JP2022133414A - zoom lens system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive-lead type zoom lens system that offers good corrections for aberrations and superior optical performance.

SOLUTION: A zoom lens system provided herein comprises a positive first lens group and a succeeding lens group following the first lens group, the first lens group consisting of one or more positive single lenses, one negative meniscus lens having a convex surface on the object side, and one or more positive lenses. When zooming from the wide-angle end to the telephoto end, the first lens group moves towards the object side, increasing a distance between the first lens group and the succeeding lens group. The succeeding lens group comprises multiple lens groups. When zooming from the wide-angle end to the telephoto end, distances among lens groups constituting the succeeding lens group change. The zoom lens system satisfies the following conditional expressions (1), (2): fG1/fn<-1.50 ...(1), 65<νpave ...(2), where fG1 represents a focal length of the first lens group, fn represents a focal length of the negative meniscus lens of the first lens group, and νpave represents an average Abbe number of the positive lenses of the first lens group for the d-ray.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a zoom lens system applied to, for example, surveillance cameras, digital cameras, and interchangeable lenses.

In recent years, there has been a demand for a compact zoom lens system with a higher zoom ratio, especially a zoom lens system with a longer focal length on the telephoto side for telephotography. In general, in a zoom lens system including a focal length in the telephoto range, aberrations increase as the focal length increases on the telephoto side, and longitudinal chromatic aberration and lateral chromatic aberration are particularly problematic. Also, as the telephoto end increases the diameter of the pupil incident on the lens, spherical aberration and coma, which are greatly dependent on the pupil diameter, increase. growing. Cameras in recent years tend to have higher pixel counts, and it is required to remove these aberration corrections in a well-balanced manner.

As a zoom lens system including a telephoto range, a positive lead type is generally used. For example, Patent Document 1 discloses a five-group zoom lens system composed of five lens groups, positive, negative, positive, negative, and positive, in order from the object side, and a positive, negative, positive, positive, and positive lens group, in order from the object side. A six-group zoom lens system is disclosed which consists of six positive, negative, and positive lens groups. Patent Document 2 discloses a three-group zoom lens system composed of three lens groups, positive, negative, and positive, in order from the object side, and five lens groups, positive, negative, positive, negative, and positive, in order from the object side. A five-group zoom lens system composed of one lens group is disclosed. Further, Patent Document 3 discloses a three-group zoom lens system composed of three lens groups, positive, negative, and positive, in order from the object side, and four lenses, positive, negative, positive, and positive, in order from the object side. A four-group zoom lens system composed of groups is disclosed.

JP 2011-209347 A JP 2011-099924 A JP 2008-122775 A

However, the zoom lens system of Patent Document 1 is insufficient in correcting spherical aberration and astigmatism, and the zoom lens systems of Patent Documents 2 and 3 have residual longitudinal chromatic aberration on the telephoto side, especially secondary spectrum. Therefore, the optical performance of any of the zoom lens systems of Patent Documents 1 to 3 tends to deteriorate.

SUMMARY OF THE INVENTION It is an object of the present invention to realize excellent optical performance by satisfactorily correcting various aberrations in a positive lead type zoom lens system.

A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length When zooming to the end, the first lens group moves toward the object side and the distance between the first lens group and the succeeding lens group increases; When zooming from the focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; and the following conditional expressions (1) and (2) are satisfied; and
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of at least one positive single lens, one negative meniscus lens with a convex surface facing the object side, and two or more positive lenses in order from the side; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1) and (2) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one lens group with negative refractive power; and the following conditional expression (1), (2) and (3″) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(3″) fG1/fGn≦−3.967
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: the focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (4') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(4′) 1.650<nn<1.835
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
nn: refractive index for the d-line of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (5'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(5″) 2.347≦fG1/R1p<3.30
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1p: paraxial radius of curvature of the most object side surface of the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (6'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(6″) 1.30<(R1n+R2n)/(R1n−R2n)≦2.293
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; when the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one negative refractive power lens group, and the negative refractive power included in the subsequent lens group Of the power lens groups, the n-th lens group with negative refractive power located closest to the object side has a negative lens closest to the object side; and the following conditional expressions (1) and (2), (7) is satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(7) fGn/R2Gn<−1.10
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: focal length of the n-th lens group,
R2Gn: the paraxial radius of curvature of the image-side surface of the most object-side negative lens in the n-th lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; when the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one negative refractive power lens group, and the negative refractive power included in the subsequent lens group Of the power lens groups, the n-th lens group with negative refractive power located closest to the object side has a negative lens closest to the image side; and the following conditional expressions (1) and (2): satisfying;
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (11'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(11″) 3.50<fG1/R2n
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (12'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(12″) 4.00<fG1/1Gd≦7.022
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
1Gd: the distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (13X) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(13X)2.50<fG1/fw
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (14X) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(14×)1.10<fG1/(fw×ft) ^1/2
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
ft: focal length of the entire system at the long focal length end,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups and the distance between each lens group changes; the subsequent lens group has at least one and that the following conditional expressions (1) and (2″) are satisfied:
(1) fG1/fn<−1.50
(2″) 72.85≦νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups and the distance between each lens group changes; the subsequent lens group has at least one and that the following conditional expressions (1), (2), and (3A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(3A) -2.456≤fG1/fGn<-0.70
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: the focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (5A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(5A) 1.40<fG1/R1p≦1.805
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1p: paraxial radius of curvature of the most object side surface of the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (6A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(6A) 3.002≦(R1n+R2n)/(R1n−R2n)
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (10″) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(10″) 44.20≦νn
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (11A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(11A) 2.40<fG1/R2n≦2.993
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (12A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(12A) 10.366≦fG1/1Gd<13.00
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
1Gd: the distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (13A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(13A) 0.80<fG1/fw≦1.467
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (1') within the conditional expression range defined by the conditional expression (1).
(1′)−3.30<fG1/fn<−1.50

The zoom lens system of the present invention preferably satisfies the following conditional expression (2') within the conditional expression range defined by the conditional expression (2).
(2′) 67<νpave

The trailing lens group includes at least one lens group with negative refractive power, and the n-th lens group with negative refractive power positioned closest to the object side in the trailing lens group has a negative lens closest to the object side. can have.

The subsequent lens group preferably includes at least one lens group with negative refractive power and satisfies the following conditional expression (3).
(3) fG1/fGn<−0.70
however,
fG1: focal length of the first lens group;
fGn: the focal length of the n-th lens group with negative refractive power located closest to the object side in the subsequent lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (3') within the conditional expression range defined by the conditional expression (3).
(3′)−5.50<fG1/fGn<−0.70

The zoom lens system of the present invention preferably satisfies the following conditional expression (4).
(4) 1.650<nn
however,
nn: refractive index for the d-line of the negative meniscus lens in the first lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (4') within the conditional expression range defined by the conditional expression (4).
(4′) 1.650<nn<1.835

The zoom lens system of the present invention preferably satisfies the following conditional expression (5).
(5) 1.40<fG1/R1p<3.30
however,
fG1: focal length of the first lens group;
R1p: paraxial radius of curvature of the most object side surface of the first lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (6).
(6) 1.30<(R1n+R2n)/(R1n−R2n)
however,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (6') within the conditional expression range defined by the conditional expression (6).
(6′) 1.30<(R1n+R2n)/(R1n−R2n)<3.30

The trailing lens group includes at least one lens group with negative refractive power, and the n-th lens group with negative refractive power positioned closest to the object side in the trailing lens group has a negative lens closest to the object side. , and the following conditional expression (7) can be satisfied.
(7) fGn/R2Gn<−1.10
however,
fGn: focal length of the n-th lens group with negative refractive power located closest to the object side in the succeeding lens group, R2Gn: paraxial radius of curvature of the image-side surface of the negative lens closest to the object side in the n-th lens group ,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (7') within the conditional expression range defined by the conditional expression (7).
(7′) −3.60<fGn/R2Gn<−1.10

The subsequent lens group includes at least one lens group with negative refractive power, and the n-th lens group with negative refractive power located closest to the object side in the subsequent lens group is a negative lens in order from the most object side. and a positive lens.

The trailing lens group includes at least one lens group with negative refractive power, and the n-th lens group with negative refractive power located closest to the object side in the trailing lens group has a negative lens closest to the image side. can have.

The negative lens closest to the image side in the n-th lens group has a concave surface facing the object side, and can satisfy the following conditional expression (8).
(8) 29<νGn
however,
νGn: Abbe number for the d-line of the most image-side negative lens in the n-th lens group,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (8') within the conditional expression range defined by the conditional expression (8).
(8′) 37<νGn

The subsequent lens group includes at least one lens group with negative refractive power, and the n-th lens group with negative refractive power located closest to the object side in the subsequent lens group is located on the image side of the first lens group. It can be a second lens group of negative refractive power located immediately behind.

