JPS6278518A - Focus detecting device - Google Patents
Focus detecting deviceInfo
- Publication number
- JPS6278518A JPS6278518A JP21951985A JP21951985A JPS6278518A JP S6278518 A JPS6278518 A JP S6278518A JP 21951985 A JP21951985 A JP 21951985A JP 21951985 A JP21951985 A JP 21951985A JP S6278518 A JPS6278518 A JP S6278518A
- Authority
- JP
- Japan
- Prior art keywords
- light
- pupil
- lens
- receiving element
- light receiving
- 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
Landscapes
- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は写真用カメラやビデオカメラ等に好適な焦点検
出装置に関し、特にＷ１影レンズの瞳を複数の領域に分
割し、各領域を通過する光束から複数の第２次物体像を
形成し、これら複数の第２次物体像の相対的位置関係を
検出することにより、撮影レンズの焦点状態を検出する
焦点検出装置に関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a focus detection device suitable for photographic cameras, video cameras, etc. In particular, the present invention relates to a focus detection device suitable for photographic cameras, video cameras, etc. The present invention relates to a focus detection device that detects the focal state of a photographic lens by forming a plurality of secondary object images from a light beam and detecting the relative positional relationship of the plurality of secondary object images.
（従来の技術）
従来より比較的高精度な受光型の焦点検出方式に所謂像
ずれ方式と呼ばれる方式がある。(Prior Art) Conventionally, there is a so-called image shift method as a relatively high-precision light-receiving focus detection method.
この像ずれ方式は例えば特開昭５２−９５２２１号公報
で提案されているように撮影レンズによる第１次物体像
の形成される予定結像面の後方に１つ若しくは２つの再
結像レンズを有する再結像系と、２つの受光素子列を有
する受光手段とを配置している。再結像系は撮影レンズ
の２つの瞳領域を通過した光束を用いて第１次物体像か
ら２つの′ｆＳ２次物体像を各々の受光素子列面上に形
成している。２つの第２次物体像の受光素子列面上の相
対的位置は撮影レンズの合焦状態により受光素子列の素
子の並び方向に横ずれ状態となって現われる。撮影レン
ズの焦点検出はこのときの２つの第２次物体像の相対的
位置関係を受光手段により検出することにより行フてい
る。この為、像ずれ方式による焦点検出装置においては
第２次物体像の受光手段面上での光学性能が焦点検出精
度に大きく影雪してくる。This image shift method is proposed, for example, in Japanese Patent Laid-Open No. 52-95221, in which one or two re-imaging lenses are installed behind the expected imaging plane where the primary object image is formed by the taking lens. A re-imaging system having a light receiving element and a light receiving means having two light receiving element rows are arranged. The re-imaging system forms two 'fS secondary object images from the primary object image on each of the light-receiving element array surfaces using the light flux that has passed through the two pupil regions of the photographing lens. The relative positions of the two secondary object images on the plane of the light-receiving element array appear to be laterally shifted in the direction in which the elements of the light-receiving element array are arranged, depending on the focusing state of the photographing lens. The focus of the photographing lens is detected by detecting the relative positional relationship between the two secondary object images using the light receiving means. For this reason, in a focus detection device using the image shift method, the optical performance of the secondary object image on the light receiving means surface greatly affects the focus detection accuracy.
像すれ方式による焦点検出装置においては、撮影レンズ
の面ピン若しくは後ビン等の合焦状態に応じて２つの第
２次物体像は２つの受光素子列上、互いにディフォーカ
ス量に比例して接近し若しくは離れて形成される。この
為、大きくディフォーカスしていても焦点検出が出来る
ようにするには、即ち焦点検出範囲を拡大するには２つ
の受光素子列を長くしなければならず、この為には両者
を互いにある程度離して構成する必要がある。しかしな
がら従来は単に再結像レンズを用いて第１次物体像から
第２次物体像を形成していた為に２つの第２次物体像の
結像間距離をあまり大きく離すことが出来なく、２つの
受光素子列の長さを拡大するのか難しかった。この為、
撮影レンズが大きくディフォーカスしていると第２次物
体像が受光素子列から外れてしまい精度の良い焦点検出
が困難であった。In a focus detection device using an image blurring method, two secondary object images approach each other on two light receiving element rows in proportion to the amount of defocus, depending on the focusing state of the surface focus or rear focus of the photographic lens. or formed separately. Therefore, in order to be able to detect focus even when the focus is significantly defocused, in other words, to expand the focus detection range, it is necessary to lengthen the two light receiving element arrays. need to be configured separately. However, in the past, a re-imaging lens was simply used to form a secondary object image from a primary object image, so it was not possible to make the distance between the two secondary object images very large. It was difficult to expand the length of the two light-receiving element rows. For this reason,
If the photographic lens is significantly defocused, the secondary object image will be removed from the light receiving element array, making it difficult to accurately detect the focus.
