JPH11231219A - Zoom lens for projection - Google Patents

Zoom lens for projection

Info

Publication number
JPH11231219A
JPH11231219A JP10035873A JP3587398A JPH11231219A JP H11231219 A JPH11231219 A JP H11231219A JP 10035873 A JP10035873 A JP 10035873A JP 3587398 A JP3587398 A JP 3587398A JP H11231219 A JPH11231219 A JP H11231219A
Authority
JP
Japan
Prior art keywords
group
zoom lens
projection zoom
lens
unit
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
JP10035873A
Other languages
Japanese (ja)
Other versions
JP4083856B2 (en
Inventor
Yoshitsugu Kono
義次 河野
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.)
Ricoh Optical Industries Co Ltd
Original Assignee
Ricoh Optical Industries Co Ltd
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 Ricoh Optical Industries Co Ltd filed Critical Ricoh Optical Industries Co Ltd
Priority to JP03587398A priority Critical patent/JP4083856B2/en
Publication of JPH11231219A publication Critical patent/JPH11231219A/en
Application granted granted Critical
Publication of JP4083856B2 publication Critical patent/JP4083856B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/22—Telecentric objectives or lens systems
    • 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
    • G02B15/146—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 more than five groups
    • G02B15/1465—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 more than five groups the first group being negative

Abstract

PROBLEM TO BE SOLVED: To actualize the zoom lens for projection which has superior properties as a projection zoom lens for a three-plate type liquid crystal projector. SOLUTION: This zoom lens is constituted by arranging 1st to 5th groups in order from the magnification side to the reduction side and providing a diaphragm between the 3rd and 4th groups. The 1st group G1 has negative refracting power and the 2nd and 3rd groups G2 and G3 have each positive refracting power; and the 4th group G4 has negative refracting power and the 5th group G5 have positive refracting power. For variable magnification from the wide-angle end to the telephoto end, the 1st group G1 and 5th group G5 are fixed, the 3rd group G3 moves so that the distance from the 1st group to the 3rd group decreases monotonously, and the 4th group G4 moves so that the distance from the 4th group to the 5th group decreases monotonously; and the diaphragm S moves together with the 3rd group and conditions of 0.8<|f1 |/f and 0.8<f5 /f are satisfied, where (f) is the focal distance of the whole system at the wide-angle end, (f1 ) is the focal distance of the 1st group, and (f5 ) is the focal distance of the 5th group.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】この発明は、投射用ズームレ
ンズに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection zoom lens.

【０００２】[0002]

【従来の技術】３色の画像を３枚の液晶パネルに個別的
に表示し、これら液晶パネルに色分解した光を照射し、
各液晶パネルにより強度変調された３色の光束をダイク
ロイックプリズム等の色合成手段により合成したのち、
共通した投射用レンズでスクリーン上に拡大像として合
成的に投射結像させて拡大されたカラー画像を表示する
「３板式液晶プロジェクタ」が普及してきている。３板
式プロジェクタにおける投射用レンズは、最適なスクリ
ーンサイズを容易に実現できるように、ズーム機能を有
する投射用ズームレンズの採用が一般的になってきてい
る。2. Description of the Related Art Images of three colors are individually displayed on three liquid crystal panels, and these liquid crystal panels are irradiated with color-separated light.
After synthesizing the three-color light flux intensity-modulated by each liquid crystal panel by a color synthesizing means such as a dichroic prism,
A “three-panel liquid crystal projector” that displays an enlarged color image by projecting and forming an enlarged image as an enlarged image on a screen using a common projection lens has become widespread. As a projection lens in a three-plate type projector, a projection zoom lens having a zoom function has been generally used so that an optimum screen size can be easily realized.

【０００３】３板式液晶プロジェクタに用いられる投射
用ズームレンズには、一般的に以下の如き属性が求めら
れる。３枚の液晶パネルにより強度変調された各光束
を、ダイクロイックプリズムやダイクロイックミラーと
いった色合成手段で合成するために、色合成手段を配備
するための空間が必要である。従って、この空間を確保
できるように、焦点距離に比して長いバックフォーカス
（最も縮小側のレンズ面から液晶パネルに至る距離）を
有すること。プロジェクタとして低電力で高い光利用効
率を得ることが望ましく、各色光の光路の合成時に前記
の色合成手段に入射する光の角度が画角により異なる
と、色シェーディングが発生し易いことから、光源部か
ら投射レンズに入射する光は光軸に対し平行に近い光束
を用いるのが良い。従って、平行光束を効率良く投射用
ズームレンズに取り込むため、縮小側、即ち、光源、液
晶パネル等のある側において高いテレセントリック性を
持つこと。スクリーン上での照度を上げて明るいカラー
画像を表示するため、光源からの光をなるべく多く投射
レンズに取り込めるよう、Ｆ／Ｎｏ．が小さく明るいレ
ンズであること。スクリーン上で３色を重ね合わせた時
に、各色の画素が互いにずれると良好なカラー画像を再
現できず、投射画像の辺縁部に青や緑あるいは赤等の縁
が現れて投影像の質が劣化するので、倍率色収差が可及
的に小さく抑えられていること。投影された画像の輪郭
が歪んで見苦しくないように、歪曲収差が可及的に小さ
く抑えられていること。プロジェクタの投影像は照度が
あまり高くなく、中心部に対する周辺部の画像の暗さが
目だちやすい。特にコンピュータのデータ等を投影する
際等は、画像の周辺部も中心部同様に観察されるため、
中心部と周辺部の明るさの違いは極力抑える必要があ
る。従って、周辺部の開口効率が高いこと。勿論、鮮明
な画像を投影するために、ＭＴＦ、解像力に関わる諸収
差が良好に補正されてること。The following attributes are generally required for a projection zoom lens used for a three-panel liquid crystal projector. In order to combine each light flux whose intensity is modulated by the three liquid crystal panels with a color combining unit such as a dichroic prism or a dichroic mirror, a space for disposing the color combining unit is required. Therefore, a back focus (distance from the lens surface closest to the reduction side to the liquid crystal panel) longer than the focal length must be provided so as to secure this space. As a projector, it is desirable to obtain high light use efficiency with low power, and if the angle of light incident on the color synthesizing means at the time of synthesizing the optical paths of the respective color lights differs depending on the angle of view, color shading is likely to occur. It is preferable to use a light beam that is nearly parallel to the optical axis as light that enters the projection lens from the part. Therefore, in order to efficiently capture the parallel light beam into the projection zoom lens, the reduction side, that is, a side having a light source, a liquid crystal panel, and the like, has high telecentricity. In order to display a bright color image by increasing the illuminance on the screen, the F / No. Is a small and bright lens. When the three colors are superimposed on the screen, if the pixels of each color deviate from each other, a good color image cannot be reproduced, and edges of blue, green or red appear at the periphery of the projected image, and the quality of the projected image deteriorates. The chromatic aberration of magnification must be kept as small as possible because of deterioration. Distortion should be kept as small as possible so that the contour of the projected image is not distorted and unsightly. The illuminance of the projected image of the projector is not so high, and the darkness of the image of the peripheral portion with respect to the central portion is easily noticeable. Especially when projecting computer data etc., the peripheral part of the image is observed as well as the central part,
It is necessary to minimize the difference in brightness between the center and the periphery. Therefore, the opening efficiency of the peripheral portion is high. Of course, in order to project a clear image, various aberrations relating to the MTF and the resolving power must be satisfactorily corrected.

