JP3448617B2 - Focus detection device - Google Patents
Focus detection deviceInfo
- Publication number
- JP3448617B2 JP3448617B2 JP8271495A JP8271495A JP3448617B2 JP 3448617 B2 JP3448617 B2 JP 3448617B2 JP 8271495 A JP8271495 A JP 8271495A JP 8271495 A JP8271495 A JP 8271495A JP 3448617 B2 JP3448617 B2 JP 3448617B2
- Authority
- JP
- Japan
- Prior art keywords
- focus detection
- pattern
- detection device
- projection
- transparent
- 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.)
- Expired - Lifetime
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- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、投射光学系により被写
体に投射して焦点検出を行なうアクティブ型の焦点検出
装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active focus detecting apparatus which detects a focus by projecting an object by a projection optical system.
【０００２】[0002]
【従来の技術】一般にレンズ交換式のカメラでは、多種
類の交換レンズに対応するため撮影レンズを通過した外
界からの光を利用して焦点検出を行う、いわゆるパッシ
ブ型の焦点検出装置が主流となっている。しかし、この
ようなパッシブ型の焦点検出装置では、外界が暗い時や
被写体のコントラストが低い時には焦点検出が困難ある
いは不能になる。このようなパッシブ型の欠点を解決す
るため、所定の照明装置から補助光を投射して焦点検出
を行うアクティブ型の焦点検出装置が知られている（例
えば、特開昭６１−１３８２２２号公報参照）。2. Description of the Related Art Generally, in the interchangeable lens type camera, a so-called passive type focus detecting device is mainly used to detect a focus by using light from the outside world that has passed through a photographing lens in order to support various kinds of interchangeable lenses. Has become. However, in such a passive focus detection device, focus detection is difficult or impossible when the external environment is dark or the contrast of the subject is low. In order to solve such a defect of the passive type, an active type focus detecting device is known in which auxiliary light is projected from a predetermined illuminating device to perform focus detection (for example, see JP-A-61-138222). ).
【０００３】図５はアクティブ型の焦点検出装置を備え
たカメラの横断面図である。このカメラでは、撮影レン
ズ７０１を通過した被写体からの光束は、メインミラー
７０２の透光部を通過してサブミラー７０３で下方に反
射され、焦点検出ユニット７０４へ入射する。一方、カ
メラ７０５の上面に設けられたアクセサリーシュー７０
６には閃光装置７０７が装着され、この閃光装置７０７
内には投影光源７０８、投影パターンフィルム７０９、
投射レンズ７１０を有する投射光学系７１１が設置され
ている。外界が暗い時や被写体のコントラストが低い時
には、投影光源７０８から例えば赤外光が発光され、投
影パターンフィルム７０９と投射レンズ７１０を通り、
被写体に投影パターンフィルム７０９の投影パターン像
が投射される。その反射光は撮影レンズ７０１とミラー
７０２，７０３を介して例えば公知の位相差方式の焦点
検出部７０４へ入射し、撮影レンズ７０１の焦点調節状
態が検出される。FIG. 5 is a cross-sectional view of a camera equipped with an active focus detection device. In this camera, the light flux from the subject that has passed through the taking lens 701 passes through the light transmitting portion of the main mirror 702, is reflected downward by the sub mirror 703, and enters the focus detection unit 704. On the other hand, the accessory shoe 70 provided on the upper surface of the camera 705
6 is equipped with a flash device 707.
A projection light source 708, a projection pattern film 709,
A projection optical system 711 having a projection lens 710 is installed. When the external environment is dark or the contrast of the subject is low, for example, infrared light is emitted from the projection light source 708, passes through the projection pattern film 709 and the projection lens 710,
The projection pattern image of the projection pattern film 709 is projected on the subject. The reflected light enters the focus detection unit 704 of, for example, a known phase difference method via the taking lens 701 and the mirrors 702 and 703, and the focus adjustment state of the taking lens 701 is detected.
