JP2003114386A5

JP2003114386A5 -

Info

Publication number: JP2003114386A5
Application number: JP2001308579A
Authority: JP
Filing date: 2001-10-04
Publication date: 2005-06-02
Anticipated expiration: 2021-10-04

Claims

ズームレンズ及びその像側に配された撮像素子を備えた電子撮像装置において、
前記ズームレンズは、物体側より順に、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群よりなり、無限遠物点合焦時における広角端から望遠端への変倍に際して前記第２レンズ群が物体側へのみ移動し、前記第３レンズ群が第２レンズ群との間隔を変化させつつ移動し、前記第２レンズ群は、空間を挟んで物体側から順に、第２群前群、第２群後群からなり、前記第２群前群は、物体側から順に、正レンズ、負レンズの２枚接合レンズからなり、前記第２群後群は、物体側から順に、負レンズ、正レンズの２枚のレンズからなり、かつ、第２レンズ群の最も像側の正レンズは非球面を有し、以下の条件を満足することを特徴とする電子撮像装置。
（１） −０．６＜（Ｃ_24F−Ｃ_23R）・Ｌ＜０．６
（２） −１．２＜（Ｃ_23F−Ｃ_24R）・Ｌ＜０．３
（３） −０．８＜Ｌ／ｆ_2R＜０．４
ただし、Ｃ_23F＝１／Ｒ_23F、Ｃ_23R＝１／Ｒ_23R、Ｃ_24F＝１／Ｒ_24F、Ｃ_24R＝１／Ｒ_24Rであり、Ｒ_23F、Ｒ_23R、Ｒ_24F、Ｒ_24Rは第２群後群の各面の曲率半径であり、Ｒ_23Fは第２群後群の入射面、Ｒ_24Rは第２群後群の射出面の光軸上の曲率半径、Ｒ_23Rは前記入射面を有する負レンズの像側面、Ｒ_24Fは前記射出面を有する正レンズの物体側面の光軸上の曲率半径、Ｌは撮像素子の有効撮像領域の対角長、ｆ_2Rは第２群後群の合成焦点距離である。In an electronic imaging device including a zoom lens and an imaging device arranged on the image side thereof,
The zoom lens includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. The second lens group moves only to the object side during zooming from the wide-angle end to the telephoto end during point focusing, and the third lens group moves while changing the distance from the second lens group. The second lens group is composed of a second group front group and a second group rear group in order from the object side across the space, and the second group front group is composed of a positive lens and a negative lens joined in order from the object side. The second group rear group consists of two lenses, a negative lens and a positive lens in order from the object side, and the most image side positive lens of the second lens group has an aspherical surface, An electronic imaging apparatus characterized by satisfying the following conditions.
(1) -0.6 <(C _24F -C _23R ) · L <0.6
(2) -1.2 <(C _23F -C _24R ) · L <0.3
(3) −0.8 <L / f _2R <0.4
However, _C23F = 1 / _R23F , _C23R = 1 / _R23R , _C24F = 1 / _R24F , _C24R = 1 / _R24R , and _R23F , _R23R , _R24F , _R24R is the second. The radius of curvature of each surface of the rear group, R _23F is the incident surface of the second group rear group, R _24R is the radius of curvature on the optical axis of the exit surface of the second group rear group, and R _23R is the incident surface. R _24F is the radius of curvature on the optical axis of the object side surface of the positive lens having the exit surface, L is the diagonal length of the effective imaging region of the image sensor, and f _2R is the second group rear group. The composite focal length.