【０００４】[0004]

【発明が解決しようとする課題】この発明は、上述した
所属性を良好に実現できる投射用ズームレンズの実現を
課題とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a projection zoom lens which can realize the above-mentioned affiliations well.

【０００５】[0005]

【課題を解決するための手段】この発明の投射用ズーム
レンズは「平面画像を拡大して投射結像させる投射用ズ
ームレンズ」である。上記平面画像は、一般に液晶パネ
ル上に表示される画像である。この発明の投射用ズーム
レンズは、図１に例示するように、拡大側（第１図の左
方）から縮小側（同右方）へ向かって順次、第１ないし
第５群Ｇ１〜Ｇ５を配してなり、第３群Ｇ３と第４群Ｇ
４の間に絞りＳを有する。第１群Ｇ１は「負の屈折力」
を持ち、第２群Ｇ２及び第３群Ｇ３は「正の屈折力」を
持つ。第４群Ｇ４は「負の屈折力」を持ち、第５群Ｇ５
は「正の屈折力」をそれぞれ有する。従って全体のパワ
ー配置は「負・正・正・負・正」である。広角端から望
遠端への変倍に際し、第１群Ｇ１および第５群Ｇ５は固
定で、第３群Ｇ３は「第１群Ｇ１から第３群Ｇ３までの
距離が単調に減少」するように移動し、第４群Ｇ４は
「第４群Ｇ４から第５群Ｇ５までの距離が単調に減少」
するように移動する。絞りＳは第３群Ｇ３とともに移動
する。広角端における全系の焦点距離：ｆ、第１群の焦
点距離：ｆ1 、第５群の焦点距離:f5 は、条件； （１） ０．８＜｜ｆ1｜／ｆ （２） ０．８ ＜ｆ5／ｆ を満足する（請求項１）。A projection zoom lens according to the present invention is a "projection zoom lens for enlarging a planar image to project and form an image." The planar image is an image generally displayed on a liquid crystal panel. In the projection zoom lens according to the present invention, as illustrated in FIG. 1, the first to fifth groups G1 to G5 are sequentially arranged from the enlargement side (left side in FIG. 1) to the reduction side (right side in FIG. 1). The third group G3 and the fourth group G
4 has an aperture S. The first group G1 is “negative refractive power”
The second group G2 and the third group G3 have “positive refractive power”. The fourth group G4 has “negative refractive power” and the fifth group G5
Have a "positive refractive power". Therefore, the overall power arrangement is "negative / positive / positive / negative / positive". At the time of zooming from the wide-angle end to the telephoto end, the first unit G1 and the fifth unit G5 are fixed, and the third unit G3 is configured such that "the distance from the first unit G1 to the third unit G3 monotonously decreases". The fourth group G4 moves and the distance from the fourth group G4 to the fifth group G5 monotonically decreases.
Move to make it. The stop S moves together with the third lens unit G3. The focal length of the entire system at the wide angle end: f, the focal length of the first group: f 1, a focal length of the fifth group: f 5 is conditional; (1) 0.8 <| f 1 | / f (2) 0.8 satisfies <f 5 / f (claim 1).

【０００６】この請求項１記載の投射用ズームレンズに
おいて、広角端における第３群Ｇ３の倍率：β3、第４
群Ｇ４の焦点距離：ｆ4、第５群Ｇ５に用いられている
凸レンズの材質のアッベ数の平均値：ν5Pは、条件； （３） −１．３＜β3＜−１．０ （４） ０．９＜｜ｆ4｜／ｆ＜１．３ （５） ６０＜ν5P を満足することができる（請求項２）。In the projection zoom lens according to the first aspect, the magnification of the third unit G3 at the wide-angle end is β 3 ,
The focal length of the group G4: f 4 , the average value of Abbe number of the material of the convex lens used in the fifth group G5: ν 5P is a condition: (3) −1.3 <β 3 <−1.0 ( 4) 0.9 <| f 4 | / f <1.3 (5) It is possible to satisfy 60 <ν 5P (claim 2).

【０００７】請求項１に記載のように、「負・正・正・
負・正」の屈折力を持つ第１群Ｇ１〜第５群Ｇ５より構
成することで、３板式液晶プロジェクタに使用するため
に十分な長いバックフォーカスを確保し、広角端におけ
るＦ／Ｎｏ．を小さく、広画角と投射用ズームレンズに
必要な変倍比の実現を可能としている。また、第３群Ｇ
３と第４群Ｇ４との間に設けられた絞りＳを、広角端か
ら望遠端への変倍に際し、液晶パネル面から遠ざかる動
き（拡大側へ向かう動き）をする第３群Ｇ３と一体的に
移動させることにより、全系の焦点距離の増加にしたが
って、絞り位置が液晶パネルから遠ざかるように、換言
すると、焦点距離の伸びに追随するように位置を変えて
いくので、前側焦点位置と、絞り位置が変倍によっても
大きくずれることがなく、変倍の全域で「縮小側におけ
るテレセントリック性の確保」を可能としている。[0007] As described in claim 1, "negative, positive, positive,
By including the first group G1 to the fifth group G5 having a negative / positive refractive power, a sufficiently long back focus for use in a three-panel liquid crystal projector is ensured, and the F / No. This makes it possible to achieve a wide angle of view and a zoom ratio required for a projection zoom lens. Also, the third group G
The stop S provided between the third lens unit G4 and the fourth lens unit G4 is integrated with the third lens unit G3 that moves away from the liquid crystal panel surface (moves toward the enlargement side) when zooming from the wide-angle end to the telephoto end. As the focal length of the entire system increases, the aperture position moves away from the liquid crystal panel, in other words, the position changes so as to follow the elongation of the focal length. The aperture position is not largely shifted by zooming, and "ensure telecentricity on the reduction side" is possible throughout the zooming range.

