JPH05134169A - Focal point detecting device - Google Patents
Focal point detecting deviceInfo
- Publication number
- JPH05134169A JPH05134169A JP3295872A JP29587291A JPH05134169A JP H05134169 A JPH05134169 A JP H05134169A JP 3295872 A JP3295872 A JP 3295872A JP 29587291 A JP29587291 A JP 29587291A JP H05134169 A JPH05134169 A JP H05134169A
- Authority
- JP
- Japan
- Prior art keywords
- focus detection
- detection system
- half mirror
- lens
- light
- 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.)
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- Automatic Focus Adjustment (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、カメラ等に用いる測距
範囲と合焦精度を改善した焦点検出装置に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detecting device used in a camera or the like, which has improved distance measuring range and focusing accuracy.
【０００２】[0002]
【従来の技術】撮影レンズによって形成された像を、再
結像光学系により二分割して光電変換素子列（受光素子
列）上に再形成し、その二像の位置ずれにより合焦検出
がなされる焦点検出光学系については、これまでに多数
の提案がある。例えば、特開昭５５ー１１８０１９号公
報、特開昭５８ー１０６５１１号公報及び特開昭６０ー
３２０１２号公報などがある。これらは、いずれも一列
の受光素子列を用いて合焦検出を行っており、以下のよ
うな特性がある。2. Description of the Related Art An image formed by a photographing lens is divided into two by a re-imaging optical system and re-formed on a photoelectric conversion element array (light-receiving element array), and a focus shift is detected by a position shift between the two images. Many proposals have been made so far regarding the focus detection optical system. For example, there are JP-A-55-118019, JP-A-58-106511 and JP-A-60-32012. In each of these, focus detection is performed using one light receiving element row, and has the following characteristics.
【０００３】焦点検出系において、測距範囲の広さと合
焦精度とは、一般に相反する関係がある。受光素子列
は、通常等間隔に各受光素子が配列してあり、隣接する
二つの受光素子間の間隔をそれぞれ１ピッチとすると、
合焦精度は１ピッチに対する相対尺度として普通表され
る。合焦精度を１ピッチのＭ分の１（Ｍは定数）である
とし、１ピッチ当たりの像面でのデフォーカス量をαと
すると、像面での合焦精度Δは（１）式である。In the focus detection system, the width of the distance measuring range and the focusing accuracy generally have a contradictory relationship. In the light receiving element array, each light receiving element is normally arranged at equal intervals, and if the interval between two adjacent light receiving elements is 1 pitch,
Focusing accuracy is usually expressed as a relative scale for one pitch. Assuming that the focusing accuracy is 1 / M of one pitch (M is a constant), and the defocus amount on the image surface per pitch is α, the focusing accuracy Δ on the image surface is given by equation (1). is there.
【０００４】 Δ＝±（１／Ｍ）α・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・（１）Δ = ± (1 / M) α ...・ ・ ・ ・ ・ ・ ・ ・ (1)
【０００５】そうして合焦精度は、Δが大きい方が悪
く、小さいほど良い。また、受光素子数をＮ（定数）と
すると、像面での測距範囲Σは（２）式である。Thus, the focusing accuracy is worse when Δ is larger and the smaller is better. Further, when the number of light receiving elements is N (constant), the distance measuring range Σ on the image plane is expressed by the equation (2).
【０００６】 Σ＝｜±Ｎα｜・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・（２）Σ = | ± Nα | ...・ ・ ・ ・ ・ ・ ・ (2)
【０００７】（１）式、（２）式から、αを大きくする
と、測距範囲Σは大きくなるが、合焦精度Δは悪くな
り、逆に、αを小さくすると、合焦精度Δは良くなる
が、測距範囲Σは小さくなり、両者が相反関係にあるこ
とが分かる。これを解決するために、複数の焦点検出系
を用いる提案がなされている。From the expressions (1) and (2), when α is increased, the range Σ is increased, but the focusing accuracy Δ is deteriorated. Conversely, when α is decreased, the focusing accuracy Δ is improved. However, the distance measuring range Σ becomes smaller, and it can be seen that the two have a reciprocal relationship. In order to solve this, a proposal using a plurality of focus detection systems has been made.
【０００８】その一つとして、特開昭６３ー８８５１１
号公報では、測距範囲の拡大と合焦精度の向上の両方を
同時に満足する焦点検出装置を提案している。図７は、
この提案による焦点検出装置を、一眼レフカメラボディ
の底部に配した例を示してある。図８は、この提案によ
る互いに直交した焦点検出系の構成を示したものであ
る。図９は、互いに直交した焦点検出系のうちの一つの
焦点検出系の構成を示したものである。図１０は、互い
に直交した焦点検出系のうちのもう一つの焦点検出系の
構成を示したもので、図９が光軸を中心に９０°回転さ
れた状態が表されている。[0008] As one of them, Japanese Patent Laid-Open No. 63-88511
Japanese Patent Laid-Open Publication No. 2003-242242 proposes a focus detection device that simultaneously satisfies both the expansion of the range-finding range and the improvement of focusing accuracy. Figure 7
An example is shown in which the focus detection device according to this proposal is arranged at the bottom of a single-lens reflex camera body. FIG. 8 shows the configuration of mutually orthogonal focus detection systems according to this proposal. FIG. 9 shows the configuration of one of the focus detection systems which are orthogonal to each other. FIG. 10 shows the configuration of another focus detection system out of the mutually orthogonal focus detection systems, and FIG. 9 shows a state in which the focus detection system is rotated by 90 ° about the optical axis.
