JPS58217907A - Focusing device of zoom lens - Google Patents

Focusing device of zoom lens

Info

Publication number
JPS58217907A
JPS58217907A JP57101078A JP10107882A JPS58217907A JP S58217907 A JPS58217907 A JP S58217907A JP 57101078 A JP57101078 A JP 57101078A JP 10107882 A JP10107882 A JP 10107882A JP S58217907 A JPS58217907 A JP S58217907A
Authority
JP
Japan
Prior art keywords
lens group
focus
zoom
lens
amount
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.)
Granted
Application number
JP57101078A
Other languages
Japanese (ja)
Other versions
JPH0310923B2 (en
Inventor
Eiji Kikko
英治 橘高
Mineo Kubota
窪田　峰夫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Seimitsu Kogyo KK
Original Assignee
Nippon Seimitsu Kogyo KK
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Seimitsu Kogyo KK filed Critical Nippon Seimitsu Kogyo KK
Priority to JP57101078A priority Critical patent/JPS58217907A/en
Publication of JPS58217907A publication Critical patent/JPS58217907A/en
Publication of JPH0310923B2 publication Critical patent/JPH0310923B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/144—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only
    • G02B15/1441—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive
    • G02B15/144113—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having four groups only the first group being positive arranged +-++

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Focusing (AREA)
  • Automatic Focus Adjustment (AREA)

Abstract

PURPOSE:To improve the precision of setting greatly by setting the movement amount of a focusing lens group on the basis of the defocusing amount of a subject image and the magnification and focal length of a variable magnification lens group at this time. CONSTITUTION:This is a focusing device which adjusts the focus of a zoom lens Z by detecting the defocusing amount DELTAP of the subject image and zoom information N on the zoom lens Z, and the magnification (m) and focal length fe of the variable magnification lens group E are preset corresponding to the zoom information N. Then, the movement amount DELTAx of the focusing lens group A is set on the basis of the defocusing amount DELTAP, the magnification (m) and focal length fe of the variable magnification lens group E.

Description

【発明の詳細な説明】 本発明は被写体像のディ・フォーカス量とズームレンズ
のズーム情報を検知して焦点調節するズームレンズのフ
ォーカシング装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a focusing device for a zoom lens that detects the defocus amount of a subject image and zoom information of a zoom lens to adjust the focus.

従来、此の種の被写体像のディ・フォーカス量を検知し
て、該ディ・フォーカス量によってフォーカスレンズ群
を駆動し焦点調節する方式は既に知られている。例えば
米国特許４１８５１９１号及び日本写真工業出版社の写
真工業別冊「現代のカメラとレンズ技術」（５７年１月
２０日発行）のｐ１０７〜ｐ１１０に可成詳細に説明さ
れているｋめに、ここでは上記方式について簡単に説明
すると、レンズの上半分を通過してきた光線によって得
られる結像パターンとレンズの下半分を通過してきた光
線によって得られる結像パターンとが非合焦時において
位相ズレを起こすことを利用して、該位相ズレの量をデ
ィ・フォーカス量（ピントズレ量）として捕え、該ディ
・フォーカス量に応じ焦点調節するものである。Conventionally, a method of detecting the defocus amount of this type of subject image and driving a focus lens group based on the defocus amount to adjust the focus is already known. For example, as described in U.S. Patent No. 4,185,191 and in considerable detail on pages 107 to 110 of the Photo Industry Special Edition ``Modern Camera and Lens Technology'' (published January 20, 1957) by Nihon Shako Kogyo Publishing Co., Ltd. Now, to briefly explain the above method, there is a phase shift between the imaged pattern obtained by the light ray passing through the upper half of the lens and the imaged pattern obtained by the light ray passed through the lower half of the lens when they are out of focus. By utilizing this phenomenon, the amount of phase shift is captured as the amount of defocus (amount of defocus), and the focus is adjusted according to the amount of defocus.

