JPS5888709A - Optical system for focusing detection - Google Patents
Optical system for focusing detectionInfo
- Publication number
- JPS5888709A JPS5888709A JP18818281A JP18818281A JPS5888709A JP S5888709 A JPS5888709 A JP S5888709A JP 18818281 A JP18818281 A JP 18818281A JP 18818281 A JP18818281 A JP 18818281A JP S5888709 A JPS5888709 A JP S5888709A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- imaging
- optical system
- focus detection
- photographic lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/34—Systems for automatic generation of focusing signals using different areas in a pupil plane
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は撮影レンズ等の焦点検出用光学系に係 ゛す
、特に−眼レフレックスカメラにおいて撮影レンズを通
過してきた光束を用いて焦点検出を行う光学系に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical system for detecting a focus such as a photographic lens, and particularly relates to an optical system for detecting a focus using a light flux that has passed through a photographic lens in an eye reflex camera. be.
従来より一眼し７レツクスカメラにおいて、撮影レンズ
を通過してきた光束を用いて焦点検出を行う所謂Ｔ Ｔ
Ｌ方式の焦点検出用光学系は種々提案されてきている
。これらのＴＴＬ方式の焦点検出用光学系として撮影レ
ンズの焦点面後方に撮影レンズの光軸に対して対称に２
つの結像レンズ（以下「再結像光学系」という。）を配
置し、撮影レンズによってできる物体像の光軸上の結像
位ヘの結像位置の変化として結像する所謂２次結像方式
の焦点検出用光学系がある。この２次結像方式の焦点検
出用光学系によれば、撮影レンズの焦点検出を再結像光
学系によって光軸と垂直方向にできる２つの物体像の結
像位置を複数の検出素子よりなる焦点検出器を用いて、
その焦点検出器からの信号出力を用いて行うことができ
る。２次結像方式の焦点検出用光学系は従来の撮影レン
ズに精度が良く又焦点外れのときでも前ピンであるか後
ピンであるかの判断が容易にかつその程度まで容易に判
断することができる等の利点がある。しかしながら２次
結像方式の焦点検出用光学系は撮影レンズの焦点面後方
に再結像光学系を配置しなければならないために光学系
が大型化し、カメラ内部に組み込む際に困難となること
、撮影レンズを通過した光束が再結像光学系に効率良く
入射するように再結像光学系の入射瞳位置を撮影レンズ
の瞳位置近傍と共役となるように光学部材を撮影レンズ
と再結像光学系との間に配置しなければならないこと、
更に撮影レンズの絞りを小さく絞ったときでも再結像光
学系に十分光束が入射するような光学配置とすること等
の問題点があった。Conventionally, in single-lens 7-lens cameras, focus detection is performed using the light flux that has passed through the photographic lens.
Various L-type focus detection optical systems have been proposed. As the focus detection optical system of these TTL methods, there are two
Two imaging lenses (hereinafter referred to as "re-imaging optical system") are arranged, and the so-called secondary imaging is formed by changing the imaging position of the object image formed by the photographing lens to the imaging position on the optical axis. There is a type of focus detection optical system. According to this secondary imaging type focus detection optical system, the focus detection of the photographing lens is made perpendicular to the optical axis by the reimaging optical system, and the imaging position of two object images is determined by a plurality of detection elements. Using a focus detector,
This can be done using the signal output from the focus detector. The secondary imaging type focus detection optical system has better accuracy than conventional photographic lenses, and even when the object is out of focus, it is easy to judge whether the focus is in the front or the back, and to that extent it is easy to judge. There are advantages such as being able to However, the secondary imaging type focus detection optical system requires a re-imaging optical system to be placed behind the focal plane of the photographic lens, which increases the size of the optical system and makes it difficult to incorporate it into the camera. The optical member is re-imaged with the photographing lens so that the entrance pupil position of the re-imaging optical system is conjugate with the vicinity of the pupil position of the photographing lens so that the light flux passing through the photographing lens efficiently enters the re-imaging optical system. must be placed between the optical system,
Furthermore, there are problems in that the optical arrangement must be such that a sufficient amount of light is incident on the re-imaging optical system even when the aperture of the photographic lens is narrowed down.