【０００４】図６は位相差方式による焦点検出の原理を
示す。図において、８０１はフィルム面と等価な撮影レ
ンズ７０１の予定結像面であり、８０２はコンデンサー
レンズ８０３と一対の再結像レンズ８０４，８０５を有
する焦点検出光学系に対して予定結像面８０１と共役な
面である。撮影レンズ７０１により予定結像面８０１上
に形成された前ピン像Ａ、合焦像Ｂおよび後ピン像Ｃ
は、コンデンサーレンズ８０３と一対の再結像レンズ８
０４，８０５によって予定結像面８０２上にそれぞれ第
１の像Ａ１，Ｂ１，Ｃ１および第２の像Ａ２，Ｂ２，Ｃ
２として再結像される。ここで、第１と第２の像の間隔
は撮影レンズ７０１の焦点調節状態によって変化する。
したがって、予定結像面８０２あるいはその近傍にＣＣ
Ｄなどの光電変換器８０６を配置し、その出力に基づい
て第１と第２の像が最もよく一致するときの２像の間隔
を求め、その像間隔に基づいて撮影レンズ７０１の焦点
調節状態を検出することができる。なお、図６におい
て、８０７は撮影レンズの光軸、８０８は一対の絞り開
口を再結像レンズ８０４，８０５の直前に形成するため
の絞りマスクである。FIG. 6 shows the principle of focus detection by the phase difference method. In the figure, 801 is a planned image forming surface of the taking lens 701 equivalent to a film surface, and 802 is a planned image forming surface 801 for a focus detection optical system having a condenser lens 803 and a pair of re-imaging lenses 804 and 805. It is a surface conjugate with. The front focus image A, the in-focus image B, and the rear focus image C formed on the expected image forming surface 801 by the taking lens 701.
Is a condenser lens 803 and a pair of re-imaging lenses 8
04 and 805, the first image A1, B1, C1 and the second image A2, B2, C are respectively formed on the planned image forming surface 802.
It is re-imaged as 2. Here, the interval between the first and second images changes depending on the focus adjustment state of the taking lens 701.
Therefore, the CC may be formed on the planned image plane 802 or in the vicinity thereof.
A photoelectric converter 806 such as D is arranged, the distance between the two images when the first and second images best match each other is obtained based on the output, and the focus adjustment state of the photographing lens 701 is determined based on the image distance. Can be detected. In FIG. 6, reference numeral 807 is an optical axis of the photographing lens, and 808 is an aperture mask for forming a pair of aperture openings immediately before the re-imaging lenses 804 and 805.
【０００５】図７は、従来の焦点検出装置の投影パター
ンフィルム７０９のパターンの一例を示す。従来の投影
パターンでは、不透明部６０１の幅ｐ、透明部６０２の
幅ｑおよびそれらの繰り返し周期（ｐ＋ｑ）が全く不規
則に形成されている。これは、位相差方式の焦点検出装
置に同一幅の不透明部６０１を複数個設けると、再結像
レンズ８０４，８０５により形成される２つの投影パタ
ーン像の一致する組が複数組検出されることになり、焦
点検出を誤ることになるからである。FIG. 7 shows an example of a pattern of a projection pattern film 709 of a conventional focus detection device. In the conventional projection pattern, the width p of the opaque portion 601, the width q of the transparent portion 602, and their repeating period (p + q) are formed irregularly. This is because when a plurality of opaque parts 601 having the same width are provided in the phase difference type focus detection device, a plurality of sets in which two projection pattern images formed by the re-imaging lenses 804 and 805 coincide with each other are detected. This is because the focus detection is erroneous.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、従来の
焦点検出装置では、投影パターンフィルムの不透明部の
幅と透明部の幅がそれぞれの部分で異なり、その繰り返
し周期も全く不規則に形成されているので、次のような
問題がある。投影パターンフィルムのパターンの約半分
を占める不透明部は、透過率が０（被写体には全く投射
されない）であり、不透明部の幅の分だけ投影光源から
の光量が遮られて被写体に投射される光量が少なくな
り、投影パターン像が暗くなって焦点検出精度が低下す
るという問題がある。また、バッテリーの電力が有効に
利用されていないという問題もある。さらに、不透明部
により遮られて被写体に光が投射されない部分に被写体
の反射率差があると、補助光による照明では被写体のコ
ントラスト差が現れないので、焦点検出不能になる確率
が高くなり、被写体を確実に捕捉できないという問題が
ある。However, in the conventional focus detection device, the width of the opaque portion and the width of the transparent portion of the projection pattern film are different in each portion, and the repetition cycle thereof is also irregular. Therefore, there are the following problems. The opaque portion, which occupies about half of the pattern of the projection pattern film, has a transmittance of 0 (not projected onto the subject at all), and the amount of light from the projection light source is blocked by the width of the opaque portion and projected onto the subject. There is a problem that the amount of light decreases, the projected pattern image becomes dark, and the focus detection accuracy decreases. There is also a problem that the power of the battery is not effectively used. Furthermore, if there is a difference in the reflectance of the subject in the part where the light is not projected onto the subject because it is blocked by the opaque part, the contrast difference of the subject does not appear in the illumination with the auxiliary light, and the probability of focus detection becoming higher increases. However, there is a problem in that it cannot be reliably captured.