しかし、ズームレンズのフォーカシング装置にあっては
、先に本願同一出願人によって提示されている特願昭５
７−２６１９８号に記すように、」１記ディ・フォーカ
ス量はレンズ系の焦点距離によって可変されるために、
被写体像のディ・フォーカス量を検知するとともに、そ
の時のズームレンズの焦点距離を検知し、該焦点距離に
応じて前記ディ・フォーカス量の単位量に対するズーム
レンズにおけるフォーカスレンズ群の移動の量を可変な
すことによって、前記ディ・フォーカス量に応じフォー
カスレンズ群の移動量を設定しなければならない。However, regarding a focusing device for a zoom lens, there is
As described in No. 7-26198, since the amount of defocus described in item 1 is varied depending on the focal length of the lens system,
In addition to detecting the defocus amount of the subject image, the focal length of the zoom lens at that time is also detected, and the amount of movement of the focus lens group in the zoom lens relative to the unit amount of the defocus amount is varied according to the focal length. By doing this, the amount of movement of the focus lens group must be set in accordance with the defocus amount.

ところが、ズームレンズのフォーカシング装置において
は上記以外にもう一つ被写体像のディ・フォーカス量を
可変する要素があることがわかった。それは、ズームレ
ンズが一般的に第１図で示されるように、Ａはフォーカ
スレンズＬ　Ｂはバリエータ−レンズ群、Ｃはコンペン
セーターレンズ、Ｄはマスターレンズであって前記ズー
ムレンズ（Ｚ）のレンズ系を構成するとともに、前記フ
ォーカスレンズ群（Ａ）ｌＧｉいたレンズ系を特に変倍
レンズ群（Ｅ）と称し、まず被写体をフォーカスレンズ
群（Ａ）によって結像（Ｑｌ）を結んで、該結像（Ｑｌ
）をバリエータ−レンズ群（Ｄ）によって変倍し結像（
Ｑｌ）ヲ結ぶ。更に、コンベン七−ターレンズ群（Ｃ）
が前記バリエータ−レンズ群（Ｂ）によって変倍された
結像（Ｑｌ）に生じた像点移動を補正した後、ズーミン
グには参加せず停止しているマスターレンズ群（Ｄ）に
よって前記変倍し・た結像（Ｑｌ）を被写体像（Ｑ５）
として撮像ディバイス（例えば、撮像管や固体撮像ディ
バイス等）及び焦点検出素子の適宜な面に結ぶようレン
ズ系が構成されており、又、上記各レンズ群の働きから
考えて、上記のズームレンズを第２図のごとくフォーカ
スレンズ群（Ａ）と変倍レンズ群（Ｅ）とによって簡単
にレンズ系を示すことが出来る。つまり、前記したよう
にズームレンズ（Ｚ）は、一旦、前記フォーカスレンズ
群（Ａ）によって結ばれた結像（Ｑｌ）を前記変倍レン
ズ群（Ｅ）によって変倍され像点移動が補正された結像
を被写体像（Ｑ３）として扱うために、前記フォーカス
レンズ群（、Ａ）の位置関係によってその時の上記ディ
・フォーカス量が可変されることである。このことを更
に第２図をもって簡単に説明すると、（１）図は合焦時
を示すもので、変倍レンズ群（Ｅ）の焦点距離をｆｅと
すると、該変倍レンズ群（Ｅ）から結像（Ｑ＋）及び被
写体像（Ｑ３）までの距離ａ及びｂはそれぞれ下記の式
で示すことが出来る。一般式ａ　　　　ｂ　　　ｆｅ 及び、その時の倍率　　　ｂ ｍ　＝　−−（２）式 の両式から、 及び、 ；、　ｂ　＝　ｆｅ　（１＋　ｍ　）　　　　　　　（
４）式となる。そこで、例えば、ｆｅ＝２０％、ｍ　＝
　１倍とすると、当然、ａ　＝　ｂ　＝２０％となり、
この条件下において、例えば、（２）図のごとくフォー
カスレンズ群（Ａ）が１％前方に七ノドされた所謂前ピ
ン状態にある場合のディ・フォーカス量（Δｐ、　）は
（１）式より、 ａ＋Δｘｂ−Δｐ　　ｆｅ ２０＋１　２０−Δｐ１１０ 、°、Δｐ１÷０．９０９１％ となる。但し、上式中のΔＸはフォーカスレンズｍ（Ａ
　）をどの位い移動すれば合焦状態になりうるかの移動
量である。又、（３）図のごとくフォーカスレンズ群（
Ａ）が１％後方にセットされた所謂後ピン状態にある場
合のディ・フォーカス量（Δｐ２　）は（１）式より、 ２０−１２０＋Δｐ２１０ 、°、Δｐ２キ１．１１１％ となり、フォーカスレンズ群（Ａ）の位置関係によって
その時のディ・フォーカス量（Δｐ）が異なることが理
解されよう。又、同時にフォーカスレンズ群（Ａ）によ
る移動量（ΔＸ）とディ〜 ・フォーカス量（Δｐ）の変化がリニアなものでないこ
とが理解される。However, it has been found that in a zoom lens focusing device, there is another element other than the above that changes the amount of defocus of a subject image. As shown in FIG. 1, A is a focus lens LB, B is a variator lens group, C is a compensator lens, and D is a master lens of the zoom lens (Z). The lens system comprising the focus lens group (A) IGi is particularly referred to as the variable magnification lens group (E). Statue (Ql
