JPS6173937A - Camera equipped with ttl viewfinder and automatic focusing optical system - Google Patents
Camera equipped with ttl viewfinder and automatic focusing optical systemInfo
- Publication number
- JPS6173937A JPS6173937A JP19704984A JP19704984A JPS6173937A JP S6173937 A JPS6173937 A JP S6173937A JP 19704984 A JP19704984 A JP 19704984A JP 19704984 A JP19704984 A JP 19704984A JP S6173937 A JPS6173937 A JP S6173937A
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical system
- infrared light
- viewfinder
- automatic focusing
- 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)
- Viewfinders (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明はＴＴＬ光学ファインダーとＴＴＬオートフォー
カス光学系特に赤外光を被写体に投光し、その反射光を
受光するアクティブオートフォーカス用光学系とを備え
たカメラに関するものである。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a TTL optical finder and a TTL autofocus optical system, particularly an active autofocus optical system that projects infrared light onto a subject and receives the reflected light. This relates to a camera equipped with a camera.
従来、カメラにおいてｍ−７ミラーで撮影光束から分割
されたＴＴＬ ７アインダ一光束中にマイクロプリズム
等の測距手段を配置した構成とした光学系は知られてい
る。この測距手段に代えてアクティブオートフォーカス
用光学系を配置することＡＰ光学系は共に光の利用効率
が悪い。一方、ビデオカメラ等ではＴＴＬファインダー
の代）に撮像素子からの電気信号によシ像をＣＲＴ （
ブラウン管Ｃ上に表示する電子ビューファインダー（Ｅ
ＶＦ’）が用いられることが多く、この場合はファイン
ダーの明るさもオート７オーカスの効率も高いが消費電
力の増大や重量Ｑ大きさの増加という欠点があった。2. Description of the Related Art Conventionally, in a camera, an optical system is known in which a distance measuring means such as a micro prism is arranged in a TTL 7 eyeliner light beam divided from a photographing light beam by an M-7 mirror. Providing an active autofocus optical system in place of the distance measuring means causes poor light utilization efficiency in both AP optical systems. On the other hand, in video cameras, etc., the image is transferred to a CRT (instead of a TTL viewfinder) using electrical signals from an image sensor.
Electronic viewfinder (E) displayed on cathode ray tube C
VF') is often used, and in this case, the brightness of the finder and the efficiency of the auto7 orcus are high, but there are drawbacks such as increased power consumption and increased weight Q.
本発明の目的は赤外光を利用するＴＴＬアクティブオー
トフォーカス光学系とＴＴＬファインダー光学系とを組
合せて備え、且つファインダーの明るさもオートフォー
カスの光の利用効率も極めて、高いカメラを提供するに
ある。An object of the present invention is to provide a camera that is equipped with a combination of a TTL active autofocus optical system that uses infrared light and a TTL finder optical system, and that has extremely high finder brightness and autofocus light usage efficiency. .
本発明によれば、撮影光学系中に可視光を透過および反
射し赤外光を実質的に完全に透過する第１の光分割器を
配置すると共に、該第１の光分割器での透過による分割
光路中に可視光を実質的に完全に反射し赤外光を実質的
に完全に透過する第２の光分割器を配置し、撮影光学系
ならびに上記第１および第２の光分割器を経由した可視
光をファインダー光となし、他方、撮影光学系ならびに
上記第１および第２の光分割器を経由して赤外光の被写
体への投光および被写体から反射する赤外光の受光の少
なくとも一方を行うことを特徴とするＴＴＬファインダ
ーおよびオートフォーカス光学系を備えたカメラが提供
される。According to the present invention, a first light splitter that transmits and reflects visible light and substantially completely transmits infrared light is disposed in the photographing optical system, and the first light splitter transmits and reflects visible light and substantially completely transmits infrared light. A second light splitter that substantially completely reflects visible light and substantially completely transmits infrared light is disposed in the split optical path, and includes a photographing optical system and the first and second light splitters. The visible light that has passed through the camera is used as finder light, and the infrared light is projected onto the subject and the infrared light reflected from the subject is received via the photographic optical system and the first and second light splitters. Provided is a camera equipped with a TTL finder and an autofocus optical system that performs at least one of the following.
〔発明の実施例〕
第１図は本発明をズームレンズを撮影レンズとするカメ
ラに適用した実施例である。[Embodiment of the Invention] FIG. 1 shows an embodiment in which the present invention is applied to a camera using a zoom lens as a photographing lens.