本発明は小型でしかも撮影レンズを通過した光束を効率
的に用い、かつ撮影レンズの絞りを小さき
く絞っても精度良く焦点検出６行うことのできる２次結
像方式の焦点検出用光学系の提供を目的とするものであ
る。The present invention provides a secondary imaging type focus detection optical system that is compact, efficiently uses the light flux that has passed through the photographic lens, and can perform focus detection6 with high precision even when the aperture of the photographic lens is narrowed down. It is intended for the purpose of providing.
本発明の目的を達成するための焦点検出用光学系の特徴
は、撮影レンズの焦点面近傍にフィールドレンズを配置
し、前記撮影レンズによる物体像の光軸方向の結像位置
に応じて、結像位置が光軸と垂直方向に変化するように
光軸を挾んで２つの結像レンズを並べた再結像光学系を
前記フィールドレンズの後方に配置し、前記再結像光学
系の２つの結像レンズの各々の焦点位置に物体像の結像
状態を検出するためのｉ数の素子より成る焦点検出器を
配置し、該２つの焦点検出器からの信号出力を用いて前
記撮影レンズの合焦状態を検出する焦点検出用光学系に
おいて、前記結像レンズはレンズの一部を直線状に切断
除去した少なくとも１枚のレンズ片からなり、前記再結
像光学系は前記結像レンズの切断線に沿って貼合わせ若
しくは一体成形し若しくは近接させて配置したものから
なり、前記フィールｌ“レンズは前記結像レンズの切断
線の長さを直径とする円を前記撮影レンズの瞳位置近傍
でかつ瞳径内に結像する屈折力を有していることである
。A feature of the focus detection optical system for achieving the object of the present invention is that a field lens is disposed near the focal plane of the photographic lens, and the focus detection optical system is configured to form a field lens in the vicinity of the focal plane of the photographic lens, and to adjust the focus according to the imaging position of the object image by the photographic lens in the optical axis direction. A re-imaging optical system in which two imaging lenses are arranged with the optical axis in between so that the image position changes in a direction perpendicular to the optical axis is disposed behind the field lens; A focus detector consisting of i number of elements for detecting the imaging state of the object image is arranged at each focal position of the imaging lens, and the signal output from the two focus detectors is used to detect the imaging lens. In the focus detection optical system for detecting the in-focus state, the imaging lens is made up of at least one lens piece obtained by cutting a part of the lens in a straight line, and the re-imaging optical system is configured to The feel l'lens is formed by pasting or integrally molding along the cutting line, or placing them close to each other, and the feel l' lens has a circle whose diameter is the length of the cutting line of the imaging lens near the pupil position of the photographing lens. It has the refractive power to form an image within the pupil diameter.
次に本発明の実施例について詳述する。Next, embodiments of the present invention will be described in detail.