) is magnified by the variator lens group (D) and imaged (
Ql) Tie. Furthermore, the convenor lens group (C)
After correcting the image point shift that occurs in the image (Ql) that is magnified by the variator lens group (B), the magnification is changed by the master lens group (D), which is stopped and does not participate in zooming. The image formation (Ql) is the subject image (Q5)
The lens system is configured to connect to an appropriate surface of the imaging device (e.g., image pickup tube, solid-state imaging device, etc.) and focus detection element, and considering the function of each lens group, the zoom lens described above is As shown in FIG. 2, the lens system can be easily represented by a focus lens group (A) and a variable magnification lens group (E). In other words, as described above, in the zoom lens (Z), the image (Ql) formed by the focus lens group (A) is magnified by the variable magnification lens group (E) and the image point shift is corrected. In order to treat the image formed as a subject image (Q3), the amount of defocus at that time is varied depending on the positional relationship of the focus lens group (A). To further briefly explain this using Fig. 2, Fig. (1) shows the state in focus, and if the focal length of the variable magnification lens group (E) is fe, then from the variable magnification lens group (E) The distances a and b to the image formation (Q+) and the subject image (Q3) can be respectively expressed by the following formulas. From both the general formula a b fe and the magnification at that time b m = −− (2), and ;, b = fe (1+ m ) (
4) Equation becomes. So, for example, fe=20%, m=
If it is 1 times, naturally a = b = 20%,
Under this condition, for example, when the focus lens group (A) is in the so-called front focus state where the focus lens group (A) is moved forward by 1% as shown in figure (2), the defocus amount (Δp, ) is calculated from equation (1). , a+Δxb−Δp fe 20+1 20−Δp110 , °, Δp1÷0.9091%. However, ΔX in the above formula is the focus lens m (A
) is the amount of movement needed to bring the camera into focus. (3) As shown in the figure, the focus lens group (
The defocus amount (Δp2) when A) is in the so-called rear focus state where it is set 1% backward is 20-120+Δp210,°, Δp2ki 1.111% from equation (1), and the focus lens group ( It will be understood that the defocus amount (Δp) at that time differs depending on the positional relationship of A). At the same time, it is understood that changes in the amount of movement (ΔX) and the amount of focus (Δp) by the focus lens group (A) are not linear.