【０００８】条件（１）および（２）は、倍率色収差を
低減する条件である。一般に、レンズにおいては、軸上
・軸外とも、光線高が高くなる程各収差の発生量が大き
くなる。色収差もその性質は同じで、色間の画素ずれに
直接関わる倍率色収差の低減には「軸外光線高の高くな
る群」のパワーを制御するのが有効である。条件
（１）、（２）は、絞りから「前後に最も離れている
群」、即ち、軸外光線高が最も高くなる群である第１群
と第５群のパワーを制限するものであり、各々下限を越
えると、パワーの絶対値が大きくなることにより、倍率
色収差の発生量が大きくなり、他の群での補正が困難と
なる。条件（３）、（４）は、投射用ズームレンズのコ
ンパクトさ、即ち、短いレンズ全長を保ったまま、投射
用ズームレンズとして十分な変倍比を確保しつつ、結像
性能を低下させないためのものである。条件（３）の下
限を越えると、第２群から第３群に至る軸上光線が、光
軸に対し大きな角度を持つため、第１群と第３群との間
における諸収差の発生量が大となり、逆に上限を越える
と、第３群から第４群に至る軸上光線が光軸に対し大き
な角度を持つため、第３群と第５群の間での諸収差の発
生量が大となる。また、条件（３）が満足されない状態
で、結像性能を満足させようとすると、レンズ全長を拡
大し、各群のパワーを小さくする必要が生じる。条件
（４）の上限を越えると、３板式プロジェクタに必要な
長いバックフォーカスの確保が困難になり、下限を越え
ると、特に望遠側において大きな非点収差が発生し、他
の群での補正が困難となる。条件（５）は、倍率色収差
を抑えるための条件であり、条件（２）のように第５群
のパワーを制御する他に、条件（５）のように、第５群
の凸レンズの材質を低分散なものにすることで、倍率色
収差を「より小さく」抑えることができる。The conditions (1) and (2) are conditions for reducing chromatic aberration of magnification. In general, in a lens, both on-axis and off-axis, the higher the ray height, the larger the amount of each aberration generated. Chromatic aberration has the same property, and it is effective to control the power of the "group in which the off-axis ray height is high" in order to reduce the chromatic aberration of magnification directly related to pixel shift between colors. Conditions (1) and (2) limit the power of the first group and the fifth group that are “the group farthest to the front and back” from the stop, ie, the group in which the off-axis ray height is the highest. If the lower limit of each is exceeded, the absolute value of the power becomes large, so that the amount of chromatic aberration of magnification becomes large, and it becomes difficult to perform correction in other groups. Conditions (3) and (4) are for keeping the compactness of the projection zoom lens, that is, for keeping the short entire lens length, ensuring a sufficient zoom ratio as the projection zoom lens, and not deteriorating the imaging performance. belongs to. If the lower limit of the condition (3) is exceeded, the axial rays from the second group to the third group have a large angle with respect to the optical axis, so that the amount of various aberrations generated between the first and third groups Is larger than the upper limit. On the other hand, since the axial rays from the third group to the fourth group have a large angle with respect to the optical axis, the amount of generation of various aberrations between the third and fifth groups Is large. To satisfy the imaging performance in a state where the condition (3) is not satisfied, it is necessary to increase the entire length of the lens and reduce the power of each unit. When the value exceeds the upper limit of the condition (4), it becomes difficult to secure a long back focus required for the three-plate type projector. It will be difficult. Condition (5) is a condition for suppressing chromatic aberration of magnification. In addition to controlling the power of the fifth group as in Condition (2), the material of the convex lens in the fifth group is changed as in Condition (5). By making the dispersion low, chromatic aberration of magnification can be suppressed “smaller”.

【０００９】上記請求項２記載の投射用ズームレンズに
おいては、「第２群に非球面を用いる」ことができる
（請求項３）。即ち、第２群に非球面を用いると、性能
のさらなる向上が図られ、特に広角側で「像面がマイナ
ス側に倒れる」のを防ぐのに有効である。請求項３記載
の投射用ズームレンズにおいては、第２群の非球面に加
え、第４群中に非球面を採用することができる（請求項
４）。このように、第４群にも非球面を用いること像性
能の向上につながり、主に望遠側で像面がマイナス側に
倒れるのを防ぐのに有効である。請求項３または４に記
載の投射用ズームレンズにおいて、第２群の非球面は、
「絞りから最も離れた面」となる「最も第１群寄りの
面」に用いることができる（請求項５）。このようにす
ると、第２群に採用する非球面の効果を、より良く発揮
させることができる。同様に、請求項４記載の投射用ズ
ームレンズにおいて、第４群の非球面は「絞りから最も
離れた面」となる「最も第５群寄りの面」に用いること
ができ（請求項６）、このようにすることにより、第４
群に採用する非球面の効果を、よりよく発揮させること
ができる。In the projection zoom lens according to the second aspect, it is possible to use an aspherical surface for the second lens unit. That is, when an aspherical surface is used for the second lens unit, the performance is further improved, and it is particularly effective to prevent the image plane from falling to the minus side on the wide-angle side. In the projection zoom lens according to the third aspect, an aspherical surface can be employed in the fourth group in addition to the aspherical surface in the second group (claim 4). As described above, the use of the aspherical surface for the fourth lens unit also leads to improvement of image performance, and is effective mainly for preventing the image surface from falling on the telephoto side to the minus side. The projection zoom lens according to claim 3, wherein the aspheric surface of the second group is
It can be used as "the surface closest to the first group" which is "the surface farthest from the stop" (claim 5). By doing so, the effect of the aspherical surface employed in the second lens unit can be more effectively exerted. Similarly, in the projection zoom lens according to the fourth aspect, the aspherical surface of the fourth group can be used as the "surface closest to the fifth group", which is the "surface farthest from the stop" (claim 6). By doing so, the fourth
The effect of the aspherical surface employed in the group can be more effectively exhibited.

【００１０】[0010]

【発明の実施の形態】実施の形態を、図１，図５，図９
および図１３に示す。これら実施の形態を示す各図にお
いて、「Ｇ１」は第１群、「Ｇ２」は第２群、「Ｇ３」
は第３群を示し、「Ｇ４」は第４群、「Ｇ５」は第５群
を示す。また「Ｓ」は絞りを示す。図５の実施の形態に
おいて、第２群Ｇ２および第４群には「樹脂レンズ」が
貼着され（貼着面は球面）、この樹脂レンズが貼着され
たレンズは「ハイブリッドレンズ」であり、上記樹脂レ
ンズの表面が非球面となっている。また、上記図１，図
５，図９，図１３において、符号Ｐは「色合成プリズ
ム」を示す。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments are shown in FIGS.
And FIG. In each of the drawings showing these embodiments, “G1” represents the first group, “G2” represents the second group, and “G3”.
Indicates the third group, “G4” indicates the fourth group, and “G5” indicates the fifth group. “S” indicates an aperture. In the embodiment of FIG. 5, a “resin lens” is attached to the second group G2 and the fourth group (the attachment surface is a spherical surface), and the lens to which this resin lens is attached is a “hybrid lens”. The surface of the resin lens is aspheric. In FIGS. 1, 5, 9 and 13, the symbol P indicates a “color combining prism”.

【００１１】[0011]

