JPH10307258A - Compact zoom lens - Google Patents
Compact zoom lensInfo
- Publication number
- JPH10307258A JPH10307258A JP11827097A JP11827097A JPH10307258A JP H10307258 A JPH10307258 A JP H10307258A JP 11827097 A JP11827097 A JP 11827097A JP 11827097 A JP11827097 A JP 11827097A JP H10307258 A JPH10307258 A JP H10307258A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- object side
- group
- positive
- image
- 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
Links
Landscapes
- Lenses (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は小型ズームレンズ
に関する。The present invention relates to a small zoom lens.
【０００２】[0002]
【従来の技術】ＣＣＤ等の固体撮像素子を用いる従来か
らのビデオカメラに加え、近来、デジタルスチルカメラ
が普及してきている。これらビデオカメラやデジタルス
チルカメラに用いる固体撮像素子は、フルカラーの画像
を取り込めるように、１枚を複数の色に塗分けられた色
分解用のカラーフィルタを配備されているものが多い。2. Description of the Related Art In addition to a conventional video camera using a solid-state imaging device such as a CCD, a digital still camera has recently become widespread. Many of solid-state imaging devices used in these video cameras and digital still cameras are provided with a color separation color filter in which one image is divided into a plurality of colors so that a full-color image can be captured.
【０００３】この型のカラー画像用の固体撮像素子は
「ＣＣＤ」に代表されるように、受光面とカラーフィル
タとの間に隙間があり、結像光束が斜めから固体撮像素
子に入射すると、受光面に達する光がフィルタにケラれ
て実質的な開口効率が低下したり、フィルタ画素と受光
素子との対応関係がずれて「色ずれ」の原因になった
り、モアレ防止用の水晶フィルタの実効厚さが軸上と周
辺とで異なってしまうという問題を生じる。In a solid-state image pickup device of this type for a color image, as represented by a "CCD", there is a gap between a light receiving surface and a color filter. The light reaching the light receiving surface is vignetted by the filter, causing the aperture efficiency to decrease substantially, the correspondence between the filter pixel and the light receiving element being shifted, causing “color shift”, and the use of a crystal filter for preventing moiré. There is a problem that the effective thickness is different between the on-axis and the periphery.
【０００４】このため、このようなカラー画像用の固体
撮像素子に結像を行なうレンズ系では、射出瞳位置を像
面から十分に離すことにより「テレセントリック性」を
高める必要がある。For this reason, in a lens system that forms an image on such a solid-state image pickup device for a color image, it is necessary to improve the "telecentricity" by sufficiently separating the exit pupil position from the image plane.
【０００５】固体撮像素子は一般に銀塩フィルムに比し
て光感度が低い。従って、撮影レンズが暗いと、デジタ
ルスチルカメラによる撮影では「銀塩写真の場合に比し
て長い露光時間」を必要とし、手振れや被写体の動きに
よる撮影画像の「流れ」が発生しやすい。このような問
題を回避するため、ビデオカメラやデジタルスチルカメ
ラ用の撮影レンズはできるだけ明るいレンズであること
が望ましい。[0005] A solid-state image sensor generally has lower light sensitivity than a silver halide film. Therefore, if the photographing lens is dark, photographing with a digital still camera requires a longer exposure time than in the case of silver halide photography, and a "flow" of a photographed image due to camera shake or movement of a subject is likely to occur. In order to avoid such a problem, it is desirable that a photographing lens for a video camera or a digital still camera be as bright as possible.
【０００６】従来から広く知られた２群ズームレンズ
は、負の屈折力を有する第１群を物体側に、正の屈折力
を持つ第２群を像側に配して構成されるが、これらの多
くは射出瞳位置が像面に近いためテレセントリック性が
低く、カラー画像用の固体撮像素子に撮影対象を結像さ
せるレンズとしては好ましくない。[0006] A conventionally known two-unit zoom lens is configured by arranging a first unit having a negative refractive power on the object side and a second unit having a positive refractive power on the image side. Many of these have low telecentricity because the exit pupil position is close to the image plane, which is not preferable as a lens for forming an image of a subject on a solid-state image pickup device for a color image.
【０００７】上記２群ズームレンズの像側に正の屈折力
を持つ第３群を配することにより、射出瞳位置を像面か
ら離すことが考えられ、１眼レフスチルカメラ用として
知られているが（特公平３−２０７３５号公報、同７−
５２２６号公報）、これらは一般に、第３群の屈折力が
極めて弱いため、射出瞳位置を像面から大きく離すこと
ができない。By arranging the third lens unit having a positive refractive power on the image side of the two-unit zoom lens, the position of the exit pupil is considered to be away from the image plane, and is known for single-lens reflex still cameras. (Japanese Patent Publication No. 3-20735, 7-
However, since the refractive power of the third lens group is generally extremely weak, the position of the exit pupil cannot be largely separated from the image plane.
【０００８】３群ズームレンズで、射出瞳位置を像面か
ら大きく離すようにしたものとして特開平６−９４９９
６号公報開示ものがあるが、このレンズでは、射出瞳位
置を像面から遠ざけるために「絞り」を第１，第２群間
に固定しているため、第１，第２群の移動が絞りによる
制約を受け、変倍比が２倍弱程度に留まっている。ま
た、上記各公報開示の３群ズームレンズは「最小のＦ／
Ｎｏ．」が２．８〜３．６と大きく、十分に明るいレン
ズであるとは言い難い。Japanese Patent Laid-Open Publication No. 6-9499 discloses a three-group zoom lens in which the exit pupil position is largely separated from the image plane.
However, in this lens, the “aperture” is fixed between the first and second lens groups in order to move the exit pupil position away from the image plane. Due to the restriction of the aperture, the zoom ratio remains at less than twice. Further, the three-group zoom lens disclosed in each of the above publications has a “minimum F /
No. Is 2.8 to 3.6, which is large, and it cannot be said that the lens is sufficiently bright.
【０００９】勿論、ズームレンズは小型であることが望
ましい。Of course, it is desirable that the zoom lens be small.
【００１０】[0010]
【発明が解決しようとする課題】この発明は上述した事
情に鑑み、射出瞳位置が像面から十分に離れ、最小のＦ
／Ｎｏ．として２．０程度を実現でき、性能良好で３倍
程度の大きい変倍比が可能で、デジタルスチルカメラや
ビデオカメラの撮影用レンズに適した明るい小型ズーム
レンズの実現を課題とする。SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention has a structure in which the exit pupil position is sufficiently away from the image plane and the minimum F
/ No. It is an object of the present invention to realize a bright and small zoom lens which is excellent in performance and capable of achieving a large zoom ratio of about 3 times and which is suitable for a photographing lens of a digital still camera or a video camera.
【００１１】[0011]
【課題を解決するための手段】請求項１記載の発明の小
型ズームレンズは、図１に示すように、物体側（図の左
方）から像側へ向かって順次、第１〜第３群を配して成
る。第１群ＧＩは「負の屈折力」を有し、第２群ＧIIは
「正の屈折力」を有し、第３群ＧIIIは「正の屈折力」
を有する。第２群ＧIIの物体側に設けられた開口絞りＳ
は、ズーミング時に第２群ＧIIと一体に移動する。As shown in FIG. 1, the small zoom lens according to the first aspect of the present invention sequentially includes the first to third lens groups from the object side (left side in the figure) to the image side. It is arranged. The first group GI has a “negative refractive power”, the second group GII has a “positive refractive power”, and the third group GIII has a “positive refractive power”.
