JP2007298831A5

JP2007298831A5 -

Info

Publication number: JP2007298831A5
Application number: JP2006127719A
Authority: JP
Filing date: 2006-05-01
Publication date: 2009-05-07
Anticipated expiration: 2026-05-01

Claims

A first lens group having an optical path bending optical element and having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power in order from the object side along the optical axis. If consists of a fourth lens group having positive refractive power,
When the focal length changes from the wide-angle end state to the telephoto end state, the first lens group and the third lens group are fixed with respect to the image plane, and the distance between the first lens group and the second lens group Increases, the distance between the second lens group and the third lens group decreases, the distance between the third lens group and the fourth lens group decreases,
A zoom lens, wherein an image on an image plane can be shifted by shifting all or part of the third lens group as a shift lens group in a direction substantially orthogonal to the optical axis.

The zoom lens according to claim 1 , wherein the following condition is satisfied.
0.75 <βbt × (1-βat) <1.2
However,
βat: used lateral magnification of the third lens group in the telephoto end state βbt: used lateral magnification in the entire lens system between the third lens group and the image plane in the telephoto end state

The zoom lens according to claim 1 , wherein the zoom lens satisfies the following condition.
0.3 <fw / f3 <0.5
However,
f3: focal length of the third lens unit fw: focal length of the entire zoom lens system in the wide-angle end state

The zoom lens according to any one of claims 1 to 3 , wherein the following condition is satisfied.
0.5 <f4 / f3 <1.1
However,
f3: focal length of the third lens group f4: focal length of the fourth lens group

The third lens group includes, in order from the object side along the optical axis, a positive lens having a convex surface facing the object side, a positive lens having a convex surface facing the object side, and a negative lens having a concave surface facing the image surface side. negative zoom lens according to claim 1, any one of 4, characterized in that it is a cemented lens having a refractive power.

An aperture stop is provided between the second lens group and the third lens group;
The zoom lens according to any one of claims 1 to 5, wherein the aperture stop is disposed adjacent to the object side of the third lens group.

The optical path bending optical element is a right angle prism;
The zoom lens according to claim 1, wherein the following condition is satisfied.
ndp> 1.80
However,
ndp: refractive index of d-line of the right-angle prism

The first lens group includes a negative lens;
The zoom lens according to any one of claims 1 to 7, wherein the following condition is satisfied.
nd1> 1.90
However,
nd1: d-line refractive index of the negative lens in the first lens group

The zoom lens according to claim 1, wherein the following condition is satisfied.
1.5 <f1 / (− f2) <4.0
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group

The fourth lens group includes, in order from the object side along the optical axis, a positive lens having a convex surface facing the object side, a positive lens having a convex surface facing the object side, and a negative lens having a concave surface facing the image surface side. The zoom lens according to claim 1, comprising a cemented lens having negative refractive power.

The zoom lens according to claim 1, wherein the second lens group is a focusing lens group.

An optical apparatus comprising the zoom lens according to any one of claims 1 to 11 .

A first lens group having an optical path bending optical element and having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power in order from the object side along the optical axis. If consists of a fourth lens unit having a positive refractive power,
When the focal length changes from the wide-angle end state to the telephoto end state, the first lens group and the third lens group are fixed with respect to the image plane, and the distance between the first lens group and the second lens group A zoom lens in which the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group decreases,
An image shift method for a zoom lens that enables an image shift on an image plane by shifting all or part of the third lens group as a shift lens group in a direction substantially orthogonal to the optical axis.

A first lens group having an optical path bending optical element and having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power in order from the object side along the optical axis. If consists of a fourth lens group having positive refractive power,
A zoom lens capable of shifting an image on the image plane by shifting the whole or a part of the third lens group as a shift lens group in a direction substantially orthogonal to the optical axis;
When the focal length changes from the wide-angle end state to the telephoto end state, the first lens group and the third lens group are fixed with respect to the image plane, and the distance between the first lens group and the second lens group Increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group decreases. 4. A method of varying a focal length of a zoom lens, wherein the four lens groups are moved along the optical axis.