【０００９】図７〜図１０で１は撮影レンズ、２はクイ
ックリターンミラー、３は予定結像面、４は予定結像面
３の近傍に配置されたコンデンサーレンズ、６はコンデ
ンサーレンズ４の後方に配置され、合焦精度を確保し得
る間隔で互いに垂直な方向に並ぶ二対の開口部を有する
明るさ絞り、７は明るさ絞り６の各後方にそれぞれ配置
され、互いに垂直な方向に並ぶ二対のセパレータレン
ズ、８，９はセパレータレンズ７から射出した光束の結
像位置に配置され、光軸に垂直な方向に並ぶ二対の受光
素子列である。図１１，図１２及び図１３は、それぞれ
光軸方向から見た明るさ絞り６，セパレータレンズ７及
び受光素子列８，９の平面図である。このとき、各開口
部を通過する光束は、互いに独立である。In FIGS. 7 to 10, 1 is a taking lens, 2 is a quick return mirror, 3 is a planned image forming plane, 4 is a condenser lens arranged near the planned image forming plane 3, and 6 is a rear side of the condenser lens 4. The aperture diaphragms 7 having two pairs of apertures arranged in a direction perpendicular to each other at an interval capable of ensuring focusing accuracy, 7 are arranged behind each aperture diaphragm 6 and arranged in a direction perpendicular to each other. Two pairs of separator lenses, 8 and 9 are two pairs of light receiving element arrays arranged at the image forming position of the light flux emitted from the separator lens 7 and arranged in the direction perpendicular to the optical axis. 11, 12 and 13 are plan views of the aperture stop 6, the separator lens 7 and the light receiving element rows 8 and 9 as seen from the optical axis direction. At this time, the light fluxes passing through the respective openings are independent of each other.
【００１０】互いに直交した焦点検出系を焦点検出系
１，焦点検出系２とすると、焦点検出系１，２の検出デ
フォーカス量Ｄは、（３）式、（４）式のようになる。Assuming that the focus detection systems which are orthogonal to each other are the focus detection system 1 and the focus detection system 2, the detection defocus amounts D of the focus detection systems 1 and 2 are expressed by the equations (3) and (4).
【００１１】 Ｄ1 ＝（ＦW1／β1 ）Ｐ1 ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・（３）D 1 = (F W1 / β 1 ) P 1 ... (3)
【００１２】 Ｄ2 ＝（ＦW2／β2 ）Ｐ2 ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・（４）D 2 = (F W2 / β 2 ) P 2 ... ... (4)
【００１３】ただし、Ｄは焦点検出系の検出デフォーカ
ス量、Ｐは焦点検出系の受光素子列上の像位相差量、β
は焦点検出系の像倍率、ＦW は焦点検出系の検出重心光
束のＦナンバーであり、下添字１，２はそれぞれ焦点検
出系１，２に関するものである。なお、重心光束とは、
明るさ絞りの中心を通る光線により規定される光束のこ
とである。However, D is the detected defocus amount of the focus detection system, P is the image phase difference amount on the light receiving element array of the focus detection system, β
Is the image magnification of the focus detection system, F W is the F number of the detected centroid light flux of the focus detection system, and the subscripts 1 and 2 relate to the focus detection systems 1 and 2, respectively. The centroid light flux is
A luminous flux defined by a light ray passing through the center of the aperture stop.
【００１４】要するに、焦点検出系１，２のＦW1，
β1 ，ＦW2，β2 を適切に設定することにより、合焦精
度は若干劣るものの測距デフォーカス範囲が広い焦点検
出系１と、測距デフォーカス範囲が狭いながらも合焦精
度のすぐれた焦点検出系２とで焦点検出装置を構成し、
測距範囲の拡大と合焦精度の向上の両方を同時に満足す
る焦点検出装置を得ることができる。しかし、この光学
系では、一次結像面とコンデンサーレンズとセパレータ
レンズ及び受光素子列の位置関係、コンデンサーレンズ
の形状が、焦点検出系１，２で共通なので、受光素子列
を同一平面に配置するには、焦点検出系１，２の像倍率
は等しくしなければならない。このため、十分に測距範
囲の拡大と合焦精度の向上の両方を同時に満足するに
は、ＦW1，ＦW2の差を大きくする必要がある。また、焦
点検出系１の受光素子列の方向のコントラストが低い場
合、焦点検出系２で焦点合わせを行うことができる。In short, F W1 of the focus detection systems 1 and 2,
By properly setting β 1 , F W2 , and β 2 , the focusing accuracy is slightly inferior, but the focus detection system 1 has a wide ranging defocus range, and the focusing accuracy is excellent even though the ranging defocus range is narrow. And a focus detection system 2 to form a focus detection device,
It is possible to obtain a focus detection device that simultaneously satisfies both the expansion of the range-finding range and the improvement of focusing accuracy. However, in this optical system, the positional relationship among the primary image forming surface, the condenser lens, the separator lens, and the light receiving element array, and the shape of the condenser lens are common to the focus detection systems 1 and 2, so the light receiving element arrays are arranged on the same plane. Therefore, the image magnifications of the focus detection systems 1 and 2 must be equal. Therefore, it is necessary to increase the difference between F W1 and F W2 in order to satisfy both the expansion of the distance measurement range and the improvement of focusing accuracy at the same time. When the contrast in the direction of the light receiving element array of the focus detection system 1 is low, the focus detection system 2 can perform focusing.