【０００７】本発明の目的は、被写体に投射する光量を
増加して確実に被写体を捕捉し、焦点検出精度を向上さ
せることにある。It is an object of the present invention to increase the amount of light projected on a subject to reliably capture the subject and improve focus detection accuracy.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に、請求項１の発明は、投影光源と投影パターンフィル
ムと投射レンズとを有する投射光学系により被写体に補
助光を投射し、焦点検出光学系により撮影レンズを通過
した被写体からの一対の光束を光電変換器上に導いて一
対の被写体像を結像し、前記一対の被写体像の像ずれ量
に基づいて前記撮影レンズの焦点調節状態を検出する焦
点検出装置に適用され、前記投影パターンフィルムのパ
ターンは光透過率の異なる複数の半透明部を有する。請
求項２の焦点検出装置の前記投影パターンフィルムのパ
ターンは透明部を含むようにしたものである。請求項３
の焦点検出装置の前記投影パターンフィルムのパターン
は不透明部を含むようにしたものである。請求項４の焦
点検出装置は、前記パターンの透明部、半透明部、不透
明部の幅をすべて同一としたものである。請求項５の焦
点検出装置は、前記パターンの透明部、半透明部、不透
明部の幅をランダムに設定したものである。請求項６の
焦点検出装置は、前記パターンの透明部、半透明部、不
透明部を周期的に配列したものである。請求項７の焦点
検出装置は、前記パターンの透明部、半透明部、不透明
部をランダムに配列したものである。請求項８の焦点検
出装置は、半透明部の光透過率を７０〜３０％としたも
のである。請求項９の焦点検出装置は、前記投射光学系
をカメラの外部に取り付けるようにしたものである。請
求項１０の焦点検出装置は、前記投射光学系をカメラに
内蔵したものである。In order to achieve the above object, the invention of claim 1 projects focus light by projecting auxiliary light onto a subject by a projection optical system having a projection light source, a projection pattern film and a projection lens. An optical system guides a pair of light fluxes from the subject that have passed through the taking lens onto a photoelectric converter to form a pair of subject images, and the focus adjustment state of the taking lens based on the image shift amount of the pair of subject images. The pattern of the projection pattern film has a plurality of semitransparent portions having different light transmittances. The pattern of the projection pattern film of the focus detection device according to claim 2 includes a transparent portion. Claim 3
The pattern of the projection pattern film of the focus detecting device of No. 1 includes an opaque portion. According to a fourth aspect of the focus detection device, the transparent portion, the semi-transparent portion, and the opaque portion of the pattern have the same width. According to a fifth aspect of the focus detection apparatus, the widths of the transparent portion, the semi-transparent portion, and the opaque portion of the pattern are randomly set. According to a sixth aspect of the focus detection apparatus, the transparent portion, the semi-transparent portion, and the opaque portion of the pattern are periodically arranged. According to a seventh aspect of the focus detection apparatus, the transparent portion, the semi-transparent portion, and the opaque portion of the pattern are randomly arranged. In the focus detection device according to claim 8, the light transmittance of the semitransparent portion is 70 to 30%. According to a ninth aspect of the focus detection apparatus, the projection optical system is attached to the outside of the camera. According to a tenth aspect of the focus detection device, the projection optical system is built in a camera.