The zoom lens system of the present invention preferably satisfies the following conditional expression (9).
(9) θgFn−(0.6440−0.001682×νn)<0
however,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group,
θgFn: partial dispersion ratio on the short wavelength side of the negative meniscus lens in the first lens group;
θgF = (ng-nF)/(nF-nC)
ng: refractive index for g-line,
nF: refractive index for F line,
nC: refractive index for C line,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (10).
(10) 34<νn
however,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (10') within the conditional expression range defined by the conditional expression (10).
(10′) 34<νn<50

The zoom lens system of the present invention preferably satisfies the following conditional expression (11).
(11) 2.40<fG1/R2n
however,
fG1: focal length of the first lens group;
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (11') within the conditional expression range defined by the conditional expression (11).
(11′) 3.50<fG1/R2n<5.10

The zoom lens system of the present invention preferably satisfies the following conditional expression (12).
(12) 4.00<fG1/1Gd<13.00
however,
fG1: focal length of the first lens group;
1Gd: the distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group;
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (13).
(13) 0.80<fG1/fw
however,
fG1: focal length of the first lens group;
fw: focal length of the entire system at the short focal length end,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (13′) and further conditional expression (13″) within the conditional expression range defined by conditional expression (13).
(13′) 1.40<fG1/fw<9.80
(13″) 2.50<fG1/fw<6.60

The zoom lens system of the present invention preferably satisfies the following conditional expression (14).
(14) 0.60<fG1/(fw×ft) ^1/2
however,
fG1: focal length of the first lens group;
fw: focal length of the entire system at the short focal length end,
ft: focal length of the entire system at the long focal length end,
is.

The zoom lens system of the present invention preferably satisfies the following conditional expression (14′) and further conditional expression (14″) within the conditional expression range defined by conditional expression (14).
(14′) 1.10<fG1/(fw×ft) ^1/2 <2.50
(14″) 1.10<fG1/(fw×ft) ^1/2 <2.00

A positive meniscus lens having a convex surface facing the object side can be positioned immediately before the object side of the negative meniscus lens in the first lens group.

One or two positive lenses can be positioned on the image side of the negative meniscus lens in the first lens group.

During zooming from the short focal length extremity to the long focal length extremity, the first lens group can move toward the object side.

According to the present invention, it is possible to satisfactorily correct various aberrations in a positive lead type zoom lens system to realize excellent optical performance.

FIG. 2 is a lens configuration diagram of the zoom lens system according to Numerical Example 1 of the present invention when focusing on infinity at the short focal length extremity; 2A to 2D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 1 when focusing on infinity. 3A to 3D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 1 at the short focal length extremity when focusing on infinity. 4A to 4D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 1 when focusing on infinity. 5A to 5D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 1 at the long focal length extremity when focusing on infinity. FIG. 10 is a lens configuration diagram of the zoom lens system according to Numerical Example 2 of the present invention at the short focal length extremity when focusing on infinity. 7A to 7D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 6 when focusing on infinity. 8A to 8D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 6 at the short focal length extremity when focusing on infinity. 9A to 9D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 6 when focusing on infinity. 10A to 10D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 6 at the long focal length extremity when focusing on infinity. FIG. 10 is a lens configuration diagram of the zoom lens system according to Numerical Example 3 of the present invention at the short focal length extremity when focusing on infinity. FIGS. 12A to 12D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 11 when focusing on infinity. 13A to 13D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 11 at the short focal length extremity when focusing on infinity. 14A to 14D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 11 when focusing on infinity. 15A to 15D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 11 at the long focal length extremity when focusing on infinity. FIG. 11 is a lens configuration diagram of the zoom lens system according to Numerical Example 4 of the present invention at the short focal length extremity when focusing on infinity. FIGS. 17A to 17D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 16 when focusing on infinity. 18A to 18D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 16 at the short focal length extremity when focusing on infinity. 19A to 19D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 16 when focusing on infinity. 20A to 20D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 16 at the long focal length extremity when focusing on infinity. FIG. 11 is a lens configuration diagram of the zoom lens system according to Numerical Example 5 of the present invention at the short focal length extremity when focusing on infinity. 22A to 22D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 21 when focusing on infinity. 23A to 23D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 21 at the short focal length extremity when focusing on infinity. 24A to 24D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 21 when focusing on infinity. 25A to 25D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 21 at the long focal length extremity when focusing on infinity. FIG. 11 is a lens configuration diagram of the zoom lens system according to Numerical Example 6 of the present invention at the short focal length extremity when focusing on infinity. 27A to 27D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 26 when focusing on infinity. 28A to 28D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 26 at the short focal length extremity when focusing on infinity. 29A to 29D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 26 when focusing on infinity. 30A to 30D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 26 at the long focal length extremity when focusing on infinity. FIG. 12 is a lens configuration diagram of the zoom lens system according to Numerical Example 7 of the present invention at the short focal length extremity when focusing on infinity. FIGS. 32A to 32D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 31 when focusing on infinity. 33A to 33D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 31 at the short focal length extremity when focusing on infinity. 34A to 34D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 31 when focusing on infinity. 35A to 35D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 31 at the long focal length extremity when focusing on infinity. FIG. 12 is a lens configuration diagram of the zoom lens system according to Numerical Example 8 of the present invention at the short focal length extremity when focusing on infinity. 37A to 37D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 36 when focusing on infinity. 38A to 38D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 36 at the short focal length extremity when focusing on infinity. 39A to 39D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 36 when focusing on infinity. 40A to 40D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 36 at the long focal length extremity when focusing on infinity. FIG. 11 is a lens configuration diagram of the zoom lens system according to Numerical Example 9 of the present invention at the short focal length extremity when focusing on infinity. 42A to 42D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 41 when focusing on infinity. 43A to 43D are lateral aberration diagrams of the zoom lens system constructed as shown in FIG. 41 at the short focal length extremity when focusing on infinity. FIGS. 44A to 44D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 41 when focusing on infinity. 45A to 45D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 41 at the long focal length extremity when focusing on infinity. FIG. 10 is a lens configuration diagram of the zoom lens system according to Numerical Example 10 of the present invention at the short focal length extremity when focusing on infinity. FIGS. 47A to 47D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 46 when focusing on infinity. 48A to 48D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 46 at the short focal length extremity when focusing on infinity. 49A to 49D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 46 when focusing on infinity. FIGS. 50A to 50D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 46 at the long focal length extremity when focusing on infinity. FIG. 11 is a lens configuration diagram of the zoom lens system according to Numerical Example 11 of the present invention at the short focal length extremity when focusing on infinity. 52A to 52D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 51 when focusing on infinity. 53A to 53D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 51 at the short focal length extremity when focusing on infinity. 54A to 54D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 51 when focusing on infinity. 55A to 55D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 51 at the long focal length extremity when focusing on infinity. FIG. 12 is a lens configuration diagram of the zoom lens system according to Numerical Example 12 of the present invention at the short focal length extremity when focusing on infinity. FIGS. 57A to 57D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 56 when focusing on infinity. 58A to 58D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 56 at the short focal length extremity when focusing on infinity. 59A to 59D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 56 when focusing on infinity. 60A to 60D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 56 at the long focal length extremity when focusing on infinity. FIG. 13 is a lens configuration diagram of the zoom lens system according to Numerical Example 13 of the present invention at the short focal length extremity when focusing on infinity. 62A to 62D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 61 when focusing on infinity. 63A to 63D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 61 at the short focal length extremity when focusing on infinity. 64A to 64D are diagrams of various aberrations at the long focal length extremity of the zoom lens system constructed as shown in FIG. 61 when focusing on infinity. 65A to 65D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 61 at the long focal length extremity when focusing on infinity. FIG. 12 is a lens configuration diagram of the zoom lens system according to Numerical Example 14 of the present invention at the short focal length extremity when focusing on infinity. 67A to 67D are diagrams of various aberrations at the short focal length extremity of the zoom lens system constructed as shown in FIG. 66 when focusing on infinity. 68A to 68D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 66 at the short focal length extremity when focusing on infinity. FIGS. 69A to 69D are various aberration diagrams at the long focal length extremity of the zoom lens system constructed as shown in FIG. 66 when focusing on infinity. 70A to 70D are lateral aberration diagrams of the zoom lens system configured as shown in FIG. 66 at the long focal length extremity when focusing on infinity. FIG. 3 is a simple movement diagram showing a zoom trajectory of Numerical Example 1 of the zoom lens system according to the present invention; FIG. 10 is a simple movement diagram showing a zoom trajectory of Numerical Example 2 of the zoom lens system according to the present invention; FIG. 10 is a simplified movement diagram showing a zoom trajectory of Numerical Example 3 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 4 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 5 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 6 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 7 of the zoom lens system according to the present invention; FIG. 11 is a simplified movement diagram showing the zoom trajectory of Numerical Example 8 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing the zoom trajectory of Numerical Example 9 of the zoom lens system according to the present invention; FIG. 10 is a simple movement diagram showing the zoom trajectory of Numerical Example 10 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 11 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing a zoom trajectory of Numerical Example 12 of the zoom lens system according to the present invention; FIG. 11 is a simple movement diagram showing zoom trajectories of Numerical Examples 13 and 14 of the zoom lens system according to the present invention;

≪Positive/negative positive/negative 4-group zoom lens system≫
In Numerical Example 1-5, the zoom lens system of the present embodiment has, in order from the object side, a first lens group G1A with a positive refractive power and a negative The second lens group (subsequent lens group, n-th lens group) G2A with refractive power, the third lens group (subsequent lens group) G3A with positive refractive power, and the fourth lens group (subsequent lens group) with negative refractive power ) G4A. The third lens group G3A includes a diaphragm S that moves integrally with the third lens group G3A. I is the image plane.

During zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), each lens group behaves as follows.
The first lens group G1A moves monotonously toward the object side through Numerical Examples 1-5 (FIGS. 71-75).
In Numerical Examples 1, 3, and 4, the second lens group G2A once moves toward the image side and then returns to the object side (FIGS. 71, 73, and 74). move to the side (Fig. 72, Fig. 75).
In Numerical Examples 1, 3, and 4, the third lens group G3A once moves to the image side, and then moves beyond the position of the short focal length extremity to the object side (FIGS. 71, 73, and 74). In Examples 2 and 5, it moves monotonously toward the object side (FIGS. 72 and 75).
Through Numerical Examples 1-5, the fourth lens group G4A once moves to the image side, and then moves to the object side beyond the position of the short focal length extremity (FIGS. 71 to 75).
As a result, the distance between the first lens group G1A and the second lens group G2A increases, the distance between the second lens group G2A and the third lens group G3A decreases, and the distance between the third lens group G3A and the fourth lens group G4A increases. increases or decreases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinite object to a close object is performed by moving the fourth lens group G4A toward the image side (the fourth lens group G4A constitutes a focus lens group).

In Numerical Example 1-4, the first lens group G1A includes, in order from the object side, a positive meniscus lens 11A convex to the object side, a negative meniscus lens 12A convex to the object side, and a positive meniscus lens convex to the object side. 13A. The negative meniscus lens 12A and the positive meniscus lens 13A are cemented in Numerical Examples 1, 2, and 4, and are not cemented in Numerical Example 3.
In Numerical Example 5, the first lens group G1A includes, in order from the object side, a biconvex positive lens 11A', a positive meniscus lens 12A' convex to the object side, and a negative meniscus lens 13A' convex to the object side. and a positive meniscus lens 14A' convex to the object side. The negative meniscus lens 13A' and the positive meniscus lens 14A' are cemented together.

In Numerical Example 1-3, the second lens group (n-th lens group) G2A includes, in order from the object side, a biconcave negative lens 21A, a positive meniscus lens 22A convex to the object side, a biconcave negative lens or an image lens. and a negative meniscus lens 23A convex to the side. The biconcave negative lens 21A and the positive meniscus lens 22A are cemented together.
In Numerical Example 4, the second lens group (n-th lens group) G2A includes, in order from the object side, a biconcave negative lens 21A', a biconvex positive lens 22A', and a negative meniscus lens 23A' convex to the image side. , a biconvex positive lens 24A', a biconvex positive lens 25A', and a biconcave negative lens 26A'. The biconcave negative lens 21A' and the biconvex positive lens 22A' are cemented together, and the biconvex positive lens 25A' and the biconcave negative lens 26A' are cemented together.
In Numerical Example 5, the second lens group (n-th lens group) G2A includes, in order from the object side, a biconcave negative lens 21A'', a positive meniscus lens 22A'' convex to the object side, and a biconcave negative lens 23A''. and a negative meniscus lens 24A″ convex to the image side. The biconcave negative lens 21A'' and the positive meniscus lens 22A'' are cemented together.

≪Positive, negative, negative, positive, negative, 5-group zoom lens system≫
In Numerical Example 6, the zoom lens system of this embodiment includes, in order from the object side, the first lens group G1B with positive refractive power and the second lens group G1B with negative refractive power, as shown in the simple movement diagram of FIG. A lens group (subsequent lens group, n-th lens group) G2B, a third lens group (subsequent lens group) G3B with negative refractive power, a fourth lens group (subsequent lens group) G4B with positive refractive power, and a negative and a fifth lens group (subsequent lens group) G5B having a refractive power of . The third lens group G3B includes a diaphragm S that moves integrally with the third lens group G3B. I is the image plane.

When zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the first lens group G1B, the second lens group G2B, the third lens group G3B, and the fifth lens group G5B monotonously move toward the object side. After the fourth lens group G4B moves once to the image side, it moves to the object side beyond the position of the short focal length extremity.
As a result, the distance between the first lens group G1B and the second lens group G2B increases, the distance between the second lens group G2B and the third lens group G3B increases, and the distance between the third lens group G3B and the fourth lens group G4B increases. increases, and the distance between the fourth lens group G4B and the fifth lens group G5B decreases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinity object to a close object is performed by moving the fourth lens group G4B toward the object side (the fourth lens group G4B constitutes a focus lens group).

The first lens group G1B is composed of, in order from the object side, a positive meniscus lens 11B convex to the object side, a negative meniscus lens 12B convex to the object side, and a positive meniscus lens 13B convex to the object side. The negative meniscus lens 12B and the positive meniscus lens 13B are cemented together.

The second lens group (n-th lens group) G2B is composed of, in order from the object side, a biconcave negative lens 21B, a biconvex positive lens 22B, and a negative meniscus lens 23B convex to the image side. The biconcave negative lens 21B and the biconvex positive lens 22B are cemented together.

≪Positive, positive, negative, positive, negative, 5-group zoom lens system≫
In Numerical Example 7, the zoom lens system of this embodiment has, in order from the object side, a first lens group G1C with positive refractive power and a second A lens group (subsequent lens group) G2C, a third lens group (subsequent lens group, n-th lens group) G3C with negative refractive power, a fourth lens group (subsequent lens group) G4C with positive refractive power, and a negative and a fifth lens group (subsequent lens group) G5C having a refractive power of . The fourth lens group G4C includes a diaphragm S that moves integrally with the fourth lens group G4C. I is the image plane.

When zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the first lens group G1C, the fourth lens group G4C, and the fifth lens group G5C monotonously move toward the object side, and the second lens The group G2C is fixed with respect to the image plane I (does not move in the optical axis direction), and the third lens group G3C moves monotonously toward the image side.
As a result, the distance between the first lens group G1C and the second lens group G2C increases, the distance between the second lens group G2C and the third lens group G3C increases, and the distance between the third lens group G3C and the fourth lens group G4C increases. decreases, and the distance between the fourth lens group G4C and the fifth lens group G5C decreases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinite object to a close object is performed by moving the fifth lens group G5C toward the image side (the fifth lens group G5C constitutes a focus lens group).

The first lens group G1C is composed of, in order from the object side, a positive meniscus lens 11C convex to the object side, a negative meniscus lens 12C convex to the object side, and a positive meniscus lens 13C convex to the object side. The negative meniscus lens 12C and the positive meniscus lens 13C are cemented together.

The third lens group (n-th lens group) G3C is composed of, in order from the object side, a biconcave negative lens 31C, a positive meniscus lens 32C convex to the object side, and a biconcave negative lens 33C. The biconcave negative lens 31C and the positive meniscus lens 32C are cemented together.

≪Positive, negative, positive, negative, positive, 5-group zoom lens system≫
In Numerical Example 8, the zoom lens system of this embodiment has, in order from the object side, a first lens group G1D with positive refractive power and a second A lens group (subsequent lens group, n-th lens group) G2D, a third lens group (subsequent lens group) G3D with positive refractive power, a fourth lens group (subsequent lens group) G4D with negative refractive power, and a positive and a fifth lens group (subsequent lens group) G5D having a refractive power of . The third lens group G3D includes a diaphragm S that moves integrally with the third lens group G3D. I is the image plane.

When zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the first lens group G1D, the third lens group G3D, the fourth lens group G4D, and the fifth lens group G5D monotonously move toward the object side. After the second lens group G2D moves once to the image side, it returns to the object side. At this time, the third lens group G3D and the fifth lens group G5D move together.
As a result, the distance between the first lens group G1D and the second lens group G2D increases, the distance between the second lens group G2D and the third lens group G3D decreases, and the distance between the third lens group G3D and the fourth lens group G4D increases. decreases, and the distance between the fourth lens group G4D and the fifth lens group G5D increases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an object at infinity to an object at close range is performed by moving the fourth lens group G4D toward the image side (the fourth lens group G4D constitutes a focus lens group).

The first lens group G1D is composed of, in order from the object side, a positive meniscus lens 11D convex to the object side, a negative meniscus lens 12D convex to the object side, and a positive meniscus lens 13D convex to the object side. The negative meniscus lens 12D and the positive meniscus lens 13D are cemented together.

The second lens group (n-th lens group) G2D is composed of, in order from the object side, a biconcave negative lens 21D, a positive meniscus lens 22D convex to the object side, and a negative meniscus lens 23D convex to the image side. The biconcave negative lens 21D and the positive meniscus lens 22D are cemented together.

≪Positive, negative, positive, negative, positive, negative, positive 6-group zoom lens system≫
In Numerical Example 9, the zoom lens system of this embodiment has, in order from the object side, a first lens group G1E with positive refractive power and a second A lens group (subsequent lens group, n-th lens group) G2E, a positive refractive power third lens group (subsequent lens group) G3E, a positive refractive power fourth lens group (subsequent lens group) G4E, and a negative and a sixth lens group (subsequent lens group) G6E with positive refractive power. The third lens group G3E includes a diaphragm S that moves integrally with the third lens group G3E. I is the image plane.

When zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the first lens group G1E, the third lens group G3E, the fourth lens group G4E, the fifth lens group G5E, and the sixth lens group G6E moves monotonously toward the object side, and the second lens group G2E is fixed with respect to the image plane I (does not move in the optical axis direction). At this time, the fourth lens group G4E and the sixth lens group G6E move together.
As a result, the distance between the first lens group G1E and the second lens group G2E increases, the distance between the second lens group G2E and the third lens group G3E decreases, and the distance between the third lens group G3E and the fourth lens group G4E increases. increases, the distance between the fourth lens group G4E and the fifth lens group G5E decreases, and the distance between the fifth lens group G5E and the sixth lens group G6E increases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinite object to a close object is performed by moving the fifth lens group G5E toward the image side (the fifth lens group G5E constitutes a focus lens group).

The first lens group G1E is composed of, in order from the object side, a positive meniscus lens 11E convex to the object side, a negative meniscus lens 12E convex to the object side, and a positive meniscus lens 13E convex to the object side. The negative meniscus lens 12E and the positive meniscus lens 13E are cemented together.

The second lens group (n-th lens group) G2E is composed of, in order from the object side, a biconcave negative lens 21E, a positive meniscus lens 22E convex to the object side, and a negative meniscus lens 23E convex to the image side. The biconcave negative lens 21E and the positive meniscus lens 22E are cemented together.

≪Positive, negative, and positive 3-group zoom lens system≫
In Numerical Examples 10-12, the zoom lens system of the present embodiment has, in order from the object side, a first lens group G1F with a positive refractive power and a negative It is composed of a second lens group (subsequent lens group, n-th lens group) G2F with refractive power and a third lens group (subsequent lens group) G3F with positive refractive power. The third lens group G3F includes a diaphragm S that moves integrally with the third lens group G3F. I is the image plane.

During zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), each lens group behaves as follows.
The first lens group G1F and the third lens group G3F move monotonically toward the object side through Numerical Examples 10-12 (FIGS. 80-82).
In Numerical Examples 10 and 11, the second lens group G2F once moves to the object side and then returns to the image side (FIGS. 80 and 81). Go back (Fig. 82).
As a result, the distance between the first lens group G1F and the second lens group G2F increases, and the distance between the second lens group G2F and the third lens group G3F decreases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinity object to a close object is performed by moving the second lens group G2F toward the object side (the second lens group G2F constitutes a focus lens group).

The first lens group G1F is composed of, in order from the object side, a positive meniscus lens 11F convex to the object side, a negative meniscus lens 12F convex to the object side, and a positive meniscus lens 13F convex to the object side. The negative meniscus lens 12F and the positive meniscus lens 13F are cemented together.

The second lens group (n-th lens group) G2F is composed of, in order from the object side, a biconcave negative lens 21F, a positive meniscus lens 22F convex to the object side, and a biconcave negative lens 23F. The biconcave negative lens 21F and the positive meniscus lens 22F are cemented together.

≪Positive, negative, negative, positive, 4-group zoom lens system≫
In Numerical Examples 13 and 14, the zoom lens system of this embodiment has, in order from the object side, a first lens group G1G with positive refractive power and a The second lens group (subsequent lens group, n-th lens group) G2G, the third lens group (subsequent lens group) G3G with negative refractive power, and the fourth lens group (subsequent lens group) G4G with positive refractive power consists of The fourth lens group G4G includes a diaphragm S that moves integrally with the fourth lens group G4G. I is the image plane.

When zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the first lens group G1G and the fourth lens group G4G are fixed with respect to the image plane I (not moved in the optical axis direction). ), the second lens group G2G and the third lens group G3G monotonously move toward the image side.
As a result, the distance between the first lens group G1G and the second lens group G2G increases, the distance between the second lens group G2G and the third lens group G3G decreases, and the distance between the third lens group G3G and the fourth lens group G4G increases. decreases.
There is a degree of freedom in the behavior of each lens group during zooming, and various design changes are possible.

Focusing from an infinity object to a close object is performed by moving the first lens group G1G toward the object side (the first lens group G1G constitutes a focus lens group).

The first lens group G1G includes, in order from the object side, a positive meniscus lens 11G convex to the object side, a negative meniscus lens 12G convex to the object side, a positive meniscus lens 13G convex to the object side, and a convex meniscus lens 13G to the object side. and a positive meniscus lens 14G. The negative meniscus lens 12G and the positive meniscus lens 13G are cemented together.

The second lens group (n-th lens group) G2G is composed of, in order from the object side, a biconcave negative lens 21G, a biconvex positive lens 22G, and a biconcave negative lens 23G. The biconcave negative lens 21G and the positive meniscus lens 22G are not cemented in Numerical Example 13, but are cemented in Numerical Example 14.

<<Zoom lens system of the present embodiment summarizing all numerical examples 1-14>>
The zoom lens system of this embodiment comprises, in order from the object side, a first lens group (G1A to G1G) with positive refractive power, and subsequent lens groups (G2A to G4A, G2B to G5B, G2C-G5C, G2D-G5D, G2E-G6E, G2F-G3F, G2G-G4G), the so-called positive lead type zoom lens system has spherical aberration, coma, astigmatism, chromatic aberration, etc. over the entire zoom range. By satisfactorily correcting various aberrations, it is possible to improve optical performance.

Generally, in a zoom lens system, the entrance pupil diameter increases toward the telephoto end. In particular, the first lens group closest to the object side has the largest entrance pupil diameter. I am improving the configuration.

More specifically, the first lens group (G1A to G1G) includes, in order from the object side, one or more positive lenses (11A, 11A' and 12A', 11B, 11C, 11D, 11E, 11F, and 11G), A negative meniscus lens (12A, 13A', 12B, 12C, 12D, 12E, 12F, 12G) with a convex surface facing the object side and one or more positive lenses (13A, 14A', 13B, 13C, 13D, 13E, 13F, 13G and 14G).

By arranging the positive single lens (11A, 11A', 11B, 11C, 11D, 11E, 11F, 11G) closest to the object side in the first lens group, the largest entrance pupil diameter is efficiently converged, It is possible to reduce the burden of aberration correction by the succeeding lens in one lens group. If a negative lens is placed closest to the object side in the first lens group, the incident light diverges and the luminous flux entering the succeeding lens in the first lens group becomes even larger. The burden of aberration correction becomes excessive. If the positive lens closest to the object in the first lens group is a cemented lens cemented with a negative lens, the positive power of the cemented lens as a whole is weakened and the convergence effect is reduced. The power of the lens becomes strong, and spherical aberration and coma aberration occur in the cemented lens alone.

It is also possible to arrange a plurality of positive single lenses in the first lens group in order from the most object side. This makes it possible to reduce the aberration correction burden of each positive single lens (share the burden of aberration correction), obtain a higher aberration correction effect, and further reduce the f-number on the telephoto side. (to brighten) becomes possible.

One or more positive single lenses located closest to the object side in the first lens group, followed by negative meniscus lenses (12A, 13A', 12B, 12C, 12D, 12E, 12F, 12G) with convex surfaces facing the object side. ) are placed. By giving this negative meniscus lens a strong negative power to some extent, it is possible to satisfactorily correct spherical aberration, coma aberration, chromatic aberration, and the like. If a negative meniscus lens with a flat or concave surface facing the object side is used in place of this negative meniscus lens, the difference between the normal to the surface and the incident angle of light rays will increase, resulting in large aberrations. In particular, off-axis aberrations (coma, astigmatism, and chromatic aberration of magnification) become difficult to correct with subsequent lenses in the first lens group.

The negative meniscus lens in the first lens group is followed by one or more positive lenses (13A, 14A', 13B, 13C, 13D, 13E, 13F, 13G and 14G). Since the negative meniscus lens must have a certain degree of strong negative power for aberration correction, spherical aberration and coma aberration may occur on the image-side concave surface of the negative meniscus lens. One or more positive lenses following the negative meniscus lens have the role of correcting this spherical aberration and coma.

Here, the performance may be degraded due to relative eccentricity between the image-side surface of the negative meniscus lens and the object-side surface of the positive lens immediately behind it. Therefore, by cementing the image-side surface of the negative meniscus lens and the object-side surface of the positive lens immediately behind it, it is possible to reduce the deterioration in performance caused by manufacturing errors. If the image-side surface of the negative meniscus lens and the object-side surface of the positive lens immediately after it are not cemented, a certain amount of air space should be provided between the two lenses (both surfaces), and the curvature radii of both lenses (both surfaces) should be different. By attaching the , it can be used as an air lens to correct spherical aberration and coma. In this case, it is possible to reduce manufacturing errors by inserting a spacing ring between both lenses (both surfaces), or by fixing with a frame such that one chamfered portion is brought into contact with the other surface.

The positive lens arranged in the first lens group preferably has a positive meniscus shape with a convex surface facing the object side. This makes it possible to reduce the difference between the normal to the surface and the incident angle of the ray, thereby suppressing the occurrence of aberration. Since the first lens group as a whole has a positive power, if the focus is only on shortening the overall lens length, the image-side surface of the positive lens in the first lens group should be increased to increase the power of the positive lens. is designed to be a convex surface (biconvex lens). However, in this case, the angle difference between the normal to the surface and the incident angle of the light ray becomes large, resulting in large aberration.