【００１５】この提案によれば、複数の焦点検出系の少
なくとも一つについては、図１４に示すように撮影レン
ズを射出し一対の受光素子列８に入射する二光束が、そ
れぞれ異なった角度θb , θc でハーフミラーで構成さ
れるクイックリターンミラー２に入射する。したがっ
て、この二光束は異なる屈折作用を受け、また、ハーフ
ミラーの分光透過率が入射角により変化するので、二光
束のセンサーに入射する分光特性も異なり、正確な測距
ができなくなる。これに対して、特開昭６３ー１１８１
１２号公報や特開昭６４ー５６４０７号公報では、セパ
レータレンズを非対称に構成することにより、ハーフミ
ラーでの異なる屈折作用を補正する方法を提案してい
る。また、特開平２ー１３２４０７号公報は、ハーフミ
ラーの分光透過率が入射角度によって変化しないような
誘電体多層膜の蒸着方法を公開している。According to this proposal, with respect to at least one of the plurality of focus detection systems, two light fluxes emitted from the photographing lens and incident on the pair of light receiving element rows 8 as shown in FIG. b, enters quick return mirror 2 consists of a half mirror theta c. Therefore, the two light fluxes are subjected to different refraction effects, and the spectral transmittance of the half mirror changes depending on the incident angle. Therefore, the spectral characteristics of the two light fluxes incident on the sensor are different, and accurate distance measurement cannot be performed. On the other hand, Japanese Patent Laid-Open No. 63-1181
No. 12 and Japanese Patent Laid-Open No. 64-56407 propose a method of correcting different refraction effects in a half mirror by making a separator lens asymmetric. Further, JP-A-2-132407 discloses a vapor deposition method of a dielectric multilayer film in which the spectral transmittance of the half mirror does not change depending on the incident angle.
【００１６】[0016]
【発明が解決しようとする課題】上記のような手段で、
測距範囲の拡大と合焦精度の向上の両方を、ともに満足
する焦点検出装置を構成できる。また、被写体のコント
ラスト方向によらず、測距可能な焦点検出装置を構成す
ることができる。更に、ハーフミラーを用いるクイック
リターンミラーに二光束が異なる入射角度で入射すると
きの屈折作用の違い、入射角度によるハーフミラーの分
光透過率の変化への対策案もある。しかし、セパレータ
レンズを非対称に形成する方法は、クイックリターンミ
ラーで受ける異なった屈折作用を確実にキャンセルする
ために、組立時の誤差に対しての補正が必要であり、製
作性、組立性が良くない。特に、複数の焦点検出系のセ
パレータレンズを一体的に形成するときに、この傾向は
顕著になる。また、ハーフミラーの分光透過率が入射角
度で変化しないようにするには、誘電体多層膜の膜厚の
許容誤差を厳しくする必要がある。それでも、入射角度
によるハーフミラーの分光透過率の変化を、なくすこと
はできない。With the above means,
It is possible to configure a focus detection device that satisfies both the expansion of the range-finding range and the improvement of focusing accuracy. Further, it is possible to configure a focus detection device capable of distance measurement regardless of the contrast direction of the subject. Furthermore, there are also countermeasures against a difference in refraction when two light fluxes are incident on a quick return mirror using a half mirror at different incident angles and a change in the spectral transmittance of the half mirror depending on the incident angle. However, the method of forming the separator lens asymmetrically requires the correction of the error at the time of assembling in order to surely cancel the different refraction effect that is received by the quick return mirror, and the manufacturability and the assemblability are good. Absent. In particular, this tendency becomes remarkable when a plurality of focus detection system separator lenses are integrally formed. Further, in order to prevent the spectral transmittance of the half mirror from changing with the incident angle, it is necessary to tighten the tolerance of the thickness of the dielectric multilayer film. Even so, the change in the spectral transmittance of the half mirror due to the incident angle cannot be eliminated.
【００１７】本発明は、上記の事情に鑑み、測距範囲の
拡大と合焦精度の向上の両方を同時に満足し、ハーフミ
ラー透過時の影響を受けず、製作実装が容易な焦点検出
装置の提供を目的としている。また、被写体のコントラ
スト方向によらず測距可能であり、ハーフミラー透過時
の影響を受けず、製作実装が容易な焦点検出装置の提供
も目的としている。In view of the above circumstances, the present invention provides a focus detection device which satisfies both the expansion of the distance measuring range and the improvement of focusing accuracy at the same time, is not affected by the transmission of the half mirror, and is easy to manufacture and mount. It is intended to be provided. Another object of the present invention is to provide a focus detection device that can measure distance regardless of the contrast direction of a subject, is not affected by transmission through a half mirror, and is easy to manufacture and mount.
【００１８】[0018]
【課題を解決するための手段】本発明による焦点検出装
置は、撮影レンズの異なる領域をそれぞれ通過する二光
束による光強度分布を光電変化手段で受け該光電変化手
段から得られる該光強度分布を表す出力信号の位相差を
利用する複数の焦点検出系と、該撮影レンズと複数の該
焦点検出系の間に光軸に対して傾斜させて配置したハー
フミラーとを含む焦点検出装置において、複数の該焦点
検出系のうち最も焦点検出精度の高い焦点検出系に対す
る該ハーフミラーへの該二光束の入射角の差が、他の焦
点検出系に対する該ハーフミラーへの該二光束の入射角
の差より大きくないことを特徴としている。A focus detecting apparatus according to the present invention receives a light intensity distribution of two light beams passing through different regions of a photographing lens by a photoelectric changing means, and obtains the light intensity distribution obtained from the photoelectric changing means. In a focus detection device including a plurality of focus detection systems that utilize the phase difference of the output signals that are expressed, and a half mirror that is disposed between the photographing lens and the plurality of focus detection systems with a tilt with respect to the optical axis, Of the focus detection system having the highest focus detection accuracy among the focus detection systems, the difference in the incident angle of the two light beams to the half mirror is equal to the angle of incidence of the two light beams to the other half focus mirror. It is characterized by not being larger than the difference.