【０００９】[0009]
【作用】光透過率の異なる複数の半透明部を有するパタ
ーンの投影パターンフィルムを用いた投射光学系により
被写体に補助光を投射し、焦点検出光学系により撮影レ
ンズを通過した被写体からの一対の光束を光電変換器上
に導いて一対の被写体像を結像し、一対の被写体像の像
ずれ量に基づいて撮影レンズの焦点調節状態を検出す
る。なお、上記パターンに透明部および／または不透明
部を含むようにしてもよい。The auxiliary optical system projects a supplemental light onto a subject by means of a projection optical system using a projection pattern film having a pattern having a plurality of translucent portions having different light transmittances, and a pair of a pair of subjects from the subject passing through the photographing lens by the focus detection optical system. The light flux is guided onto the photoelectric converter to form a pair of subject images, and the focus adjustment state of the photographing lens is detected based on the image shift amount of the pair of subject images. The pattern may include a transparent portion and / or an opaque portion.
【００１０】[0010]
【実施例】図１〜図４により本発明の焦点検出装置の実
施例を説明する。なお、実施例の焦点検出装置とその焦
点検出装置を備えたカメラの構成は図５および図６に示
すものと同様であり、それらの図を参照しながら本発明
の実施例を説明する。図１は一実施例の投影パターンフ
ィルム７０９Ａを示す。このパターンは、透過率の異な
る複数の半透明部１０１〜１０６と、複数の透明部１１
１〜１１４と、複数の不透明部１２１〜１２６とを有
し、各半透明部、各透明部および各不透明部の幅をすべ
て同一に設定するとともに、半透明部、透明部および不
透明部をランダムに配列したものである。なお、半透明
部１０１〜１０６の光透過率は３０〜７０％とする。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the focus detecting device of the present invention will be described with reference to FIGS. Note that the configurations of the focus detection device of the embodiment and the camera including the focus detection device are the same as those shown in FIGS. 5 and 6, and an embodiment of the present invention will be described with reference to these drawings. FIG. 1 shows a projection pattern film 709A according to one embodiment. This pattern includes a plurality of translucent portions 101 to 106 having different transmittances and a plurality of transparent portions 11
1-114 and a plurality of opaque portions 121 to 126, the widths of the semi-transparent portions, the transparent portions and the opaque portions are all set to be the same, and the semi-transparent portions, the transparent portions and the opaque portions are random. It is arranged in. The light transmittance of the semitransparent portions 101 to 106 is 30 to 70%.
【００１１】図２は一実施例の投影パターンフィルム７
０９Ｂを示す。このパターンは、透過率の異なる複数の
半透明部２０１〜２０４と、複数の透明部２１１〜２１
６と、複数の不透明部２２１〜２２６とを有し、各半透
明部、各透明部および各不透明部の幅をすべて同一に設
定するとともに、半透明部、透明部および不透明部を周
期Ｌ１で周期的に配列したものである。なお、半透明部
２０１〜２０４の光透過率は３０〜７０％とする。FIG. 2 shows a projection pattern film 7 of one embodiment.
09B is shown. This pattern includes a plurality of translucent portions 201 to 204 having different transmittances and a plurality of transparent portions 211 to 21.
6 and a plurality of opaque portions 221 to 226, the widths of the semitransparent portions, the transparent portions and the opaque portions are all set to be the same, and the semitransparent portion, the transparent portion and the opaque portion are arranged at a cycle L1. It is arranged periodically. The light transmittance of the semitransparent portions 201 to 204 is 30 to 70%.