本発明は以上述べたことに鑑みて、予めズームレンズ（
Ｚ）の焦点距離（ｆｚ　）等のズーム情報（Ｎ）に対応
して変倍レンズ群（Ｅ）の倍率（ｍ）と焦点距離（ｆｅ
）を設定しておき、フォーカシングの際に、焦点検出素
子によって検知されるディ・フォーカス量（Δｐ）と、
ズームレンズの鏡筒等に設けたグレーコード若しくはポ
テンショメーター等によって前記ズーム情報（Ｎ）を検
知し、前記ディ・フォーカス量（Δｐ）と前記変倍レン
ズ群（Ｅ）の倍率（ｍ）と焦点距離（ｆｅ　）とを、下
式 によってフォーカスレンズ群（Ａ）の移動量（ΔＸ）を
設定なすようにしたズームレンズのフォーカシング装置
を提供なすものである。In view of the above, the present invention provides a zoom lens (
The magnification (m) and focal length (fe
) is set, and the defocus amount (Δp) detected by the focus detection element during focusing is
The zoom information (N) is detected by a gray code or potentiometer provided on the lens barrel of the zoom lens, and the defocus amount (Δp), the magnification (m) of the variable magnification lens group (E), and the focal length are detected. This invention provides a focusing device for a zoom lens in which the amount of movement (ΔX) of the focus lens group (A) is set according to the following formula.

又、上記（５）式は下記によって求めることが出来る。Moreover, the above equation (5) can be obtained as follows.

例えば第２図の（２）図に於いて、から、 １　　　　ｉ　　　　ｉ　　　ｂ：；Δｐ　−ｆ　ｅａ
±Δｘ　　ｆｅ　　ｂ〒Δｐ　　ｆｅ（ｂ〒Δｐ）よっ
て、 ｂ′：＋Δｐ　−ｆ　ｅ ｂ￥Ｊｐ−ｆｅ ｆｅＩＩｂ′：＋ｆｅ・Δｐ−ａｂ±ａ’Δｐ＋ａｓｆ
ｅｂ￥Δｐ−ｆｅ 」二人に、前記（３）式及び（４）式を代入することに
よって、 となる。但し、倍率（ｍ）はズームレンズ（２）の焦点
距離（ｆｚ）をフォーカスレンズ群（Ａ）の焦点距離（
ｆａ）で割ったもの。つまりｍ＝ｆｚ／ｆａｏ又、符号
（±）は基準点ｑ＋　Ｎ　Ｑ３より変倍レンズ群（Ｅ）
側に変化する場合を総べて負（−）とする。For example, in (2) of Figure 2, from 1 i i b:; Δp − f ea
±Δx fe b〒Δp fe(b〒Δp) Therefore, b': +Δp -f e b\Jp-fe feIIb': +fe・Δp-ab±a'Δp+asf
By substituting the above equations (3) and (4) for the two people, the following is obtained. However, the magnification (m) is calculated by subtracting the focal length (fz) of the zoom lens (2) from the focal length (fz) of the focus lens group (A).
divided by fa). In other words, m=fz/fao Also, the sign (±) is the reference point q+ N From Q3, the variable magnification lens group (E)
All cases where the value changes to the side are negative (-).

以下、第３図の本発明にかかるズームレンズのフォーカ
シング装置の一実施例に基づきフォーカシング動作を簡
単に説明する。Hereinafter, a focusing operation will be briefly described based on an embodiment of a focusing device for a zoom lens according to the present invention shown in FIG.