第１図は従来の２次結像方式の焦点検出用光学系の一部
分の概略図である。１は撮影レンズ、２は撮影レンズの
絞り、５は撮影レンズ１の焦点面８近傍に配置されたフ
ィールドレンズ、４は再結像光学系でフィールドレンズ
乙の後方に撮影レンズ１の光軸９に対称に２つの結像レ
ンズ４□４３を配置したものである。５は焦点検出器で
光軸９と垂ＴＫ方向に配された複数の素子よりなる２つ
の光電１変換素子５１．５ｇを各々結像レンズ４ｘ、４
ｇの焦点位置に配置したものである。撮影レンズ１の結
像面が予定された焦点面８上にあるとき、即ち合焦状態
にあるときは再結像光学系４によって光軸９上の物体像
点１０は各々光電変換素子５１．５ｇの所定位置８１．
８ａ上に結像されるようになっている。そして撮影レン
ズ１が合焦状態にあるか否かを２つの光電変換素子５ｘ
、５ｍの出力を比較して行うことができる。例えば前ピ
ン状態にあれば撮影レンズ１による物体像は焦点面８よ
り撮影レンズ１側に結像されているから、再結像レンズ
４により物体像は各々光軸９の方向即ち矢印で示す方向
に結像することになるから、光電変換素子５１．５ｍか
らの出力状態を比較すれば撮影レンズ１０合焦状態を容
易に検出することができる。結像レンズ４１．４鷹の入
射瞳７ｚ、７ｍはフィールドレンズ５により撮影レンズ
１の瞳位置２ｏ近傍と共役になっている。即ち同図の点
線で示すように結像レンズ４ｚ、４ｎの人、射瞳７１，
７寓は撮影レンズ１の瞳面上に円形６ｚ、６寓のように
フィールドレンズ６により結像されている。FIG. 1 is a schematic diagram of a portion of a conventional secondary imaging type focus detection optical system. 1 is a photographic lens, 2 is an aperture of the photographic lens, 5 is a field lens placed near the focal plane 8 of the photographic lens 1, and 4 is a re-imaging optical system with an optical axis 9 of the photographic lens 1 behind the field lens B. Two imaging lenses 4□43 are arranged symmetrically. 5 is a focus detector, and two photoelectric conversion elements 51.5g each consisting of a plurality of elements arranged in the optical axis 9 and the vertical TK direction are connected to imaging lenses 4x and 4, respectively.
It is placed at the focal point of g. When the imaging plane of the photographing lens 1 is on a predetermined focal plane 8, that is, when in focus, the re-imaging optical system 4 converts object image points 10 on the optical axis 9 into photoelectric conversion elements 51. 5g predetermined position 81.
The image is formed on 8a. Then, two photoelectric conversion elements 5x detect whether or not the photographing lens 1 is in focus.
, 5m can be compared. For example, in the front focus state, the object image by the photographing lens 1 is focused on the photographing lens 1 side from the focal plane 8, so the object image is formed by the re-imaging lens 4 in the direction of the optical axis 9, that is, in the direction indicated by the arrow. Therefore, the in-focus state of the photographic lens 10 can be easily detected by comparing the output states from the photoelectric conversion element 51.5m. The entrance pupils 7z and 7m of the imaging lens 41.4 are conjugated with the vicinity of the pupil position 2o of the photographic lens 1 by the field lens 5. That is, as shown by the dotted lines in the figure, the imaging lenses 4z and 4n, the exit pupils 71,
7 is formed into a circular image 6z on the pupil plane of the photographing lens 1 by the field lens 6 like 6.
第２図は第１図に示す結像レンズ４ｘ、／ｂが各々分離
して再結像光学系を構成しているときの撮影レンズ１の
瞳径２１に対して結像レンズ４１．４１１の入射ｍ ７
ｘ、 ７ｓが各々実線で示すような円６１．６ｚの如く
結像する状態を示している。同図より明らかのように撮
影レンズ１の絞り径を小さくしていくと結像レンＸ”４
１１４１には点線で示す円６ｓと実線で示す円６ｚ、
６ｇとの重なった部分を通過する光束しか入射しなくな
る。これは光電変換素子５ｘ、５ｇへの入射光量の不足
をもたらし暗い被写体に対する焦点検出能力を低下させ
ることになり好ましくない〇第５図、第４図、第５図は
本発明に係る再結像光学系の説明図である。本発明に係
る結像レンズ４１．４１１は第３図に示すように、一部
分を直線状に切断除去した形状４ｏを有している。再結
像光学系は第３図に示すレンズＬを２個その切断線に沿
って貼合わせ、若しくは一体成形若しくは枠等により一
体保持して配置した第４図に示す形状を有している。そ
して第４図の点線で示す切断線を直径とする円４ｓが再
結像光学系の入射瞳としてフィールドレンズ６により撮
影レンズ１の瞳位置２ｏの近傍と共役でしかも第５図に
示すように瞳径２１内に円形９４のように結像している
。そして第４図の点線で示す円４３以外には光束が入射
しないように結像レンズ’ｂ、４愈の前方若しくは後方
に円４３の内部のみを透過する不図示のマスクが付けら
れている。FIG. 2 shows the diameter of the imaging lens 41.411 with respect to the pupil diameter 21 of the photographic lens 1 when the imaging lenses 4x and /b shown in FIG. Incident m 7
