JP2003029148A5 - - Google Patents
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- JP2003029148A5 JP2003029148A5 JP2002128696A JP2002128696A JP2003029148A5 JP 2003029148 A5 JP2003029148 A5 JP 2003029148A5 JP 2002128696 A JP2002128696 A JP 2002128696A JP 2002128696 A JP2002128696 A JP 2002128696A JP 2003029148 A5 JP2003029148 A5 JP 2003029148A5
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- JP
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- focal length
- lens group
- lens
- length extremity
- refractive power
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- 230000014509 gene expression Effects 0.000 claims description 5
- 230000003287 optical effect Effects 0.000 claims description 2
- 238000013459 approach Methods 0.000 description 1
- 210000001747 pupil Anatomy 0.000 description 1
Description
【0006】
本発明によるズームレンズ系は、物体側から順に、正の屈折力を有する第1レンズ群と、負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レンズ群と、負の屈折力を有する第4レンズ群、とから構成され、各群を光軸方向に移動させてズーミングを行い、次の条件式(1)ないし(3)を満足することを特徴としている。
(1)1.1<f23T/f23W<1.8
(2)0.2<LD23W/fW<0.45
(3)0.01<(D23W−D23T)/f T <0.05
但し、
f23W:短焦点距離端での第2レンズ群と第3レンズ群の合成焦点距離、
f23T:長焦点距離端での第2レンズ群と第3レンズ群の合成焦点距離、
LD23W:短焦点距離端での第2レンズ群の最も物体側の面から第3レンズ群の最も像側の面までの距離、
fW:短焦点距離端での全系の焦点距離、
f T :長焦点距離端での全系の焦点距離、
D23W:短焦点距離端での第2レンズ群と第3レンズ群の軸上空気間隔、
D23T:長焦点距離端での第2レンズ群と第3レンズ群の軸上空気間隔、
である。[0006]
The zoom lens system according to the present invention comprises, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a negative lens. And a fourth lens group having a refractive power of, and moving each group in the optical axis direction for zooming to satisfy the following conditional expressions (1) to (3).
(1) 1.1 <f 23T / f 23W <1.8
(2) 0.2 <LD 23 W / f W <0.45
(3) 0.01 <(D 23W −D 23T ) / f T <0.05
However,
f 23 W : combined focal length of the second lens group and the third lens group at the short focal length extremity,
f 23 T : combined focal length of the second lens group and the third lens group at the long focal length extremity,
LD 23 W : The distance from the most object side surface of the second lens group to the most image side surface of the third lens group at the short focal length extremity
f W : Focal length of the entire system at the short focal length extremity
f T : focal length of the entire system at the long focal length extremity
D 23 W : axial air gap between the second lens group and the third lens group at the short focal length extremity,
D 23 T : On-axis air gap between the second lens group and the third lens group at the long focal length extremity
It is.
【0016】
条件式(2)は、短焦点距離端での第2レンズ群の最も物体側の面から第3レンズ群の最も像側の面までの距離を規定するものである。
条件式(2)の下限を超えると、負の第2レンズ群と正の第3レンズ群の間隔が狭くなるため短焦点距離端においてバックフォーカスが極めて短くなり、第4レンズ群の径が大きくなってしまう。条件式(2)の上限を超えると、第2レンズ群と第3レンズ群の間隔が広くなりすぎるため、短焦点距離端において入射瞳位置が像面側に寄るので第1レンズ群の径が大きくなってしまい、径方向の小型化が困難となる。[0016]
Conditional expression (2) defines the distance from the most object side surface of the second lens unit to the most image side surface of the third lens unit at the short focal length extremity.
If the lower limit of conditional expression (2) is exceeded, the distance between the negative second lens group and the positive third lens group becomes narrow, so the back focus becomes extremely short at the short focal length extremity, and the diameter of the fourth lens group becomes large. turn into. If the upper limit of conditional expression (2) is exceeded, the distance between the second lens group and the third lens group becomes too large, and the entrance pupil position approaches the image plane side at the short focal length extremity. It becomes large, making it difficult to miniaturize in the radial direction.
Claims (1)
(1)1.1<f23T/f23W<1.8
(2)0.2<LD23W/fW<0.45
(3)0.01<(D23W−D23T)/f T <0.05
但し、
f23W:短焦点距離端での第2レンズ群と第3レンズ群の合成焦点距離、
f23T:長焦点距離端での第2レンズ群と第3レンズ群の合成焦点距離、
LD23W:短焦点距離端での第2レンズ群の最も物体側の面から第3レンズ群の最も像側の面までの距離、
fW:短焦点距離端での全系の焦点距離、
f T :長焦点距離端での全系の焦点距離、
D23W:短焦点距離端での第2レンズ群と第3レンズ群の軸上空気間隔、
D23T:長焦点距離端での第2レンズ群と第3レンズ群の軸上空気間隔。From the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a negative refractive power What is claimed is: 1. A zoom lens system comprising a group of lenses, wherein each group is moved in the optical axis direction for zooming to satisfy the following conditional expressions (1) to (3).
(1) 1.1 <f 23T / f 23W <1.8
(2) 0.2 <LD 23 W / f W <0.45
(3) 0.01 <(D 23W −D 23T ) / f T <0.05
However,
f 23 W : combined focal length of the second lens group and the third lens group at the short focal length extremity,
f 23 T : combined focal length of the second lens group and the third lens group at the long focal length extremity,
LD 23 W : The distance from the most object side surface of the second lens group to the most image side surface of the third lens group at the short focal length extremity
f W : Focal length of the entire system at the short focal length extremity
f T : focal length of the entire system at the long focal length extremity
D 23 W : axial air gap between the second lens group and the third lens group at the short focal length extremity,
D23T : On-axis air gap between the second lens unit and the third lens unit at the long focal length extremity.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002128696A JP2003029148A (en) | 2001-05-08 | 2002-04-30 | Zoom lens system |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001-137324 | 2001-05-08 | ||
JP2001137324 | 2001-05-08 | ||
JP2002128696A JP2003029148A (en) | 2001-05-08 | 2002-04-30 | Zoom lens system |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2003029148A JP2003029148A (en) | 2003-01-29 |
JP2003029148A5 true JP2003029148A5 (en) | 2004-11-18 |
Family
ID=26614747
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2002128696A Withdrawn JP2003029148A (en) | 2001-05-08 | 2002-04-30 | Zoom lens system |
Country Status (1)
Country | Link |
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JP (1) | JP2003029148A (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4563061B2 (en) * | 2004-03-29 | 2010-10-13 | オリンパス株式会社 | Telephoto lens and telephoto lens device |
JP4806943B2 (en) * | 2005-03-11 | 2011-11-02 | 株式会社ニコン | Zoom lens |
KR100616643B1 (en) * | 2004-12-21 | 2006-08-28 | 삼성전기주식회사 | Lens System For Subminiature Camera Module |
JP4994796B2 (en) * | 2006-11-14 | 2012-08-08 | キヤノン株式会社 | Zoom lens and imaging apparatus having the same |
JP5849884B2 (en) * | 2012-05-29 | 2016-02-03 | コニカミノルタ株式会社 | Telephoto lens, imaging optical device and digital equipment |
JP5846065B2 (en) * | 2012-07-25 | 2016-01-20 | コニカミノルタ株式会社 | Telephoto lens, imaging optical device and digital equipment |
JP6925190B2 (en) * | 2017-07-12 | 2021-08-25 | 株式会社タムロン | Zoom lens and imaging device |
-
2002
- 2002-04-30 JP JP2002128696A patent/JP2003029148A/en not_active Withdrawn