にスライド自在に挿入される固定筒１４と、第１回転筒７などの内周面側に配置され、図２に示す如く第１回転筒７、第２回転筒１０などが回転させられたとき、第１群レンズ５、第２群レンズ１２の位置を調整する３本の第１群カム溝１５、３本の第２群カム溝１６、第２群カム溝１６に対し、望遠撮影位置で角度“θａ”だけ位相が遅れるように形成され、遮光手段４に回転力を与える第１遮光カム溝１７、第２群カム溝１６に対し、望遠撮影位置で、角度“θｂ”だけ位相が進むように形成され、遮光手段４に回転力を与える第２遮光カム溝１８が形成されたカム溝筒１９と、を備えており、第１回転筒７、第２回転筒１０などが回転させられて、第２直進筒９、第３直進筒１３が繰り出されたとき、第１群レンズ５の位置と、第２群レンズ１２の位置とを調整して、広角撮影、望遠撮影などを行わせながら、遮光手段４を駆動して、出射面側の開口形状を調整し、撮影に不要な有害光をカットさせる。
【０００７】
遮光手段４は、図３に示す如く直進案内部８の端部に固定され、第２群レンズ１２を支持する枠部２０、図４に示す如く枠部２０の外周部分に取り付けられ、第１回転筒７、第２回転筒１０などが回転させられて、カム溝筒１９がＣＣＷ方向（反時計方向）に回転したとき、各第２群カム溝１６によって付勢されて、枠部２０を光軸方向に移動させる３つの駆動軸２１、印刷、塗装、シート材などによって、周辺部分が遮光されて、中央部分に広角撮影に必要な開口部２２が形成された面部２３などによって構成されるレンズ枠２４と、図５に示す如くレンズ枠２４の外周部に回転自在にはめ込まれる３つの係止部２５が形成された枠部２６、枠部２６の外周部分に取り付けられ、第１回転筒７、第２回転筒１０などが回転させられて、カム溝筒１９がＣＣＷ方向に回転したとき、第１遮光カム溝１７によって付勢されて、枠部２６をＣＣＷ方向に回転させる駆動軸２７、印刷、塗装、シート材などによって、周辺部分が遮光されて、中央部分に広角撮影に必要な開口部２８が形成された面部２９などによって構成される第１遮光枠３０と、図６に示す如くレンズ枠２４の外周部に回転自在にはめ込まれる３つの係止部３１が形成された枠部３２、枠部３２の外周部分に取り付けられ、第１回転筒７、第２回転筒１０などが回転させられて、カム溝筒１９がＣＣＷ方向に回転したとき、第２遮光カム溝１８によって付勢されて、枠部３２をＣＷ方向（時計方向）に回転させる駆動軸３３、印刷、塗装、シート材などによって、周辺部分が遮光されて、中央部分に広角撮影に必要な開口部３４が形成された面部３５などによって構成される第２遮光枠３６と、を備えている。
そして、第１回転筒７、第２回転筒１０などがＣＣＷ方向に回転させられ、第１回転筒７、第２回転筒１０などと一体となって回転するカム溝筒１９に形成された各第２群カム溝１６によって、レンズ枠２４に形成された各駆動軸２１が付勢されて、第２群レンズ１２が繰り出され、鏡胴３内に収納されている変倍光学系２が収納状態から望遠撮影状態にされるとき、図７に示す如くカム溝筒１９に形成された第１遮光カム溝１７により、第１遮光枠３０に設けられた駆動軸２７がＣＣＷ方向に回転付勢されて、角度“０”〜“θａ”の範囲で回転させられるとともに、カム溝筒１９に形成された第２遮光カム溝１８により、第２遮光枠３６に設けられた駆動軸３３がＣＷ方向に回転付勢されて、角度“０”〜“θｂ”の範囲で、回転させられる。
これにより、図８に示す如く変倍光学系２の倍率に応じて、レンズ枠２４に形成された開口部２２の各隅部分３７、３８、３９、４０が各々遮光され、望遠撮影時の有害光がカットされ、フレアの発生が防止させられる。
【０００８】
このように、この形態では、第１回転筒７、第２回転筒１０などが回転させられて、鏡胴３の長さが調整され、変倍光学系２が望遠撮影状態にされるとき、第１回転筒７、第２回転筒１０などと一体となって回転するカム溝筒１９によって、第１遮光枠３０をＣＣＷ方向に付勢させて、第１遮光枠３０に形成されている開口部２８を角度“０”〜“θａ”の範囲で回転させるとともに、第２遮光枠３６をＣＷ方向に付勢させて第２遮光枠３６に形成されている開口部２８を角度“０”〜“θｂ”の範囲で回転させるようにしているので、変倍光学系２が望遠撮影状態にされているとき、レンズ枠２４に形成されている開口部２２の四隅を遮光させて、望遠撮影時の有害光をカットさせ、フレアの発生を防止させることができる。
また、上述した形態では、第１回転筒７、第２回転筒１０が回転させられて、鏡胴３の長さが調整され、変倍光学系２が望遠撮影状態にされるとき、第１回転筒７、第２回転筒１０などと一体となったカム溝筒１９を回転させて、第１遮光枠３０をＣＣＷ方向に回転させ、第２遮光枠３６をＣＷ方向に回転させるようにしているが、このようなカム溝筒１９に代えて、図９に示す如く第１群レンズ５が固定された第１直進筒６に対して、回転することなく直進する第２直進筒１３に、望遠撮影位置で、角度“θａ”だけ、ＣＣＷ方向にずれるように第１遮光カム溝４１を形成させるとともに、望遠撮影位置で、角度“θｂ”だけ、ＣＷ方向にずれるように第２遮光カム溝４２を形成させ、図１０に示す如くこれら第１遮光カム溝４１、第２遮光カム溝４２に、第１遮光枠３０の駆動軸２７、第２遮光枠３６の駆動軸３３を各々、はめ込ませるようにしても良い。
このように構成させても、第２直進筒１３が繰り出されて、変倍光学系２が望遠撮影状態にされるとき、図１１に示す如く第１遮光カム溝４１によって第１遮光枠３０をＣＣＷ方向に付勢させて、第１遮光枠３０に形成されている開２８口部２８を角度“０”〜“θａ”の範囲で回転させるとともに、第２遮光カム溝４２によって第２遮光枠３６をＣＷ方向に付勢させて、第２遮光枠３６に形成されている開口部３４を角度“０”〜“θｂ”の範囲で回転させて、レンズ枠２４に形成されている開口部２２の四隅を遮光させ、望遠撮影時の有害光をカットさせ、フレアの発生を防止させることができる。