This shows a state in which images x and 7s are respectively formed into a circle 61.6z as shown by solid lines. As is clear from the figure, as the aperture diameter of the photographing lens 1 is made smaller, the imaging lens
1141, a circle 6s shown by a dotted line and a circle 6z shown by a solid line,
Only the light beam that passes through the overlapped portion with 6g will be incident. This is undesirable because it causes an insufficient amount of light incident on the photoelectric conversion elements 5x and 5g and reduces the focus detection ability for dark objects. FIG. 3 is an explanatory diagram of an optical system. As shown in FIG. 3, the imaging lens 41,411 according to the present invention has a shape 4o in which a portion is cut and removed in a straight line. The re-imaging optical system has the shape shown in FIG. 4, in which two lenses L shown in FIG. 3 are pasted together along their cutting lines, or are integrally molded or held together by a frame or the like. A circle 4s whose diameter is the dotted line in FIG. An image is formed like a circle 94 within the pupil diameter 21. A mask (not shown) that transmits only the inside of the circle 43 is attached to the front or rear of the imaging lens 'b and the fourth lens so that the light beam does not enter any area other than the circle 43 indicated by the dotted line in FIG.
結像レンズが円形９４より小さい直径まで絞られた場合
には不図示のマスク又は絞りもそれに応じて小さい径の
ものに切替えることが望ましい。そのような場合でも再
結像レンズの絞り内に含まれる切断線の長さを直径とす
る円は、結像レンズの瞳径内に結像するようにできる。When the imaging lens is stopped down to a diameter smaller than the circular shape 94, it is desirable to switch the mask or aperture (not shown) to one with a smaller diameter accordingly. Even in such a case, a circle whose diameter is the length of the cutting line included within the aperture of the re-imaging lens can be imaged within the pupil diameter of the imaging lens.
尚、本発明の方式では従来の方式が第２図に示すように
再結像レンズの光軸６４と瞳６１の瞳中心が一致してい
たが、本発明では第４図に示すように光軸４４と瞳中心
４ｓは一致しない。又再結像光学系４の小型化を図るに
は第４図の点線で示す円４！Ｉ以外のレンズ部分を切断
除去しておくことが望ましい。In the method of the present invention, as shown in FIG. 2, in the conventional method, the optical axis 64 of the re-imaging lens and the pupil center of the pupil 61 coincided, but in the present invention, as shown in FIG. The axis 44 and the pupil center 4s do not coincide. Also, to reduce the size of the re-imaging optical system 4, use the circle 4 shown by the dotted line in FIG. It is desirable to cut and remove the lens portion other than I.
第５図に示すように、再結像光学系の入射瞳に相当する
円形９４が撮影レンズ１の瞳径２１に結像するようにな
っているので撮影レンズ１の絞り径を小さくして瞳径２
１を小さくしていっても再結像光学系４に光束を十分多
く入射させることができる。As shown in FIG. 5, a circle 94 corresponding to the entrance pupil of the re-imaging optical system is imaged on the pupil diameter 21 of the photographic lens 1, so the aperture diameter of the photographic lens 1 is made small and the pupil diameter is Diameter 2
Even if 1 is made small, a sufficiently large amount of light flux can be made incident on the re-imaging optical system 4.
これにより撮影レン７：１を通過した光束を焦点検出に
効率良く用いることができ暗い被写体に対する焦点検出
能力を高めたり、信号処理時間を早めたりすることが可
能となる。更に再結像光学系を第４図に示す形状とする
ことにより再結像光学系の小型化を図ることができる。As a result, the light flux passing through the photographic lens 7:1 can be efficiently used for focus detection, thereby making it possible to improve the focus detection ability for dark subjects and to speed up the signal processing time. Furthermore, by forming the re-imaging optical system into the shape shown in FIG. 4, the re-imaging optical system can be made smaller.