ズームレンズ及びその像側に配された撮像素子を備えた電子撮像装置において、
前記ズームレンズは、物体側より順に、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群よりなり、無限遠物点合焦時における広角端から望遠端への変倍に際して前記第２レンズ群が物体側へのみ移動し、前記第３レンズ群が第２レンズ群との間隔を変化させつつ移動し、前記第２レンズ群は、空間を挟んで物体側から順に、第２群前群、第２群後群からなり、前記第２群前群は１枚の正レンズからなり、前記第２群後群は、物体側から順に、負レンズ、正レンズの２枚のレンズからなり、かつ、第２レンズ群の最も像側の正レンズは非球面を有し、以下の条件を満足することを特徴とする電子撮像装置。
（１） −０．６＜（Ｃ_24F−Ｃ_23R）・Ｌ＜０．６
（２） −１．２＜（Ｃ_23F−Ｃ_24R）・Ｌ＜０．３
（３） −０．８＜Ｌ／ｆ_2R＜０．４
ただし、Ｃ_23F＝１／Ｒ_23F、Ｃ_23R＝１／Ｒ_23R、Ｃ_24F＝１／Ｒ_24F、Ｃ_24R＝１／Ｒ_24Rであり、Ｒ_23F、Ｒ_23R、Ｒ_24F、Ｒ_24Rは第２群後群の各面の曲率半径であり、Ｒ_23Fは第２群後群の入射面、Ｒ_24Rは第２群後群の射出面の光軸上の曲率半径、Ｒ_23Rは前記入射面を有する負レンズの像側面、Ｒ_24Fは前記射出面を有する正レンズの物体側面の光軸上の曲率半径、Ｌは撮像素子の有効撮像領域の対角長、ｆ_2Rは第２群後群の合成焦点距離である。In an electronic imaging device including a zoom lens and an imaging device arranged on the image side thereof,
The zoom lens includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. The second lens group moves only to the object side during zooming from the wide-angle end to the telephoto end during point focusing, and the third lens group moves while changing the distance from the second lens group. The second lens group includes, in order from the object side across the space, the second group front group and the second group rear group, the second group front group includes one positive lens, and the second group rear group includes The negative lens and the positive lens are composed of two lenses in order from the object side, and the positive lens closest to the image side of the second lens group has an aspherical surface and satisfies the following conditions: Electronic imaging device.
(1) -0.6 <(C _24F -C _23R ) · L <0.6
(2) -1.2 <(C _23F -C _24R ) · L <0.3
(3) −0.8 <L / f _2R <0.4
However, _C23F = 1 / _R23F , _C23R = 1 / _R23R , _C24F = 1 / _R24F , _C24R = 1 / _R24R , and _R23F , _R23R , _R24F , _R24R is the second. The radius of curvature of each surface of the rear group, R _23F is the incident surface of the second group rear group, R _24R is the radius of curvature on the optical axis of the exit surface of the second group rear group, and R _23R is the incident surface. R _24F is the radius of curvature on the optical axis of the object side surface of the positive lens having the exit surface, L is the diagonal length of the effective imaging region of the image sensor, and f _2R is the second group rear group. The composite focal length.

ズームレンズ及びその像側に配された撮像素子を備えた電子撮像装置において、
前記ズームレンズは、物体側より順に、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、正の屈折力を有する第３レンズ群よりなり、無限遠物点合焦時における広角端から望遠端への変倍に際して前記第２レンズ群が物体側へのみ移動し、前記第３レンズ群が第２レンズ群との間隔を変化させつつ移動し、前記第２レンズ群は、空間を挟んで物体側から順に、第２群前群、第２群後群からなり、前記第２群前群は、物体側から順に、正レンズ、負レンズの２枚接合レンズからなり、前記第２群後群は１枚の正レンズからなり、かつ、第２レンズ群の最も像側の正レンズは非球面を有し、以下の条件を満足することを特徴とする電子撮像装置。
（２） −１．２＜（Ｃ_23F−Ｃ_24R）・Ｌ＜０．３
（３） −０．８＜Ｌ／ｆ_2R＜０．４
ただし、Ｃ_23F＝１／Ｒ_23F、Ｃ_24R＝１／Ｒ_24Rであり、Ｒ_23F、Ｒ_24Rは第２群後群の各面の曲率半径であり、Ｒ_23Fは第２群後群の入射面、Ｒ_24Rは第２群後群の射出面の光軸上の曲率半径、Ｌは撮像素子の有効撮像領域の対角長、ｆ_2Rは第２群後群の合成焦点距離である。In an electronic imaging device including a zoom lens and an imaging device arranged on the image side thereof,
The zoom lens includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. The second lens group moves only to the object side during zooming from the wide-angle end to the telephoto end during point focusing, and the third lens group moves while changing the distance from the second lens group. The second lens group is composed of a second group front group and a second group rear group in order from the object side across the space, and the second group front group is composed of a positive lens and a negative lens joined in order from the object side. The second group rear group is composed of one positive lens, and the most image side positive lens of the second lens group has an aspherical surface, and satisfies the following conditions: Electronic imaging device.
(2) -1.2 <(C _23F -C _24R ) · L <0.3
(3) −0.8 <L / f _2R <0.4
However, C _23F = 1 / R _23F , C _24R = 1 / R _24R , R _23F , R _24R are the radii of curvature of each surface of the second group rear group, and R _23F is the incidence of the second group rear group Surface, R _24R is the radius of curvature on the optical axis of the exit surface of the second group rear group, L is the diagonal length of the effective imaging region of the image sensor, and f _2R is the combined focal length of the second group rear group.