本実施例では、赤外光を投射された被写体から反射した
赤外光を撮影レンズを通して受光するＴＴＬ赤外受光系
としてのオートフォーカス光学系を例に採る。以下オー
トフォーカスをＡＦ’と略記する。ズーム部１を通過し
た光束は光分割器２の光分割面２′によシ撮影用光束と
ファインダー及びＡｆ’用光束とに分割される。該分割
面２′で反射された撮影用光束は絞３および結像レンズ
系４を通シフイルム面又は撮像素子面Ｆに結像する。一
方、光分割面２′を透過した光束はファインダー及びＡ
Ｆのための対物レンズ５を通シ、第２の光分割面６によ
りＡＦ用光路とファインダー用光路に分割される。光分
割面６を透過した後のＡＦ用光路には受光用補助レンズ
７が配置され、要素１〜７よシなるＡＦ’受光用光学系
のほぼ焦点位置に赤外受光素子８が配置されている。一
方、光分割面６を反射したファインダー光路には一次ピ
ント面にピント板９が配置され、次いで全反射ミラー１
０で反射され、像正立用レンズ１１で二次ピント面１２
に正立正像を結び、アイピース１３によシこれが観察さ
れる。This embodiment takes as an example an autofocus optical system as a TTL infrared receiving system that receives infrared light reflected from an object onto which infrared light is projected through a photographing lens. Hereinafter, autofocus will be abbreviated as AF'. The light beam that has passed through the zoom section 1 is divided by the light splitting surface 2' of the light splitter 2 into a light beam for photographing and a light beam for the finder and Af'. The photographing light beam reflected by the dividing surface 2' passes through an aperture 3 and an imaging lens system 4 and forms an image on a film surface or an image pickup element surface F. On the other hand, the light beam transmitted through the light splitting surface 2' is transmitted through the finder and the A
The light passes through an objective lens 5 for F, and is divided into an AF optical path and a finder optical path by a second light splitting surface 6. A light-receiving auxiliary lens 7 is arranged in the AF optical path after passing through the light splitting plane 6, and an infrared light-receiving element 8 is arranged almost at the focal point of the AF' light-receiving optical system consisting of elements 1 to 7. There is. On the other hand, in the finder optical path reflected by the light splitting surface 6, a focusing plate 9 is placed on the primary focusing surface, and then a total reflection mirror 1
0, and is reflected by the image erecting lens 11 at the secondary focus surface 12.
This is observed through the eyepiece 13.
さてこの光分割面２′及び６がどの波長の光について鳥
同じ比率で強度分割をするもの、例えばどの波長の光も
５０チ透過、５０％反射するものとし、かつ全光束をカ
バーするー・−クミラーである ゛と仮定するとＡＦ系
およびファインダー系には撮影レンズ入射光の夫々２５
チの光が到達する。しかしファインダーを明るくし、ま
たＡＦ系の性能を向上するには、この効率はさらに上げ
ることが望ましい。このためには、ＡＦ光学系に関して
は、光学ファインダーを用いないカメラでは光分割器２
を可視光完全反射、赤外光完全透過の特性を持つダイク
ロイックミラーとすればよいが、そうするとＴＴＬ光学
ファインダーを備えているカメラではファインダー観察
が不可能になる。またＡ１１ｔ’光束とファインダー光
束を撮影光束中から別々の光分割器で取出せば各々の光
到達効率は上げられるが、光分割器が撮影光学系中に２
つ必要となシ、スペース上もコスト上も好ましくない。Now, let's say that these light splitting surfaces 2' and 6 split the intensity of light of any wavelength at the same ratio, for example, that light of any wavelength is transmitted through 50 pixels and reflected by 50%, and covers the entire luminous flux. - Assuming that the AF system and finder system are
Chi's light arrives. However, in order to brighten the finder and improve the performance of the AF system, it is desirable to further increase this efficiency. For this purpose, the AF optical system requires a light splitter 2 for cameras that do not use an optical viewfinder.
It is possible to use a dichroic mirror that completely reflects visible light and completely transmits infrared light, but if this is done, viewfinder observation becomes impossible with a camera equipped with a TTL optical finder. Furthermore, if the A11t' luminous flux and the finder luminous flux are extracted from the photographing optical system using separate light splitters, the efficiency of each light reaching the light beam can be increased, but if the light splitter is in the photographic optical system, two
However, it is not desirable in terms of space and cost.
特に、絞シ３を絞った状態でもファインダー及びＡＦに
影響を及ぼさないようこれら２つのプリズムは絞より前
方に配置することが必要であることから、レンズ第１面
から絞までの距離が増大するため全長の増大と同時に前
玉径の増大をも招くので好ましくない。In particular, it is necessary to place these two prisms in front of the aperture so that they do not affect the viewfinder and AF even when the aperture is stopped down, so the distance from the first surface of the lens to the aperture increases. Therefore, this is not preferable since it causes an increase in the diameter of the front lens as well as an increase in the overall length.