The first lens group is composed of, in order from the object side, a positive lens, a negative meniscus lens with a convex surface facing the object side, and a positive lens. The center is sandwiched between the two positive lenses on both sides, resulting in a symmetrical arrangement, which makes it possible to reduce the thickness (group thickness) of the first lens group with a small number of lenses and to achieve both good aberration correction.

If the first lens group were to be fixed during zooming, the diameter of the first lens group (front lens diameter) would increase in order to allow off-axis light to enter at the short focal length extremity, resulting in off-axis coma and other aberrations. tend to As in the present embodiment, by moving (extending) the first lens group toward the object side during zooming, the outer diameter (front lens diameter) of the first lens group can be suppressed and the size can be reduced. Excellent optical performance can be achieved by suppressing coma aberration and the like.

The subsequent lens group following the first lens group includes at least one negative refractive power lens group. is defined as the "nth lens group". By changing the distance between the n-th lens group having negative refractive power and the lens groups arranged in front and behind it, it is possible to obtain a relatively large zoom ratio. Also, for example, when a zoom lens system is applied to an interchangeable lens type camera system, the back focus tends to be insufficient on the wide-angle side where the focal length is short. Optimal setting makes it possible to secure the back focus and improve the optical performance at the same time.

By arranging the negative lens closest to the object side in the n-th lens group with negative refractive power, it is possible to effectively secure the back focus. The image side surface of the negative lens closest to the object side in the n-th lens group preferably has a concave surface facing the image side (in other words, a convex surface facing the object side). In the n-th lens group with negative refractive power, the diameter of the entrance pupil is smaller than that of the first lens group. Since the divergence between the normal line and the incident angle of the light ray can be made small and the curvature can be strong to some extent, it is possible to both correct the aberration and secure the back focus.

By arranging the positive lens following the negative lens closest to the object side in the n-th lens group with negative refractive power, coma aberration and chromatic aberration of magnification on the wide-angle side, spherical aberration on the telephoto side, and even over the entire zoom range. Longitudinal chromatic aberration can be satisfactorily corrected. By cementing the most object-side negative lens in the n-th lens group with negative refractive power and the following positive lens, spherical aberration of each wavelength can be easily uniformed on the telephoto side.

As the zoom ratio increases, and in particular the focal length on the wide-angle side increases, it becomes necessary to provide a further negative lens in the n-th lens group in order to increase the negative power of the n-th lens group. Therefore, it is preferable to provide not only (in addition to) the negative lens closest to the object side in the n-th lens group but also the negative lens closest to the image side in the n-th lens group. Since the light incident on this most image side negative lens is divergent light, it is preferable that this most image side negative lens have a concave surface facing the object side. This makes it possible to suppress variations in coma and astigmatism over the entire zoom range even when the zoom ratio is increased.

The n-th lens group having negative refractive power is composed of, in order from the object side, a cemented lens of a negative lens having a cemented surface with a convex surface facing the object side and a positive lens, and a negative lens. , The n-th lens group has a symmetrical arrangement in which the positive lens in the center is sandwiched between two negative lenses on both sides. can be compatible.

Conditional expressions (1) and (1') define the ratio between the focal length of the first lens group and the focal length of the negative meniscus lens in the first lens group. By satisfying conditional expression (1), spherical aberration, coma, and chromatic aberration can be satisfactorily corrected. Furthermore, by satisfying conditional expression (1'), in addition to the above effects, spherical aberration, coma, astigmatism, and chromatic aberration can be corrected well over the entire zoom range.
If the upper limits of conditional expressions (1) and (1') are exceeded, the power of the negative meniscus lens in the first lens group becomes too weak, making it difficult to correct spherical aberration, coma and chromatic aberration.
If the lower limit of conditional expression (1') is exceeded, the power of the negative meniscus lens in the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, astigmatism, and chromatic aberration over the entire zoom range. end up

Conditional expressions (2) and (2') define the average Abbe number for the d-line of the positive lens in the first lens group. By satisfying the conditional expression (2), axial chromatic aberration on the telephoto side and lateral chromatic aberration over the entire zoom range can be satisfactorily corrected. In addition, variations in spherical aberration, coma, and astigmatism during zooming can be reduced. This effect can be obtained more significantly by satisfying the conditional expression (2').
If the lower limit of conditional expression (2) is not reached, it becomes difficult to correct axial chromatic aberration on the telephoto side and lateral chromatic aberration over the entire zoom range. If chromatic aberration is to be corrected below the lower limit of conditional expression (2), the power of each lens in the first lens group must be excessively increased, resulting in spherical aberration, coma, Variation in astigmatism becomes large.

Conditional expressions (3) and (3′) define the ratio between the focal length of the first lens group and the focal length of the n-th lens group with negative refractive power located closest to the object side among the subsequent lens groups. ing. Spherical aberration, coma, astigmatism, and chromatic aberration can be satisfactorily corrected by satisfying conditional expression (3). Furthermore, by satisfying conditional expression (3'), in addition to the above effects, the amount of zooming movement of the first lens group is suppressed to reduce the size of the lens system, and off-axis coma aberration, astigmatism, It is possible to satisfactorily correct lateral chromatic aberration.
If the upper limits of conditional expressions (3) and (3') are exceeded, the power of the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, astigmatism, and chromatic aberration.
If the lower limit of conditional expression (3') is not reached, the power of the first lens group becomes too weak, and the amount of zooming movement of the first lens group increases. As a result, the overall length of the lens increases, and the first lens group must be made radially large to allow off-axis light to pass through (increasing the diameter of the front lens is unavoidable). Astigmatism and lateral chromatic aberration worsen.

Conditional expressions (4) and (4') define the refractive index for the d-line of the negative meniscus lens in the first lens group. By satisfying conditional expression (4), spherical aberration, coma, astigmatism, and chromatic aberration can be satisfactorily corrected over the entire zoom range. Furthermore, by satisfying conditional expression (4'), in addition to the above effects, spherical aberration, coma aberration, longitudinal chromatic aberration, and lateral chromatic aberration can be corrected favorably.
If the lower limits of conditional expressions (4) and (4') are exceeded, the curvature of the image-side concave surface of the negative meniscus lens in the first lens group becomes too strong, resulting in spherical aberration, coma, and astigmatism over the entire zoom range. It becomes difficult to correct aberrations and chromatic aberrations.
If the upper limit of conditional expression (4') is exceeded, the difference in refractive index between the negative meniscus lens in the first lens group and the positive lens located immediately behind it on the image side will become too large, causing spherical aberration and coma. Aberration correction becomes difficult. If the refractive index of the positive lens positioned immediately after the image side of the negative meniscus lens in the first lens group is increased in order to reduce the difference in refractive index, a high-dispersion material will be selected, which reduces longitudinal chromatic aberration. and correction of chromatic aberration of magnification becomes difficult.

Conditional expression (5) defines the ratio between the focal length of the first lens group and the paraxial radius of curvature of the surface of the first lens group closest to the object side. By satisfying conditional expression (5), spherical aberration, coma, astigmatism, and chromatic aberration of magnification can be satisfactorily corrected.
If the upper limit of conditional expression (5) is exceeded, the curvature of the surface closest to the object side of the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, and astigmatism over the entire zoom range. .
If the lower limit of conditional expression (5) is not reached, the curvature of the object-side surface of the lens closest to the object in the first lens group becomes weak. The curvature must be strong, and as a result, it becomes difficult to correct spherical aberration, coma and astigmatism.

Conditional expressions (6) and (6') define the shape (shaping factor) of the negative meniscus lens in the first lens group. By satisfying the conditional expression (6), the angle formed by the incident ray of the off-axis light beam and the surface normal can be reduced, and coma, astigmatism, and lateral chromatic aberration can be satisfactorily corrected. Furthermore, by satisfying conditional expression (6'), in addition to the above effects, spherical aberration, coma, astigmatism, and chromatic aberration can be corrected satisfactorily over the entire zoom range.
If the lower limits of conditional expressions (6) and (6') are exceeded, the object-side surface of the negative lens in the first lens group becomes flat or concave, and the angle formed by the incident ray of the off-axis light beam and the normal to the surface becomes growing. As a result, it becomes difficult to correct coma, astigmatism, and lateral chromatic aberration.
If the upper limit of conditional expression (6') is exceeded, the image-side surface of the negative meniscus lens in the first lens group becomes a concave surface with a strong curvature, reducing spherical aberration, coma, astigmatism, and chromatic aberration over the entire zoom range. Correction becomes difficult.

Conditional expressions (7) and (7′) are defined by the focal length of the n-th lens group with negative refractive power located closest to the object side in the succeeding lens group and the negative lens closest to the object side in this n-th lens group. to the paraxial radius of curvature of the image-side surface. By satisfying conditional expression (7), coma aberration mainly on the telephoto side can be satisfactorily corrected. Furthermore, by satisfying the conditional expression (7'), in addition to the above effects, it is possible to suppress fluctuations in curvature of field during zooming.
If the upper limits of conditional expressions (7) and (7') are exceeded, the curvature of the image side surface of the negative lens closest to the object side in the n-th lens group becomes too weak and the object side surface becomes a concave surface with a strong curvature. As a result, it becomes difficult to correct coma aberration mainly on the telephoto side.
If the lower limit of conditional expression (7') is not reached, the curvature of the image-side surface of the negative lens closest to the object in the n-th lens group becomes too strong, resulting in large fluctuations in curvature of field during zooming. .