【００１２】図３は一実施例の投影パターンフィルム７
０９Ｃを示す。このパターンは、透過率の異なる複数の
半透明部３０１〜３０４と、複数の透明部３１１〜３１
８と、複数の不透明部３２１〜３２４とを有し、各半透
明部、各透明部および各不透明部の幅をランダムに設定
するとともに、透明部の右隣に半透明部または不透明部
を配列したものである。なお、半透明部２０１〜２０４
の光透過率は３０〜７０％とする。FIG. 3 shows a projection pattern film 7 according to one embodiment.
09C is shown. This pattern includes a plurality of translucent portions 301 to 304 having different transmittances and a plurality of transparent portions 311 to 31 1.
8 and a plurality of opaque parts 321 to 324, the widths of the semitransparent parts, the transparent parts, and the opaque parts are randomly set, and the semitransparent parts or the opaque parts are arranged on the right side of the transparent part. It was done. In addition, the semi-transparent portions 201 to 204
The light transmittance is 30 to 70%.
【００１３】図４は一実施例の投影パターンフィルム５
０９Ｄを示す。このパターンは、透過率の異なる複数の
半透明部４０１〜４０５と、複数の透明部４１１〜４１
８と、複数の不透明部４２１〜４２３とを有し、各半透
明部、各透明部および各不透明部の幅をすべて同一に設
定するとともに、透明部の右隣に半透明部または不透明
部を配列したものである。なお、半透明部２０１〜２０
４の光透過率は３０〜７０パーセントとする。FIG. 4 shows a projection pattern film 5 of one embodiment.
09D is shown. This pattern includes a plurality of translucent portions 401 to 405 having different transmittances and a plurality of transparent portions 411 to 41.
8 and a plurality of opaque parts 421 to 423, all the translucent parts, each transparent part and each opaque part are set to have the same width, and a translucent part or an opaque part is provided on the right side of the transparent part. It is arranged. The semi-transparent parts 201 to 20
The light transmittance of No. 4 is 30 to 70%.
【００１４】上述した各実施例のパターンでは、不透明
部の幅の和がフィルム全体の半分よりも小さく、半分よ
り広い部分に半透明部と透明部が形成されるので、これ
らのパターンを透過する光量は半透明部を含まない従来
のパターンよりも多くなり、被写体を明るく照明でき、
従来よりも明るい投影パターン像に基づいて焦点検出が
行なわれ、焦点検出精度を向上させることができる。ま
た、不透明部により遮られて被写体に光が投射されない
部分に被写体の反射率差が存在する確率が低くなり、確
実に被写体を捕捉でき、焦点検出不能になる確率を低減
できる。また、パターンを透過する光量が増えることに
より、より遠くの被写体に投影パターン像が投射でき、
より遠くの被写体でも焦点検出が可能となる。さらにま
た、半透明部、透明部および不透明部の幅をすべて同一
にしても、投影パターンフィルム全体の透過率がランダ
ムに配列され、光電変換器上の一対の投影パターン像の
一致する箇所が複数個存在するようなことがなく、焦点
検出を誤ることがない。これらの投影パターンフィルム
は、例えば図５に示すように、投射光学系７１１の投射
レンズ７１０の一方の焦点位置近くに配置され、投射レ
ンズ７１０はそれらの投影パターン像を被写体上に投射
し、投影光源７０８、例えば発光ダイオードからの光で
の照明により被写体上のコントラストが小さくなって
も、その被写体上に投影パターン像によるコントラスト
を作り出す。これにより、焦点検出が困難または不能と
なる問題が解決され、焦点検出が可能となる。In the patterns of the above-mentioned respective embodiments, the sum of the widths of the opaque portions is smaller than half of the entire film, and the semitransparent portion and the transparent portion are formed in a portion wider than half of the film, so that these patterns are transmitted. The amount of light is larger than that of the conventional pattern that does not include semi-transparent parts, and it can illuminate the subject brightly,
Focus detection is performed based on a projection pattern image that is brighter than before, and focus detection accuracy can be improved. Further, the probability that the difference in reflectance of the subject exists in the portion where the light is not projected onto the subject because it is blocked by the opaque portion is reduced, and the subject can be reliably captured, and the probability that focus detection cannot be performed can be reduced. Also, by increasing the amount of light that passes through the pattern, it is possible to project a projected pattern image on a distant subject,
Focus detection is possible even for a distant subject. Furthermore, even if the widths of the semi-transparent portion, the transparent portion, and the opaque portion are all the same, the transmittance of the entire projection pattern film is randomly arranged, and there are a plurality of matching portions of the pair of projection pattern images on the photoelectric converter. There is no such thing as an individual, and there is no error in focus detection. As shown in FIG. 5, for example, these projection pattern films are arranged near one focus position of the projection lens 710 of the projection optical system 711, and the projection lens 710 projects those projection pattern images on the subject to project them. Even if the contrast on the subject is reduced by illumination with light from the light source 708, for example, a light emitting diode, the contrast based on the projected pattern image is created on the subject. This solves the problem that focus detection is difficult or impossible, and enables focus detection.