【実施例】図１，図５，図９および図１３に示す各実施
の形態に関する具体的な実施例を１例ずつ挙げる。各実
施例において、「Ｒi」はスクリーン側（拡大側）から
数えて第ｉ番目の面（絞りの面を含む）の曲率半径、
「Ｄi」はスクリーン側から数えて第ｉ番目の面から第
ｉ＋１番目の面までの軸上間隔、「Ｎj」はスクリーン
側から数えて第ｊ番目のレンズのｄ線に対する屈折率
を、同様にνjはスクリーン側から数えて第ｊ番目のレ
ンズのアッベ数を示す。また「Ｄ0（ｉ＝０）」は、ス
クリーンからレンズ第１面までの距離、最終面の
「Ｄi」は「色合成プリズムＰの液晶パネル側の面から
液晶パネル面までの距離」である。フォーカシングによ
る「無限遠からの繰り出し」は、各実施例とも第１群で
行い、可変間隔の欄で示す第１群と第２群の間隔は「繰
り出し量を含んだ値」である。非球面の表示は、一般に
使用される式： Ｚ＝（１／Ｒi）・ｈ2／［１＋√｛１−（Ｋ＋１）・
（１／Ｒi）2・ｈ2｝］＋Ａ・ｈ4＋Ｂ・ｈ6＋Ｃ・ｈ8＋
Ｄ・ｈ10＋Ｅ・ｈ12＋．．． において、Ｚを光軸方向の座標、ｈを光軸直交方向の座
標とし、軸上曲率半径：Ｒi、円錐定数：Ｋ、高次の非
球面係数：Ａ，Ｂ，Ｃ，Ｄ，Ｅ，．．．を与えることに
より特定される。DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples relating to the respective embodiments shown in FIGS. 1, 5, 9 and 13 will be described one by one. In each embodiment, “R i ” is the radius of curvature of the ith surface (including the stop surface) counted from the screen side (enlargement side),
“D i ” is the axial distance from the ith surface to the (i + 1) th surface counted from the screen side, “N j ” is the refractive index for the d-line of the j-th lens counted from the screen side, Similarly, ν j indicates the Abbe number of the j-th lens counted from the screen side. “D 0 (i = 0)” is the distance from the screen to the first surface of the lens, and “D i ” on the last surface is “the distance from the surface of the color combining prism P on the liquid crystal panel side to the liquid crystal panel surface”. is there. The “extending from infinity” by focusing is performed by the first lens unit in each embodiment, and the interval between the first and second lens units shown in the column of the variable interval is “a value including the extending amount”. The representation of the aspheric surface can be expressed by the commonly used formula: Z = (1 / R i ) · h 2 / [1 + √ ｛1- (K + 1) ·
(1 / R i ) 2 · h 2 }] + A · h 4 + B · h 6 + Ch · h 8 +
D · h 10 + E · h 12 +. . . , Z is the coordinate in the optical axis direction, h is the coordinate in the optical axis orthogonal direction, the on-axis radius of curvature: R i , the conical constant: K, the higher order aspherical coefficients: A, B, C, D, E, . . . Is specified.

【００１２】最初に挙げる実施例１は、図１に示した実
施の形態に関する実施例である。 実施例１ ｉ Ｒi Ｄi ｊ Ｎj νj 0 2650.0 １ 136.047 3.498 1 1.69680 55.5 ２ -1534.478 0.2 ３ 66.162 2.0 2 1.48749 70.4 ４ 28.232 9.064 ５ -52.538 1.8 3 1.51823 59.0 ６ 69.861 可変 ７ 50.249(*) 2.741 4 1.58913 61.3 ８ 88.222 可変 ９ 92.369 1.8 5 1.80518 25.5 １０ 42.723 6.38 6 1.77250 49.6 １１ -104.004 0.647 １２ 77.509 2.94 7 1.77250 49.6 １３ 345.956 9.94 １４ ∞（絞り） 可変 １５ 385.818 4.628 8 1.80518 25.5 １６ -30.783 1.8 9 1.58144 40.9 １７ 70.926 4.069 １８ -29.825 1.8 10 1.59270 35.5 １９ 3173.371(*) 可変 ２０ -135.229 2.4 11 1.84666 23.8 ２１ 69.653 11.127 12 1.49700 81.6 ２２ -45.387 0.2 ２３ 128.979 8.395 13 1.63854 55.5 ２４ -94.629 0.355 ２５ 91.174 8.072 14 1.58913 61.3 ２６ -210.512 10.0 ２７ ∞ 50.0 15 1.51680 64.2 ２８ ∞ 5.9 。Example 1 given first is an example relating to the embodiment shown in FIG. Example 1 i R i D i j N j ν j 0 2650.0 1 136.047 3.498 1 1.69680 55.5 2 -1534.478 0.2 3 66.162 2.0 2 1.48749 70.4 4 28.232 9.064 5 -52.538 1.8 3 1.51823 59.0 6 69.861 Variable 7 50.249 (*) 2.741 4 1.58913 61.3 8 88.222 Variable 9 92.369 1.8 5 1.80518 25.5 10 42.723 6.38 6 1.77250 49.6 11 -104.004 0.647 12 77.509 2.94 7 1.77250 49.6 13 345.956 9.94 14 17 70.926 4.069 18 -29.825 1.8 10 1.59270 35.5 19 3173.371 (*) Variable 20 -135.229 2.4 11 1.84666 23.8 21 69.653 11.127 12 1.49700 81.6 22 -45.387 0.2 23 128.979 8.395 13 1.63854 55.5 24 -94.629 0.355 25 91.174 8.072 14 1.58913 61.3 -210.512 10.0 27 ∞ 50.0 15 1.51680 64.2 28 ∞ 5.9.

【００１３】（＊）を付したレンズ面は「非球面」であ
り、第１４面は絞り面である。また、第２７，２８面は
色合成プリズムの面を示す。 非球面： 第７面 k=-0.04322,A=-0.80635E-8,B=-0.19570E-8,C=
0.41153E-11,D=-0.26997E-15,E=-0.14000E-16 第１９面 K=45642.2,A=0.16847E-5,B=-0.73329E-8,C=
0.50908E-10,D=-0.13816E-12 可変量 焦点距離 51.72 61.17 72.17 Ｄ６ 1.838 2.01 2.5 Ｄ８ 12.566 7.092 2.030 Ｄ１４ 8.536 17.524 27.419 Ｄ１９ 11.348 7.663 2.339 条件式のパラメータの値 条件（１）のパラメータの値 ０．９ 条件（２）のパラメータの値 ０．８５ 条件（３）のパラメータの値 −１．２１ 条件（４）のパラメータの値 １．０５ 条件（５）のパラメータの値 ６６．１ 実施例１に関する、広角端（ｆ＝５１，７２）における
収差図を図２に、中間焦点距離（ｆ＝６１．１７）にお
ける収差図を図３に、望遠端（ｆ＝７２．１７）におけ
る収差図を図４に示す。The lens surface marked with (*) is “aspherical”, and the fourteenth surface is a stop surface. The 27th and 28th surfaces indicate the surfaces of the color combining prism. Aspheric surface: 7th surface k = -0.04322, A = -0.80635E-8, B = -0.19570E-8, C =
0.41153E-11, D = -0.26997E-15, E = -0.14000E-16 19th page K = 45642.2, A = 0.16847E-5, B = -0.73329E-8, C =
0.50908E-10, D = -0.13816E-12 Variable Focal length 51.72 61.17 72.17 D6 1.838 2.01 2.5 D8 12.566 7.092 2.030 D14 8.536 17.524 27.419 D19 11.348 7.663 2.339 Parameter value of condition (1) Parameter value of condition (1) 0 .9 Parameter Value of Condition (2) 0.85 Parameter Value of Condition (3) -1.21 Parameter Value of Condition (4) 1.05 Parameter Value of Condition (5) 66.1 Example 1 2 is an aberration diagram at the wide-angle end (f = 51, 72), FIG. 3 is an aberration diagram at an intermediate focal length (f = 61.17), and an aberration diagram at the telephoto end (f = 72.17). As shown in FIG.

【００１４】次に挙げる実施例２は、図５に示す実施の
形態に関する実施例である。A second embodiment described below is an embodiment relating to the embodiment shown in FIG.