前記第２レンズ群の各レンズ群が以下の条件を満足することを特徴とする請求項１記載の電子撮像装置。
（４）３０＜ν₂₁−ν₂₂−ν₂₃−ν₂₄＜５５
ただし、ν₂₁、ν₂₂、ν₂₃、ν₂₄はそれぞれ第２レンズ群の物体側から順の第１レンズ、第２レンズ、第３レンズ、第４レンズにおけるｄ線基準の媒質のアッベ数である。The electronic imaging apparatus according to claim 1, wherein each lens group of the second lens group satisfies the following condition.
(4) 30 <ν ₂₁ −ν ₂₂ −ν ₂₃ −ν ₂₄ <55
However, ν ₂₁ , ν ₂₂ , ν ₂₃ , and ν ₂₄ are the Abbe numbers of the d-line reference medium in the first lens, the second lens, the third lens, and the fourth lens in order from the object side of the second lens group. is there.

以下の条件を満足する請求項１、３又は４の何れか１項記載の電子撮像装置。
（９） −０．３＜ｆ_2F／Ｒ_21R＜０．８
ただし、Ｒ_21Rは第２レンズ群の最も物体側レンズの像側面の光軸上曲率半径、ｆ_2Fは第２群前群の合成焦点距離である。The electronic imaging device according to claim 1, wherein the electronic imaging device satisfies the following condition.
(9) −0.3 <f _2F / R _21R <0.8
Where R _21R is the radius of curvature on the optical axis of the image side surface of the second lens group closest to the object side lens, and f _2F is the combined focal length of the front group of the second group.

前記第２レンズ群の最も像側の正レンズにおける非球面形状が以下の条件を満足することを特徴とする請求項１から５の何れか１項記載の電子撮像装置。
（５）１．２×１０^-2・Ｌ＞｜Asp24 ｜＞５・｜Asp21F｜
ただし、Asp21Fは第２レンズ群の最も物体側の正レンズの物体側面の光軸上での曲率半径を有する球面に対し、光軸からの高さが０．３Ｌでの非球面偏倚量、Asp24 は第２レンズ群の最も像側の正レンズの非球面の光軸上での曲率半径を有する球面に対し、光軸からの高さが０．３Ｌでの非球面偏倚量であり、第２レンズ群の最も物体側の正レンズの物体側面が球面の場合は非球面偏倚量Asp21Fを０とする。6. The electronic imaging apparatus according to claim 1, wherein the aspherical shape of the positive lens closest to the image side of the second lens group satisfies the following condition.
(5) 1.2 × 10 ^-2 · L> | Asp24 |> 5 ・ | Asp21F |
However, Asp21F is a spherical surface having a radius of curvature on the optical axis of the object side surface of the positive lens closest to the object side in the second lens group, the aspherical deviation amount when the height from the optical axis is 0.3 L, Asp24 Is the aspherical deviation when the height from the optical axis is 0.3 L with respect to the spherical surface having the radius of curvature on the optical axis of the aspherical surface of the positive lens closest to the image side of the second lens group. When the object side surface of the positive lens closest to the object side in the lens group is spherical, the aspherical deviation amount Asp21F is set to zero.

第２レンズ群の最も像側レンズは像側面のみが非球面であって、第２群後群中に空間を設けないことを特徴とする請求項１から６の何れか１項記載の電子撮像装置。 7. The electronic imaging according to claim 1, wherein the most image side lens of the second lens group has an aspherical surface only on the image side surface, and no space is provided in the rear group of the second group. apparatus.

以下の条件を満足する請求項１から７の何れか１項記載の電子撮像装置。
（６） −１．２＜（Ｒ_21F−Ｒ_22R）／（Ｒ_21F＋Ｒ_22R）＜０．３
ただし、Ｒ_21Fは第２群前群における入射面、Ｒ_22Rは第２群前群の射出面の光軸上の曲率半径である。The electronic imaging device according to claim 1, wherein the following conditions are satisfied.
(6) −1.2 <(R _21F −R _22R ) / (R _21F + R _22R ) <0.3
However, R _21F is the entrance surface in the second group front group, and R _22R is the radius of curvature on the optical axis of the exit surface of the second group front group.