以上の説明で結像レン／”４１．４１を１枚のレンズと
して説明したが、複数のレンズより構成すれば結像性能
は向上するので好ましい〇
第６図は本発明を一眼レフレックスカメ７に用いたとき
の焦点検出光学系の一部分の実施例の概略図である。In the above explanation, the imaging lens/41.41 was explained as one lens, but it is preferable to configure it with a plurality of lenses because the imaging performance will be improved. FIG. 2 is a schematic diagram of an embodiment of a portion of a focus detection optical system when used in the present invention.
不図示の撮影レンズ及びその後方に配置されている不図
示のクイックリターンミラーの一部ヲ通過した被写体か
らの光束１００は、焦点面近傍に配置されたフィールド
レンズ１０１付近に結像する。A light beam 100 from an object that has passed through a photographing lens (not shown) and a portion of a quick return mirror (not shown) placed behind it forms an image near a field lens 101 placed near the focal plane.
フィールドレンズ１０１の上方にはスリット開口１０２
′を有するマスク１０２を配置し焦点検出用の光束以外
をカットしている。スリット開口１０２′は後述する光
電変換素子１０７１．１０７ｍの配置方向を考慮光束１
００は斜辺に反射面を持つプリズム１０′５を介して再
結像光学系１０４により斜辺に反射面を有するプリズム
１０５を介して光電変換素子１ｏ７１と１０７ｍ上に各
々結像する。フィールドレンズ１０１上の一点１０８に
結像した光束１００は点線で示す光束１００’の光路を
経て各々の光電変換素子１ｏ７１と１０７１上の一点１
０Ｅｈ、 １０８ｍに結像する。尚、１ｏ６は光電変換
素子が配置されている基板である。１０９は再結像光学
系１０４の前方に配置した第４図の点線で示す円４ｓ部
分のみを透過するような円形開口のマスクであり、焦点
検出に必要な光束のみを通過せしめている。Above the field lens 101 is a slit opening 102.
A mask 102 having a shape of 1 is arranged to cut off light other than the light beam for focus detection. The slit aperture 102' is designed with light flux 1 in consideration of the arrangement direction of photoelectric conversion elements 1071 and 107m, which will be described later.
00 is imaged by the re-imaging optical system 104 via a prism 10'5 having a reflective surface on its oblique side onto the photoelectric conversion elements 1o71 and 107m via a prism 105 having a reflective surface on its oblique side. The light beam 100 focused on a point 108 on the field lens 101 passes through the optical path of the light beam 100' shown by the dotted line to a point 1 on each of the photoelectric conversion elements 1o71 and 1071.
0Eh, imaged at 108m. Note that 1o6 is a substrate on which a photoelectric conversion element is arranged. Reference numeral 109 denotes a mask having a circular aperture that is arranged in front of the re-imaging optical system 104 and allows only a portion of the circle 4s indicated by the dotted line in FIG.
第７図は第６図の実施例におけるフィールドレンズ１０
１とプリズム１０！１を一体化し光学系の小型化を図っ
たものである。FIG. 7 shows the field lens 10 in the embodiment shown in FIG.
1 and prism 10!1 are integrated to reduce the size of the optical system.
更に第８図はフィールドレンズ１０１．プリズムｉｏｓ
、マスク１０９．そして再結像光学系１０４を一体化し
て光学系の小型化を図ったものであり、各光学要素を個
別に製作して一体化しても良く又全ての光学要素を一体
化成形しても良い０但しこのときはマスク１０９は後か
ら付加することになる。Furthermore, FIG. 8 shows a field lens 101. prism ios
, mask 109. The re-imaging optical system 104 is integrated to reduce the size of the optical system, and each optical element may be manufactured individually and integrated, or all optical elements may be integrally molded. 0 However, in this case, the mask 109 will be added later.