【００１９】更に、詳しく述べる。撮影レンズから射出
した二光束の進む方向が、クイックリターンミラーの回
転軸と平行な場合、二光束のクイックリターンミラーへ
の入射角は等しくなり、同じ屈折作用を受け、分光透過
率は同じになる。本発明では、測距デフォーカス範囲が
広い焦点検出系と、測距デフォーカス範囲は狭いが合焦
精度のすぐれた焦点検出系のうち、合焦精度のすぐれた
焦点検出系に用いる撮影レンズから射出した二光束の進
む方向を、クイックリターンミラーの回転軸とほぼ平行
にすることにより、測距範囲の拡大と合焦精度の向上の
両方を同時に満足し、ハーフミラー透過時の影響を受け
ず、製作実装が容易な焦点検出装置を構成した。この場
合、測距デフォーカス範囲が広い焦点検出系は、ハーフ
ミラーでの屈折作用の受け方、分光透過率の変化が二光
束で異なり、合焦精度が落ちる。しかし元来、合焦精度
が高くない系なので、大きな影響はない。更に、一般的
に測距デフォーカス範囲が広い焦点検出系は、Ｆw が暗
いため、ハーフミラーへの入射角の差が小さいので、ハ
ーフミラーの影響も受けにくい。Further details will be described. When the directions of the two light fluxes emitted from the shooting lens are parallel to the rotation axis of the quick return mirror, the incident angles of the two light fluxes on the quick return mirror are equal, the same refraction effect is applied, and the spectral transmittance is the same. .. In the present invention, from a focus detection system having a wide ranging defocus range and a photographing lens used in a focus detecting system having a good focusing precision, of a focus detecting system having a narrow ranging defocus range but having excellent focusing precision, By making the direction of travel of the two emitted light beams substantially parallel to the rotation axis of the quick return mirror, both the expansion of the distance measurement range and the improvement of focusing accuracy are satisfied at the same time, and there is no effect when passing through the half mirror. , A focus detection device that is easy to manufacture and mount. In this case, in the focus detection system having a wide distance measurement defocus range, the way in which the half mirror receives the refraction effect and the change in the spectral transmittance differ between the two light beams, so that the focusing accuracy decreases. However, since it is a system that does not have high focusing accuracy, it has no significant effect. Further, in general, a focus detection system having a wide distance measuring defocus range has a small F w , and therefore the difference in the incident angle to the half mirror is small, so that it is less susceptible to the influence of the half mirror.
【００２０】また、本発明による焦点検出装置は、次の
ような特徴を有している。１．焦点検出系２よりも焦点
検出系１の方が、セパレータレンズの焦点距離を長くし
てある。２．焦点検出系２よりも焦点検出系１の方が、
硝路長を短くしてある。３．焦点検出系１と焦点検出系
２の両系のセンサーである受光素子列を、ほぼ同一面上
に配置してある。これら三つの特徴を有することによっ
て、Ｆw1，Ｆw2の差を大きくしなくても、測距範囲の拡
大と合焦精度の向上の両方を同時に満足することができ
る。Ｆw1，Ｆw2の差を大きくしなくてもよいということ
は、Ｆw1を極端に明るくする必要がないことであり、Ｆ
ナンバーの比較的暗い撮影レンズを用いても、合焦精度
のすぐれた焦点検出系１による焦点合わせが可能にな
る。The focus detecting device according to the present invention has the following features. 1. The focus detection system 1 has a longer focal length of the separator lens than the focus detection system 2. 2. The focus detection system 1 is better than the focus detection system 2
The glass path length is shortened. 3. The light receiving element arrays, which are sensors for both the focus detection system 1 and the focus detection system 2, are arranged on substantially the same plane. By having these three characteristics, it is possible to simultaneously satisfy both the expansion of the range-finding range and the improvement of focusing accuracy without increasing the difference between F w1 and F w2 . The fact that the difference between F w1 and F w2 does not have to be large means that it is not necessary to make F w1 extremely bright.
Even if a taking lens having a relatively dark number is used, focusing can be performed by the focus detection system 1 having excellent focusing accuracy.
【００２１】本発明による焦点検出装置は、次のような
特徴を有しても構成できる。１．焦点検出系２のセパレ
ータレンズの主点位置よりも、焦点検出系１のセパレー
タレンズの主点位置を、一次結像面側に設ける。２．焦
点検出系１と焦点検出系２の両系のセンサーである受光
素子列を、ほぼ同一面上に配置する。この構成によって
も、上述したのと同様な効果が得られる。The focus detection device according to the present invention can be constructed even if it has the following features. 1. The position of the principal point of the separator lens of the focus detection system 1 is provided closer to the primary imaging plane side than the position of the principal point of the separator lens of the focus detection system 2. 2. The light receiving element arrays, which are sensors for both the focus detection system 1 and the focus detection system 2, are arranged on substantially the same plane. Also with this configuration, the same effect as described above can be obtained.
【００２２】[0022]
【実施例】図１〜図４は、本発明装置の第１実施例に関
するものである。図１は一眼レフカメラに適用した場合
の概略断面図で、カメラボディの底部に配置してある。
図２は焦点検出系の斜視図、図３は焦点検出系１の構成
図、図４は焦点検出系２の構成図で、図３を光軸を中心
に９０°回転させた状態を表している。1 to 4 relate to a first embodiment of the device of the present invention. FIG. 1 is a schematic sectional view when applied to a single-lens reflex camera, and is arranged at the bottom of a camera body.
2 is a perspective view of the focus detection system, FIG. 3 is a configuration diagram of the focus detection system 1, and FIG. 4 is a configuration diagram of the focus detection system 2, showing a state in which FIG. 3 is rotated by 90 ° about the optical axis. There is.