【０００９】
【発明の効果】
以上説明したように本発明によれば、請求項１のカメラでは、倍率などが変更されたとき、倍率などに対応させて、出射開口形状を変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができる。
また、請求項２のカメラでは、倍率などが変更されて、望遠撮影状態にされたとき、入射開口の四隅部分をカットさせて、鏡胴内等の反射に起因する有害光を減少させ、フレアなどの発生を防止させることができる。
また、請求項３のカメラでは、第１回転筒、第２回転筒などが回転させられて、第１直進筒と第２直進筒との位置関係が調整され、変倍光学系の倍率などが変更されたとき、倍率などに対応させて、出射開口形状を機械的に変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができる。
また、請求項４のカメラでは、第１直進筒と第２直進筒との位置関係が調整されて、変倍光学系の倍率などが変更されたとき、倍率などに対応させて、出射開口形状を機械的に変更させ、広角撮影を行うときにも、また望遠撮影を行うときにも、鏡胴内等の反射に起因する有害光を減少させて、フレアなどの発生を防止させることができる。
【図面の簡単な説明】
【図１】本発明によるカメラの一形態で使用される変倍光学系、鏡胴部分の詳細な構成例を示す要部断面図ある。
【図２】図１に示すカム溝筒の詳細な構成例を示す展開図である。
【図３】図１に示す遮光手段の詳細な構成例を示す要部断面図である。
【図４】図１に示すレンズ枠の詳細な構成例を示す正面図である。
【図５】図１に示す第１遮光枠の詳細な構成例を示す正面図である。
【図６】図１に示す第２遮光枠の詳細な構成例を示す正面図である。
【図７】図１に示す遮光手段の動作例を示す正面図である。
【図８】図１に示す遮光手段の遮光効果例を示す模式図である。
【図９】本発明によるカメラの他の一形態で使用される第２直進筒の詳細な構成例を示す展開図である。
【図１０】図９に示す第２直進筒と、第１遮光枠と、第２遮光枠との関係例を示す正面図である。
【図１１】図９に示す第２直進筒を用いた遮光手段の動作例を示す正面図である。
【図１２】一般的に変倍光学系の一例を示す概略構成図である。
【図１３】図１２に示す変倍光学系の各光束例を示す模式図である。
【図１４】図１２に示す変倍光学系の各光束例を示す模式図である。
【図１５】図１２に示す変倍光学係を使用したカメラで、望遠撮影を行うときの光束例を示す要部断面図である。
【図１６】図１２に示す変倍光学係を使用したカメラで、広角撮影を行うときの光束例を示す要部断面図である。
【符号の説明】
１：カメラ、２：変倍光学系、３：鏡胴、４：遮光手段、５：第１群レンズ、６：第１直進筒、７：第１回転筒、８：直線案内部、９：第２直進筒、１０：第２回転筒、１１：直線案内部、１２：第２群レンズ、１３：第３直進筒、１４：固定筒、１５：第１群カム溝、１６：第２群カム溝、１７：第１遮光カム溝、１８：第２遮光カム溝、１９：カム溝筒、２０：枠部、２１：駆動軸、２２：開口部、２３：面部、２４：レンズ枠、２５：係止部、２６：枠部、２７：駆動軸、２８：開口部、２９：面部、３０：第１遮光枠、３１：係止部、３２：枠部、３３：駆動軸、３４：開口部、３５：面部、３６：第２遮光枠、３７：隅部分、３８：隅部分、３９：隅部分、４０：隅部分、４１：第１遮光カム溝、４２：第２遮光カム溝[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a camera having a variable power optical system, and more particularly to a camera that prevents flare from occurring when performing wide-angle shooting and telephoto shooting.
[0002]
[Prior art]
As a variable power optical system attached to a camera, the one shown in FIG. 12 is conventionally known.
The variable power optical system 100 shown in this figure is an optical system having six groups and six lenses composed of six lenses 101 to 106, and a first group composed of lenses 101 to 104 as shown in FIGS. By changing the magnification by changing the distance between the lens 107 and the second group lens 108 including the lenses 105 and 106, wide-angle shooting and telephoto shooting can be performed.