【００１５】なお、投影パターンフィルムのパターンは
上述した実施例に限定されない。例えば、パターンの複
数の光透過率が異なる半透明部の幅をランダムにし、こ
れらの半透明部の光透過率を一定の規則で変化するよう
に形成してもよい。また、上述した実施例では投射光学
系７１１を閃光装置７０７内に設ける例を示したが、閃
光装置７０７外に投射光学系７１１を単独で設置するよ
うにしてもよい。さらに、投射光学系７１１を、カメラ
７０５の上面に設けられたアクセサリーシュー７０６だ
けでなく、カメラ７０５に適当な取り付け部を設けてそ
こに取り付けるようにしてもよいし、あるいはカメラ７
０５に内蔵してもよい。さらに、上述した実施例ではパ
ターンの半透明部の光透過率を３０〜７０％としたが、
半透明部の光透過率は上述した実施例に限定されず、例
えば限りなく透明に近い部分を透明部とし、限りなく不
透明に近い部分を不透明部とし、両者の中間の部分を半
透明部としてもよい。さらにまた、上述した実施例では
半透明部、透明部および不透明部によりパターンを形成
する例を示したが、複数の半透明部のみでパターンを形
成してもよいし、複数の半透明部に透明部および／また
は不透明部を加えてパターンを形成してもよい。The pattern of the projection pattern film is not limited to the above-mentioned embodiment. For example, a plurality of translucent portions having different light transmittances of the pattern may have random widths, and the light transmittances of these semitransparent portions may be changed according to a certain rule. Further, although the projection optical system 711 is provided inside the flash device 707 in the above-described embodiment, the projection optical system 711 may be separately installed outside the flash device 707. Further, the projection optical system 711 may be attached not only to the accessory shoe 706 provided on the upper surface of the camera 705 but also to the camera 705 provided with an appropriate attachment portion, or to be attached thereto.
May be built in 05. Further, in the above-described embodiment, the light transmittance of the semitransparent portion of the pattern is set to 30 to 70%,
The light transmittance of the semi-transparent portion is not limited to the above-mentioned embodiment, for example, a portion that is almost transparent is a transparent portion, a portion that is almost opaque is an opaque portion, and an intermediate portion between the two is a semi-transparent portion. Good. Furthermore, in the above-described embodiment, an example in which the pattern is formed by the semi-transparent portion, the transparent portion and the opaque portion is shown, but the pattern may be formed only by a plurality of semi-transparent portions, or by a plurality of semi-transparent portions. Patterns may be formed by adding transparent parts and / or opaque parts.