Having. An aperture stop S provided on the object side of the second group GII
Move together with the second group GII during zooming.
【００１２】広角端（図１(ａ)）から望遠端（図１
(ｂ)）へのズーミングに際し、第１群ＧＩは、光軸上を
先ず像側へ移動し、途中で移動方向を物体側へ反転する
ことにより「像側に凸の凸弧状に移動」して焦点位置の
変動を補正し、第２群ＧIIは、光軸上を「物体側へ単調
に移動」して変倍を行なう。また、第３群ＧIII は、光
軸上を先ず物体側へ移動し、途中で移動方向を像側へ反
転することにより「物体側に凸の凸弧状に移動」して変
倍を行なう。From the wide-angle end (FIG. 1A) to the telephoto end (FIG. 1A).
During zooming to (b)), the first lens group GI first moves to the image side on the optical axis, and “moves in a convex arc shape convex to the image side” by reversing the moving direction to the object side in the middle. The second group GII performs "magnification" by "moving monotonously to the object side" on the optical axis. The third lens group GIII first moves to the object side on the optical axis, and reverses the moving direction to the image side on the way, thereby "moving in a convex arc convex toward the object side" to perform zooming.
【００１３】開口絞りＳはズーミングに際して、第２群
ＧIIと一体に移動するので、開口絞りにより第２群ＧII
の移動が妨げられることがない。Since the aperture stop S moves integrally with the second lens group GII during zooming, the second lens group GII is moved by the aperture stop.
Movement is not hindered.
【００１４】第Ｉ群（Ｉ＝１〜３）の焦点距離をｆI 、
広角端における全系の合成焦点距離をｆW 、望遠端にお
ける第２群の結像倍率をｍ(2T)とするとき、これらは条
件： （１） ２．８＜｜ｆ1｜／ｆW＜３．０（ｆ1＜０） （２） ｆ3／ｆW＜２．９ （３） ０．７３＜ｆ2／ｆ3＜０．８６（ｆ2＞０，ｆ3＞０） （４） １．４４＜｜ｍ(2T)｜＜１．５６（ｍ(2T)＜０） を満足する。「望遠端における第２群の結像倍率：ｍ(2
T)」は、望遠端における群配置で、第１群の像点を物点
とする第２群の結像倍率である。The focal length of the first lens unit (I = 1 to 3) is f I ,
Assuming that the combined focal length of the entire system at the wide-angle end is f W , and the imaging magnification of the second lens unit at the telephoto end is m (2T), these conditions are: (1) 2.8 <| f 1 | / f W <3.0 (f 1 <0) (2) f 3 / f W <2.9 (3) 0.73 <f 2 / f 3 <0.86 (f 2 > 0, f 3 > 0) ( 4) Satisfies 1.44 <| m (2T) | <1.56 (m (2T) <0). "The imaging magnification of the second group at the telephoto end: m (2
“T)” is the group magnification at the telephoto end, and is the imaging magnification of the second group having the image point of the first group as the object point.
【００１５】上記のように、ズーミングに際して第３群
を「物体側に凸の凸弧状に移動」させることにより、第
２群のパワー負担を軽減させつつ、第２群による変倍を
補助し、第２群の移動量を小さくして、ズームレンズと
しての小型化と高変倍とを実現させることが可能とな
る。As described above, during zooming, by moving the third lens unit in a “convex arc shape convex toward the object side”, the power load on the second lens unit is reduced, and zooming by the second lens unit is assisted. By reducing the amount of movement of the second lens unit, it is possible to realize downsizing as a zoom lens and high zooming.
【００１６】条件（１）は、全系を小型化し、収差を良
好に補正するため、第１群の焦点距離：ｆ1 の範囲を規
制する条件であり、下限を越えると、第１群の負の屈折
力が強く成りすぎ、レンズ全系の小型化には有利である
が、球面収差を始めとする諸収差が悪化するため好まし
くない。また条件（１）の上限を越えると、収差は良好
になるが、レンズ全系を小型化することが困難になる。Condition (1) is a condition for restricting the range of the focal length f1 of the first lens group in order to reduce the size of the entire system and favorably correct aberrations. Negative refractive power becomes too strong, which is advantageous for miniaturization of the entire lens system, but is not preferable because various aberrations including spherical aberration deteriorate. When the value exceeds the upper limit of the condition (1), the aberration is improved, but it is difficult to reduce the size of the entire lens system.
【００１７】条件（２）は、第３群の正の屈折力を規制
する条件であり、上限を越えると、第３群の正のパワー
が不十分となって射出瞳位置が像面に近づき、テレセン
トリック性が失われる。Condition (2) is a condition for regulating the positive refractive power of the third lens unit. If the upper limit is exceeded, the positive power of the third lens unit becomes insufficient, and the exit pupil position approaches the image plane. , Telecentricity is lost.
【００１８】条件（３）は、共に正の屈折力を持つ第
２，第３群の屈折力の配分を規制する条件であり、第
２，第３群の構成枚数を少なく保って小型化を容易に
し、なおかつ収差を良好に補正するための条件である。
条件（３）の下限を越えると、第３群の屈折力が不十分
となって第３群を用いる効果が少なく、第３群の屈折力
不足を補うために、第２群の屈折力負担が過大となって
球面収差が悪化し、像の平坦性も悪くなる。Condition (3) is a condition for regulating the distribution of the refractive power of the second and third lens units, both of which have a positive refractive power. This is a condition for facilitating and favorably correcting aberrations.
When the value goes below the lower limit of the condition (3), the refractive power of the third lens unit becomes insufficient, and the effect of using the third lens unit is small. To compensate for the insufficient refractive power of the third lens unit, the refractive power burden of the second lens unit is reduced. Is excessive, the spherical aberration is deteriorated, and the flatness of the image is also deteriorated.
【００１９】条件（３）の上限を越えると、第３群の屈
折力負担が大きくなり、第２群の屈折力負担が緩和さ
れ、収差が良好となり、像の平坦性も良好になるが、負
の第１群、正の第２群双方の屈折力が弱くなる傾向とも
合致し、レンズ全系の小型化が困難になる。When the value exceeds the upper limit of the condition (3), the refractive power burden of the third lens unit increases, the refractive power burden of the second lens unit is reduced, the aberration becomes good, and the flatness of the image becomes good. This is consistent with the tendency of the refractive power of both the negative first lens unit and the positive second lens unit to be weak, making it difficult to reduce the size of the entire lens system.
【００２０】条件（４）は、ズームレンズ全長に関する
条件である。 変倍比：３程度を実現しようとする場合に、条件（４）
の上限を越えると、望遠端において全長が長くなりすぎ
て小型化に不利であるし、下限を越えると、望遠端では
全長が短くなるが、これに伴い、望遠端で所定の全系焦
点距離を確保するために第１群の屈折力が弱くなるの
で、第１群の移動量が増大してしまう。Condition (4) is a condition relating to the total length of the zoom lens. To achieve a zoom ratio of about 3, condition (4)
Exceeds the upper limit, the overall length becomes too long at the telephoto end, which is disadvantageous for miniaturization.If the lower limit is exceeded, the overall length becomes shorter at the telephoto end. Since the refractive power of the first lens unit is weakened in order to secure the distance, the amount of movement of the first lens unit increases.