In such a variable power optical system 100, at the time of wide-angle shooting or telephoto shooting, when the light beam (center light beam) incident on the optical axis and the aperture size corresponding to the 35 mm film are 24 × 36, the short side (= 24), a light beam (short side light beam) incident on the long side (= 36) when the aperture size is 24 × 36, a light beam (long side light beam) incident on the long side (= 36), and a diagonal when the aperture size is 24 × 36 A member for supporting each of the lenses 101 to 106, a member for changing the magnification, and the like are inserted inside a light beam necessary for photographing (hereinafter, these are referred to as necessary light beams) such as a light beam (diagonal light beam) incident on the camera. Each of these members must be arranged so that they do not exist.
[0003]
[Problems to be solved by the invention]
By the way, in recent years, the size of the entire camera is often reduced by reducing the size of the lens barrel supporting the lenses 101 to 106 and the like, and it is difficult to attach a hood or the like to the tip of the lens barrel.
For this reason, even when the variable-magnification optical system 100 is telephoto and an object on the side of an intense light source such as sunlight is being photographed, even when intense light is prevented from entering the viewfinder, There is a problem in that sunlight is reflected on the lens end face, the inner wall of the lens barrel, and the like, and the reflected light reaches the film, causing flare.
Therefore, in such a variable power optical system 100, as shown in FIG. 15, in the inside of the lens barrel 109, each portion (flare source portion 110) outside the diagonal light beam is provided with irregularities, Is applied to reduce the reflectance, thereby diffusing the reflected light, or disposing the harmful light cut sheet 111 outside the short-side luminous flux during telephoto shooting to cut the harmful luminous flux, thereby reducing the flare. The occurrence is prevented.
However, when such a variable power optical system 100 is used, the harmful light cut sheet 111 does not hit the first group lens 108 and the harmful light cut sheet 111 even when performing wide-angle shooting as shown in FIG. Since it is necessary to dispose the harmful light cut sheet 111 attached to the end 113, the harmful light cut sheet 111 attached to the end 113 cannot be disposed when the moving distance of the variable power optical system 100 is large. The harmful light cut sheet 111 must be made smaller so that the short side light beam and the like are not cut by the sheet 111.