【００２３】１は撮影レンズ、２はハーフミラーからな
るクイックリターンミラー、３は予定結像面、４は予定
結像面の近傍に配置したコンデンサーレンズ、５はコン
デンサーレンズ４の後方に配置したミラー、６はミラー
５の後方に配置した明るさ絞り、７はセパレータレンズ
である。明るさ絞り６は、合焦精度を確保し得る間隔で
紙面と垂直な方向に並ぶ一対の焦点検出系１の開口部
（図２では省略）と合焦精度を確保し得る間隔で紙面を
含む方向に並ぶ一対の焦点検出系２の開口部（図２では
省略）を有する。セパレータレンズ７は、二対の開口部
を有する明るさ絞り６の各後方にそれぞれ配置され焦点
検出系１の透過するレンズ肉厚が焦点検出系２の透過す
るレンズ肉厚より薄い二対のレンズからなる。８，９は
それぞれ受光素子列で、受光素子列８はセパレータレン
ズ７から射出した焦点検出系１の光束の結像位置に配置
してあり、受光素子列９はセパレータレンズ７から射出
した焦点検出系２の光束の結像位置に配置してある。Reference numeral 1 is a taking lens, 2 is a quick return mirror consisting of a half mirror, 3 is a planned image forming surface, 4 is a condenser lens arranged near the planned image forming surface, and 5 is a mirror arranged behind the condenser lens 4. , 6 is an aperture stop arranged behind the mirror 5, and 7 is a separator lens. The aperture stop 6 includes a pair of apertures (not shown in FIG. 2) of the focus detection system 1 arranged in a direction perpendicular to the paper surface at intervals that can ensure the focusing accuracy and a paper surface at intervals that can ensure the focusing accuracy. It has a pair of apertures (not shown in FIG. 2) of the focus detection system 2 aligned in the direction. The separator lenses 7 are arranged behind the aperture stop 6 having two pairs of apertures, and the lens thickness that the focus detection system 1 transmits is thinner than the lens thickness that the focus detection system 2 transmits. Consists of. Reference numerals 8 and 9 denote light-receiving element rows, respectively. The light-receiving element row 8 is arranged at the image forming position of the light flux of the focus detection system 1 emitted from the separator lens 7, and the light-receiving element row 9 detects focus detection emitted from the separator lens 7. It is arranged at the image forming position of the light flux of the system 2.
【００２４】焦点検出系１では、撮影レンズ１を通過し
た二光束は、ハーフミラーからなるクイックリターンミ
ラー２に同じ入射角で入射し、サブミラーで反射する。
もし、合焦状態であれば、二光束は予定結像面３で結像
する。更に、光束は、コンデンサーレンズ４を経てセパ
レータレンズ７を透過し、受光素子列８上に一対の二次
像Ｉ11，Ｉ12を結像する。焦点検出系２では、撮影レン
ズ１を通過した二光束は、ハーフミラーからなるクイッ
クリターンミラー２に異なる入射角で入射し、サブミラ
ーで反射する。更に、撮影レンズの予定結像面３を透過
した光束は、コンデンサーレンズ４を経てセパレータレ
ンズ７を透過し、受光素子列９上に一対の二次像Ｉ21，
Ｉ22を結像する。In the focus detection system 1, the two light fluxes that have passed through the taking lens 1 enter the quick return mirror 2 consisting of a half mirror at the same incident angle and are reflected by the sub mirror.
If in focus, the two light beams form an image on the planned image forming plane 3. Further, the light flux passes through the condenser lens 4 and the separator lens 7, and forms a pair of secondary images I 11 and I 12 on the light receiving element array 8. In the focus detection system 2, the two light fluxes that have passed through the taking lens 1 enter the quick return mirror 2 formed of a half mirror at different incident angles and are reflected by the sub mirror. Further, the light flux that has passed through the planned image forming surface 3 of the taking lens passes through the condenser lens 4 and the separator lens 7, and then a pair of secondary images I 21 ,
Image I 22 .
【００２５】第１実施例のレンズデータを下記表１及び
表２に示す。Ｒは曲率半径、Ｄはレンズ肉厚または空気
間隔、Ｎはｄ線の屈折率、βは焦点検出系の像倍率、Ｆ
w は焦点検出系の検出重心光束のＦナンバーであり、下
添字１，２はそれぞれ焦点検出系１、焦点検出系２に関
するものである。焦点検出系１と焦点検出系２は、同じ
コンデンサーレンズを用いているので、表１，２におい
てＲ11とＲ21，Ｒ12とＲ22，Ｄ11とＤ21，Ｄ12とＤ22は
それぞれ同じ値となる。The lens data of the first embodiment are shown in Tables 1 and 2 below. R is the radius of curvature, D is the lens thickness or the air gap, N is the refractive index of the d-line, β is the image magnification of the focus detection system, and F is
w is the F number of the detected centroid light flux of the focus detection system, and the subscripts 1 and 2 relate to the focus detection system 1 and the focus detection system 2, respectively. Since the focus detection system 1 and the focus detection system 2 use the same condenser lens, in Tables 1 and 2, R 11 and R 21 , R 12 and R 22 , D 11 and D 21 , D 12 and D 22 , respectively. It will be the same value.