【００２１】なお、図１において、符号ＣＧは固体撮像
素子のカバーガラスを示し、符号Ｆは赤外光遮断フィル
タ（ＩＲＣＦ）とロウパスフィルタ（ＬＰＦ）を合わせ
たフィルタを示す。像面の位置には「固体撮像素子の受
光面」が位置する。前述のカラーフィルタはフィルタＦ
と像面との間に配備される。In FIG. 1, reference numeral CG indicates a cover glass of the solid-state imaging device, and reference numeral F indicates a filter obtained by combining an infrared cutoff filter (IRCF) and a low-pass filter (LPF). The “light receiving surface of the solid-state imaging device” is located at the position of the image plane. The aforementioned color filter is a filter F
And an image plane.
【００２２】請求項１記載の小型ズームレンズにおい
て、第１群ＧＩは「物体側から像側へ向かって順に、物
体側に凸面を向けた負メニスカスレンズ、像面に強い屈
折面を向けた負レンズ、物体側に凸面を向けた正メニス
カスレンズを配し」て構成することができ、第２群ＧII
は「物体側から像側へ向かって順に、物体側に強い屈折
面を向けた正レンズ、物体側に凸面を向けた正メニスカ
スレンズ、像側に強い屈折面を向けた負レンズ、正レン
ズ、物体側に凸面を向けた正メニスカスレンズを配し」
て構成することができる（請求項２）。In the miniature zoom lens according to the first aspect, the first group GI includes, in order from the object side to the image side, a negative meniscus lens having a convex surface facing the object side, and a negative meniscus lens having a strong refractive surface facing the image surface. Lens, a positive meniscus lens having a convex surface facing the object side ", and the second group GII
`` In order from the object side to the image side, a positive lens with a strong refractive surface facing the object side, a positive meniscus lens with a convex surface facing the object side, a negative lens with a strong refractive surface facing the image side, a positive lens, A positive meniscus lens with the convex surface facing the object side is arranged. ''
(Claim 2).
【００２３】このように、第１群ＧＩにおいて、負レン
ズを物体側に配することにより、ズームレンズのレンズ
外径を小さくし、第１群の構成レンズ枚数を３枚と少な
くすることが可能となる。また、第２群ＧIIで発生する
球面収差、コマ収差、非点収差を補正するため、第２群
ＧIIにおける「物体側の２枚の正レンズ」により球面収
差の発生を極力抑えて「全体として正の屈折力」を得、
続いて負レンズにより補正過剰とし、続く２枚の正レン
ズで各収差の画角差を平均化するのである。As described above, by disposing the negative lens on the object side in the first group GI, it is possible to reduce the lens outer diameter of the zoom lens and reduce the number of constituent lenses of the first group to three. Becomes In order to correct the spherical aberration, coma, and astigmatism generated in the second group GII, the generation of spherical aberration is minimized by the "two positive lenses on the object side" in the second group GII. Positive refractive power "
Subsequently, overcorrection is performed by a negative lens, and the difference in angle of view of each aberration is averaged by two subsequent positive lenses.
【００２４】上記請求項２記載の小型ズームレンズにお
いて、第１群における正メニスカスレンズ（第１群で最
も像側に配備される）の物体側レンズ面を「光軸を離れ
るに従い正の屈折力が強くなる形状の非球面」とするこ
とができる（請求項３）。このような非球面の採用によ
り、特に短焦点側距離で増大する負の歪曲収差の補正が
容易になる。In the small zoom lens according to the second aspect, the object-side lens surface of the positive meniscus lens in the first group (which is arranged closest to the image side in the first group) has a positive refractive power as the distance from the optical axis increases. (An aspherical surface having a shape in which is stronger) (claim 3). The use of such an aspherical surface facilitates the correction of negative distortion that increases particularly at the short focal length.
【００２５】上記請求項２または３記載の小型ズームレ
ンズにおいて、第２群において最も物体側に配備される
正レンズの物体側レンズ面を「光軸を離れるに従い正の
屈折力が弱くなる形状の非球面」とすることができる
（請求項４）。このような非球面の採用により、補正不
足となりがちな球面収差を良好に補正することが可能と
なる。The small zoom lens according to claim 2 or 3, wherein the object-side lens surface of the positive lens disposed closest to the object side in the second group has a shape such that the positive refractive power decreases as the distance from the optical axis increases. It can be an "aspheric surface" (claim 4). By employing such an aspherical surface, it becomes possible to satisfactorily correct spherical aberration that tends to be insufficiently corrected.
【００２６】上記請求項１〜４の任意の１に記載の小型
ズームレンズにおいては、第３群を「屈折力の強い面を
物体側にした両凸レンズ」とすることができる(請求項
５)。ズームレンズを小型化するには、第３群のレンズ
枚数も成るべく少ないことが望ましく、請求項５記載の
発明のように、第３群を単一のレンズで構成することに
より、第３群の付加が小型化に対する妨げとならないよ
うにでき、第３群ＧIII をなす両凸レンズの「屈折力の
強い面を物体側に向ける」ことにより、テレセントリッ
ク性を高めることができる。In the small zoom lens according to any one of the first to fourth aspects, the third group may be a "biconvex lens having a surface having a strong refractive power on the object side" (claim 5). . In order to reduce the size of the zoom lens, it is desirable that the number of lenses in the third lens unit is as small as possible. As in the invention according to claim 5, the third lens unit is constituted by a single lens. Can be prevented from hindering miniaturization, and the telecentricity can be enhanced by "facing the surface having a strong refractive power to the object side" of the biconvex lens forming the third group GIII.
【００２７】上記請求項２〜５の任意の１に記載の記載
の小型ズームレンズにおいて、第１群の「物体側から２
枚目の負レンズ」、第２群の「物体側から第１枚目の正
レンズ、第３枚目の負レンズ、第４枚目の正レンズ」に
は、レンズ形状に自由度があるが、これらの形状として
「第１群の物体側から２枚目の負レンズを、両凹レンズ
とし、第２群の、物体側から第１枚目の正レンズを、物
体側に凸面を向けた正メニスカスレンズ、物体側から第
３枚目の負レンズを、凹面を像側に向けた負メニスカス
レンズ、物体側から第４枚目の正レンズを両凸レンズ」
とすることができ（請求項６）、「第１群の物体側から
２枚目の負レンズを両凹レンズとし、第２群の、物体側
から第１枚目の正レンズを両凸レンズ、物体側から第３
枚目の負レンズを両凹レンズ、物体側から第４枚目の正
レンズを両凸レンズ」とすることもできる（請求項
７）。[0027] In the small zoom lens according to any one of claims 2 to 5, in the first group, "2 from the object side".
The “negative lens of the sheet” and the “positive first lens, third negative lens, and fourth positive lens from the object side” of the second group have a certain degree of freedom in lens shape. The shape of these lenses is as follows: “The second negative lens of the first group from the object side is a biconcave lens, and the first positive lens of the second group from the object side is a positive lens with the convex surface facing the object side. Meniscus lens, third negative lens from object side, negative meniscus lens with concave surface facing image side, fourth positive lens from object side biconvex lens "
(Claim 6), "The second negative lens from the object side in the first group is a biconcave lens, the first positive lens from the object side in the second group is a biconvex lens, Third from the side
The second negative lens may be a biconcave lens, and the fourth positive lens from the object side may be a biconvex lens.