以下の条件を満足する請求項１から８の何れか１項記載の電子撮像装置。
（７） −２．５＜ｆ₃／ｆ_2R＜０．３
（８）０．０２＜ｄ₂₂／Ｌ＜０．２２
ただし、ｆ_2Rは第２群後群の合成焦点距離、ｆ₃は第３レンズ群の焦点距離、ｄ₂₂は第２群前群の射出面から第２群後群の入射面までの間隔である。The electronic imaging device according to claim 1, wherein the following conditions are satisfied.
(7) -2.5 <f ₃ / f _2R <0.3
(8) 0.02 <d ₂₂ /L<0.22
Where f _2R is the combined focal length of the second group rear group, f ₃ is the focal length of the third lens group, and d ₂₂ is the distance from the exit surface of the second group front group to the entrance surface of the second group rear group. is there.

無限遠物点合焦時における広角端から望遠端への変倍に際して、前記第３レンズ群が像側に凸の軌跡で移動することを特徴とする請求項１から９の何れか１項記載の電子撮像装置。 10. The zoom lens according to claim 1, wherein the third lens unit moves along a locus convex toward the image side upon zooming from the wide-angle end to the telephoto end during focusing on an object point at infinity. Electronic imaging device.

前記第１レンズ群と第２レンズ群との間に絞りを配したことを特徴とする請求項１から１０の何れか１項記載の電子撮像装置。 The electronic imaging apparatus according to claim 1, wherein a diaphragm is disposed between the first lens group and the second lens group.

変倍時に前記絞りが第２レンズ群と一体で移動することを特徴とする請求項１１記載の電子撮像装置。 12. The electronic imaging apparatus according to claim 11, wherein the diaphragm moves integrally with the second lens group at the time of zooming.

以下の条件を満足することを特徴とする請求項１から１２の何れか１項記載の電子撮像装置。
（Ａ）１．０８＜Ｒ_22R／Ｒ_21F＜１０
ただし、Ｒ_21Fは第２群前群の入射面の光軸上曲率半径、Ｒ_22Rは第２群前群の射出面の光軸上曲率半径である。The electronic imaging apparatus according to claim 1, wherein the following condition is satisfied.
(A) 1.08 <R _22R / R _21F <10
However, R _21F is the radius of curvature on the optical axis of the entrance surface of the second group front group, and R _22R is the radius of curvature on the optical axis of the exit surface of the second group front group.

以下の条件を満足することを特徴とする請求項１から１３の何れか１項記載の電子撮像装置。
（10） −１．５＜ｆ₂／ｆ_2R＜０．３
ただし、ｆ₂は第２レンズ群全体の合成焦点距離、ｆ_2Rは第２群後群の合成焦点距離である。The electronic imaging apparatus according to claim 1, wherein the following condition is satisfied.
(10) −1.5 <f ₂ / f _2R <0.3
Here, f ₂ is the combined focal length of the entire second lens group, and f _2R is the combined focal length of the second group rear group.

前記第３レンズ群は１枚の正レンズで構成されていることを特徴とする請求項１から１３の何れか１項記載の電子撮像装置。 The electronic imaging apparatus according to claim 1, wherein the third lens group includes a single positive lens.

前記第３レンズ群の正レンズが以下の条件を満足することを特徴とする請求項１５記載の電子撮像装置。
（11） −１．０＜（Ｒ₃₁＋Ｒ₃₂）／（Ｒ₃₁−Ｒ₃₂）＜１．２
ただし、Ｒ₃₁、Ｒ₃₂はそれぞれ第３レンズ群の正レンズの物体側面及び像側面の光軸上曲率半径である。The electronic imaging apparatus according to claim 15, wherein the positive lens of the third lens group satisfies the following condition.
(11) −1.0 <(R ₃₁ + R ₃₂ ) / (R ₃₁ −R ₃₂ ) <1.2
Here, R ₃₁ and R ₃₂ are the curvature radii on the optical axis of the object side surface and the image side surface of the positive lens of the third lens group, respectively.

前記第３レンズ群の移動により近距離物点への合焦を行うことを特徴とする請求項１から１６の何れか１項記載の電子撮像装置。 The electronic imaging apparatus according to claim 1, wherein focusing on a short-distance object point is performed by movement of the third lens group.

前記ズームレンズの広角端半画角ω_Wが２７°から４２°の範囲にあることを特徴とする請求項１から１７の何れか１項記載の電子撮像装置。18. The electronic imaging apparatus according to claim 1, wherein a wide angle end half field angle ω _{W of the} zoom lens is in a range of 27 ° to 42 °.