Conditional expressions (8) and (8′) define the Abbe number for the d-line of the negative lens closest to the image side in the n-th lens group. By satisfying conditional expression (8), it is possible to satisfactorily correct lateral chromatic aberration over the entire zoom range, mainly axial chromatic aberration on the telephoto side. This effect can be obtained more significantly by satisfying the conditional expression (8').
If the lower limit of conditional expression (8) is not reached, it becomes difficult to correct lateral chromatic aberration over the entire zoom range, mainly axial chromatic aberration on the telephoto side.

Conditional expression (9) is a relation to be satisfied between the Abbe number for the d-line of the negative meniscus lens in the first lens group and the partial dispersion ratio on the short wavelength side (from the g-line to the F-line) (anomalous dispersion of the negative meniscus lens ). By satisfying conditional expression (9), the anomalous dispersion of the negative meniscus lens in the first lens group is optimally set, and the secondary spectrum of axial chromatic aberration can be suppressed.
If the conditional expression (9) is not satisfied, a glass material with high anomalous dispersion is used for the negative meniscus lens in the first lens group, which increases the secondary spectrum of axial chromatic aberration.

Conditional expressions (10) and (10') define the Abbe number for the d-line of the negative meniscus lens in the first lens group. By satisfying the conditional expression (10), longitudinal chromatic aberration and lateral chromatic aberration can be satisfactorily corrected. Furthermore, by satisfying conditional expression (10'), in addition to the above effect, fluctuations in spherical aberration, coma, and astigmatism during zooming can be suppressed.
If the lower limits of conditional expressions (10) and (10') are not reached, longitudinal chromatic aberration and lateral chromatic aberration will be overcorrected.
If the upper limit of conditional expression (10') is exceeded, longitudinal chromatic aberration and lateral chromatic aberration will be undercorrected. If chromatic aberration is to be corrected while the upper limit of conditional expression (10') is exceeded, the power of each lens in the first lens group becomes stronger (must be strengthened), resulting in spherical aberration and coma during zooming. , the fluctuation of astigmatism becomes large.

Conditional expressions (11) and (11') define the ratio between the focal length of the first lens group and the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group. By satisfying the conditional expression (11), it is possible to simultaneously correct spherical aberration, coma aberration, and chromatic aberration that the negative meniscus lens bears. This effect can be obtained more significantly by satisfying the conditional expression (11'). Furthermore, by satisfying the conditional expression (11′), in addition to the above effects, spherical aberration and coma generated on the image-side concave surface of the negative meniscus lens can be well corrected.
If the lower limit of conditional expression (11) is exceeded, the radius of curvature of the image-side concave surface of the negative meniscus lens in the first lens group becomes too large, and as a result, the power of the negative meniscus lens becomes weak. It becomes difficult to simultaneously correct spherical aberration, coma, and chromatic aberration.
If the upper limit of conditional expression (11′) is exceeded, the curvature of the image-side concave surface of the negative meniscus lens in the first lens group becomes too strong, and correction of spherical aberration and coma generated on this image-side concave surface becomes difficult. It becomes difficult.

Conditional expression (12) defines the relationship between the focal length of the first lens group and the distance on the optical axis from the surface closest to the object side to the surface closest to the image side of the first lens group (group thickness of the first lens group). It defines the ratio. By satisfying conditional expression (12), the size of the first lens group and thus the entire lens system can be reduced (the total length of the lens can be shortened), and spherical aberration, coma, astigmatism, and chromatic aberration (magnification chromatic aberration) can be reduced. can be corrected.
If the upper limit of conditional expression (12) is exceeded, the power of the first lens group becomes too weak, and the amount of zooming movement (extending amount) of the first lens group increases. As a result, the overall length of the lens increases, and the first lens group must be enlarged in the radial direction to allow off-axis light to pass through (increasing the diameter of the front lens is unavoidable). Astigmatism and lateral chromatic aberration worsen.
If the lower limit of conditional expression (12) is not reached, the power of the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, astigmatism, and chromatic aberration. Alternatively, the size of the first lens group and thus the entire lens system is increased (the total length of the lens is increased).

Conditional expressions (13), (13′) and (13″) define the ratio of the focal length of the first lens group to the focal length of the entire system at the short focal length extremity. Conditional expression (13) Spherical aberration, coma, astigmatism, and chromatic aberration can be satisfactorily corrected by satisfying conditional expression (13′), and in addition to the above effects, The lens system can be made compact by suppressing the amount of zooming movement, and off-axis coma, astigmatism, and chromatic aberration of magnification can be well corrected. can be obtained more remarkably by satisfying
If the lower limit of conditional expression (13) is not reached, the power of the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, astigmatism, and chromatic aberration.
If the upper limit of conditional expression (13') is exceeded, the power of the first lens group will become too weak, and the amount of zooming movement (extending amount) of the first lens group will increase. As a result, the overall length of the lens increases, and the first lens group must be enlarged in the radial direction to allow off-axis light to pass through (increasing the diameter of the front lens is unavoidable). Astigmatism and lateral chromatic aberration worsen.

Conditional expressions (14), (14′) and (14″) determine the focal length of the first lens group, the focal length of the entire system at the short focal length extremity, and the focal length of the entire system at the long focal length extremity. By satisfying conditional expression (14), spherical aberration, coma, astigmatism, and chromatic aberration can be satisfactorily corrected, and by satisfying conditional expression (14'). In addition to the effects described above, it is possible to reduce the size of the lens system by suppressing the amount of movement of the first lens group for zooming, and to satisfactorily correct off-axis coma, astigmatism, and chromatic aberration of magnification. Additional effects can be obtained more remarkably by satisfying conditional expression (14'').
If the lower limit of conditional expression (14) is not reached, the power of the first lens group becomes too strong, making it difficult to correct spherical aberration, coma, astigmatism, and chromatic aberration.
If the upper limit of conditional expression (14') is exceeded, the power of the first lens group will become too weak, and the amount of zooming movement (extending amount) of the first lens group will increase. As a result, the overall length of the lens increases, and the first lens group must be enlarged in the radial direction to allow off-axis light to pass through (increasing the diameter of the front lens is unavoidable). Astigmatism and lateral chromatic aberration worsen.

Specific Numerical Examples 1-14 are shown below. In the various aberration diagrams and lateral aberration diagrams and in the tables, d-line, g-line, and C-line are aberrations for each wavelength, S is sagittal, M is meridional, FNO. is the half angle of view (°), Y is the image height, fB is the back focus, L is the total lens length, R is the radius of curvature, d is the lens thickness or lens spacing, N(d) is the refractive index for the d-line, ν(d) is the Abbe number for the d-line, and fn is the first lens group. θgFn, the focal length of the negative meniscus lens in the first lens group, indicates the partial dispersion ratio on the short wavelength side of the negative meniscus lens in the first lens group. The back focus is the distance from the surface closest to the image side of the entire lens system to the image plane I (FIGS. 71 to 84). F-number, focal length, half angle of view, image height, back focus, total lens length, and lens spacing d, which changes with zooming, are shown in the order short focal length end - middle focal length - long focal length end. there is The unit of length is [mm]. No aspheric lenses are used throughout all Numerical Examples 1-14. However, it is also possible to obtain the effect of aberration correction by using an aspherical surface or a diffractive surface in any part of the optical system.

[Numerical Example 1]
1 to 5 and Tables 1 to 4 show Numerical Example 1 of the zoom lens system according to the present invention. Figure 1 is a lens configuration diagram when focusing on infinity at the short focal length extremity. Aberration diagrams and lateral aberration diagrams, FIGS. 4A to 4D and FIGS. 5A to 5D are various aberration diagrams and lateral aberration diagrams when focusing on infinity at the long focal length extremity. Table 1 is surface data, Table 2 is various data when focusing on a subject at infinity (magnification = 0), Table 3 is lens group data, and Table 4 is when focusing on a subject at a finite distance. Various data.

The zoom lens system of Numerical Example 1 comprises, in order from the object side, a first lens group G1A with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2A with negative refractive power, It is composed of a third lens group (subsequent lens group) G3A with positive refractive power and a fourth lens group (subsequent lens group) G4A with negative refractive power. The third lens group G3A includes a diaphragm S that moves integrally with the third lens group G3A.

The first lens group G1A consists of, in order from the object side, a positive meniscus lens 11A convex to the object side, a negative meniscus lens 12A convex to the object side, and a positive meniscus lens 13A convex to the object side. The negative meniscus lens 12A and the positive meniscus lens 13A are cemented together.

The second lens group G2A consists of, in order from the object side, a biconcave negative lens 21A, a positive meniscus lens 22A convex to the object side, and a biconcave negative lens 23A. The biconcave negative lens 21A and the positive meniscus lens 22A are cemented together.

The third lens group G3A includes, in order from the object side, a biconvex positive lens 31A, a biconvex positive lens 32A, a biconcave negative lens 33A, a diaphragm S, a negative meniscus lens 34A convex to the object side, and a biconvex lens. It consists of a positive lens 35A and a positive meniscus lens 36A convex to the object side. The biconvex positive lens 32A and the biconcave negative lens 33A are cemented together.