【００２８】上記の条件（１）〜（４）は互いに有機的
に関連しあって「性能の良好性を確保しつつ小型化と高
いテレセントリック性」を実現している。The above-mentioned conditions (1) to (4) are organically related to each other and realize "small size and high telecentricity while ensuring good performance".
【００２９】[0029]
【発明の実施の形態】以下、具体的な実施の形態を説明
する。図１〜図３はそれぞれ、以下に挙げる実施例１〜
３のレンズ構成を示す。実施例１〜３において、第１群
ＧＩは３枚のレンズで構成され、第２群ＧIIは５枚のレ
ンズで構成され、第３群ＧIIIは１枚のレンズで構成さ
れている（請求項２，６，７）。カバーガラスＣＧおよ
びフィルタＦは、実施例１〜３においては第３群ＧIII
の直後に配備したが、これらカバーガラスＣＧとフィル
タＦは、第３群ＧIII と像面との間のどこに在っても良
い。DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments will be described below. 1 to 3 show Examples 1 to 3 listed below, respectively.
3 shows a third lens configuration. In the first to third embodiments, the first group GI includes three lenses, the second group GII includes five lenses, and the third group GIII includes one lens. 2, 6, 7). The cover glass CG and the filter F are the third group GIII in Examples 1 to 3.
The cover glass CG and the filter F may be located anywhere between the third lens group GIII and the image plane.
【００３０】[0030]
【実施例】図１に例示するように、各実施例において、
物体側から数えて第ｉ番目の面（絞りＳの面および固体
撮像素子のカバーガラスＣＧ、フィルタＦの面を含む）
をｒi(ｉ＝１〜２２)、物体側から数えて第ｉ番目の面
と第ｉ＋１番目の面の光軸上の面間隔をｄi(ｉ＝１〜２
１）、物体側から数えてｊ番目のレンズもしくはカバー
ガラス・フィルタの屈折率およびアッベ数を、それぞれ
ｎjおよびνj（ｊ＝１〜１１；ｊ＝１０はカバーガラス
ＣＧ、ｊ＝１１はフィルタＦ）とする。フィルタＦは
「ロウパスフィルタと赤外線カットフィルタ」とで構成
されている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in FIG.
I-th surface counted from the object side (including the surface of the stop S, the cover glass CG of the solid-state imaging device, and the surface of the filter F)
The r i (i = 1~22), the i-th surface counted from the object side and the surface spacing on the optical axis of the i + 1 th surface d i (i = 1 to 2
1) The refractive index and Abbe number of the j-th lens or cover glass filter counted from the object side are respectively n j and ν j (j = 1 to 11; j = 10 is the cover glass CG, j = 11 is the cover glass CG). Filter F). The filter F includes a “low-pass filter and an infrared cut filter”.
【００３１】また、ｆは「全系の焦点距離」、ωは「半
画角」、Ｆ／Ｎｏ．は「明るさ」、Ｙ’は「像高」、ｆ
I（Ｉ＝１〜３）は「第Ｉ群の焦点距離」、ｆWは「広角
端における全系の合成焦点距離」、ｍ(2T)は「望遠端に
おける第２群の結像倍率」である。F is the “focal length of the entire system”, ω is the “half angle of view”, and F / No. Is "brightness", Y 'is "image height", f
I (I = 1 to 3) is "the focal length of the Group I", f W is "combined focal length of the entire system at the wide-angle end", m (2T) is "imaging magnification of the second lens group at the telephoto end" It is.
【００３２】実施例１〜３とも、第５面（ｉ＝５）及び
第８面（ｉ＝８：絞りの直後の面）に「非球面」を採用
している（請求項４，５）。非球面は周知の如く、光軸
方向にＺ軸、光軸直交方向にＹ軸を取るとき、周知の非
球面式： Ｚ＝（Ｙ2/ｒ）／［１＋√{１−(１＋Ｋ)(Ｙ/ｒ)2}］＋
Ａ・Ｙ4＋Ｂ・Ｙ6＋Ｃ・Ｙ8＋Ｄ・Ｙ10＋．． で与えられる曲線を光軸の回りに回転して得られる曲面
で、近軸曲率半径：ｒ、円錐定数：Ｋ、高次の非球面係
数：Ａ，Ｂ，Ｃ，Ｄを与えて形状を特定する。なお、高
次の非球面係数の表記において「Ｅとそれに続く数字」
は「１０のべき乗」を表す。例えば「Ｅ−９」は１０~9
を意味し、この数値がその直前の数値に掛かるのであ
る。In each of the first to third embodiments, an "aspheric surface" is used for the fifth surface (i = 5) and the eighth surface (i = 8: the surface immediately after the stop). . As is well known, when the aspheric surface takes the Z axis in the optical axis direction and the Y axis in the direction orthogonal to the optical axis, a well-known aspheric surface formula: Z = (Y 2 / r) / [1 + √ {1- (1 + K) ( Y / r) 2 }] +
A · Y 4 + B · Y 6 + C · Y 8 + D · Y 10 +. . Is a curved surface obtained by rotating the curve given by 回 り around the optical axis, and specifies the shape by giving the paraxial radius of curvature: r, the conic constant: K, and the higher order aspherical coefficients: A, B, C, D I do. In addition, in the notation of the higher order aspheric coefficient, "E and the number following it"
Represents “power of 10”. For example, “E-9” is 10 to 9
This means that this number is multiplied by the number immediately before it.
【００３３】 実施例１ ｆ＝５．７〜１６．５ｍｍ、Ｆ/Ｎｏ．＝２．０〜３．７、ω＝３３．２〜１ ２．０度、Ｙ’＝３．４７ ｉ ｒi ｄi ｊ ｎj νj １ １６．３７４ １．５７ １ １．６９６８０ ５５．４６ ２ ７．２１８ ２．３２ ３ −８２．１８０ ０．８０ ２ １．５１６８０ ６４．２０ ４ ９．７６８ １．７５ ５ １４．７３１ １．５１ ３ １．８２０２７ ２９．７０ ６ ５５．３９１ 可変 ７ ∞（絞り） ０．５０ ８ ６．６１７ １．８６ ４ １．５８９１３ ６１．２８ ９ ７３．３８６ ０．７２ 10 １７．６９８ １．２６ ５ １．６５１６０ ５８．４０ 11 ２４．９９３ ０．２７ 12 ２０．８８４ ２．２０ ６ １．８４６６６ ２３．７８ 13 ５．２０７ ０．８４ 14 ４５．８５４ １．１１ ７ １．７４４００ ４４．９０ 15 −２３．２０１ ０．１４ 16 ６．４８１ ３．５２ ８ １．６９６８０ ５５．４６ 17 ７．０７２ 可変 18 １２．６８８ ２．０７ ９ １．４８７４９ ７０．４４ 19 −２０．５８６ 可変 20 ∞ ２．００ 10 １．５１６８０ ６４．２０ 21 ∞ １．１０ 11 １．５４０７２ ４７．２０ 22 ∞ 。Example 1 f = 5.7 to 16.5 mm, F / No. = 2.0~3.7, ω = 33.2~1 2.0 degrees, Y '= 3.47 i r i d i j n j ν j 1 16.374 1.57 1 1.69680 55. 46 2 7.218 2.32 3 -82.180 0.80 2 1.51680 64.204 9.768 1.75 5 14.731 1.51 3 1.882027 29.70 6 55.391 Variable 7 ∞ (aperture) 0.50 8 6.617 1.86 4 1.58913 61.28 9 73.386 0.72 10 17.698 1.26 5 1.65160 58.40 11 24.993 0.27 12 20.88 2.20 6 1.86666 23.78 13 5.207 0.84 14 45.854 1.11 7 1.74400 44.90 15 -23.201 0.14 16 6.481 3.528 1.69680 55.4 6 17 7.072 Variable 18 12.688 2.07 9 1.48749 70.44 19 -20.586 Variable 20 {2.00 10 1.51680 64.20 21} 1.10 11 1.54072 47.20 22 ∞.