図中、Ａは前群繰り出しの方式で距離合わせの機能を持
つフォーカスレンズ（ｆｏｃｕｓｓ　１ｅｒｕ＋）　群
でフォーカス環（１０）に支持されている。又、該フォ
ーカス環（１０）にはフォーカス状態を得るためのカメ
ラから被写体までの距離を表示する簡易な距離を刻んだ
距離環（１１）が設けられており、手動の際、カメラか
ら被写体までの距離が判っていれば該フォーカス環（１
０）を手動で回動し距離環（１１）の距離を一致させさ
えすればフォーカス状態がほぼ得られるようになってい
る。更に、前記フォーカス環（１０）にはフォーカシン
グ装置のフォーカシング（焦点調節）制御装置（６０）
から出力される信号によって駆動制御されるフォーカス
モーター（８０）の駆動力を受は回動する歯車（９０）
が噛合し該フォーカス環（１０）を駆動するための歯車
部（１２）が設けられている。Ｂは焦点距離を変える変
倍のために大きく変位移動するバリエーターレンズ（Ｖ
ｎｒｉａｔｏｒ　１０１１１１　）群、Ｃは変倍に伴っ
て生じた像点移動を補正するためのコンベン七−ターレ
ンズ（ｃｃ＊ｎｐｅｒｕ＋ｎＬｏｒ　１ｅｎｓ　）群で
あり、ともに固定環（３０）のカム溝（３１）に摺動可
能に支持され、又、ズーム環（２０）に設けられたカム
溝（２１，２２）に沿って移動させられることによって
ズーム効果を得る。一方、前記ズーム環（２０）にはズ
ーム効果を得るための変倍の際に可変する焦点距離と対
応したズームレンズのズーム情報（Ｎ）が設けられてい
る。Ｄはリレー系であってズーミングには参加せず固定
環（３０）に固定支持され被写体像を所定の大きさと明
るさで結像させる役目を持ったマスターレンズ（＋ｎｎ
５Ｌｅｒ　１ｅｎｓ　）群であり、該マスターレンズ群
（Ｄ）には半透鏡をもっタヒームスプリッター（Ｄ＋　
）とモーター（７０）によって制御される絞り装置の絞
りが光軸を中心に設げられている。４０はカメラ本体で
、前記したフォーカスレンズ群（Ａ）、及び、バリエー
タ−レンズ群（Ｂ　）　、！：コンペンセーターレンズ
群（ｃ　）とマスターレンズ群（Ｄ）からなる変倍レン
ズ群（Ｅ）とによっで構成されたズームレンズ（Ｚ）の
焦点面（Ｚｌ）に撮像ディバイス（５０：例えば、撮像
管や固体撮像ディバイス等）が設置され被写体像を光電
変換等の処理をする。In the figure, A is a focus lens (focus 1eru+) group that has a distance adjustment function and is supported by a focus ring (10) by extending the front group. In addition, the focus ring (10) is provided with a distance ring (11) inscribed with a simple distance to display the distance from the camera to the subject to obtain the focus state, and when manual operation is performed, the distance ring (11) is inscribed with a simple distance from the camera to the subject. If you know the distance of the focus ring (1
0) manually to match the distance of the distance ring (11), the focus state can almost be obtained. Furthermore, the focusing ring (10) includes a focusing (focus adjustment) control device (60) of a focusing device.
A gear (90) rotates by receiving the driving force of a focus motor (80) which is driven and controlled by a signal output from the focus motor (80).
A gear portion (12) is provided to mesh with the focus ring (10) and drive the focus ring (10). B is a variator lens (V
101111) group, and C is a convex lens (cc*nperu+nLor 1ens) group for correcting the image point shift that occurs with zooming, and both slide into the cam groove (31) of the fixed ring (30). It is movably supported and moves along cam grooves (21, 22) provided in the zoom ring (20) to obtain a zoom effect. On the other hand, the zoom ring (20) is provided with zoom information (N) of the zoom lens corresponding to the focal length that is changed during magnification change to obtain a zoom effect. D is a relay system, and a master lens (+nn
The master lens group (D) has a semi-transparent mirror and a tahīm splitter (D+
) and an aperture of an aperture device controlled by a motor (70), centered on the optical axis. 40 is a camera body, which includes the aforementioned focus lens group (A), variator lens group (B), ! : An imaging device (50: For example, A camera tube, solid-state imaging device, etc.) is installed to process the subject image, such as photoelectric conversion.