The fourth lens group G4A is composed of, in order from the object side, a positive meniscus lens 41A convex to the image side and a biconcave negative lens 42A.

(Table 1)
Surface data surface number R d N(d) ν(d)
1 66.223 5.940 1.51633 64.14
2 990.033 0.150
3 119.740 1.700 1.78590 44.20
4 41.913 8.270 1.48749 70.24
5 533.575 d5
6 -200.863 1.200 1.79952 42.22
7 20.538 2.960 1.84666 23.78
8 77.368 2.101
9 -49.938 1.100 1.80400 46.58
10 3743.504 d10
11 74.271 3.220 1.72916 54.68
12 -101.460 0.200
13 33.328 4.920 1.49700 81.55
14 -58.601 1.200 1.80610 33.27
15 97.682 2.700
16 stops ∞ 15.026
17 78.451 1.100 1.80610 33.27
18 30.401 1.242
19 67.476 4.540 1.58913 61.13
20 -67.476 0.200
21 26.356 3.730 1.58313 59.37
22 200.093 d22
23 -225.082 2.110 1.78472 25.68
24 -47.838 1.968
25 -44.791 1.000 1.69680 55.53
26 29.861 -
fn: -82.849
θgFn: 0.5631
(Table 2)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.15
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 5.14 6.48
f 56.500 132.085 291.188
W 14.5 6.0 2.7
Y 14.24 14.24 14.24
fB 52.474 57.967 81.814
L 163.502 201.850 233.845
d5 2.392 53.371 79.101
d10 39.049 18.199 3.044
d22 3.010 5.736 3.310
(Table 3)
Lens group data group Starting surface Focal length
1 1 166.473
2 (successor, n) 6 -33.874
3 (subsequent) 11 35.379
4 (subsequent) 23 -39.835
(Table 4)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.012 -0.027 -0.058
d5 2.392 53.371 79.101
d10 39.049 18.199 3.044
d22 3.163 6.455 5.408
fB 52.321 57.248 79.716
Object-image distance 1500.0 1500.0 1500.0
Magnification -0.041 -0.090 -0.191
d5 2.392 53.371 79.101
d10 39.049 18.199 3.044
d22 3.553 8.216 10.562
fB 51.931 55.487 74.562

[Numerical Example 2]
6 to 10 and Tables 5 to 8 show Numerical Example 2 of the zoom lens system according to the present invention. Fig. 6 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 7 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 9A to 9D and FIGS. 10A to 10D are various aberration diagrams and lateral aberration diagrams when focusing on infinity at the long focal length extremity. Table 5 is surface data, Table 6 is various data when focusing on a subject at infinity (magnification = 0), Table 7 is lens group data, and Table 8 is when focusing on a subject at a finite distance. Various data.

The lens configuration of Numerical Example 2 is the same as the lens configuration of Numerical Example 1 except for the following points.
(1) The negative lens 23A of the second lens group G2A is a negative meniscus lens convex to the image side.

(Table 5)
Surface data surface number R d N(d) ν(d)
1 61.393 6.401 1.51633 64.14
2 902.173 0.150
3 95.930 1.700 1.77250 49.60
4 36.721 8.600 1.49700 81.55
5 141.796 d5
6 -177.869 1.200 1.77250 49.60
7 29.098 3.290 1.84666 23.78
8 86.418 2.000
9 -62.371 1.100 1.75700 47.82
10-2093.121 d10
11 99.539 3.220 1.77250 49.60
12 -149.308 0.200
13 36.913 4.920 1.43875 94.94
14 -59.665 1.200 1.85026 32.27
15 214.161 2.700
16 stops ∞ 14.600
17 53.687 1.100 1.80610 33.27
18 31.115 1.020
19 75.699 4.540 1.48749 70.24
20 -52.963 0.200
21 25.649 3.730 1.51633 64.14
22 367.504 d22
23 -151.738 2.110 1.78472 25.68
24 -43.324 1.970
25 -41.608 1.000 1.69680 55.53
26 27.738 -
fn: -77.992
θgFn: 0.5520
(Table 6)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.15
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 5.21 6.30
f 56.475 131.498 291.112
W 14.6 6.1 2.7
Y 14.24 14.24 14.24
fB 52.790 60.197 80.531
L 180.222 209.742 239.581
d5 2.392 53.073 85.419
d10 53.667 23.179 3.000
d22 4.422 6.342 3.681
(Table 7)
Lens group data group Starting surface Focal length
1 1 186.993
2 (successor, n) 6 -42.087
3 (subsequent) 11 35.447
4 (subsequent) 23 -35.658
(Table 8)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.012 -0.026 -0.058
d5 2.392 53.073 85.419
d10 53.667 23.179 3.000
d22 4.551 6.913 5.480
fB 52.661 59.626 78.732
Object-image distance 1500.0 1500.0 1500.0
Magnification -0.041 -0.090 -0.188
d5 2.392 53.073 85.419
d10 53.667 23.179 3.000
d22 4.881 8.309 9.804
fB 52.330 58.230 74.408

[Numerical Example 3]
11 to 15 and Tables 9 to 12 show Numerical Example 3 of the zoom lens system according to the present invention. Fig. 11 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 12 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 14A to 14D and FIGS. 15A to 15D are various aberration diagrams and lateral aberration diagrams when focusing on infinity at the long focal length extremity. Table 9 is surface data, Table 10 is various data when focusing on an object at infinity (magnification = 0), Table 11 is lens group data, and Table 12 is when focusing on a finite distance object. Various data.

The lens configuration of Numerical Example 3 is the same as the lens configuration of Numerical Example 1 except for the following points.
(1) The negative meniscus lens 12A and the positive meniscus lens 13A of the first lens group G1A are not cemented.

(Table 9)
Surface data surface number R d N(d) ν(d)
1 72.233 5.940 1.56384 60.67
2 2154.156 0.150
3 198.530 1.695 1.65412 39.68
4 53.924 1.018
5 64.003 6.793 1.48749 70.24
6 351.929 d6
7 -122.680 1.200 1.72000 41.98
8 23.598 3.290 1.84666 23.78
9 145.444 2.000
10 -85.911 1.100 1.83400 37.16
11 104.904 d11
12 85.156 3.220 1.60311 60.64
13 -100.708 0.200
14 31.321 4.920 1.43875 94.94
15 -69.807 1.200 1.80610 33.27
16 264.365 2.700
17 stop ∞ 15.347
18 63.407 1.100 1.80610 33.27
19 28.316 1.524
20 196.667 4.540 1.58913 61.13
21 -70.259 0.200
22 27.416 3.730 1.58313 59.37
23 149.019 d23
24 -1112.327 2.110 1.78472 25.68
25 -59.735 1.970
26 -53.548 1.000 1.69680 55.53
27 38.046 -
fn: -113.707
θgFn: 0.5737
(Table 10)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.14
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 4.96 6.52
f 56.497 105.725 290.400
W 14.6 7.6 2.8
Y 14.24 14.24 14.24
fB 49.997 49.721 81.617
L 169.218 197.275 247.917
d6 2.400 46.685 93.054
d11 45.623 23.956 3.000
d23 5.252 9.966 3.300
(Table 11)
Lens group data group Starting surface Focal length
1 1 194.587
2 (successor, n) 7 -41.025
3 (subsequent) 12 40.075
4 (subsequent) 24 -55.109
(Table 12)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.012 -0.021 -0.058
d6 2.400 46.685 93.054
d11 45.623 23.956 3.000
d23 5.517 10.870 6.742
fB 48.732 48.817 78.175
Object-image distance 1500.0 1500.0 1500.0
Magnification -0.041 -0.073 -0.190
d6 2.400 46.685 93.054
d11 45.623 23.956 3.000
d23 6.194 13.155 15.603
fB 48.055 46.532 69.314

[Numerical Example 4]
16 to 20 and Tables 13 to 16 show Numerical Example 4 of the zoom lens system according to the present invention. Fig. 16 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 17 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 19A to 19D and FIGS. 20A to 20D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 13 is surface data, Table 14 is various data when focusing on an object at infinity (magnification = 0), Table 15 is lens group data, and Table 16 is when focusing on a finite distance object. Various data.

The lens configuration of Numerical Example 4 is the same as the lens configuration of Numerical Example 1 except for the following points.
(1) The second lens group G2A comprises, in order from the object side, a biconcave negative lens 21A', a biconvex positive lens 22A', a negative meniscus lens 23A' convex to the image side, and a biconvex positive lens 24A'. , a biconvex positive lens 25A' and a biconcave negative lens 26A'. The biconcave negative lens 21A' and the biconvex positive lens 22A' are cemented together, and the biconvex positive lens 25A' and the biconcave negative lens 26A' are cemented together.
(2) The third lens group G3A includes, in order from the object side, a biconvex positive lens 31A', a biconvex positive lens 32A', a negative meniscus lens 33A' convex to the image side, and a biconvex positive lens 34A'. consists of The biconvex positive lens 32A' and the negative meniscus lens 33A' are cemented together.