【００３４】 非球面 第５面： Ｋ＝ ２．２０００３，Ａ＝ ４．４０３１２Ｅ−５， Ｂ＝−３．５０５５８Ｅ−６，Ｃ＝ １．５３４９６Ｅ−７， Ｄ＝−３．００２４９Ｅ−９ 第８面： Ｋ＝−０．７００１５，Ａ＝ ５．１３４９２Ｅ−５， Ｂ＝−４．８２５４１Ｅ−７，Ｃ＝ ４．９０４９９Ｅ−８ 。Aspheric Surface Fifth Surface: K = 2.2003, A = 4.40312E-5, B = −3.505558E-6, C = 1.53496E-7, D = −3.0249E-9 Eighth Surface: K = -0.70015, A = 5.1492E-5, B = -4.82541E-7, C = 4.990499E-8.
【００３５】 可変量： ｆ ５．７０ ９．７０ １６．５０ ｄ6 １６．２３ ５．７３ １．６０ ｄ17 １．０４ ４．２０ １３．５３ ｄ19 １．００ ２．７２ ０．９３ 。Variable amount: f 5.70 9.70 16.50 d 6 16.23 5.73 1.60 d 17 1.04 4.20 13.53 d 19 1.00 2.72 0.93.
【００３６】条件式のパラメータの値： ｜ｆ1｜/｜ｆW｜＝２．８１，ｆ3／ｆW＝２．８８，ｆ2
/ｆ3＝０．７３８，｜ｍ(2T)｜＝１．５５９ 。The values of the parameters of the conditional expression: | f 1 | / | f W | = 2.81, f 3 / f W = 2.88, f 2
/ f 3 = 0.738, | m (2T) | = 1.559.
【００３７】 実施例２ ｆ＝５．７〜１６．５ｍｍ、Ｆ/Ｎｏ．＝２．１〜３．７、ω＝３３．２〜１ １．９度、Ｙ’＝３．４７ ｉ ｒi ｄi ｊ ｎj νj １ １６．９５８ ０．８０ １ １．６９６８０ ５５．４６ ２ ７．３８０ ２．２７ ３ −７９．９４２ ０．８０ ２ １．６０３１１ ６０．６９ ４ １１．９３４ １．５８ ５ １５．０１６ １．５５ ３ １．８２０２７ ２９．７０ ６ ７６．５２０ 可変 ７ ∞（絞り） ０．５０ ８ ８．３７９ １．８９ ４ １．６２２９９ ５８．１２ ９ −５０．８２４ ０．１０ 10 １２．７９４ １．２１ ５ １．８０６１０ ４０．７３ 11 １１１．１２６ ０．４１ 12 −７３．５４３ ４．５６ ６ １．８４６６６ ２３．７８ 13 ４．９４０ ０．７３ 14 ３６．４０４ １．０４ ７ １．８３４００ ３７．３４ 15 −３０．９２４ ０．８２ 16 ５．８６３ １．１０ ８ １．６９６８０ ５５．４６ 17 ６．４６７ 可変 18 １４．５４５ １．８５ ９ １．６１２７２ ５８．５８ 19 −２５．８３２ 可変 20 ∞ ２．００ 10 １．５１６８０ ６４．２０ 21 ∞ １．１０ 11 １．５４０７２ ４７．２０ 22 ∞ 。Example 2 f = 5.7 to 16.5 mm, F / No. = 2.1~3.7, ω = 33.2~1 1.9 degrees, Y '= 3.47 i r i d i j n j ν j 1 16.958 0.80 1 1.69680 55. 46 2 7.380 2.27 3 -79.942 0.80 2 1.60311 60.69 4 11.934 1.58 5 15.016 1.55 3 1.82027 29.706 6 76.520 Variable 7 ∞ (Aperture) 0.50 8 8.379 1.89 4 1.622999 58.129-50.824 0.10 10 12.794 1.21 5 1.80610 40.73 11 111.126 0.41 12-73.543 4.556 6 1.86666 23.78 13 4.940 0.73 14 36.404 1.04 7 1.83400 37.34 15-30.924 0.82 16 5.863 1. 10 8 1.66980 55.46 17 6.467 Variable 18 14.545 1.85 9 1.61272 58.58 19 -25.832 Variable 20 ∞ 2.00 10 1.51680 64.20 21 １．１ 1.10 11 1.54072 47 .20 22 ∞.
【００３８】 非球面 第５面： Ｋ＝ ０．４７０３１，Ａ＝ ７．５３８５８Ｅ−５， Ｂ＝−２．３６１７３Ｅ−６，Ｃ＝ １．１７３７５Ｅ−７， Ｄ＝−２．０２７９Ｅ−９ 第８面： Ｋ＝−０．８１８５２，Ａ＝ ２．２３０３２Ｅ−５， Ｂ＝−３．４３７２３Ｅ−７，Ｃ＝ １．３４８６２Ｅ−８ 。Aspheric Surface Fifth Surface: K = 0.47031, A = 7.538858E-5, B = -2.36173E-6, C = 1.17375E-7, D = −2.0279E-9 Eighth Surface: K = -0.81852, A = 2.23032E-5, B = -3.43723E-7, C = 1.34862E-8.
【００３９】 可変量： ｆ ５．７０ ９．７０ １６．５０ ｄ6 １７．４１ ６．３７ １．６０ ｄ17 １．１８ ４．３８ １２．５７ ｄ19 １．００ １．８０ ０．９９ 。The variable amount: f 5.70 9.70 16.50 d 6 17.41 6.37 1.60 d 17 1.18 4.38 12.57 d 19 1.00 1.80 0.99.
【００４０】条件式のパラメータの値： ｜ｆ1｜/｜ｆW｜＝２．９４，ｆ3／ｆW＝２．７１，ｆ2
/ｆ3＝０．７８０，｜ｍ(2T)｜＝１．４４２ 。Values of the parameters of the conditional expression: | f 1 | / | f W | = 2.94, f 3 / f W = 2.71, f 2
/ f 3 = 0.780, | m (2T) | = 1.442.