又、前記ビームスプリッタ−（Ｄｌ）によって分割され
た光は第２のビームスプリフタ−（Ｄ２）によって前記
撮像ディバイス（５０）に作られ像とまったく同様なピ
ントをもった被写体像を第２の焦点面（Ｚｌ）に結像さ
せ、該被写体像をフォーカシング装置のフォーカシング
制御装置（６０）に設けられた焦点検出素子によって捕
え、前記被写体像のディ・フォーカス量（Δｐ：ピント
のズレ量）を前記フォーカシング制御装置（６０）によ
って検知することによって撮像ディバイス（５０）に作
られた被写体像のフォーカス状態を間接的に検知する。Furthermore, the light split by the beam splitter (Dl) is produced by a second beam splitter (D2) on the imaging device (50), and a second image of the subject with exactly the same focus as the image is created by the second beam splitter (D2). An image is formed on the focal plane (Zl), the object image is captured by a focus detection element provided in the focusing control device (60) of the focusing device, and the amount of defocus (Δp: amount of defocus) of the object image is determined. The focus state of the subject image formed on the imaging device (50) is indirectly detected by detection by the focusing control device (60).

一方、前記フォーカシング制御装置（６０）はズーム環
（２０）に設けられたズーム情報（Ｎ）を検知し、予め
前記ズーム情報（Ｎ）に対応し変倍レンズ群（Ｅ）の倍
率（ｍ）と焦・点距離（ｆｅ）を設定しておくことによ
って、前記ディ・フォーカス量（Δｐ）と該変倍レンズ
群（Ｅ）の倍率（ｍ）と焦点距離（ｆｅ）とを前記の関
係式 に基づき処理し、フォーカスレンズ群（Ａ）の移動量（
ΔＸ）を設定し、フォーカスモーター（８０）を適宜方
向に駆動制御しフォーカス環（１０）を変位せしめてフ
ォーカスレンズ群（Ａ）を被写体像が合焦し得る位置に
セットなすものである。On the other hand, the focusing control device (60) detects zoom information (N) provided on the zoom ring (20), and adjusts the magnification (m) of the variable power lens group (E) in advance in accordance with the zoom information (N). By setting the focal point distance (fe), the defocus amount (Δp), the magnification (m) of the variable magnification lens group (E), and the focal length (fe) can be expressed by the above relational expression. The amount of movement of the focus lens group (A) (
ΔX), the focus motor (80) is driven and controlled in an appropriate direction, the focus ring (10) is displaced, and the focus lens group (A) is set at a position where the subject image can be focused.

伺、上記ズーム情報（Ｎ）はズームレンズ（Ｚ）の焦点
距離（ｆｚ）若しくは該焦点距離（ｆｚ）に対応し設け
られた変倍レンズ群（Ｅ）の倍率（ｍ）と焦点距離（ｆ
ｅ）の少なくともいずれか一方に対応し抵抗体若しくは
グレーコード等によって設けられたものである。そして
、ズーム操作に連動し可変される該ズーム情報（Ｎ）を
読み取り、例えばマイクロコンピュータ−を内蔵したフ
ォーカシング制御装置（６０）によって前記ディ・フォ
ーカス量（Δｐ）と変倍レンズ群（Ｅ）の倍率（ｍ）と
焦点距離（ｆｅ）とを上記（５）式に基づいて処理を行
ないフォーカスレンズ群（Ａ）の移動量（ΔＸ）を設定
する。The above zoom information (N) is based on the focal length (fz) of the zoom lens (Z) or the magnification (m) and focal length (f) of the variable power lens group (E) provided corresponding to the focal length (fz).
It corresponds to at least one of e) and is provided by a resistor, a gray cord, or the like. Then, the zoom information (N), which is varied in conjunction with the zoom operation, is read, and the defocus amount (Δp) and the variable magnification lens group (E) are adjusted by a focusing control device (60) having a built-in microcomputer, for example. The magnification (m) and focal length (fe) are processed based on the above equation (5) to set the amount of movement (ΔX) of the focus lens group (A).