【００１６】[0016]
【発明の効果】以上説明したように本発明によれば、投
影パターンフィルムを、光透過率の異なる複数の半透明
部を有するパターンとしたので、不透明部の幅の和が投
影パターンフィルム全体の半分よりも小さく、半分より
広い部分に半透明部と透明部が形成されるので、このよ
うなパターンを透過する光量は半透明部を含まない従来
のパターンよりも多くなり、被写体を明るく照明でき、
従来よりも明るい投影パターン像に基づいて焦点検出が
行なわれ、焦点検出精度を向上させることができる。ま
た、不透明部により遮られて被写体に光が投射されない
部分に被写体の反射率差が存在する確率が低くなり、確
実に被写体を捕捉でき、焦点検出不能になる確率を低減
できる。さらに、パターンを透過する光量が増えること
により、より遠くの被写体に投影パターン像が投射で
き、より遠くの被写体でも焦点検出が可能となる。さら
にまた、半透明部、透明部および不透明部の幅をすべて
同一にしても、投影パターンフィルム全体の透過率がラ
ンダムに配列され、光電変換器上の一対の投影パターン
像の一致する箇所が複数個存在するようなことがなく、
焦点検出を誤ることがない。なお、透明部、半透明部お
よび不透明部の幅をすべて同一にすれば製作しやすくな
る。As described above, according to the present invention, the projection pattern film is a pattern having a plurality of semi-transparent portions having different light transmittances. Therefore, the sum of the widths of the opaque portions is the same as that of the entire projection pattern film. Since the semi-transparent part and the transparent part are formed in the area smaller than half and wider than half, the amount of light transmitted through such a pattern is larger than that of the conventional pattern that does not include the semi-transparent part, and the subject can be illuminated brightly. ,
Focus detection is performed based on a projection pattern image that is brighter than before, and focus detection accuracy can be improved. Further, the probability that the difference in the reflectance of the subject exists in the portion where the light is not projected onto the subject because it is blocked by the opaque portion is reduced, and the subject can be reliably captured, and the probability that focus detection cannot be performed can be reduced. Furthermore, since the amount of light that passes through the pattern increases, a projection pattern image can be projected on a distant subject, and focus detection can be performed on a distant subject. Furthermore, even if the widths of the semi-transparent portion, the transparent portion, and the opaque portion are all the same, the transmittance of the entire projection pattern film is randomly arranged, and there are a plurality of matching portions of the pair of projection pattern images on the photoelectric converter. There is no such thing as an individual,
There is no mistake in focus detection. In addition, if the widths of the transparent portion, the semi-transparent portion and the opaque portion are all the same, it is easy to manufacture.
【図１】一実施例の投影パターンフィルムのパターンを
示す図。FIG. 1 is a diagram showing a pattern of a projection pattern film of one example.
【図２】投影パターンフィルムの他のパターンを示す
図。FIG. 2 is a diagram showing another pattern of a projection pattern film.
【図３】投影パターンフィルムの他のパターンを示す
図。FIG. 3 is a diagram showing another pattern of a projection pattern film.
【図４】投影パターンフィルムの他のパターンを示す
図。FIG. 4 is a diagram showing another pattern of the projection pattern film.
【図５】焦点検出装置を搭載したカメラの横断面図。FIG. 5 is a cross-sectional view of a camera equipped with a focus detection device.
【図６】位相差方式による焦点検出の原理を示す図。FIG. 6 is a diagram showing a principle of focus detection by a phase difference method.
【図７】投影パターンフィルムの従来のパターンを示す
図。FIG. 7 is a diagram showing a conventional pattern of a projection pattern film.
１０１〜１０６，２０１〜２０４，３０１〜３０４，４
０１〜４０５ 半透明部
１１１〜１１４，２１１〜２１６，３１１〜３１８，４
１１〜４１８ 透明部
１２１〜１２６，２２１〜２２６，３２１〜３２４，４
２１〜４２３ 不透明部
７０９Ａ，７０９Ｂ，７０９Ｃ，７０９Ｄ 投影パター
ンフィルム101-106, 201-204, 301-304, 4
01-405 Semi-transparent parts 111-114, 211-216, 311-318, 4
11-418 Transparent parts 121-126, 221-226, 321-324, 4
21-423 Opaque parts 709A, 709B, 709C, 709D Projection pattern film
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭57−118106（ＪＰ，Ａ) 特開 平２−51114（ＪＰ，Ａ) 特開 平６−281854（ＪＰ，Ａ) 実開 昭55−55805（ＪＰ，Ｕ) 実開 平２−24313（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) G02B 7/28 - 7/40 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-118106 (JP, A) JP-A-2-51114 (JP, A) JP-A-6-281854 (JP, A) Actual development Sho-55- 55805 (JP, U) Actual development 2-24313 (JP, U) (58) Fields investigated (Int.Cl. 7 , DB name) G02B 7/ 28-7/40
Claims (10)
レンズとを有する投射光学系により被写体に補助光を投
射し、焦点検出光学系により撮影レンズを通過した被写
体からの一対の光束を光電変換器上に導いて一対の被写
体像を結像し、前記一対の被写体像の像ずれ量に基づい
て前記撮影レンズの焦点調節状態を検出する焦点検出装
置において、 前記投影パターンフィルムのパターンは光透過率の異な
る複数の半透明部を有することを特徴とする焦点検出装
置。1. A pair of light flux from the subject, which has passed through the photographing lens by a focus detection optical system, is projected onto the subject by a projection optical system having a projection light source, a projection pattern film, and a projection lens. In the focus detection device that forms a pair of subject images by guiding to, and detects the focus adjustment state of the photographing lens based on the image shift amount of the pair of subject images, the pattern of the projection pattern film has a light transmittance. A focus detection device having a plurality of different translucent portions.