【００４１】 実施例３ ｆ＝５．７〜１６．５ｍｍ、Ｆ/Ｎｏ．＝２．０〜３．７、ω＝３３．３〜１ ２．１度、Ｙ’＝３．４７ ｉ ｒi ｄi ｊ ｎj νj １ １７．４３８ ０．９０ １ １．６９６８０ ５５．４６ ２ ７．８１９ ２．２４ ３ −１１０．９９２ ０．８０ ２ １．５６３８４ ６０．８３ ４ ９．９３３ １．８７ ５ １５．４８７ １．５７ ３ １．８２０２７ ２９．７０ ６ ７４．３７９ 可変 ７ ∞（絞り） ０．５０ ８ ７．１６６ ２．０４ ４ １．６２２９９ ５８．１２ ９ −９３．５９４ ０．１０ 10 １１．８７０ １．２５ ５ １．７４９５０ ３５．０４ 11 ７５．８４５ ０．４５ 12 −６８．０７５ ３．００ ６ １．８４６６６ ２３．７８ 13 ４．８０２ ０．９０ 14 ３５．２７４ １．１１ ７ １．８３４００ ３７．３４ 15 −２７．３２９ ０．２５ 16 ５．６０８ １．０８ ８ １．６９６８０ ５５．４６ 17 ５．９３８ 可変 18 １０．８８３ ２．４１ ９ １．４８７４９ ７０．４４ 19 −１９．６０４ 可変 20 ∞ ２．００ 10 １．５１６８０ ６４．２０ 21 ∞ １．１０ 11 １．５４０７２ ４７．２０ 22 ∞ 。Example 3 f = 5.7 to 16.5 mm, F / No. = 2.0~3.7, ω = 33.3~1 2.1 degrees, Y '= 3.47 i r i d i j n j ν j 1 17.438 0.90 1 1.69680 55. 46 2 7.819 2.24 3 -110.992 0.80 2 1.56384 60.83 4 9.933 1.87 5 15.487 1.57 3 1.82027 29.70 6 74.379 Variable 7 ∞ (aperture) 0.50 8 7.166 2.04 4 1.6229 58.129 -93.594 0.10 10 11.870 1.25 5 1.775050 35.04 11 75.845 0.45 12 -68.075 3.006 1.84666 23.78 13 4.802 0.90 14 35.274 1.11 7 1.83400 37.34 15 -27.329 0.25 16 5.608 1. 08 8 1.69680 5 5.46 17 5.938 Variable 18 10.883 2.41 9 1.48749 70.44 19 -19.604 Variable 20 ∞ 2.00 10 1.51680 64.20 21 １．１ 1.10 11 1.54072 47 .20 22 ∞.
【００４２】 非球面 第５面： Ｋ＝ ３．７９２７１，Ａ＝−４．３１５４３Ｅ−６， Ｂ＝−４．７７８９３Ｅ−６，Ｃ＝ １．５６０２５Ｅ−７， Ｄ＝−３．５６１６５Ｅ−９ 第８面： Ｋ＝−０．７０９ ，Ａ＝ ４．６３７５５Ｅ−５， Ｂ＝−７．７８９３Ｅ−７，Ｃ＝ ７．０２６８０Ｅ−８ 。Aspheric Surface Fifth Surface: K = 3.779271, A = −4.31543E-6, B = −4.77893E−6, C = 1.56025E−7, D = −3.556165E−9 8 planes: K = -0.709, A = 4.63755E-5, B = -7.78993E-7, C = 7.028680E-8.
【００４３】 可変量： ｆ ５．７０ ９．７０ １６．５０ ｄ6 １５．６２ ５．０４ １．６０ ｄ17 １．２０ ４．６５ １４．９０ ｄ19 １．００ ２．６２ ０．４９ 。Variable amount: f 5.70 9.70 16.50 d 6 15.62 5.04 1.60 d 17 1.20 4.65 14.90 d 19 1.00 2.62 0.49.
【００４４】条件式のパラメータの値： ｜ｆ1｜/｜ｆW｜＝２．８９，ｆ3／ｆW＝２．５６，ｆ2
/ｆ3＝０．８５１，｜ｍ(2T)｜＝１．５５５ 。The values of the parameters of the conditional expression: | f 1 | / | f W | = 2.89, f 3 / f W = 2.56, f 2
/ f 3 = 0.851, | m (2T) | = 1.555.
【００４５】図４〜図６に順次、実施例１に関する収差
図を示す。図４は広角端、図５は中間焦点距離、図６は
望遠端に関するものである。図７〜図９に順次、実施例
２に関する収差図を示す。図７は広角端、図８は中間焦
点距離、図９は望遠端に関するものである。図１０〜図
１２に順次、実施例３に関する収差図を示す。図１０は
広角端、図１１は中間焦点距離、図１２は望遠端に関す
るものである。これらの収差図において、「ＳＡ」は球
面収差、「ＳＣ」は正弦条件、「Ａｓｔ」は非点収差、
「Ｄｉｓｔ」は歪曲収差を示し、「ｄおよびｇ」は収差
がｄ線およびｇ線に関するものであることを示す。球面
収差および正弦条件の図において実線が球面収差、破線
が正弦条件である。また非点収差の図において実線はサ
ジタル光線、破線はメリディオナル光線を示す。4 to 6 show aberration diagrams for the first embodiment in order. 4 relates to the wide-angle end, FIG. 5 relates to the intermediate focal length, and FIG. 6 relates to the telephoto end. 7 to 9 sequentially show aberration diagrams relating to the second embodiment. 7 relates to the wide-angle end, FIG. 8 relates to the intermediate focal length, and FIG. 9 relates to the telephoto end. 10 to 12 sequentially show aberration diagrams for the third embodiment. 10 relates to the wide-angle end, FIG. 11 relates to the intermediate focal length, and FIG. 12 relates to the telephoto end. In these aberration diagrams, “SA” is spherical aberration, “SC” is a sine condition, “Ast” is astigmatism,
“Dist” indicates distortion, and “d and g” indicate that the aberration is with respect to d-line and g-line. In the diagram of the spherical aberration and the sine condition, the solid line indicates the spherical aberration and the broken line indicates the sine condition. In the figure of astigmatism, a solid line indicates a sagittal ray and a broken line indicates a meridional ray.
【００４６】実施例１〜３とも、広角・中間・望遠の何
れにおいても収差は良好に補正され、性能良好で、明る
く、広画角である。変倍比は実施例１〜３を通じて２．
８９と３に近い高変倍比である。In all of the first to third embodiments, the aberration is well corrected at any of the wide-angle, intermediate, and telephoto positions, and the performance is good, bright, and wide. The zoom ratio is 1. through Examples 1-3.
A high zoom ratio close to 89 and 3.
【００４７】またレンズ全長が最大と成る「広角端にお
けるレンズ全長」は、実施例１で４３．１４ｍｍ、実施
例２で４５．０４ｍｍ、実施例３で４３．０６ｍｍであ
り、コンパクトである。The "lens length at the wide-angle end" at which the total length of the lens becomes the maximum is 43.14 mm in the first embodiment, 45.04 mm in the second embodiment, and 43.06 mm in the third embodiment, which are compact.