（発明が解決しようとする問題点）
本発明は像ずれ方式の焦点検出装置において、２つの第
２次物体像の光学性能を良好に維持しつつ、結像間距離
を長くし、２つの受光素子列の長さを拡大し、焦点検出
範囲の拡大を図った焦点検出装置の提供を目的とする。(Problems to be Solved by the Invention) The present invention provides an image shift type focus detection device that maintains good optical performance of the two secondary object images, increases the distance between the images, and It is an object of the present invention to provide a focus detection device in which the length of an element array is expanded and the focus detection range is expanded.
（問題点を解決するための手段）
撮影レンズの像面側にｎ「記撮影レンズの瞳を２つの領
域に分割し、分割した２つの瞳領域を通過する光束から
各々第２次物体像を形成する再結像系を配置し、前記再
結像系の像面近傍に２つの受光素子列より成る受光手段
を配置し、前記受光手段により前記２つの第２次物体像
の相対的位置関係を検出することにより前記撮影レンズ
の焦点状態を検出する焦点検出装置において、前記２つ
の受光素子列を前記瞳の分割方向に直線的に同一平面上
に配置し、前記再結像系は再結像レンズと該再結像レン
ズを通過した光束を前記瞳の分割方向と同一方向に反射
させ、＋＋汀記２つの受光素子列に各々導光する為の少
なくとも２つの反射鏡を有する１対の反射部材とを打し
ていることである。(Means for solving the problem) The pupil of the photographing lens is divided into two regions, and a secondary object image is obtained from the light flux passing through the two divided pupil regions. A re-imaging system to form the image is arranged, a light receiving means consisting of two light receiving element arrays is arranged near the image plane of the re-imaging system, and the relative positional relationship between the two secondary object images is determined by the light receiving means. In the focus detection device that detects the focus state of the photographic lens by detecting the focus state of the photographing lens, the two light receiving element arrays are arranged on the same plane linearly in the pupil division direction, and the reimaging system is configured to perform reimaging. A pair of reflecting mirrors each having at least two reflecting mirrors for reflecting the light flux that has passed through the image lens and the re-imaging lens in the same direction as the dividing direction of the pupil and guiding the light to the two light-receiving element arrays, respectively. It is hitting the reflective member.
この他、本発明の特徴は実施例において記載されている
。Other features of the invention are described in the Examples.
（実施例）
第１図（Ａ） 、 （Ｂ）は本発明の一実施例の光学系
の概略図である。同図（Ａ＞は平面図、同図（１３）は
正面図である。図中１は撮影レンズ、２は撮影レンズ１
の射出瞳、３は撮影ししズ１の予定結像面、４はフィー
ルドレンズ、５は視野マスク、６は再結像系で第２図に
その斜視図を示す。再結像系６は１対の再結像レンズ６
−１１ 、６−２１と２つの反射面を有する反射部材６
−１２ 、６−２２を有している。(Embodiment) FIGS. 1A and 1B are schematic diagrams of an optical system according to an embodiment of the present invention. The same figure (A> is a plan view, and the same figure (13) is a front view. In the figure, 1 is a photographing lens, and 2 is a photographing lens 1.
2 is a perspective view of the exit pupil of , 3 is the expected imaging plane of the photographic lens 1, 4 is a field lens, 5 is a field mask, and 6 is a re-imaging system. The re-imaging system 6 includes a pair of re-imaging lenses 6
-11, 6-21 and a reflective member 6 having two reflective surfaces
-12, 6-22.
７は再結像レンズ６−１１ 、６−２１の１１１方に配
置した２つの開口を有する絞り、８は受光手段で同一平
面上に２つの受光素子列８−１．８−２を有している。7 is a stop having two apertures arranged on the 111 side of the re-imaging lenses 6-11 and 6-21, and 8 is a light receiving means having two light receiving element rows 8-1, 8-2 on the same plane. ing.
２つの受光素子列８−１．８−２は第１図（Ｃ）に示す
ようにＸ軸方向、即ち瞳２の分割方向と同一方向に直線
的に略同一平面上に２つに分離して構成されている。The two light-receiving element arrays 8-1 and 8-2 are linearly separated into two on substantially the same plane in the X-axis direction, that is, in the same direction as the dividing direction of the pupil 2, as shown in FIG. 1(C). It is composed of
本実施例ではフィールドレンズ４により再結像レンズ６
−１１ 、６−２１の瞳と撮影レンズ１の射出瞳２とが
略共役関係となるように構成し、撮影レンズ１の射出瞳
２を２つの領域２ａ 、 ２ｂに分割している。In this embodiment, the re-imaging lens 6 is formed by the field lens 4.