以上のように本発明によると、被写体像のディ・フォー
カス量（Δｐ）とその時の変倍レンズ群（Ｅ）の倍率（
ｍ）と焦点距離（ｆｅ）とによってフォーカスレンズ群
（Ａ）の移動量（ΔＸ）を設定なすようにしたため、ズ
ームレンズ（Ｚ）の焦点距離（ｆｚ）のみ考慮した従来
のフォーカシング装置に対してフォーカスレンズ群（Ａ
）の移動量（ΔＸ）の設定精度を著しく高めることが出
来るといった優れた効果を有゛する。As described above, according to the present invention, the defocus amount (Δp) of the subject image and the magnification of the variable power lens group (E) at that time (
Since the amount of movement (ΔX) of the focus lens group (A) is set based on the focal length (fe) and the focal length (fe), it is different from the conventional focusing device that only considers the focal length (fz) of the zoom lens (Z). Focus lens group (A
) has the excellent effect of being able to significantly improve the setting accuracy of the movement amount (ΔX).

【図面の簡単な説明】[Brief explanation of drawings]

第１図は一般的なズームレンズのレンズ光学系を簡易的
に示す図、第２図は第１図を更に簡易的に示す図、第３
図は本発明にがかる一実施例のズームレンズのフォーカ
シング装置を示すものである。 図中、Ａ・・・フォーカスレンズ群、Ｂ・・・バリエー
タ−レンズ君Ｌ　Ｃ・・・コンビン七−ターレンズ群、
Ｄ・・・マスターレンズ群、Ｅ・・・変倍レンズ群、Ｚ
・・・ズームレンズ、ｆｚ・・・ズームレンズの焦点距
離、ｆｅ・・・変倍レンズ群の焦点距離、ｍ・・・変倍
レンズ群の倍率。Figure 1 is a diagram that simply shows the lens optical system of a general zoom lens, Figure 2 is a diagram that shows Figure 1 even more simply, and Figure 3
The figure shows a focusing device for a zoom lens according to an embodiment of the present invention. In the figure, A: Focus lens group, B: Variator lens L, C: Combiner lens group,
D... Master lens group, E... Variable magnification lens group, Z
...Zoom lens, fz...focal length of the zoom lens, fe...focal length of the variable power lens group, m...magnification of the variable power lens group.

Claims (2)

【特許請求の範囲】[Claims] （１）被写体像（ＱΔ）のディ・フォーカス量（Δｐ）
とズームレンズのズーム情報（Ｎ）を検知して焦点調節
するズームレンズのフォーカシング装置に於いて、予め
前記ズーム情報（Ｎ）に対応し変倍レンズ群（Ｅ）の倍
率（ｍ）と焦点距離（ｆｅ）を設定しておき、上記ディ
・フォーカス量（Δｐ）と前記変倍リンス群（Ｅ）の倍
率（ｍ）と焦点距離（ｆｅ　）とによってフォーカスレ
ンズ群（Ａ）の移動量（ΔＸ）を設定なすようにしたこ
とを特徴とするズームレンズのフォーカシング装置。(1) Defocus amount (Δp) of subject image (QΔ)
In a zoom lens focusing device that detects the zoom information (N) of the zoom lens and adjusts the focus, the magnification (m) and focal length of the variable magnification lens group (E) are determined in advance in response to the zoom information (N). (fe) is set, and the amount of movement (ΔX ). （２）　　上記のフォーカスレンズ群（Ａ）の移動量（
ΔＸ）は、ディ・フォーカス量（Δｐ）と変倍レンズ群
（Ｅ）の倍率（ｍ）と焦点距離（ｆｅ）とを関係式 ％式％） （但し、符号（土）は基準点ｑ１、ｑ３に対し変倍レン
ズ側に変化する場合を総べて負（−）とする。）に基づ
き設定される特許請求の範囲第（１）項に記載のズーム
レンズのフォーカシング装置。(2) Amount of movement of the above focus lens group (A) (
ΔX) is the relation between the defocus amount (Δp), the magnification (m) of the variable magnification lens group (E), and the focal length (fe). A focusing device for a zoom lens according to claim 1, wherein the zoom lens focusing device is set based on q3, where all cases where the value changes toward the variable power lens side are negative (-).
JP57101078A 1982-06-12 1982-06-12 Focusing device of zoom lens Granted JPS58217907A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57101078A JPS58217907A (en) 1982-06-12 1982-06-12 Focusing device of zoom lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57101078A JPS58217907A (en) 1982-06-12 1982-06-12 Focusing device of zoom lens