又図示していないがマスク１０２を第７図や第８図に示
す光学部材と一体化しても良く、更に第６図に示す各々
の光学要素を適当に一体化して光学系の小型化を図るこ
とは容易に行うことができる。Although not shown, the mask 102 may be integrated with the optical members shown in FIGS. 7 and 8, and each optical element shown in FIG. 6 may be appropriately integrated to reduce the size of the optical system. That can be done easily.
以上のように本発明によれば従来の２次結像方式の焦点
検出用光学系に比べて撮影レンズを通過した光束を効率
良く用いることができ、焦点検出を精度良く行うことが
でき、更に焦点検出用光学系の小型化を図ることができ
る焦点検出用光学系を達成することができる。As described above, the present invention makes it possible to use the light flux that has passed through the photographic lens more efficiently than the conventional focus detection optical system using the secondary imaging method, and to perform focus detection with high precision. It is possible to achieve a focus detection optical system that can be made smaller.
第１図は従来の２次結像方式の焦点検出用光学系の一部
分の概略図、第２図は第１図における撮影レンズ１の瞳
径２１と再結像光学系４の入射瞳との関係を示す説明図
、第６図は本発明に係る結像レンズの説明図、第４図は
本発明に係る再結像光学系の説明図、第５図は本発明に
係る再結像光学系４の入射瞳９４と撮影レンズ１の瞳径
２１との関係を示す説明図、第６図は本発明の一実施例
の光学系の概略図、第７図、第８図は第６図の一部分の
説明図である。
図中、８は撮影レンズ１の焦点面、６はフィールドレン
ズ、５ｘ、５ｍは光電変換素子、４１．４８は結像レン
ズ、Ｌは一部分を直線的に切断除去したレンズ、１００
．１００’は焦点検出用の光束、１０２，１０９はマス
ク、１０１はフィールドレンズ、１０５，１０５はプリ
ズム、１０４は再結像光学系、１０７１．１０７露は光
電変換素子である。
特許出願人 キャノン株式会社FIG. 1 is a schematic diagram of a part of a conventional secondary imaging type focus detection optical system, and FIG. 2 is a diagram showing the relationship between the pupil diameter 21 of the photographing lens 1 and the entrance pupil of the re-imaging optical system 4 in FIG. An explanatory diagram showing the relationship, FIG. 6 is an explanatory diagram of the imaging lens according to the present invention, FIG. 4 is an explanatory diagram of the re-imaging optical system according to the present invention, and FIG. 5 is an explanatory diagram of the re-imaging optical system according to the present invention. An explanatory diagram showing the relationship between the entrance pupil 94 of the system 4 and the pupil diameter 21 of the photographing lens 1, FIG. 6 is a schematic diagram of an optical system according to an embodiment of the present invention, and FIGS. FIG. In the figure, 8 is the focal plane of the photographing lens 1, 6 is the field lens, 5x, 5m is the photoelectric conversion element, 41.48 is the imaging lens, L is the lens with a portion cut off linearly, 100
．． 100' is a light beam for focus detection, 102 and 109 are masks, 101 is a field lens, 105 and 105 are prisms, 104 is a re-imaging optical system, and 1071 and 107 are photoelectric conversion elements. Patent applicant Canon Co., Ltd.