【００２６】[0026]
【表１】 焦点検出系１ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ11＝ ∞ Ｄ11＝ １．８ ２ Ｒ12＝ ９．７３ Ｄ12＝ ２．７ Ｎ11＝１．４９７１ ３ Ｒ13＝−１９．４５ Ｄ13＝１３．１ ４ Ｒ14＝ ２．２８ Ｄ14＝ １．０ Ｎ12＝１．４９７１ ５ Ｒ15＝ ∞ β1 ＝−０．４４ ＦW1＝ ６．０[Table 1] Focus detection system 1 No. RD N 1 R 11 = ∞ D 11 = 1.8 2 R 12 = 9.73 D 12 = 2.7 N 11 = 1.4971 3 R 13 = −19.45 D 13 = 13.1 4 R 14 = 2.28 D 14 = 1.0 N 12 = 1.4971 5 R 15 = ∞ β 1 = −0.44 F W1 = 6.0
【００２７】[0027]
【表２】 焦点検出系２ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ21＝ ∞ Ｄ21＝ １．８ ２ Ｒ22＝ ９．７３ Ｄ22＝ ２．７ Ｎ21＝１．４９７１ ３ Ｒ23＝−１９．４５ Ｄ23＝１３．１ ４ Ｒ24＝ １．９２ Ｄ24＝ ４．８ Ｎ22＝１．４９２２ ５ Ｒ25＝ ∞ β2 ＝−０．３５ ＦW2＝１５．０[Table 2] Focus detection system 2 No. RD N 1 R 21 = ∞ D 21 = 1.8 2 R 22 = 9.73 D 22 = 2.7 N 21 = 1.4971 3 R 23 = -19.45 D 23 = 13.1 4 R 24 = 1.92 D 24 = 4.8 N 22 = 1.4922 5 R 25 = ∞ β 2 = -0.35 F W2 = 15.0
【００２８】焦点検出系２と比較して、焦点検出系１の
セパレータレンズの焦点距離は長いが、レンズ厚は薄い
ので、焦点検出系１，２はほぼ同一面に結像する。これ
により、合焦精度は若干劣るものの、測距デフォーカス
範囲が広い焦点検出系１と、測距デフォーカス範囲は狭
いが、合焦精度のすぐれた焦点検出系２が構成され、あ
わせて測距範囲の拡大と合焦精度の向上の両方を同時に
満足し、かつ、Ｆナンバーが比較的暗い撮影レンズを用
いても、合焦精度のすぐれた焦点検出系１による焦点合
わせが可能になる。このことより、ほとんどの撮影レン
ズで焦点検出系２の概略の焦点合わせを、更に、焦点検
出系１で高精度な焦点合わせができる。当然、焦点ずれ
が少ないときは、最初から焦点検出系１で焦点合わせが
できる。高精度な焦点合わせにおいては、クイックリタ
ーンミラーの屈折による影響は受けない。また、焦点検
出系１の受光素子列の方向のコントラストが低い場合、
焦点検出系２で焦点合わせを行うことができる。なお、
β1 ＝β2 のような場合でも、Ｄ14は等しくなるが、同
様に構成できるのはいうまでもない。Compared with the focus detection system 2, the separator lens of the focus detection system 1 has a long focal length, but the lens thickness is thin, so that the focus detection systems 1 and 2 form images on substantially the same plane. As a result, although the focusing accuracy is slightly inferior, a focus detection system 1 having a wide range defocusing range and a focus detection system 2 having a narrow range defocusing range but excellent focusing accuracy are configured. Even if both the widening of the distance range and the improvement of the focusing accuracy are satisfied at the same time, and even if a photographing lens having a relatively dark F number is used, focusing by the focus detection system 1 having excellent focusing accuracy becomes possible. As a result, the focus detection system 2 can be roughly focused with most of the photographing lenses, and the focus detection system 1 can be highly accurately focused. Of course, when the defocus is small, the focus detection system 1 can focus from the beginning. High-precision focusing is not affected by the refraction of the quick return mirror. When the contrast in the direction of the light receiving element array of the focus detection system 1 is low,
Focusing can be performed by the focus detection system 2. In addition,
Even in the case of β 1 = β 2 , D 14 will be equal, but it goes without saying that they can be similarly configured.
【００２９】図５〜図６は、本発明装置の第２実施例に
関するもので、図５は焦点検出系１の構成図、図６は焦
点検出系２の構成図で、図５を光軸を中心に９０°回転
させた状態を表している。基本的な構成は、第１実施例
と同じであるが、ＦW1／β1 ＝ＦW2／β2 の関係になる
ように構成したものである。第２実施例のレンズデータ
を下記表３及び表４に示す。焦点検出系１と焦点検出系
２は、同じコンデンサーレンズを用いているので、表
３，４においてＲ11とＲ21，Ｒ12とＲ22，Ｄ11とＤ21，
Ｄ12とＤ22はそれぞれ同じ値となる。5 to 6 relate to the second embodiment of the device of the present invention. FIG. 5 is a block diagram of the focus detection system 1, FIG. 6 is a block diagram of the focus detection system 2, and FIG. The figure shows a state of being rotated by 90 ° around. The basic structure is the same as that of the first embodiment, but the structure is such that F W1 / β 1 = F W2 / β 2 . The lens data of the second example are shown in Tables 3 and 4 below. Since the focus detection system 1 and the focus detection system 2 use the same condenser lens, in Tables 3 and 4, R 11 and R 21 , R 12 and R 22 , D 11 and D 21 ,
D 12 and D 22 have the same value.