【００１５】 実施例２ ｉ Ｒi Ｄi ｊ Ｎj νj ０ 2650.0 １ 195.721 3.287 1 1.69680 55.5 ２ -363.576 0.2 ３ 71.298 2.0 2 1.48749 70.4 ４ 29.221 8.257 ５ -50.891 1.8 3 1.51823 59.0 ６ 72.124 可変 ７ 50.038(*) 0.3 1.50403(#) 53.4(#) ８ 50.038 2.755 4 1.58913 61.3 ９ 94.242 可変 １０ 99.246 1.8 5 1.80518 25.5 １１ 44.325 6.36 6 1.77250 49.6 １２ -101.721 0.2 １３ 70.562 3.043 7 1.77250 49.6 １４ 270.310 9.98 １５ ∞（絞り） 可変 １６ 480.747 4.67 8 1.80518 25.5 １７ -30.603 1.8 9 1.58144 40.9 １８ 72.435 4.087 １９ -29.550 1.8 10 1.59270 35.5 ２０ 3186.63 0.3 1.50403(#) 53.4(#) ２１ 3186.63(*) 可変 ２２ -131.331 2.4 11 1.84666 23.8 ２３ 66.788 11.345 12 1.48749 70.4 ２４ -45.116 0.2 ２５ 130.635 9.19 13 1.58913 61.3 ２６ -81.453 0.885 ２７ 88.076 8.558 14 1.58913 61.3 ２８ -206.746 10.0 ２９ ∞ 50.0 15 1.51680 64.2 ３０ ∞ 5.9 。[0015] Example 2 i R i D i j N j ν j 0 2650.0 1 195.721 3.287 1 1.69680 55.5 2 -363.576 0.2 3 71.298 2.0 2 1.48749 70.4 4 29.221 8.257 5 -50.891 1.8 3 1.51823 59.0 6 72.124 Variable 7 50.038 ( *) 0.3 1.50403 (#) 53.4 (#) 8 50.038 2.755 4 1.58913 61.3 9 94.242 Variable 10 99.246 1.8 5 1.80518 25.5 11 44.325 6.36 6 1.77250 49.6 12 -101.721 0.213 70.562 3.043 7 1.77250 49.6 14 270.310 9.98 15 ∞ (aperture) Variable 16 480.747 4.67 8 1.80518 25.5 17 -30.603 1.8 9 1.58144 40.9 18 72.435 4.087 19 -29.550 1.8 10 1.59270 35.5 20 3186.63 0.3 1.50403 (#) 53.4 (#) 21 3186.63 (*) Variable 22 -131.331 2.4 11 1.84666 23.8 23 66.788 11.345 12 1.48749 70.4 24 -45.116 0.2 25 130.635 9.19 13 1.58913 61.3 26 -81.453 0.885 27 88.076 8.558 14 1.58913 61.3 28 -206.746 10.0 29 ∞ 50.0 15 1.51680 64.2 30 5.9 5.9.

【００１６】（＊）を付したレンズ面は「非球面」であ
り、第１５面は絞り面である。また、第２９，３０面は
色合成プリズムの面を示す。第７面および、第２１面は
「球面レンズをベースとして、樹脂の非球面を成形した
ハイブリッドタイプ」の非球面であり、（＃）は「樹
脂」の屈折率、アッベ数を示す。 非球面： 第７面 k=-0.15258,A=-0.10245E-6,B=-0.54750E-8,C=
0.31911E-10,D=-0.97409E-13,E=0.11019E-15 第２１面 K=45472.1,A=0.19718E-5,B=-0.86057E-8,C=
0.58921E-10,D=-0.15747E-12 可変量： 焦点距離 51.7 61.14 72.17 Ｄ６ 3.046 2.391 2.5 Ｄ９ 11.414 6.832 2 Ｄ１５ 7.679 16.460 26.051 Ｄ２１ 10.792 7.248 2.381 条件式のパラメータの値 条件（１）のパラメータの値 ０．８９ 条件（２）のパラメータの値 ０．８６ 条件（３）のパラメータの値 −１．１３ 条件（４）のパラメータの値 １．０３ 条件（５）のパラメータの値 ６４．３ 実施例２に関する、広角端（ｆ＝５１，７０）における
収差図を図６に、中間焦点距離（ｆ＝６１．１４）にお
ける収差図を図７に、望遠端（ｆ＝７２．１７）におけ
る収差図を図８に示す。The lens surface marked with (*) is an "aspheric surface", and the fifteenth surface is a stop surface. The 29th and 30th surfaces indicate the surfaces of the color combining prism. The seventh surface and the twenty-first surface are aspherical surfaces of a “hybrid type in which a resin aspherical surface is molded based on a spherical lens”, and (#) indicates the refractive index and Abbe number of “resin”. Aspheric surface: 7th surface k = -0.15258, A = -0.10245E-6, B = -0.54750E-8, C =
0.31911E-10, D = -0.97409E-13, E = 0.11019E-15 Surface 21 K = 45472.1, A = 0.19718E-5, B = -0.86057E-8, C =
0.58921E-10, D = -0.15747E-12 Variable: Focal length 51.7 61.14 72.17 D6 3.046 2.391 2.5 D9 11.414 6.832 2 D15 7.679 16.460 26.051 D21 10.792 7.248 2.381 Value of parameter in conditional expression Value of parameter in condition (1) 0.89 Parameter Value of Condition (2) 0.86 Parameter Value of Condition (3) -1.13 Parameter Value of Condition (4) 1.03 Parameter Value of Condition (5) 64.3 Example 6 is an aberration diagram at the wide-angle end (f = 51, 70), FIG. 7 is an aberration diagram at an intermediate focal length (f = 61.14), and an aberration diagram at the telephoto end (f = 72.17). Is shown in FIG.

【００１７】次に挙げる実施例３は、図９に示す実施の
形態に関する実施例である。Example 3 described below is an example relating to the embodiment shown in FIG.

【００１８】 実施例３ ｉ Ｒi Ｄi ｊ Ｎj νj ０ 2650.0 １ 70.197 4.91 1 1.58913 61.3 ２ 850.212 0.2 ３ 74.166 2.0 2 1.51680 64.2 ４ 27.834 9.021 ５ -54.151 1.8 3 1.51680 64.2 ６ 64.455 可変 ７ 57.252(*) 3.016 4 1.58913 61.3 ８ 147.260 可変 ９ 161.607 1.8 5 1.80518 25.5 １０ 49.240 5.601 6 1.81600 46.6 １１ -108.775 0.2 １２ 65.200 3.055 7 1.77250 49.6 １３ 239.047 11.840 １４ ∞（絞り） 可変 １５ -171.076 3.991 8 1.84666 23.8 １６ -28.554 1.8 9 1.59551 39.2 １７ -361.849 2.183 １８ -34.543 1.8 10 1.58144 40.9 １９ 115.277 可変 ２０ -89.849 2.4 11 1.84666 23.8 ２１ 68.531 10.539 12 1.49700 81.6 ２２ -47.552 0.2 ２３ 164.668 8.636 13 1.63854 55.5 ２４ -75.167 0.2 ２５ 75.182 9.044 14 1.58913 61.3 26 -241.086 10.0 ２７ ∞ 50.0 15 1.51680 64.2 ２８ ∞ 5.9 。[0018] Example 3 i R i D i j N j ν j 0 2650.0 1 70.197 4.91 1 1.58913 61.3 2 850.212 0.2 3 74.166 2.0 2 1.51680 64.2 4 27.834 9.021 5 -54.151 1.8 3 1.51680 64.2 6 64.455 Variable 7 57.252 (* ) 3.016 4 1.58913 61.3 8 147.260 Variable 9 161.607 1.8 5 1.80518 25.5 10 49.240 5.601 6 1.81600 46.6 11 -108.775 0.2 12 65.200 3.055 7 1.77250 49.6 13 239.047 11.840 14 絞 り (Aperture) Variable 15 -171.076 3.991 8 1.84666 23.8 16-28 9 1.59551 39.2 17 -361.849 2.183 18 -34.543 1.8 10 1.58144 40.9 19 115.277 Variable 20 -89.849 2.4 11 1.84666 23.8 21 68.531 10.539 12 1.49700 81.6 22 -47.552 0.2 23 164.668 8.636 13 1.63854 55.5 24 -75.167 0.225 1.575.1829.044 14 26 -241.086 10.0 27 ∞ 50.0 15 1.51680 64.2 28 ∞ 5.9.