【００４８】[0048]
【発明の効果】以上に説明したように、この発明によれ
ば新規な小型ズームレンズを提供できる。この発明の小
型ズームレンズは、上記の如く、射出瞳位置を像面から
十分に離すことができるためテレセントリック性に優
れ、カラー画像用の固体撮像素子における色分解用のフ
ィルターによるケラれや、色ずれを有効に軽減できる。
また、開口絞りが移動群の移動を制限しないので、上記
各実施例に見られるように「３倍近い変倍比」が可能で
ある。As described above, according to the present invention, a novel compact zoom lens can be provided. As described above, the small zoom lens according to the present invention is excellent in telecentricity because the exit pupil position can be sufficiently separated from the image plane, and has vignetting due to a color separation filter in a solid-state imaging device for a color image, The displacement can be effectively reduced.
In addition, since the aperture stop does not limit the movement of the movable group, a "zoom ratio close to three times" is possible as seen in the above-described embodiments.
【００４９】レンズ全長は、最大と成る広角端において
も上記各実施例に見られるように４３〜４５ｍｍ程度と
コンパクトである。また、各実施例に見られるように、
最小のＦ／Ｎｏ．は２．０〜２．１と明るく、広角端に
おける画角も半画角：３３度以上と広画角であり、各実
施例のように良好な性能を実現できる。またこの発明の
小型ズームレンズは第３群を移動させるので、第３群を
固定する場合よりも像面を一定に保ちやすく、収差の補
正が容易である。この発明の小型ズームレンズはこのよ
うな効果を有するため、デジタルスチルカメラやビデオ
カメラの撮影用ズームレンズとして極めて好適である。The overall length of the lens is as compact as about 43 to 45 mm at the wide-angle end, which is the maximum, as seen in the above embodiments. Also, as seen in each example,
Minimum F / No. Is as bright as 2.0 to 2.1, and the angle of view at the wide-angle end is a wide angle of view of a half angle of view: 33 degrees or more, and good performance can be realized as in each embodiment. Further, since the small zoom lens of the present invention moves the third lens unit, it is easier to keep the image plane constant than when the third lens unit is fixed, and it is easier to correct aberrations. Since the compact zoom lens of the present invention has such effects, it is extremely suitable as a photographing zoom lens of a digital still camera or a video camera.
【図１】この発明の小型ズームレンズのレンズ構成と変
倍動作を説明するための図であり、実施例１のレンズ構
成を示す図である。FIG. 1 is a diagram for explaining a lens configuration and a variable power operation of a small zoom lens according to the present invention, and is a diagram illustrating a lens configuration of a first embodiment.
【図２】実施例２のレンズ構成と変倍動作を示す図であ
る。FIG. 2 is a diagram illustrating a lens configuration and a zoom operation according to a second embodiment.
【図３】実施例３のレンズ構成と変倍動作を示す図であ
る。FIG. 3 is a diagram illustrating a lens configuration and a zooming operation according to a third embodiment.
【図４】実施例１に関する広角端の収差図である。FIG. 4 is an aberration diagram at a wide angle end according to the first embodiment.
【図５】実施例１に関する中間焦点距離の収差図であ
る。FIG. 5 is an aberration diagram at an intermediate focal length according to the first embodiment.
【図６】実施例１に関する望遠端の収差図である。FIG. 6 is an aberration diagram at a telephoto end of Example 1.
【図７】実施例２に関する広角端の収差図である。FIG. 7 is an aberration diagram at a wide angle end according to the second embodiment.
【図８】実施例２に関する中間焦点距離の収差図であ
る。FIG. 8 is an aberration diagram at an intermediate focal length according to the second embodiment.
【図９】実施例２に関する望遠端の収差図である。FIG. 9 is an aberration diagram at a telephoto end of Example 2.
【図１０】実施例３に関する広角端の収差図である。FIG. 10 is an aberration diagram at a wide angle end according to the third embodiment.
【図１１】実施例３に関する中間焦点距離の収差図であ
る。FIG. 11 is an aberration diagram at an intermediate focal length relating to Example 3.
【図１２】実施例３に関する望遠端の収差図である。FIG. 12 is an aberration diagram at a telephoto end regarding Example 3;
ＧＩ 第１群 ＧII 第２群 ＧIII 第３群 Ｓ 開口絞り GI first group GII second group GIII third group S aperture stop
Claims (7)
３群を配して成り、 第１群は、負の屈折力を有し、 第２群は、正の屈折力を有し、 第３群は、正の屈折力を有し、 上記第２群の物体側に、ズーミング時に第２群と一体に
移動する開口絞りを有し、 広角端から望遠端へのズーミングに際し、第１群は、光
軸上を先ず像側へ移動し、途中で移動方向を物体側へ反
転することにより、像側に凸の凸弧状に移動して焦点位
置の変動を補正し、第２群は光軸上を物体側へ単調に移
動して変倍を行ない、第３群は、光軸上を先ず物体側へ
移動し、途中で移動方向を像側へ反転することにより、
物体側に凸の凸弧状に移動して変倍を行ない、 第Ｉ群（Ｉ＝１〜３）の焦点距離をｆI、広角端におけ
る全系の合成焦点距離をｆW、望遠端における第２群の
結像倍率をｍ(2T)とするとき、これらが条件： （１） ２．８＜｜ｆ1｜／ｆW＜３．０（ｆ1＜０） （２） ｆ3／ｆW＜２．９ （３） ０．７３＜ｆ2／ｆ3＜０．８６（ｆ2＞０，ｆ3＞０） （４） １．４４＜｜ｍ(2T)｜＜１．５６（ｍ(2T)＜０） を満足することを特徴とする小型ズームレンズ。A first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a first lens unit having a negative refractive power. The third lens unit has a positive refractive power, and has an aperture stop on the object side of the second lens unit that moves together with the second lens unit during zooming. When zooming from the wide-angle end to the telephoto end, The first lens unit first moves on the optical axis to the image side, and in the middle, reverses the moving direction to the object side, thereby moving in a convex arc shape convex on the image side to correct the change of the focal position, The second group moves monotonously on the optical axis to the object side to perform zooming, and the third group moves first on the optical axis to the object side, and reverses the moving direction to the image side on the way.
The focal length of the first lens unit (I = 1 to 3) is f I , the combined focal length of the entire system at the wide-angle end is f W , and the focal length of the whole system at the telephoto end is f W. When the imaging magnification of the two groups is m (2T), these conditions are as follows: (1) 2.8 <| f 1 | / f W <3.0 (f 1 <0) (2) f 3 / f W <2.9 (3) 0.73 < f 2 / f 3 <0.86 (f 2> 0, f 3> 0) (4) 1.44 <| m (2T) | <1.56 ( m (2T) <0).
て、 第１群が、物体側から像側へ向かって順に、物体側に凸
面を向けた負メニスカスレンズ、像面に強い屈折面を向
けた負レンズ、物体側に凸面を向けた正メニスカスレン
ズを配してなり、 第２群が、物体側から像側へ向かって順に、物体側に強
い屈折面を向けた正レンズ、物体側に凸面を向けた正メ
ニスカスレンズ、像側に強い屈折面を向けた負レンズ、
正レンズ、物体側に凸面を向けた正メニスカスレンズを
配して成ることを特徴とする小型ズームレンズ。2. The small zoom lens according to claim 1, wherein the first lens unit includes, in order from the object side to the image side, a negative meniscus lens having a convex surface facing the object side, and a strong refractive surface facing the image surface. A negative lens, a positive meniscus lens having a convex surface facing the object side, and a second lens unit, in order from the object side to the image side, a positive lens having a strong refractive surface facing the object side, and a convex surface facing the object side. Positive meniscus lens, negative lens with a strong refractive surface facing the image side,
A small zoom lens comprising a positive lens and a positive meniscus lens having a convex surface facing the object side.