Therefore, in such a variable power optical system 100, even when the harmful light cut sheet 111 is used to prevent flare, harmful light from the diagonal direction can be cut off when performing telephoto shooting. There was a problem that it was difficult to prevent flare.
In view of the above circumstances, the present invention is directed to claim 1, wherein when the magnification or the like is changed, the exit aperture shape is changed in accordance with the magnification or the like, when performing wide-angle shooting, and also when performing telephoto shooting. Another object of the present invention is to provide a camera capable of reducing harmful light due to reflection in a lens barrel or the like and preventing occurrence of flare or the like.
[0004]
According to the second aspect, when telephoto shooting is performed by changing the magnification or the like, the four corners of the entrance aperture are cut to reduce harmful light due to reflection in the lens barrel or the like, and to reduce flare and the like. It is an object of the present invention to provide a camera capable of preventing the occurrence.
According to the third aspect, the first rotary cylinder, the second rotary cylinder, and the like are rotated to adjust the positional relationship between the first and second linear barrels, and to change the magnification of the variable power optical system. , The exit aperture shape is mechanically changed according to the magnification, etc., to reduce harmful light caused by reflection inside the lens barrel when performing wide-angle shooting or telephoto shooting. It is another object of the present invention to provide a camera capable of preventing occurrence of flare and the like.
According to a fourth aspect of the present invention, when the positional relationship between the first rectilinear barrel and the second rectilinear barrel is adjusted and the magnification of the variable power optical system is changed, the exit aperture shape is mechanically changed according to the magnification or the like. A camera that can reduce harmful light caused by reflections inside the lens barrel and prevent flare when performing wide-angle shooting or telephoto shooting. It is intended to provide.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in a camera having a variable power optical system configured by a plurality of lens groups, a variable length lens barrel that houses the variable power optical system, And a harmful light cutting unit that is arranged on the exit surface side of the rear lens group that constitutes the variable power optical system and that changes an aperture shape according to the magnification of the variable power optical system.
According to a second aspect of the present invention, in the camera according to the first aspect, the harmful light cutting means has two harmful light cutting members having an opening at a substantially wide angle, and the harmful light cutting members are moved in different directions. It is characterized in that the harmful light at the time of telephoto shooting is cut by turning to.
According to a third aspect, in the camera according to the second aspect, the lens barrel is arranged concentrically with a plurality of rotating cylinders, and when each of the rotating cylinders is rotated, A plurality of rectilinear barrels that move in the optical axis direction, and when changing the magnification of the variable power optical system, when any of the rotating cylinders is rotated, the respective rectilinear barrels cause While moving at least one of the lens groups of the system in the optical axis direction, the harmful light cutting member is rotated in a different direction by one of the rotary cylinders.
According to a fourth aspect of the present invention, in the camera according to the second aspect, the lens barrel has a plurality of straight-moving barrels arranged concentrically, and when the variable-magnification optical system is changed in magnification, each of the straight-moving barrels is used. While moving at least one or more of the lens groups of the variable power optical system in the optical axis direction, the harmful light cutting members are rotated in different directions by the difference in movement of the rectilinear barrels. Features.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is a sectional view of a main part showing a detailed configuration example of a variable power optical system and a lens barrel used in one embodiment of the camera according to the present invention.