そこで本発明実施例では、第１図において光分割面２′
および６の光学特性を適切に設定することによシ単一の
光分割器２を撮影光路内に設けるだけで、ファインダー
及びＡＦ用光学系の光到達率すなわち光利用効率を上げ
ることを可能とした。Therefore, in the embodiment of the present invention, in FIG.
By appropriately setting the optical characteristics of 2 and 6, it is possible to increase the light arrival rate of the finder and AF optical system, that is, the light utilization efficiency, simply by installing a single light splitter 2 in the photographing optical path. did.
すなわち光分割面２′は可視光についてはどの波長の可
視光についても同じ北本で強度分割を行い、赤外光につ
いてはほとんど完全に透過するような特性を持つように
構成する。このような光分割器はいわゆるー・−７ミラ
ーの構成と、可視光・赤外光のダイクロイックミラーの
構成を組合せた多層膜構成とすることによシ実現できる
。一方、光分割面６は赤外光を殆ど完全に透過し可視光
を殆んど完全に反射するグイクロイックミラーとする。That is, the light splitting surface 2' is configured to have a characteristic that the intensity of visible light of any wavelength is divided by the same Kitamoto, and infrared light is almost completely transmitted. Such a light splitter can be realized by using a multilayer structure that combines a so-called -7 mirror structure and a dichroic mirror structure for visible light and infrared light. On the other hand, the light splitting surface 6 is a gicroic mirror that almost completely transmits infrared light and almost completely reflects visible light.
これにより上記効率を大巾に上げることができる。This allows the efficiency to be greatly increased.
例えばハーフミラ−２′は可視光について５０％透過、
５０係反射で赤外光については１００チ透過という理想
的特性を有するものとし、一方、−・−７ミラー６は可
視光１００チ反射、赤外光１００チ透過という特性を有
すると仮定すると、ファインダー系には撮影レンズ入射
光の５０係が到達し、ＡＦ’光学系には１００’ｌが到
達する。従って両者がどの波長の光についても５０チ透
過、５０％反射の一一一フミラーで構成された場合に比
較して、ファインダー系は２倍のまたＡＦ系は４倍の効
率が得られる。上記は理想的特性の場合について比較し
たものであるが、実際の設計データ上の比較でも効率は
極めて高くできる。通常の赤外光受光素子は可視光にも
感度を有しているのでＡＦ倍信号Ｓハを良くするため、
可視光カットフィルターを併用するが、本実施例におい
ては、光分割器６がその効果を有しているため可視光カ
ットフィルターを省略できる。For example, half mirror 2' transmits 50% of visible light.
Assuming that it has the ideal characteristics of 50-degree reflection and 100-degree transmission of infrared light, on the other hand, the -.-7 mirror 6 has the characteristics of 100-degree reflection of visible light and 100-degree transmission of infrared light. 50 parts of the light incident on the photographing lens reaches the finder system, and 100'l reaches the AF' optical system. Therefore, compared to a case where both mirrors are configured with an 1-1 mirror that transmits 50 pixels and reflects 50% for light of any wavelength, the efficiency of the finder system is twice as high, and the efficiency of the AF system is 4 times as high. Although the above comparison is based on ideal characteristics, the efficiency can be extremely high even when compared on actual design data. Ordinary infrared light receiving elements are sensitive to visible light, so in order to improve the AF multiplication signal S,
Although a visible light cut filter is also used, in this embodiment, the visible light cut filter can be omitted because the light splitter 6 has this effect.
前記実施例のファインダー系は二次結像系の場合の概要
構成であって、具体的にはカメラのレイアウトに応じて
配置を変更した）、フィールドレンズや視野マスクを追
加しても良い。また対物レンズ５の前にハーフミラ−６
を配置し反射後の光束中に対物レンズ５を置くことも可
能である。この場合受光用補助レンズ７のパワーを強く
することが必要である。逆に前記実施例の配置で受光用
補助レンズ７を省略することも可能である。前記実施例
において、被写体への赤外光投光系は撮影光学系外部に
配置されていてよい。要素１〜７で構成されるＡＦ’光
学系はできるだけ赤外光の光量ロスを少くするようコー
ティング等の手段が併用されることが好ましい。The finder system in the embodiment described above is a general configuration of a secondary imaging system, and specifically, the arrangement was changed depending on the layout of the camera.) A field lens and a field mask may be added. In addition, a half mirror 6 is placed in front of the objective lens 5.