-11 and 6-21 and the exit pupil 2 of the photographic lens 1 are configured to have a substantially conjugate relationship, and the exit pupil 2 of the photographic lens 1 is divided into two regions 2a and 2b.
撮影レンズ１を通過した被写体からの光束は予定結像面
３近傍に第１次物体像を形成する。第１次物体像のうち
撮影レンズ１の射出ｌψ２の一方の領域２ａを通過した
光束Ｌ１は再結像レンズ６−１１に入射し、反射部材６
−１２の２つの反射面６−１２１．６−１２２で反射し
、受光素子列８−１上に第２次物体像を形成する。同様
に射出瞳２の他方の領域２ｂを通過した光束Ｌ２は再結
像レンズ６−２１に入射し、反射部材６−２２の２つの
反射面６−２２１．６−２２２で反射し、受光素子列８
−２上に第２次物体像を形成する。The light beam from the subject that has passed through the photographic lens 1 forms a primary object image near the intended image formation plane 3. Of the primary object image, the light beam L1 that has passed through one region 2a of the exit lψ2 of the photographic lens 1 enters the re-imaging lens 6-11, and
-12 is reflected by the two reflecting surfaces 6-121 and 6-122, forming a secondary object image on the light receiving element array 8-1. Similarly, the light beam L2 that has passed through the other region 2b of the exit pupil 2 enters the re-imaging lens 6-21, is reflected by the two reflective surfaces 6-221.6-222 of the reflective member 6-22, and is reflected by the light receiving element row 8
A secondary object image is formed on -2.
２つの第２次物体像の受光素子列上の相対的位置は撮、
彰レンズ１の前ピン又は後ビン等の合焦状態とディフォ
ーカス量の大小により受光素子列８−１．８−２の矢印
Ｃ−Ｉ、 Ｃ−２て示す方向の横ずれ量となって現われ
る。焦点検出はこのときの２つの第２次物体像の相対的
位置関係を受光手段８で検出することにより行っている
。The relative positions of the two secondary object images on the photodetector array are determined by
Depending on the focusing state of the front focus or rear focus of the light lens 1 and the magnitude of the defocus amount, the amount of lateral deviation of the light receiving element array 8-1.8-2 appears in the directions indicated by arrows C-I and C-2. . Focus detection is performed by detecting the relative positional relationship between the two secondary object images using the light receiving means 8 at this time.
本実施例ては再結像系６の反射部材６−１２ 。In this embodiment, the reflection member 6-12 of the re-imaging system 6.
６−２２の反射面の角度を適切に設定することにより２
つの第２次物体像を射出瞳２の分割方向と同一方向に分
割して各々の受光素子列８−１．８−２上に再結像させ
ている。2 by appropriately setting the angle of the reflecting surface in 6-22.
The two secondary object images are divided in the same direction as the division direction of the exit pupil 2 and re-imaged on each of the light receiving element rows 8-1 and 8-2.
本実施例では受光素子列８−１．８−２に入射する主光
線が略平行となるように各反射面を設定し構成の簡素化
を図っている。In this embodiment, each reflecting surface is set so that the principal rays incident on the light receiving element rows 8-1, 8-2 are substantially parallel to simplify the configuration.
以上のように本実施例では２つの反射面を有する１対の
反射部材を用いることにより、第２次物体像の光学性能
を良好に維持しつつ、結像間距離を拡大することにより
焦点検出を拡大した高精度な焦点検出を可能としている
。As described above, in this embodiment, by using a pair of reflective members having two reflective surfaces, focus detection is achieved by expanding the distance between images while maintaining good optical performance of the secondary object image. This enables highly accurate focus detection by enlarging the area.
尚、本実施例においては、反射部材６−１２．６−２２
はカラスブロックの代わりに２つの反射鏡より構成して
も良い。又、反射部材６−１２ 、６−２２を各々再結
像レンズ６−１１ 、６−２１と一体化して構成しても
良い。In addition, in this embodiment, the reflecting member 6-12.6-22
may be composed of two reflecting mirrors instead of the crow block. Further, the reflecting members 6-12 and 6-22 may be integrated with the re-imaging lenses 6-11 and 6-21, respectively.
本実施例においては２つの再結像レンズを用いた場合を
示したが、再結像レンズを１つとし、絞り７の２つの開
口を含むように構成して撮影レンズ１の射出瞳２を２つ
の領域に分割するようにしても良い。In this embodiment, a case is shown in which two re-imaging lenses are used, but the exit pupil 2 of the photographic lens 1 is configured to include one re-imaging lens and include two apertures of the diaphragm 7. It may be divided into two areas.