【００１９】（＊）を付したレンズ面は「非球面」であ
り、第１４面は絞り面である。また、第２７，２８面は
色合成プリズムの面を示す。 非球面： 第７面 k=0.43454,A=0.49737E-6,B=-0.16017E-8,C=0.6
7588E-11,D=-0.20105E-13,E=0.21832E-16 可変量： 焦点距離 51.8 61.29 72.39 Ｄ６ 3.18 2.605 2.5 Ｄ８ 12.929 7.343 2.063 Ｄ１４ 8.894 18.265 28.808 Ｄ１９ 11.761 8.550 3.393 条件式のパラメータの値 条件（１）のパラメータの値 ０．９３ 条件（２）のパラメータの値 ０．８８ 条件（３）のパラメータの値 −１．０８ 条件（４）のパラメータの値 １．１９ 条件（５）のパラメータの値 ６６．１ 実施例３に関する、広角端（ｆ＝５１，８０）における
収差図を図１０に、中間焦点距離（ｆ＝６１．２９）に
おける収差図を図１１に、望遠端（ｆ＝７２．３９）に
おける収差図を図１２に示す。The lens surface marked with (*) is an "aspheric surface", and the fourteenth surface is a stop surface. The 27th and 28th surfaces indicate the surfaces of the color combining prism. Aspheric surface: 7th surface k = 0.43454, A = 0.49737E-6, B = -0.16017E-8, C = 0.6
7588E-11, D = -0.20105E-13, E = 0.21832E-16 Variable amount: Focal length 51.8 61.29 72.39 D6 3.18 2.605 2.5 D8 12.929 7.343 2.063 D14 8.894 18.265 28.808 D19 11.761 8.550 3.393 Value of parameter in condition expression Condition ( Parameter value of condition 1) 0.93 Parameter value of condition (2) 0.88 Parameter value of condition (3) −1.08 Parameter value of condition (4) 1.19 Parameter value of condition (5) Value 66.1 Regarding Example 3, FIG. 10 shows an aberration diagram at the wide-angle end (f = 51, 80), FIG. 11 shows an aberration diagram at an intermediate focal length (f = 61.29), and a telephoto end (f = 72). .39) is shown in FIG.

【００２０】最後に挙げる実施例４は、図１３に示す実
施の形態に関する実施例である。A fourth embodiment is an embodiment relating to the embodiment shown in FIG.

【００２１】 実施例４ ｉ Ｒi Ｄi ｊ Ｎj νj 0 2650.0 １ 99.875 4.543 1 1.69680 55.5 ２ -1327.607 0.2 ３ 71.573 2.0 2 1.48749 70.4 ４ 27.130 9.402 ５ -55.338 1.8 3 1.51823 59.0 ６ 62.454 可変 ７ 48.883(*) 2.952 4 1.58913 61.3 ８ 99.179 可変 ９ 101.197 1.8 5 1.80518 25.5 １０ 45.355 5.565 6 1.77250 49.6 １１ -121.855 0.2 １２ 69.855 2.871 7 1.77250 49.6 １３ 249.543 11.229 １４ ∞（絞り） 可変 １５ 294.437 4.733 8 1.80518 25.5 １６ -31.290 1.8 9 1.58144 40.9 １７ 65.564 3.736 １８ -30.947 1.8 10 1.59270 35.5 １９ 3551.371(*) 可変 ２０ -146.235 2.4 11 1.84666 23.8 ２１ 65.547 11.931 12 1.49700 81.6 ２２ -47.217 0.2 ２３ 142.657 8.665 13 1.63854 55.5 ２４ -98.659 0.2 ２５ 87.168 9.905 14 1.58913 61.3 ２６ -163.166 10.0 ２７ ∞ 50.0 15 1.51680 64.2 ２８ ∞ 5.9 。[0021] Example 4 i R i D i j N j ν j 0 2650.0 1 99.875 4.543 1 1.69680 55.5 2 -1327.607 0.2 3 71.573 2.0 2 1.48749 70.4 4 27.130 9.402 5 -55.338 1.8 3 1.51823 59.0 6 62.454 Variable 7 48.883 ( *) 2.952 4 1.58913 61.3 8 99.179 Variable 9 101.197 1.8 5 1.80518 25.5 10 45.355 5.565 6 1.77250 49.6 11 -121.855 0.2 12 69.855 2.871 7 1.77250 49.6 13 249.543 11.229 14 絞 り (Aperture) Variable 15 294.437 4.733 8 1.80518 25.5 16-31. 9 1.58144 40.9 17 65.564 3.736 18 -30.947 1.8 10 1.59270 35.5 19 3551.371 (*) Variable 20 -146.235 2.4 11 1.84666 23.8 21 65.547 11.931 12 1.49700 81.6 22 -47.217 0.2 23 142.657 8.665 13 1.63854 55.5 24 -98.659 0.2 14 87.168 9.905 1.58913 61.3 26 -163.166 10.0 27 ∞ 50.0 15 1.51680 64.2 28 ∞ 5.9.

【００２２】（＊）を付したレンズ面は「非球面」であ
り、第１４面は絞り面である。また、第２７，２８面は
色合成プリズムの面を示す。 非球面： 第７面 K=0.08587,A=0.15561E-6,B=-0.20371E-8,C=0.6
3911E-11,D=-0.14649E-13,E=0.12477E-16 第１９面 K=55273.31,A=0.18399E-5,B=-0.13572E-8,C=
0.79504E-11,D=-0.32681E-13 可変量 焦点距離 48.36 59.20 72.31 Ｄ６ 3.273 2.536 2.5 Ｄ８ 13.782 7.720 2.0 Ｄ１４ 3.267 14.172 26.282 Ｄ１９ 12.745 8.639 2.285 条件式のパラメータの値： 条件（１）のパラメータの値 ０．９９ 条件（２）のパラメータの値 ０．９１ 条件（３）のパラメータの値 −１．０８ 条件（４）のパラメータの値 １．１６ 条件（５）のパラメータの値 ６６．１ 実施例４に関する、広角端（ｆ＝４８．３６）における
収差図を図１４に、中間焦点距離（ｆ＝５９．２）にお
ける収差図を図１５に、望遠端（ｆ＝７２．３１）にお
ける収差図を図１６に示す。The lens surface marked with (*) is an "aspheric surface", and the fourteenth surface is a stop surface. The 27th and 28th surfaces indicate the surfaces of the color combining prism. Aspheric surface: 7th surface K = 0.08587, A = 0.15561E-6, B = -0.20371E-8, C = 0.6
3911E-11, D = -0.14649E-13, E = 0.12477E-16 19th page K = 55273.31, A = 0.18399E-5, B = -0.13572E-8, C =
0.79504E-11, D = -0.32681E-13 Variable Focal length 48.36 59.20 72.31 D6 3.273 2.536 2.5 D8 13.782 7.720 2.0 D14 3.267 14.172 26.282 D19 12.745 8.639 2.285 Value of parameter in conditional expression: Value of parameter in condition (1) 0.99 Parameter Value of Condition (2) 0.91 Parameter Value of Condition (3) −1.08 Parameter Value of Condition (4) 1.16 Parameter Value of Condition (5) 66.1 Example 14 is an aberration diagram at the wide-angle end (f = 48.36), FIG. 15 is an aberration diagram at an intermediate focal length (f = 59.2), and an aberration diagram at the telephoto end (f = 72.31). Is shown in FIG.