【００３０】[0030]
【表３】 焦点検出系１ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ11＝ ∞ Ｄ11＝ １．８ ２ Ｒ12＝ ９．７３ Ｄ12＝ ２．７ Ｎ11＝１．４９７１ ３ Ｒ13＝−１９．４５ Ｄ13＝１３．１ ４ Ｒ14＝ １．９２ Ｄ14＝ ４．８ Ｎ12＝１．４９２２ ５ Ｒ15＝ ∞ β1 ＝−０．３５ ＦW1＝ ７．０[Table 3] Focus Detection System 1 No. RD N 1 R 11 = ∞ D 11 = 1.8 2 R 12 = 9.73 D 12 = 2.7 N 11 = 1.4971 3 R 13 = −19.45 D 13 = 13.1 4 R 14 = 1.92 D 14 = 4.8 N 12 = 1.4922 5 R 15 = ∞ β 1 = −0.35 F W1 = 7.0
【００３１】[0031]
【表４】 焦点検出系２ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ21＝ ∞ Ｄ21＝ １．８ ２ Ｒ22＝ ９．７３ Ｄ22＝ ２．７ Ｎ21＝１．４９７１ ３ Ｒ23＝−１９．４５ Ｄ23＝１３．１ ４ Ｒ24＝ ２．２８ Ｄ24＝ １．０ Ｎ22＝１．４９７１ ５ Ｒ25＝ ∞ β2 ＝−０．４４ ＦW2＝ ８．８[Table 4] Focus detection system 2 No. RD N 1 R 21 = ∞ D 21 = 1.8 2 R 22 = 9.73 D 22 = 2.7 N 21 = 1.4971 3 R 23 = -19.45 D 23 = 13.1 4 R 24 = 2.28 D 24 = 1.0 N 22 = 1.49715 R 25 = ∞ β 2 = −0.44 F W2 = 8.8
【００３２】焦点検出系１に比較して、焦点検出系２の
セパレータレンズの焦点距離は長いが、レンズ厚は薄い
ので、焦点検出系１，２はほぼ同一面に結像する。これ
により、焦点検出系１，２のうちコントラストの強い方
の系で、焦点検出を行うことができる。同様のコントラ
ストの場合は、クイックリターンミラーの屈折の影響の
ない焦点検出系１で、焦点検出を行うことができる。ま
た、Ｆナンバーが暗いレンズやミラー望遠レンズの場
合、焦点検出系２で焦点検出ができる。この場合、クイ
ックリターンミラーの影響を受けるが、ＦW2が暗いため
入射角の差が小さいので、大きな誤差を生じることはな
い。Compared with the focus detection system 1, the separator lens of the focus detection system 2 has a long focal length, but since the lens thickness is thin, the focus detection systems 1 and 2 form images on substantially the same plane. As a result, the focus detection can be performed by one of the focus detection systems 1 and 2 which has a higher contrast. In the case of similar contrast, focus detection can be performed by the focus detection system 1 which is not affected by refraction of the quick return mirror. In the case of a lens having a dark F number or a mirror telephoto lens, focus detection can be performed by the focus detection system 2. In this case, although affected by the quick return mirror, a large error does not occur because F W2 is dark and the difference in incident angle is small.
【００３３】[0033]
【発明の効果】以上説明したように本発明の焦点検出装
置は、測距範囲の拡大と合焦精度の向上の両方を同時に
満足し、ハーフミラー透過時の影響を受ず、製作実装が
容易である。また、被写体のコントラスト方向に関係な
く測距可能である。As described above, the focus detection device of the present invention satisfies both the expansion of the distance measurement range and the improvement of focusing accuracy at the same time, is not affected by the transmission of the half mirror, and is easy to manufacture and mount. Is. Further, distance measurement is possible regardless of the contrast direction of the subject.
【図１】本発明装置の第１実施例を適用したカメラの概
略断面図である。FIG. 1 is a schematic sectional view of a camera to which a first embodiment of the device of the present invention is applied.
【図２】本発明装置の第１実施例における焦点検出系の
斜視図である。FIG. 2 is a perspective view of a focus detection system in the first embodiment of the device of the present invention.
【図３】本発明装置の第１実施例における焦点検出系１
の構成図である。FIG. 3 is a focus detection system 1 in the first embodiment of the device of the present invention.
It is a block diagram of.
【図４】本発明装置の第１実施例における焦点検出系２
の構成図である。FIG. 4 is a focus detection system 2 in the first embodiment of the device of the present invention.
It is a block diagram of.
【図５】本発明装置の第２実施例における焦点検出系１
の構成図である。FIG. 5: Focus detection system 1 in the second embodiment of the device of the present invention
It is a block diagram of.
【図６】本発明装置の第２実施例における焦点検出系２
の構成図である。FIG. 6 is a focus detection system 2 in a second embodiment of the device of the present invention.
It is a block diagram of.
【図７】従来の焦点検出装置を内蔵したカメラの概略断
面図である。FIG. 7 is a schematic cross-sectional view of a camera including a conventional focus detection device.
【図８】図７の焦点検出装置における焦点検出系の構成
図である。8 is a configuration diagram of a focus detection system in the focus detection apparatus of FIG.
【図９】図８の焦点検出系に直交する焦点検出系の構成
図である。9 is a configuration diagram of a focus detection system orthogonal to the focus detection system of FIG.
【図１０】他の従来の焦点検出装置における焦点検出系
の構成図である。FIG. 10 is a configuration diagram of a focus detection system in another conventional focus detection device.
【図１１】図１０における明るさ絞りの正面図である。11 is a front view of the aperture stop shown in FIG.
【図１２】図１０におけるセパレータレンズの正面図で
ある。12 is a front view of the separator lens in FIG.
【図１３】図１０における受光素子列の正面図である。13 is a front view of the light receiving element array in FIG.
【図１４】別の従来の焦点検出装置における焦点検出系
の構成図である。FIG. 14 is a configuration diagram of a focus detection system in another conventional focus detection device.