て、 第１群における正メニスカスレンズの物体側レンズ面
が、光軸を離れるに従い正の屈折力が強くなる形状の非
球面であることを特徴とする小型ズームレンズ。3. The compact zoom lens according to claim 2, wherein the object-side lens surface of the positive meniscus lens in the first group is an aspherical surface having a positive refractive power that increases as the distance from the optical axis increases. And a small zoom lens.
において、 第２群において、最も物体側に配備される正レンズの物
体側レンズ面が、光軸を離れるに従い正の屈折力が弱く
なる形状の非球面であることを特徴とする小型ズームレ
ンズ。4. The small zoom lens according to claim 2, wherein the object side lens surface of the positive lens disposed closest to the object side in the second group has a weaker positive refractive power as the distance from the optical axis increases. A compact zoom lens characterized by having an aspheric shape.
ムレンズにおいて、 第３群が、屈折力の強い凸面を物体側にした両凸レンズ
であることを特徴とする小型ズームレンズ。5. The small zoom lens according to claim 1, wherein the third group is a biconvex lens having a convex surface having a strong refractive power on the object side.
小型ズームレンズにおいて、 第１群の、物体側から第２枚目の、像面に強い屈折面を
向けた負レンズが、両凹レンズであり、 第２群の、物体側から第１枚目の、物体側に強い屈折面
を向けた正レンズが、物体側に凸面を向けた正メニスカ
スレンズ、物体側から第３枚目の像側に強い屈折面を向
けた負レンズが凹面を像側に向けた負メニスカスレン
ズ、物体側から第４枚目の正レンズが両凸レンズである
ことを特徴とする小型ズームレンズ。6. The small zoom lens according to claim 2, wherein the second group of negative lenses having a strong refracting surface directed to the image surface is a biconcave lens. A positive meniscus lens having a first lens from the object side with a strong refractive surface facing the object side, a positive meniscus lens having a convex surface facing the object side, and a third image from the object side A small zoom lens characterized in that a negative lens having a strong refracting surface directed to the side is a negative meniscus lens having a concave surface directed to the image side, and a fourth positive lens from the object side is a biconvex lens.
小型ズームレンズにおいて、 第１群の、物体側から２枚目の、像面に強い屈折面を向
けた負レンズが、両凹レンズであり、 第２群の、物体側から第１枚目の、物体側に強い屈折面
を向けた正レンズが、両凸レンズ、物体側から第３枚目
の像側に強い屈折面を向けた負レンズが、両凹レンズ、
物体側から第４枚目の正レンズが両凸レンズであること
を特徴とする小型ズームレンズ。7. The small zoom lens according to claim 2, wherein the second group of negative lenses having a strong refracting surface directed to the image surface is a biconcave lens. A positive lens having a strong refractive surface facing the object side of the first group from the object side in the second group is a biconvex lens, and a negative lens having a strong refractive surface facing the third image side from the object side; The lens is a biconcave lens,
A small zoom lens, wherein the fourth positive lens from the object side is a biconvex lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11827097A JP3478464B2 (en) | 1997-05-08 | 1997-05-08 | Small zoom lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11827097A JP3478464B2 (en) | 1997-05-08 | 1997-05-08 | Small zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10307258A true JPH10307258A (en) | 1998-11-17 |
| JP3478464B2 JP3478464B2 (en) | 2003-12-15 |
Family
ID=14732492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11827097A Expired - Fee Related JP3478464B2 (en) | 1997-05-08 | 1997-05-08 | Small zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3478464B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277740A (en) * | 2001-03-19 | 2002-09-25 | Asahi Optical Co Ltd | Zoom lens system |
| US6822808B2 (en) | 1999-08-31 | 2004-11-23 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| JP2010049144A (en) * | 2008-08-25 | 2010-03-04 | Casio Comput Co Ltd | Zoom lens and projector device using the same |
-
1997
- 1997-05-08 JP JP11827097A patent/JP3478464B2/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6822808B2 (en) | 1999-08-31 | 2004-11-23 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US6862143B2 (en) | 1999-08-31 | 2005-03-01 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US6999242B2 (en) | 1999-08-31 | 2006-02-14 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US7023625B2 (en) | 1999-08-31 | 2006-04-04 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US7113347B2 (en) | 1999-08-31 | 2006-09-26 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US7113348B2 (en) | 1999-08-31 | 2006-09-26 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US7227701B2 (en) | 1999-08-31 | 2007-06-05 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| US7450318B2 (en) | 1999-08-31 | 2008-11-11 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus having the same |
| JP2002277740A (en) * | 2001-03-19 | 2002-09-25 | Asahi Optical Co Ltd | Zoom lens system |
| JP2010049144A (en) * | 2008-08-25 | 2010-03-04 | Casio Comput Co Ltd | Zoom lens and projector device using the same |
| JP4656213B2 (en) * | 2008-08-25 | 2011-03-23 | カシオ計算機株式会社 | Zoom lens and projector apparatus using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3478464B2 (en) | 2003-12-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3868092B2 (en) | Zoom lens | |
| JP3466385B2 (en) | Small zoom lens | |
| JP4366110B2 (en) | Zoom lens and optical apparatus having the same | |
| JP3451471B2 (en) | Small zoom lens | |
| JP3599689B2 (en) | Zoom lens | |
| JP4173977B2 (en) | Zoom lens system | |
| JP2003140041A (en) | Zoom lens system | |
| JPH10123418A (en) | Front diaphragm two-group zoom lens | |
| JP4447680B2 (en) | Zoom lens | |
| US8248703B2 (en) | Zoom lens and optical apparatus having the zoom lens | |
| JP3652179B2 (en) | Zoom lens | |
| JP2004240023A (en) | Fisheye lens switchable to a plurality of screen sizes | |
| JP5395495B2 (en) | Variable magnification optical system | |
| JP3698134B2 (en) | Zoom lens | |
| JP2006337793A (en) | Zoom lens and imaging apparatus using same | |
| JP2006003539A (en) | Zoom lens and imaging apparatus having same | |
| JP4585796B2 (en) | Zoom lens and imaging apparatus having the same | |
| JP4153710B2 (en) | 3 group zoom optical system | |
| JPH09203861A (en) | Zoom lens | |
| JP4537114B2 (en) | Zoom lens | |
| JP5695433B2 (en) | Zoom lens and image pickup apparatus including the same | |
| JP3706827B2 (en) | Zoom lens and optical apparatus having the same | |
| JP3566838B2 (en) | Zoom lens | |
| JPH11149044A (en) | Zoom lens | |
| JP2004226645A (en) | Variable focal length lens system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 5 Free format text: PAYMENT UNTIL: 20081003 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 5 Free format text: PAYMENT UNTIL: 20081003 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 6 Free format text: PAYMENT UNTIL: 20091003 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 7 Free format text: PAYMENT UNTIL: 20101003 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 8 Free format text: PAYMENT UNTIL: 20111003 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121003 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131003 Year of fee payment: 10 |
|
| LAPS | Cancellation because of no payment of annual fees |