て、 前記投影パターンフィルムのパターンは透明部を含むこ
とを特徴とする焦点検出装置。2. The focus detection device according to claim 1, wherein the pattern of the projection pattern film includes a transparent portion.
において、 前記投影パターンフィルムのパターンは不透明部を含む
ことを特徴とする焦点検出装置。3. The focus detection device according to claim 1, wherein the pattern of the projection pattern film includes an opaque portion.
点検出装置において、 前記パターンの透明部、半透明部、不透明部の幅をすべ
て同一とすることを特徴とする焦点検出装置。4. The focus detection device according to claim 1, wherein the transparent portion, the semi-transparent portion, and the opaque portion of the pattern have the same width. .
点検出装置おいて、 前記パターンの透明部、半透明部、不透明部の幅をラン
ダムに設定することを特徴とする焦点検出装置。5. The focus detection device according to claim 1, wherein the widths of the transparent portion, the semi-transparent portion, and the opaque portion of the pattern are set at random. apparatus.
点検出装置において、 前記パターンの透明部、半透明部、不透明部を周期的に
配列することを特徴とする焦点検出装置。6. The focus detection device according to claim 1, wherein a transparent portion, a semitransparent portion, and an opaque portion of the pattern are periodically arranged.
点検出装置において、 前記パターンの透明部、半透明部、不透明部をランダム
に配列することを特徴とする焦点検出装置。7. The focus detection device according to claim 1, wherein the transparent portion, the semitransparent portion, and the opaque portion of the pattern are randomly arranged.
点検出装置において、 半透明部の光透過率を７０〜３０％とすることを特徴と
する焦点検出装置。8. The focus detection device according to claim 1, wherein the semitransparent portion has a light transmittance of 70 to 30%.
点検出装置において、 前記投射光学系をカメラの外部に取り付けることを特徴
とする焦点検出装置。9. The focus detection device according to claim 1, wherein the projection optical system is attached to the outside of the camera.
焦点検出装置において、 前記投射光学系をカメラに内蔵することを特徴とする焦
点検出装置。10. The focus detection device according to claim 1, wherein the projection optical system is built in a camera.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8271495A JP3448617B2 (en) | 1995-04-07 | 1995-04-07 | Focus detection device |
| US08/601,847 US5771412A (en) | 1995-02-15 | 1996-02-15 | Focus detection device and method using a projection pattern material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8271495A JP3448617B2 (en) | 1995-04-07 | 1995-04-07 | Focus detection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08278533A JPH08278533A (en) | 1996-10-22 |
| JP3448617B2 true JP3448617B2 (en) | 2003-09-22 |
Family
ID=13782087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8271495A Expired - Lifetime JP3448617B2 (en) | 1995-02-15 | 1995-04-07 | Focus detection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3448617B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5803065B2 (en) * | 2010-07-30 | 2015-11-04 | 株式会社ニコン | Focus detection apparatus and imaging apparatus |
-
1995
- 1995-04-07 JP JP8271495A patent/JP3448617B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08278533A (en) | 1996-10-22 |
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