The camera (barrel) 1 shown in FIG. 1 houses a variable magnification optical system 2 for condensing a light beam from a subject at a specified magnification, a shutter mechanism for transmitting the light beam from the subject when a shutter is pressed, and the like. A lens barrel 3 which is disposed on a light exit surface side of the variable power optical system 2 and a light shielding means 4 which adjusts an opening shape on the light exit surface side when the variable power optical system 2 is scaled. When the length of the barrel 3 is adjusted and the variable power optical system 2 is set to the telephoto shooting state, the shooting is performed while the harmful light unnecessary for the shooting is cut by adjusting the opening shape on the exit surface side by the light shielding means 4. Let
The lens barrel 3 is formed of a cylindrical member, and includes a first group lens 5 that forms the variable power optical system 2, a first rectilinear barrel 6 to which a shutter mechanism for transmitting a light beam from a subject, and the like are attached. A first rotary cylinder 7 rotatably inserted into the first linear cylinder 6 and a second group lens 12 constituting the variable power optical system 2 are housed in the first linear cylinder 7 and the like. A second rectilinear barrel 9 that is slidably inserted and is fed to the exit surface side of the variable power optical system 2 when the first rotary barrel 7 rotates, and a second rotary barrel that is rotatably inserted into the first rotary barrel 7 A third rectilinear barrel 13 slidably inserted into the second rectilinear barrel 9 by the linear guide portion 11 or the like and extended to the exit surface side of the variable power optical system 2 when the second rotary barrel 10 rotates; A fixed cylinder 14 slidably inserted into the two-rotation cylinder 10; When the first rotary cylinder 7 and the second rotary cylinder 10 are rotated as shown in FIG. 2, the first group lens 5 and the second group lens 12 are disposed on the inner peripheral surface side of the cylinder 7 and the like. The three first group cam grooves 15 to be adjusted, the three second group cam grooves 16, and the second group cam grooves 16 are formed such that their phases are delayed by an angle “θa” at the telephoto shooting position. The first light-blocking cam groove 17 and the second group cam groove 16 that apply a rotational force to the light-shielding means 4 are formed so that the phase advances by an angle “θb” at the telephoto shooting position. A cam groove tube 19 in which a light-shielding cam groove 18 is formed. The first rotary tube 7, the second rotary tube 10, and the like are rotated, and the second straight barrel 9 and the third straight barrel 13 are extended. When the camera is moved, the position of the first group lens 5 and the position of the second group lens 12 are adjusted so that wide-angle shooting and telephoto shooting are performed. While performed etc., by driving the light shielding means 4 adjusts the opening shape of the emission surface side, thereby cutting unnecessary harmful light photography.
[0007]
The light-blocking means 4 is fixed to an end of the straight guide unit 8 as shown in FIG. 3 and is attached to the frame 20 for supporting the second group lens 12 and to the outer periphery of the frame 20 as shown in FIG. When the rotary cylinder 7, the second rotary cylinder 10, and the like are rotated, and the cam groove cylinder 19 rotates in the CCW direction (counterclockwise), the frame group 20 is urged by the second group cam grooves 16 and A peripheral portion is shielded by three drive shafts 21 to be moved in the optical axis direction, printing, painting, sheet material and the like, and a central portion is provided with a surface portion 23 having an opening 22 necessary for wide-angle shooting. A lens frame 24, a frame portion 26 having three locking portions 25 rotatably fitted to the outer peripheral portion of the lens frame 24 as shown in FIG. 5, and a first rotary cylinder attached to the outer peripheral portion of the frame portion 26. 7, the second rotary cylinder 10 and the like are rotated, When the cylinder 19 rotates in the CCW direction, the peripheral portion is shielded by the drive shaft 27 that is urged by the first light shielding cam groove 17 and rotates the frame 26 in the CCW direction, printing, painting, sheet material, and the like. A first light-shielding frame 30 constituted by a surface portion 29 having an opening 28 required for wide-angle photographing at a central portion, and three members rotatably fitted to the outer peripheral portion of the lens frame 24 as shown in FIG. When the cam groove cylinder 19 is rotated in the CCW direction when the first rotary cylinder 7, the second rotary cylinder 10, and the like are rotated by being attached to the frame part 32 in which the stop part 31 is formed and the outer peripheral part of the frame part 32. The peripheral portion is shielded from light by the drive shaft 33 urged by the second light shielding cam groove 18 to rotate the frame portion 32 in the CW direction (clockwise), printing, painting, sheet material, etc., and the central portion is wide-angled. Opening required for shooting And a, a second light shielding frame 36 composed of such surface part 35 which part 34 is formed.
Then, the first rotary cylinder 7, the second rotary cylinder 10 and the like are rotated in the CCW direction, and each of the cam groove cylinders 19 formed integrally with the first rotary cylinder 7 and the second rotary cylinder 10 and the like is rotated. Each drive shaft 21 formed on the lens frame 24 is urged by the second group cam groove 16, and the second group lens 12 is extended, and the variable power optical system 2 housed in the lens barrel 3 is housed. When the state is changed to the telephoto shooting state, the drive shaft 27 provided on the first light-shielding frame 30 is urged to rotate in the CCW direction by the first light-shielding cam groove 17 formed in the cam groove tube 19 as shown in FIG. Then, the drive shaft 33 provided in the second light-shielding frame 36 is rotated in the CW direction by the second light-shielding cam groove 18 formed in the cam groove tube 19 while being rotated in the range of the angle “0” to “θa”. And is rotated in the range of angles “0” to “θb”. You.