It is also possible to place the objective lens 5 in the reflected light beam. In this case, it is necessary to increase the power of the light receiving auxiliary lens 7. Conversely, it is also possible to omit the light-receiving auxiliary lens 7 in the arrangement of the embodiment described above. In the embodiments described above, the infrared light projection system to the subject may be placed outside the photographing optical system. In the AF' optical system composed of elements 1 to 7, it is preferable to use means such as coating in order to reduce the loss of the amount of infrared light as much as possible.
また前記実施例の他に、第１図において赤外受光素子８
を赤外光源に置換し、そこから発した赤外光を前記と逆
慨路を辿って被写体へ投光するＡ’Ｆ用赤外投光系を構
成した実施例も可能であり、この場合には該光源の赤外
光の投光効率が向上する効果が得られることになる。ま
た第１図において赤外受光素子８の近傍に赤外光源を並
置して赤外光の投光および受光をいずれも如上のＴＴＬ
光路を介して行う実施例も可能であシ、この場合にはＡ
Ｆ用の赤外光の投光および受光の両者の効率が向上する
効果が得られることになる。In addition to the above-mentioned embodiment, an infrared light receiving element 8 is shown in FIG.
It is also possible to construct an infrared projection system for A'F in which the infrared light source is replaced with an infrared light source and the infrared light emitted from the infrared light is projected onto the subject in the opposite direction to that described above; in this case, This results in the effect of improving the infrared light projection efficiency of the light source. In addition, in FIG. 1, an infrared light source is arranged near the infrared light-receiving element 8, and both the emission and reception of infrared light can be performed using the same TTL method.
An embodiment carried out via the optical path is also possible, in which case A
This results in the effect of improving the efficiency of both the emission and reception of the F infrared light.
なお本発明は一次結像を観察するＴＴＬ ファインダー
系を持つカメラにも本発明は適用可能である。Note that the present invention is also applicable to a camera having a TTL finder system for observing primary imaging.
以上説明したように本発明によれば、ＴＴＬ光学ファイ
ンダーとＴＴＬ赤外アクティブＡＦ光学系を同時に備え
、しかもファインダーが明るく且つＡ’ Ｆ光学系の赤
外光利用効率も向上する効果があり、ＡＦ左カメラビデ
オカメラを含め）の性能向上、小型軽量化、省電力化に
資することができる。As explained above, according to the present invention, a TTL optical finder and a TTL infrared active AF optical system are simultaneously provided, and the finder is bright and the infrared light utilization efficiency of the A'F optical system is also improved. This can contribute to improving the performance of the left camera (including the video camera), making it smaller and lighter, and saving power.
第１図は本発明の一実施例の概要構成図である。 FIG. 1 is a schematic diagram of an embodiment of the present invention.
Claims (1)
的に完全に透過する第１の光分割器を配置すると共に、
該第１の光分割器での透過による分割光路中に可視光を
実質的に完全に反射し赤外光を実質的に完全に透過する
第２の光分割器を配置し、撮影光学系ならびに上記第１
および第２の光分割器を経由した可視光をファインダー
光となし、他方、撮影光学系ならびに上記第１および第
２の光分割器を経由して赤外光の被写体への投光および
被写体から反射する赤外光の受光の少くとも一方を行う
ことを特徴とするＴＴＬファインダーおよびオートフォ
ーカス光学系を備えたカメラ。disposing a first light splitter that transmits and reflects visible light and substantially completely transmits infrared light in the photographing optical system;
A second light splitter that substantially completely reflects visible light and substantially completely transmits infrared light is disposed in the split optical path resulting from transmission by the first light splitter, and includes a photographing optical system and 1st above
The visible light that has passed through the optical system and the second light splitter is used as finder light, and the infrared light is projected onto and from the subject via the photographic optical system and the first and second light splitters. A camera equipped with a TTL viewfinder and an autofocus optical system, which performs at least one of receiving reflected infrared light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19704984A JPS6173937A (en) | 1984-09-20 | 1984-09-20 | Camera equipped with ttl viewfinder and automatic focusing optical system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19704984A JPS6173937A (en) | 1984-09-20 | 1984-09-20 | Camera equipped with ttl viewfinder and automatic focusing optical system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6173937A true JPS6173937A (en) | 1986-04-16 |
Family
ID=16367859
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19704984A Pending JPS6173937A (en) | 1984-09-20 | 1984-09-20 | Camera equipped with ttl viewfinder and automatic focusing optical system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6173937A (en) |
-
1984
- 1984-09-20 JP JP19704984A patent/JPS6173937A/en active Pending
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