１ 撮影レンズ ２ ハーフミラー ３ 予定結像面 ４ コンデンサーレンズ ６ 明るさ絞り ７ セパレータレンズ ８ 受光素子列 ９ 受光素子列 1 Photographic lens 2 Half mirror 3 Planned image plane 4 Condenser lens 6 Brightness diaphragm 7 Separator lens 8 Light receiving element array 9 Light receiving element array
─────────────────────────────────────────────────────
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【手続補正書】[Procedure amendment]
【提出日】平成４年７月６日[Submission date] July 6, 1992
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２７[Name of item to be corrected] 0027
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２７】[0027]
【表２】 焦点検出系２ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ21＝ ∞ Ｄ21＝ １．８ ２ Ｒ22＝ ９．７３ Ｄ22＝ ２．７ Ｎ21＝１．４９７１ ３ Ｒ23＝−１９．４５ Ｄ23＝１３．１ ４ Ｒ24＝ １．９２ Ｄ24＝ ４．８ Ｎ22＝１．４９７１ ５ Ｒ25＝ ∞ β2 ＝−０．３５ ＦW2＝１５．０[Table 2] Focus detection system 2 No. RD N 1 R 21 = ∞ D 21 = 1.8 2 R 22 = 9.73 D 22 = 2.7 N 21 = 1.4971 3 R 23 = -19.45 D 23 = 13.1 4 R 24 = 1.92 D 24 = 4.8 N 22 = 1.4971 5 R 25 = ∞ β 2 = -0.35 F W2 = 15.0
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３０[Name of item to be corrected] 0030
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３０】[0030]
【表３】 焦点検出系１ Ｎｏ． Ｒ Ｄ Ｎ １ Ｒ11＝ ∞ Ｄ11＝ １．８ ２ Ｒ12＝ ９．７３ Ｄ12＝ ２．７ Ｎ11＝１．４９７１ ３ Ｒ13＝−１９．４５ Ｄ13＝１３．１ ４ Ｒ14＝ １．９２ Ｄ14＝ ４．８ Ｎ12＝１．４９７１ ５ Ｒ15＝ ∞ β1 ＝−０．３５ ＦW1＝ ７．０[Table 3] Focus Detection System 1 No. RD N 1 R 11 = ∞ D 11 = 1.8 2 R 12 = 9.73 D 12 = 2.7 N 11 = 1.4971 3 R 13 = −19.45 D 13 = 13.1 4 R 14 = 1.92 D 14 = 4.8 N 12 = 1.4971 5 R 15 = ∞ β 1 = -0.35 F W1 = 7.0
Claims (2)
する二光束による光強度分布を光電変化手段で受け該光
電変化手段から得られる該光強度分布を表す出力信号の
位相差を利用する複数の焦点検出系と、該撮影レンズと
複数の該焦点検出系の間に光軸に対して傾斜させて配置
したハーフミラーとを含む焦点検出装置において、 複数の該焦点検出系のうち最も焦点検出精度の高い焦点
検出系に対する該ハーフミラーへの該二光束の入射角の
差が、他の焦点検出系に対する該ハーフミラーへの該二
光束の入射角の差より大きくないことを特徴とする焦点
検出装置。1. A plurality of focal points using a phase difference between output signals representing the light intensity distributions received by the photoelectric changing means, the light intensity distributions of two light fluxes respectively passing through different regions of the taking lens being received by the photoelectric changing means. In a focus detection device including a detection system and a half mirror that is arranged between the photographing lens and the plurality of focus detection systems while being inclined with respect to the optical axis, the focus detection system with the highest focus detection accuracy among the plurality of focus detection systems is used. A focus detection device characterized in that the difference in the incident angle of the two light beams on the half mirror with respect to the high focus detection system is not larger than the difference in the incident angle of the two light beams with respect to the other half focus mirror on the other half focus detection system. ..
れたコンデンサーレンズと、合焦精度を確保し得る間隔
で並ぶ一対の開口部を有する明るさ絞りと、その後方に
配置された再結像レンズと、光電変換素子列とから構成
され、該撮影レンズの異なる領域をそれぞれ通過した二
光束による光強度分布を光電変化手段で受け、該光電変
化手段から得られる該光強度分布を表す出力信号の位相
差を利用する複数の焦点検出系と、該撮影レンズと複数
の該焦点検出系の間に光軸に対して傾斜させて配置した
ハーフミラーとを含む焦点検出装置において、 複数の該焦点検出系のうち前方で該二光束のなす角が最
も大きい焦点検出系に対する該ハーフミラーへの該二光
束の入射角の差が、他の焦点検出系に対する該ハーフミ
ラーへの該二光束の入射角の差より大きくないことを特
徴とする焦点検出装置。2. A condenser lens arranged in the vicinity of a planned image forming surface of a photographing lens, an aperture stop having a pair of apertures arranged at an interval capable of ensuring focusing accuracy, and a rear lens arranged behind the aperture stop. It is composed of an imaging lens and a photoelectric conversion element array, and receives the light intensity distribution by the two light fluxes respectively passing through different regions of the photographing lens by the photoelectric changing means, and represents the light intensity distribution obtained from the photoelectric changing means. In a focus detection device including a plurality of focus detection systems that utilize the phase difference of output signals, and a half mirror that is arranged between the photographing lens and the plurality of focus detection systems with an inclination with respect to the optical axis, The difference between the incident angles of the two light fluxes on the half mirror with respect to the focus detection system having the largest angle between the two light fluxes in the front of the focus detection system is the two light fluxes on the half mirror with respect to another focus detection system. Incident angle of Focus detecting apparatus characterized by no greater than the difference.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3295872A JPH05134169A (en) | 1991-11-12 | 1991-11-12 | Focal point detecting device |
| US07/929,428 US5321461A (en) | 1991-08-22 | 1992-08-14 | Focus detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3295872A JPH05134169A (en) | 1991-11-12 | 1991-11-12 | Focal point detecting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05134169A true JPH05134169A (en) | 1993-05-28 |
Family
ID=17826272
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3295872A Withdrawn JPH05134169A (en) | 1991-08-22 | 1991-11-12 | Focal point detecting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05134169A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1988000585A1 (en) * | 1986-07-15 | 1988-01-28 | Fuji Kagaku Kogyo Kabushiki Kaisha | Process for preparing tetrahydroquinolone ethers and novel intermediates therefor |
| JP2009276605A (en) * | 2008-05-15 | 2009-11-26 | Nikon Corp | Light receiving device, focal point detector and imaging device |
-
1991
- 1991-11-12 JP JP3295872A patent/JPH05134169A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1988000585A1 (en) * | 1986-07-15 | 1988-01-28 | Fuji Kagaku Kogyo Kabushiki Kaisha | Process for preparing tetrahydroquinolone ethers and novel intermediates therefor |
| JP2009276605A (en) * | 2008-05-15 | 2009-11-26 | Nikon Corp | Light receiving device, focal point detector and imaging device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990204 |