As a result, the corners 37, 38, 39, and 40 of the opening 22 formed in the lens frame 24 are shielded from light in accordance with the magnification of the variable power optical system 2 as shown in FIG. Light is cut off and flare is prevented from occurring.
[0008]
As described above, in this embodiment, when the first rotary barrel 7, the second rotary barrel 10, and the like are rotated, the length of the lens barrel 3 is adjusted, and the variable power optical system 2 is set to the telephoto shooting state, The first light shielding frame 30 is urged in the CCW direction by the cam groove cylinder 19 that rotates integrally with the first rotary cylinder 7, the second rotary cylinder 10, and the like. The portion 28 is rotated in the range of the angle “0” to “θa”, and the second light shielding frame 36 is urged in the CW direction so that the opening 28 formed in the second light shielding frame 36 has the angle “0” to “θa”. When the variable magnification optical system 2 is in the telephoto shooting state, the four corners of the opening 22 formed in the lens frame 24 are shielded from light during the telephoto shooting. Harmful light can be cut off and flare can be prevented.
In the above-described embodiment, when the first rotary barrel 7 and the second rotary barrel 10 are rotated to adjust the length of the lens barrel 3 and the zoom optical system 2 is set to the telephoto shooting state, the first rotary barrel 7 and the second rotary barrel 10 are set to the first position. By rotating the cam groove cylinder 19 integrated with the rotating cylinder 7, the second rotating cylinder 10, and the like, the first light shielding frame 30 is rotated in the CCW direction, and the second light shielding frame 36 is rotated in the CW direction. However, instead of such a cam groove cylinder 19, as shown in FIG. 9, a second rectilinear cylinder 13 which moves straight without rotating with respect to the first rectilinear cylinder 6 to which the first group lens 5 is fixed, The first light shielding cam groove 41 is formed so as to be shifted in the CCW direction by an angle “θa” at the telephoto shooting position, and the second light shielding cam groove is shifted in the CW direction by an angle “θb” at the telephoto shooting position. 42, the first light shielding cam groove 41 and the second light shielding cam groove 41 are formed as shown in FIG. The drive shaft 27 of the first light-shielding frame 30 and the drive shaft 33 of the second light-shielding frame 36 may be fitted into the cam grooves 42, respectively.
Even with this configuration, when the second rectilinear barrel 13 is extended and the variable magnification optical system 2 is set to the telephoto shooting state, the first light shielding frame 30 is formed by the first light shielding cam groove 41 as shown in FIG. It is urged in the CCW direction to rotate the opening 28 formed in the first light-shielding frame 30 in the range of angles “0” to “θa”, and the second light-shielding cam groove 42 to rotate the second light-shielding frame 42. The opening 36 formed in the lens frame 24 is rotated by urging the opening 36 in the CW direction to rotate the opening 34 formed in the second light shielding frame 36 in the range of the angle “0” to “θb”. The four corners can be shielded, harmful light during telephoto shooting can be cut, and flare can be prevented.
[0009]
【The invention's effect】
As described above, according to the present invention, when the magnification or the like is changed, the exit aperture shape is changed in accordance with the magnification or the like to perform wide-angle photographing. Even when photographing, it is possible to reduce harmful light caused by reflection in the lens barrel or the like, thereby preventing occurrence of flare or the like.
Further, in the camera according to the second aspect, when the magnification or the like is changed and telephoto shooting is performed, the four corners of the entrance aperture are cut to reduce harmful light due to reflection inside the lens barrel or the like, thereby reducing flare. Can be prevented from occurring.
Further, in the camera according to the third aspect, the first rotary barrel, the second rotary barrel, and the like are rotated to adjust the positional relationship between the first straight barrel and the second straight barrel, and the magnification of the variable power optical system is adjusted. When changed, the exit aperture shape is mechanically changed in accordance with the magnification, etc., and harmful light caused by reflection inside the lens barrel, etc., when performing wide-angle shooting or telephoto shooting. And the occurrence of flare and the like can be prevented.
Further, in the camera according to the fourth aspect, when the positional relationship between the first rectilinear barrel and the second rectilinear barrel is adjusted and the magnification of the variable power optical system is changed, the shape of the exit aperture is adjusted in accordance with the magnification. When performing wide-angle shooting or telephoto shooting, it is possible to reduce harmful light caused by reflection in the lens barrel and the like, thereby preventing the occurrence of flare and the like. .