（発明の効果）
本発明によれば再結像系に所定形状の反射面を有した反
射部材を用いることにより２つの第２次物体像を瞳の分
割方向と同一方向に各々分列し、受光素子列上に良好な
る光学性能を有して形成することかでき、ディフォーカ
ス範囲を拡大した高精度の焦点検出か可能な焦点検出装
置を達成することができる。(Effects of the Invention) According to the present invention, by using a reflecting member having a reflecting surface of a predetermined shape in the re-imaging system, two secondary object images are separated in the same direction as the pupil dividing direction, It is possible to achieve a focus detection device that can be formed with good optical performance on the light receiving element array and can perform highly accurate focus detection with an expanded defocus range.
第１図（Ａ） 、 （Ｂ）は各々本発明の一実施例の光
学系の平面図と正面図、第１図（Ｃ）は第１図（Ａ）の
一部分の受光手段の説明図、第２図は本発明の再結像系
の一実施例の斜視図である。図中１は撮影レンズ、２は
射出瞳、３は予定結像面、４はフィールドレンズ、５は
視野マスク、６は再結像系、７は絞り、６−１１．６−
２１は各々再結像レンズ、８−１ 、８−２は各々受光
素ｆ列、８は受光手段、６−１２．６−２２は反射部材
である。1(A) and 1(B) are respectively a plan view and a front view of an optical system according to an embodiment of the present invention, FIG. 1(C) is an explanatory diagram of a portion of the light receiving means in FIG. 1(A), FIG. 2 is a perspective view of an embodiment of the reimaging system of the present invention. In the figure, 1 is a photographing lens, 2 is an exit pupil, 3 is a planned imaging plane, 4 is a field lens, 5 is a field mask, 6 is a reimaging system, 7 is an aperture, 6-11.6-
21 is a re-imaging lens, 8-1 and 8-2 are f arrays of light-receiving elements, 8 is a light-receiving means, and 6-12, 6-22 is a reflecting member.
Claims (1)
に分割し、分割した２つの瞳領域を通過する光束から各
々第２次物体像を形成する再結像系を配置し、前記再結
像系の像面近傍に２つの受光素子列より成る受光手段を
配置し、前記受光手段により前記２つの第２次物体像の
相対的位置関係を検出することにより前記撮影レンズの
焦点状態を検出する焦点検出装置において、前記２つの
受光素子列を前記瞳の分割方向に直線的に略同一平面上
に配置し、前記再結像系は再結像レンズと該再結像レン
ズを通過した光束を前記瞳の分割方向と同一方向に反射
させ前記２つの受光素子列に各々導光する為の少なくと
も２つの反射鏡を有する１対の反射部材とを有している
ことを特徴とする焦点検出装置。A re-imaging system that divides the pupil of the photographic lens into two regions and forms a secondary object image from each of the light beams passing through the two divided pupil regions is disposed on the image plane side of the photographic lens. A light receiving means consisting of two light receiving element arrays is arranged near the image plane of the imaging system, and the focus state of the photographing lens is determined by detecting the relative positional relationship between the two secondary object images using the light receiving means. In the focus detection device for detection, the two light-receiving element rows are arranged on substantially the same plane linearly in the direction of dividing the pupil, and the re-imaging system passes through a re-imaging lens and the re-imaging lens. A focal point comprising a pair of reflecting members each having at least two reflecting mirrors for reflecting a light beam in the same direction as the dividing direction of the pupil and guiding the light to the two light-receiving element arrays, respectively. Detection device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21951985A JPS6278518A (en) | 1985-10-02 | 1985-10-02 | Focus detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21951985A JPS6278518A (en) | 1985-10-02 | 1985-10-02 | Focus detecting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6278518A true JPS6278518A (en) | 1987-04-10 |
Family
ID=16736739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21951985A Pending JPS6278518A (en) | 1985-10-02 | 1985-10-02 | Focus detecting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6278518A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5037188A (en) * | 1988-02-24 | 1991-08-06 | Minolta Camera Kabushiki Kaisha | Optical system for detecting focusing condition |
| JPH03200207A (en) * | 1989-12-28 | 1991-09-02 | Olympus Optical Co Ltd | Optical system for focusing detection |
-
1985
- 1985-10-02 JP JP21951985A patent/JPS6278518A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5037188A (en) * | 1988-02-24 | 1991-08-06 | Minolta Camera Kabushiki Kaisha | Optical system for detecting focusing condition |
| JPH03200207A (en) * | 1989-12-28 | 1991-09-02 | Olympus Optical Co Ltd | Optical system for focusing detection |
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