Claims (2)
を配置し、前記撮影レンズによる物体像の光軸方向の結
像位置に応じて、結像位置が光軸と垂直方向に変化する
ように光軸を挾んで２つの結像レンズを並べた再結像光
学系を前記フィールドレンズの後方に配置し、前記再結
像光学系の２つの結像レンズの各々の焦点位置に物体像
の結像状態を検出するための複数の素子より成る焦点検
出器を配置し、該２つの焦点検出器からの信号出力を用
いて前記撮影レンズの合焦状態を検出する焦点検出用光
学系において、前記結像レンズはレンズの一部を直η・
状に切断除去した少なくとも１枚のレンズ片がらなり、
前記再結像光学系は前記結像レンズの切断線に沿って貼
合わせ若しくは近接させて配置したものからなり、前記
フィールドレンズは前記結像レンズの切断線の長さを直
径とする円を前記撮影レンズの瞳位置近傍でかつ瞳径内
に結像する屈折力を有していることを特徴とする焦点検
出用光学系。(1) [Field lens near the focal plane of the t lens]
and two imaging lenses are arranged with the optical axis in between so that the imaging position changes in the direction perpendicular to the optical axis according to the imaging position of the object image in the optical axis direction by the photographing lens. An imaging optical system is disposed behind the field lens, and a focus detection unit includes a plurality of elements for detecting the imaging state of an object image at the focal position of each of the two imaging lenses of the re-imaging optical system. In the focus detection optical system, the focusing state of the photographing lens is detected using the signal output from the two focus detectors, and the imaging lens has a part of the lens directly η.
Consists of at least one lens piece cut and removed in a shape,
The re-imaging optical system is made of a system that is attached to or placed close to the imaging lens along the cutting line, and the field lens has a circle whose diameter is the length of the cutting line of the imaging lens. A focus detection optical system characterized by having a refractive power that forms an image near the pupil position of a photographic lens and within the pupil diameter.
が一致していないことを特徴とする特許請求の範囲第１
項記載の焦点検出用光学系。(2) Claim 1, characterized in that the optical axis of the imaging lens and the center of the pupil through which the light beam passes do not coincide.
Focus detection optical system described in Section 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18818281A JPS5888709A (en) | 1981-11-24 | 1981-11-24 | Optical system for focusing detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18818281A JPS5888709A (en) | 1981-11-24 | 1981-11-24 | Optical system for focusing detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5888709A true JPS5888709A (en) | 1983-05-26 |
Family
ID=16219195
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18818281A Pending JPS5888709A (en) | 1981-11-24 | 1981-11-24 | Optical system for focusing detection |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5888709A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6060612A (en) * | 1983-09-13 | 1985-04-08 | Canon Inc | Focus detector of camera |
| US4526458A (en) * | 1983-08-01 | 1985-07-02 | Minolta Camera Kabushiki Kaisha | Focus condition detecting device for cameras |
| US4529287A (en) * | 1983-08-09 | 1985-07-16 | Minolta Camera Kabushiki Kaisha | Focus condition detection device for cameras |
| US4552445A (en) * | 1983-08-16 | 1985-11-12 | Minolta Camera Kabushiki Kaisha | Focus condition detecting device for cameras |
| US4662735A (en) * | 1985-01-16 | 1987-05-05 | Minolta Camera Kabushiki Kaisha | Plastic lens elements supporting structure |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5671380A (en) * | 1979-11-15 | 1981-06-13 | Canon Inc | Television camera |
| JPS56130725A (en) * | 1980-03-18 | 1981-10-13 | Nippon Kogaku Kk <Nikon> | Optical device for focus detection |
-
1981
- 1981-11-24 JP JP18818281A patent/JPS5888709A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5671380A (en) * | 1979-11-15 | 1981-06-13 | Canon Inc | Television camera |
| JPS56130725A (en) * | 1980-03-18 | 1981-10-13 | Nippon Kogaku Kk <Nikon> | Optical device for focus detection |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4526458A (en) * | 1983-08-01 | 1985-07-02 | Minolta Camera Kabushiki Kaisha | Focus condition detecting device for cameras |
| US4529287A (en) * | 1983-08-09 | 1985-07-16 | Minolta Camera Kabushiki Kaisha | Focus condition detection device for cameras |
| US4552445A (en) * | 1983-08-16 | 1985-11-12 | Minolta Camera Kabushiki Kaisha | Focus condition detecting device for cameras |
| JPS6060612A (en) * | 1983-09-13 | 1985-04-08 | Canon Inc | Focus detector of camera |
| US4662735A (en) * | 1985-01-16 | 1987-05-05 | Minolta Camera Kabushiki Kaisha | Plastic lens elements supporting structure |
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