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part showing a detailed configuration example of a variable power optical system and a lens barrel used in an embodiment of a camera according to the present invention.
FIG. 2 is a developed view showing a detailed configuration example of the cam groove cylinder shown in FIG.
FIG. 3 is a sectional view of a principal part showing a detailed configuration example of a light shielding unit shown in FIG. 1;
FIG. 4 is a front view showing a detailed configuration example of the lens frame shown in FIG. 1;
FIG. 5 is a front view showing a detailed configuration example of a first light shielding frame shown in FIG. 1;
FIG. 6 is a front view showing a detailed configuration example of a second light shielding frame shown in FIG. 1;
FIG. 7 is a front view showing an operation example of the light shielding means shown in FIG.
FIG. 8 is a schematic diagram showing an example of a light shielding effect of the light shielding unit shown in FIG.
FIG. 9 is a developed view showing a detailed configuration example of a second rectilinear barrel used in another embodiment of the camera according to the present invention.
FIG. 10 is a front view showing a relational example of a second rectilinear barrel, a first light shielding frame, and a second light shielding frame shown in FIG.
FIG. 11 is a front view showing an operation example of the light shielding means using the second rectilinear barrel shown in FIG.
FIG. 12 is a schematic configuration diagram generally illustrating an example of a variable power optical system.
13 is a schematic diagram showing an example of each light beam of the variable power optical system shown in FIG.
14 is a schematic diagram showing an example of each light beam of the variable power optical system shown in FIG.
15 is a cross-sectional view of a main part showing an example of a light beam when performing telephoto shooting with a camera using the variable power optical system shown in FIG.
16 is a cross-sectional view of a main part showing an example of a light beam when performing wide-angle shooting with a camera using the variable power optical system shown in FIG.
[Explanation of symbols]
1: camera, 2: variable power optical system, 3: lens barrel, 4: light blocking means, 5: first group lens, 6: first rectilinear barrel, 7: first rotary barrel, 8: linear guide, 9: Second straight barrel, 10: second rotary barrel, 11: linear guide portion, 12: second group lens, 13: third straight barrel, 14: fixed barrel, 15: first group cam groove, 16: second group Cam groove, 17: first light shielding cam groove, 18: second light shielding cam groove, 19: cam groove cylinder, 20: frame, 21: drive shaft, 22: opening, 23: surface, 24: lens frame, 25 : Locking portion, 26: frame portion, 27: drive shaft, 28: opening portion, 29: surface portion, 30: first light shielding frame, 31: locking portion, 32: frame portion, 33: drive shaft, 34: opening Part, 35: surface part, 36: second light shielding frame, 37: corner part, 38: corner part, 39: corner part, 40: corner part, 41: first light shielding cam groove, 42: second light shielding cam groove

Claims

In a camera having a variable power optical system composed of a plurality of lens groups,
A variable-length lens barrel that houses the variable power optical system,
Harmful light cutting means arranged on the exit surface side of the rear group lens constituting the variable power optical system, and changing an aperture shape according to the magnification of the variable power optical system. camera.

The camera according to claim 1,
The harmful light cutting means has two harmful light cutting members having an opening at a substantially wide angle, and the harmful light cutting members are rotated in different directions to cut harmful light during telephoto shooting. And the camera.

The camera according to claim 2,
The lens barrel has a plurality of concentrically arranged rotating cylinders and a plurality of rectilinearly arranged cylinders which are concentrically arranged and move in the optical axis direction when each of the rotating cylinders is rotated. When any one of the rotary barrels is rotated by changing the magnification of the system, at least one or more of the lens groups of the variable power optical system is moved in the optical axis direction by the straight-moving barrel, and the rotation is performed. A camera, wherein each of the harmful light cutting members is rotated in a different direction by any one of the cylinders.

The camera according to claim 2,
The lens barrel has a plurality of linearly-moving barrels arranged concentrically, and when varying the magnification of the variable-magnification optical system, at least one of the lens groups of the variable-magnification optical system is controlled by each of the linearly-moving barrels. A camera characterized in that each of the harmful light cutting members is rotated in a different direction by a movement difference of each rectilinear cylinder while being moved in an optical axis direction.