Publications (2)

Publication Number Publication Date
JPS58217907A true JPS58217907A (en) 1983-12-19
JPH0310923B2 JPH0310923B2 (en) 1991-02-14

Family

ID=14291058

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57101078A Granted JPS58217907A (en) 1982-06-12 1982-06-12 Focusing device of zoom lens

Country Status (1)

Country Link
JP (1) JPS58217907A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6278519A (en) * 1985-10-02 1987-04-10 Canon Inc Automatic focusing device
JPS62170924A (en) * 1986-01-22 1987-07-28 Nippon Kogaku Kk <Nikon> Automatic focusing device
JPS62215220A (en) * 1986-03-17 1987-09-21 Canon Inc Automatic focusing device
JPS6479711A (en) * 1987-09-21 1989-03-24 Fuji Photo Film Co Ltd Automatic focusing adjuster
JPS6479713A (en) * 1987-09-21 1989-03-24 Fuji Photo Film Co Ltd Automatic focusing device for zoom lens
JPH01118110A (en) * 1988-06-07 1989-05-10 Canon Inc Automatic focusing device
JPH01131509A (en) * 1988-06-07 1989-05-24 Canon Inc Variable power optical system
JPH06175004A (en) * 1993-09-13 1994-06-24 Nikon Corp Autofocusing device
JPH06175005A (en) * 1993-09-13 1994-06-24 Nikon Corp Autofocusing device and photographing optical system capable of being attached to camera with autofocusing device
US6208811B1 (en) 1985-10-02 2001-03-27 Canon Kabuhsiki Kaisha Automatic focussing system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5893014A (en) * 1981-11-30 1983-06-02 Ricoh Co Ltd Producer of image forming position signal for zoom lens

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5893014A (en) * 1981-11-30 1983-06-02 Ricoh Co Ltd Producer of image forming position signal for zoom lens

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0234003B2 (en) * 1985-10-02 1990-08-01 Canon Kk
JPS6278519A (en) * 1985-10-02 1987-04-10 Canon Inc Automatic focusing device
US6208811B1 (en) 1985-10-02 2001-03-27 Canon Kabuhsiki Kaisha Automatic focussing system
JPS62170924A (en) * 1986-01-22 1987-07-28 Nippon Kogaku Kk <Nikon> Automatic focusing device
JPS62215220A (en) * 1986-03-17 1987-09-21 Canon Inc Automatic focusing device
JPH0234004B2 (en) * 1986-03-17 1990-08-01 Canon Kk
JPS6479711A (en) * 1987-09-21 1989-03-24 Fuji Photo Film Co Ltd Automatic focusing adjuster
JPS6479713A (en) * 1987-09-21 1989-03-24 Fuji Photo Film Co Ltd Automatic focusing device for zoom lens
JPH0234005B2 (en) * 1988-06-07 1990-08-01 Canon Kk
JPH01131509A (en) * 1988-06-07 1989-05-24 Canon Inc Variable power optical system
JPH01118110A (en) * 1988-06-07 1989-05-10 Canon Inc Automatic focusing device
JPH0234006B2 (en) * 1988-06-07 1990-08-01 Canon Kk
JPH06175004A (en) * 1993-09-13 1994-06-24 Nikon Corp Autofocusing device
JPH06175005A (en) * 1993-09-13 1994-06-24 Nikon Corp Autofocusing device and photographing optical system capable of being attached to camera with autofocusing device

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