【００２３】各収差図において、「Ｇ」は波長５３５ｎ
ｍの光線の収差、「Ｂ」は波長４５０ｎｍの光線の収
差、「Ｒ」は波長６２０ｎｍの光線の収差を示し、
「Ｍ」は波長５３５ｎｍの光線のメリディオナル像面
を、「Ｓ」は同サジタル像面を示す。また「ω」は半画
角を示す。In each aberration diagram, “G” indicates a wavelength of 535 n.
m, the aberration of the light beam with a wavelength of 450 nm, “R” the aberration of the light beam with a wavelength of 620 nm,
“M” indicates a meridional image plane of a light beam having a wavelength of 535 nm, and “S” indicates a sagittal image plane. “Ω” indicates a half angle of view.

【００２４】[0024]

【発明の効果】以上に説明したように、この発明によれ
ば新規な投射用ズームレンズを実現できる。この投射用
ズームレンズは、３板式液晶ディスプレイ用の投射用ズ
ームレンズに求められる諸属性を良好に満足することが
できる。即ち、各実施例とその収差図から分かるよう
に、広角端におけるＦ／Ｎｏ．が２．０程度と小さく、
半画角：約２３〜２５°程度と広画角で、変倍比：１．
４〜１．５を実現している。各実施例とも、ワイド端に
おける近軸像点位置に対する像面湾曲量は最大でも約
０.１５ｍｍ少なく抑えられ、したがって、このレンズ
を使用した液晶プロジェクタにおいては、平坦な投射画
像を得ることができる。更に、歪曲収差は各実施例と
も、広角端において約−２％以内、望遠端において約＋
１.５％以内と小さく抑えられ、投射される画像は輪郭
の歪みの少ないものとすることができる。As described above, according to the present invention, a novel projection zoom lens can be realized. This projection zoom lens can satisfactorily satisfy various attributes required for a projection zoom lens for a three-panel liquid crystal display. That is, as can be seen from the examples and the aberration diagrams thereof, the F / No. Is as small as 2.0,
Half angle of view: Wide angle of view of about 23-25 °, zoom ratio: 1.
4 to 1.5 are realized. In each of the embodiments, the amount of curvature of field with respect to the paraxial image point position at the wide end is suppressed to about 0.15 mm at the maximum, and therefore, in a liquid crystal projector using this lens, a flat projection image can be obtained. . Further, in each embodiment, the distortion is within about -2% at the wide-angle end, and about ++ at the telephoto end.
The projected image can be reduced to 1.5% or less, and the projected image can have less contour distortion.

【００２５】また、各実施例とも高い開口効率を有し、
像の周辺部においても中心部に比べて遜色ない明るい像
が得られる。Further, each embodiment has a high aperture efficiency,
A bright image is obtained at the periphery of the image as well as at the center.

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

【図１】実施例１の投射用ズームレンズのｆ＝５１．７
２における断面図である。FIG. 1 shows f = 51.7 of a projection zoom lens according to a first embodiment.
It is sectional drawing in 2.

【図２】実施例１の投射用ズームレンズのｆ＝５１．７
２における収差図である。FIG. 2 shows f = 51.7 of the projection zoom lens according to the first embodiment.
FIG. 3 is an aberrational diagram at 2.

【図３】実施例１の投射用ズームレンズのｆ＝６１．１
７における収差図である。FIG. 3 shows f = 61.1 of the projection zoom lens according to the first embodiment.
FIG. 7 is an aberration diagram at 7.

【図４】実施例１の投射用ズームレンズのｆ＝７２．１
７における収差図である。FIG. 4 shows f = 72.1 of the projection zoom lens according to the first embodiment.
FIG. 7 is an aberration diagram at 7.

【図５】実施例２の投射用ズームレンズのｆ＝５１．７
０における断面図である。FIG. 5 shows f = 51.7 of the projection zoom lens according to the second embodiment.
FIG.

【図６】実施例２の投射用ズームレンズのｆ＝５１．７
０における収差図である。FIG. 6 shows f = 51.7 of the projection zoom lens according to the second embodiment.
FIG. 7 is an aberration diagram at 0.

【図７】実施例２の投射用ズームレンズのｆ＝６１．１
４における収差図である。FIG. 7 shows f = 61.1 of the projection zoom lens according to the second embodiment.
FIG. 4 is an aberrational diagram at 4.

【図８】実施例２の投射用ズームレンズのｆ＝７２．１
７における収差図である。FIG. 8 shows f = 72.1 of the projection zoom lens according to the second embodiment.
FIG. 7 is an aberration diagram at 7.

【図９】実施例３の投射用ズームレンズのｆ＝５１．８
０における断面図である。FIG. 9 shows f = 51.8 of the projection zoom lens according to the third embodiment.
FIG.

【図１０】実施例３の投射用ズームレンズのｆ＝５１．
８０における収差図である。FIG. 10 shows f = 51.
It is an aberrational figure in 80.

【図１１】実施例３の投射用ズームレンズのｆ＝６１．
２９における収差図である。FIG. 11 shows a projection zoom lens according to a third embodiment, f = 61.
29 is an aberration diagram at 29. FIG.

【図１２】実施例３の投射用ズームレンズのｆ＝７２．
３９における収差図である。FIG. 12 shows a projection zoom lens according to a third embodiment, f = 72.
It is an aberrational figure in 39.

【図１３】実施例４の投射用ズームレンズのｆ＝４８．
３６における断面図である。FIG. 13 shows f = 48.
It is sectional drawing in 36.

【図１４】実施例４の投射用ズームレンズのｆ＝４８．
３６における収差図である。FIG. 14 is a view showing f = 48.
36 is an aberration diagram at 36. FIG.

【図１５】実施例４の投射用ズームレンズのｆ＝５９．
２における収差図である。FIG. 15 shows f = 59.
FIG. 3 is an aberrational diagram at 2.

【図１６】実施例４の投射用ズームレンズのｆ＝７２．
３１における収差図である。FIG. 16 shows f = 72.
31 is an aberration diagram at 31. FIG.

【符号の説明】[Explanation of symbols]

Ｇ１ 第１群 Ｇ２ 第２群 Ｇ３ 第３群 Ｇ４ 第４群 Ｇ５ 第５群 Ｓ 絞り G1 First group G2 Second group G3 Third group G4 Fourth group G5 Fifth group S Aperture

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】平面画像を拡大して投射結像させる投射用
ズームレンズであって、 拡大側から縮小側へ向かって順次、第１ないし第５群を
配してなり、第３群と第４群の間に絞りを有し、 第１群は負の屈折力、第２および第３群は正の屈折力、
第４群は負の屈折力、第５群は正の屈折力をそれぞれ有
し、 広角端から望遠端への変倍に際し、第１群および第５群
が固定で、第３群が、第１群から第３群までの距離が単
調に減少するように移動し、第４群が、第４群から第５
群までの距離が単調に減少するように移動し、絞りが第
３群とともに移動を行い、 広角端における全系の焦点距離：ｆ、第１群の焦点距
離：ｆ1 、第５群の焦点距離:f5 が、条件； （１） ０．８＜｜ｆ1｜／ｆ （２） ０．８ ＜ｆ5／ｆ を満足することを特徴とする投射用ズームレンズ。1. A projection zoom lens for projecting and forming an image by enlarging a planar image, comprising a first group to a fifth group arranged in order from an enlargement side to a reduction side. A first group having a negative refractive power, second and third groups having a positive refractive power,
The fourth unit has a negative refractive power, and the fifth unit has a positive refractive power. In zooming from the wide-angle end to the telephoto end, the first and fifth units are fixed, and the third unit is The distance from the first group to the third group moves so as to decrease monotonically, and the fourth group moves from the fourth group to the fifth group.
Distance to the group is moved so as to decrease monotonically performs moving diaphragm together with the third group, the focal length of the entire system at the wide angle end: f, the focal length of the first group: f 1, the focal point of the fifth group distance: f 5 is, conditions; (1) 0.8 <| f 1 | / f (2) 0.8 < projection zoom lens which satisfies the f 5 / f. 【請求項２】請求項１記載の投射用ズームレンズにおい
て、 広角端における第３群の倍率：β3、第４群の焦点距
離：ｆ4、第５群に用いられている凸レンズの材質のア
ッベ数の平均値：ν5Pが、条件； （３） −１．３＜β3＜−１．０ （４） ０．９＜｜ｆ4｜／ｆ＜１．３ （５） ６０＜ν5P を満足することを特徴とする投射用ズームレンズ。2. The projection zoom lens according to claim 1, wherein a magnification of the third lens unit at the wide-angle end: β 3 , a focal length of the fourth lens unit: f 4 , and a material of the convex lens used in the fifth lens unit. Average value of Abbe number: ν 5P is a condition; (3) −1.3 <β 3 <−1.0 (4) 0.9 <| f 4 | / f <1.3 (5) 60 <ν A projection zoom lens that satisfies 5P . 【請求項３】請求項２記載の投射用ズームレンズにおい
て、 第２群に非球面が用いられていることを特徴とする投射
用ズームレンズ。3. The projection zoom lens according to claim 2, wherein an aspherical surface is used for the second group. 【請求項４】請求項３記載の投射用ズームレンズにおい
て、 第４群に非球面が用いられていることを特徴とする投射
用ズームレンズ。4. The projection zoom lens according to claim 3, wherein an aspherical surface is used for the fourth lens unit. 【請求項５】請求項３または４記載の投射用ズームレン
ズにおいて、 第２群に用いられた非球面が、第２群の最も第１群寄り
の面であることを特徴とする投射用ズームレンズ。5. The projection zoom lens according to claim 3, wherein the aspherical surface used in the second group is a surface of the second group closest to the first group. lens. 【請求項６】請求項４記載の投射用ズームレンズにおい
て、 第４群に用いられた非球面が、第４群の最も第５群寄り
の面であることを特徴とする投射用ズームレンズ。6. The projection zoom lens according to claim 4, wherein the aspherical surface used in the fourth group is the surface of the fourth group closest to the fifth group.
JP03587398A 1998-02-18 1998-02-18 Projection zoom lens Expired - Fee Related JP4083856B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP03587398A JP4083856B2 (en) 1998-02-18 1998-02-18 Projection zoom lens

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Publication Number Publication Date
JPH11231219A true JPH11231219A (en) 1999-08-27
JP4083856B2 JP4083856B2 (en) 2008-04-30

Family

ID=12454125

Family Applications (1)

Application Number Title Priority Date Filing Date
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001050171A1 (en) * 1999-12-29 2001-07-12 Carl Zeiss Projection lens comprising adjacent aspheric lens surfaces
JP2001311872A (en) * 2000-04-27 2001-11-09 Nitto Kogaku Kk Zoom lens for projection and projector device
JP2002031754A (en) * 2000-07-14 2002-01-31 Hitachi Ltd Lens device for projection and projection type picture display device
JP2002148516A (en) * 2000-11-08 2002-05-22 Fuji Photo Optical Co Ltd Zoom lens and projection type display device using the same
US6590716B2 (en) 2001-04-27 2003-07-08 Seiko Epson Corporation Projection zoom lens
JP2006106109A (en) * 2004-09-30 2006-04-20 Nikon Corp Aspherical lens and optical apparatus having the same
JP2008083229A (en) * 2006-09-26 2008-04-10 Fujinon Corp Projection zoom lens and projection display device
US7817345B2 (en) 2008-02-04 2010-10-19 Canon Kabushiki Kaisha Zoom lens and image projection apparatus including the same
CN111443451A (en) * 2020-05-25 2020-07-24 深圳市沃特隆科技有限公司 360-degree shooting outer lens for camera external connection and use method thereof

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001050171A1 (en) * 1999-12-29 2001-07-12 Carl Zeiss Projection lens comprising adjacent aspheric lens surfaces
KR100854052B1 (en) * 1999-12-29 2008-08-26 칼 짜이스 에스엠테 아게 Projection objective lens comprising adjacent aspheric lens surfaces
US7154678B2 (en) 1999-12-29 2006-12-26 Carl Zeiss Semiconductor Manufacturing Technologies Ag Projection objective having adjacently mounted aspheric lens surfaces
US6646718B2 (en) 1999-12-29 2003-11-11 Carl Zeiss Semiconductor Manufacturing Technologies Ag Projection objective having adjacently mounted aspheric lens surfaces
JP2001311872A (en) * 2000-04-27 2001-11-09 Nitto Kogaku Kk Zoom lens for projection and projector device
JP4616966B2 (en) * 2000-04-27 2011-01-19 日東光学株式会社 Projection zoom lens and projector apparatus
US6975460B2 (en) 2000-07-14 2005-12-13 Hitachi, Ltd. Projection lens apparatus and projection type image display apparatus
US7142367B2 (en) 2000-07-14 2006-11-28 Hitachi, Ltd. Projection lens apparatus and projection type image display apparatus
JP2002031754A (en) * 2000-07-14 2002-01-31 Hitachi Ltd Lens device for projection and projection type picture display device
JP2002148516A (en) * 2000-11-08 2002-05-22 Fuji Photo Optical Co Ltd Zoom lens and projection type display device using the same
US6590716B2 (en) 2001-04-27 2003-07-08 Seiko Epson Corporation Projection zoom lens
JP2006106109A (en) * 2004-09-30 2006-04-20 Nikon Corp Aspherical lens and optical apparatus having the same
JP2008083229A (en) * 2006-09-26 2008-04-10 Fujinon Corp Projection zoom lens and projection display device
US7817345B2 (en) 2008-02-04 2010-10-19 Canon Kabushiki Kaisha Zoom lens and image projection apparatus including the same
CN111443451A (en) * 2020-05-25 2020-07-24 深圳市沃特隆科技有限公司 360-degree shooting outer lens for camera external connection and use method thereof

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