(Table 13)
Surface data surface number R d N(d) ν(d)
1 70.162 6.719 1.48749 70.24
2 1062.964 0.150
3 72.242 1.700 1.79952 42.22
4 40.808 7.950 1.49700 81.55
5 95.931 d5
6 -99.283 1.100 1.65412 39.68
7 46.676 3.671 1.84666 23.78
8 -227.495 1.850
9 -45.478 1.100 1.74400 44.79
10 -130.368 4.240
11 1010.844 3.020 1.69680 55.53
12 -57.629 0.200
13 47.198 4.388 1.58913 61.13
14 -554.056 1.120 1.90366 31.31
15 39.442 d15
16 stops ∞ 9.970
17 1476.750 2.844 1.49700 81.55
18 -113.772 1.000
19 2490.306 5.600 1.58913 61.13
20 -27.109 1.000 1.74950 35.33
21 -601.561 0.500
22 149.878 3.977 1.80440 39.58
23 -66.211 d23
24 -65.900 1.840 1.80518 25.43
25 -34.671 1.160
26 -33.551 0.800 1.61800 63.33
27 52.978 -
fn: -120.191
θgFn: 0.5672
(Table 14)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 2.35
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 5.10 6.03
f 123.700 199.066 290.532
W 6.5 4.0 2.8
Y 14.24 14.24 14.24
fB 37.599 59.674 90.719
L 159.21 197.42 234.86
d5 8.870 51.240 68.920
d15 18.930 7.360 6.820
d23 27.910 13.250 2.500
(Table 15)
Lens group data group Starting surface Focal length
1 1 181.463
2 (subsequent, n) 6 -164.680
3 (subsequent) 17 57.648
4 (subsequent) 24 -53.157
(Table 16)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.025 -0.040 -0.059
d5 8.870 51.240 68.920
d15 18.930 7.360 6.820
d23 29.564 15.585 5.254
fB 35.945 57.339 87.965
Object-image distance 3000.0 3000.0 3000.0
Magnification -0.042 -0.067 -0.099
d5 8.870 51.240 68.920
d15 18.930 7.360 6.820
d23 30.745 17.241 7.197
fB 34.764 55.683 86.022

[Numerical Example 5]
21 to 25 and Tables 17 to 20 show Numerical Example 5 of the zoom lens system according to the present invention. Fig. 21 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 22 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 24A to 24D and FIGS. 25A to 25D are various aberration diagrams and lateral aberration diagrams when focusing on infinity at the long focal length extremity. Table 17 is surface data, Table 18 is various data when the subject is focused at infinity (magnification=0), Table 19 is lens group data, and Table 20 is when the subject is focused at a finite distance. Various data.

The lens configuration of Numerical Example 5 is the same as the lens configuration of Numerical Example 1 except for the following points.
(1) The first lens group G1A includes, in order from the object side, a biconvex positive lens 11A', a positive meniscus lens 12A' convex to the object side, a negative meniscus lens 13A' convex to the object side, and a and a convex positive meniscus lens 14A'. The negative meniscus lens 13A' and the positive meniscus lens 14A' are cemented together.
(2) The second lens group G2A includes, in order from the object side, a biconcave negative lens 21A″, a positive meniscus lens 22A″ convex to the object side, a negative biconcave lens 23A″, and a negative meniscus convex to the image side. lens 24A''. The biconcave negative lens 21A'' and the positive meniscus lens 22A'' are cemented together.
(3) The third lens group G3A includes, in order from the object side, a biconvex positive lens 31A'', a positive meniscus lens 32A'' convex to the object side, a biconcave negative lens 33A'', and a biconvex positive lens 34A''. , a diaphragm S, a negative meniscus lens 35A'' convex to the object side, a positive biconvex lens 36A'', and a positive meniscus lens 37A'' convex to the object side. A biconcave negative lens 33A'' and a biconvex positive lens 34A'' are joined.

(Table 17)
Surface data surface number R d N(d) ν(d)
1 132.862 7.230 1.48749 70.24
2 -708.635 0.150
3 69.897 7.447 1.49700 81.55
4 136.784 0.150
5 92.773 1.695 1.79952 42.22
6 46.408 11.599 1.49700 81.55
7 87.512 d7
8 -520.244 1.200 1.77250 49.60
9 30.265 5.734 1.80518 25.43
10 412.171 1.469
11 -887.405 1.100 1.74400 44.79
12 81.437 2.514
13 -65.497 1.100 1.83400 37.16
14 -371.185 d14
15 86.267 4.495 1.48749 70.24
16 -124.694 0.200
17 42.457 3.989 1.61800 63.33
18 546.797 1.070
19 -142.524 2.500 1.85026 32.27
20 93.572 5.163 1.49700 81.55
21 -452.005 2.700
22 stops ∞ 14.795
23 114.423 1.100 1.80610 33.27
24 38.699 2.064
25 91.308 4.540 1.53775 74.70
26 -71.519 0.200
27 37.686 4.752 1.72916 54.68
28 201.792 d28
29 -223.981 2.110 1.78472 25.68
30 -50.837 1.970
31 -46.569 1.000 1.69680 55.53
32 47.853 -
fn: -118.062
θgFn: 0.5672
(Table 18)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.15
Short focal length end Intermediate focal length Long focal length end
FNO. 3.50 3.68 4.62
f 56.528 132.322 291.175
W 14.7 6.1 2.8
Y 14.24 14.24 14.24
fB 55.633 55.706 80.363
L 225.880 243.399 254.981
d7 2.392 53.073 73.932
d14 70.809 33.953 3.000
d28 3.010 6.631 3.651
(Table 19)
Lens group data group Starting surface Focal length
1 1 189.485
2 (successor, n) 8 -42.969
3 (subsequent) 15 44.318
4 (subsequent) 29 -58.910
(Table 20)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.012 -0.026 -0.057
d7 2.392 53.073 73.932
d14 70.809 33.953 3.000
d28 3.253 7.933 7.497
fB 55.390 54.404 76.517
Object-image distance 3000.0 3000.0 3000.0
Magnification -0.020 -0.044 -0.095
d7 2.392 53.073 73.932
d14 70.809 33.953 3.000
d28 3.423 8.813 10.157
fB 55.220 53.524 73.857

[Numerical Example 6]
26 to 30 and Tables 21 to 24 show Numerical Example 6 of the zoom lens system according to the present invention. Fig. 26 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 27 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 29A to 29D and FIGS. 30A to 30D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 21 is surface data, Table 22 is various data when focusing on an object at infinity (magnification = 0), Table 23 is lens group data, and Table 24 is when focusing on a finite distance object. Various data.

The zoom lens system of Numerical Example 6 comprises, in order from the object side, a first lens group G1B with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2B with negative refractive power, A third lens group (subsequent lens group) G3B with negative refractive power, a fourth lens group (subsequent lens group) G4B with positive refractive power, and a fifth lens group (subsequent lens group) G5B with negative refractive power. consists of The third lens group G3B includes a diaphragm S that moves integrally with the third lens group G3B.

The first lens group G1B is composed of, in order from the object side, a positive meniscus lens 11B convex to the object side, a negative meniscus lens 12B convex to the object side, and a positive meniscus lens 13B convex to the object side. The negative meniscus lens 12B and the positive meniscus lens 13B are cemented together.

The second lens group G2B consists of, in order from the object side, a biconcave negative lens 21B, a biconvex positive lens 22B, and a negative meniscus lens 23B convex to the image side. The biconcave negative lens 21B and the biconvex positive lens 22B are cemented together.

The third lens group G3B includes, in order from the object side, a biconvex positive lens 31B, a negative meniscus lens 32B convex to the object side, a positive meniscus lens 33B convex to the object side, an aperture stop S, and a biconvex positive lens 34B. and a biconcave negative lens 35B. The biconvex positive lens 34B and the biconcave negative lens 35B are cemented together.

The fourth lens group G4B is composed of, in order from the object side, a biconvex positive lens 41B, a biconcave negative lens 42B, a biconvex positive lens 43B, and a biconvex positive lens 44B.

The fifth lens group G5B consists of, in order from the object side, a biconcave negative lens 51B, a biconvex positive lens 52B, and a biconcave negative lens 53B. The biconcave negative lens 51B and the biconvex positive lens 52B are cemented together.

(Table 21)
Surface data surface number R d N(d) ν(d)
1 81.092 9.232 1.51633 64.14
2 554.790 0.150
3 122.914 2.000 1.80440 39.58
4 52.621 13.576 1.49700 81.55
5 931.131 d5
6 -637.805 2.000 1.76200 40.10
7 94.934 5.356 1.84666 23.78
8 -944.748 4.713
9 -129.931 2.000 1.71736 29.52
10 -933.933 d10
11 77.506 6.200 1.77250 49.60
12 -768.348 5.060
13 519.703 2.200 1.72047 34.71
14 48.529 1.482
15 41.922 5.000 1.48749 70.24
16 74.460 7.740
17 stop ∞ 2.375
18 137.306 4.820 1.71736 29.52
19 -69.450 1.440 1.65844 50.88
20 46.122 d20
21 7259.316 3.380 1.65412 39.68
22 -120.548 3.890
23 -33.907 4.030 1.72342 37.96
24 99.779 2.250
25 183.180 5.880 1.59522 67.73
26 -44.994 0.450
27 95.346 8.154 1.48749 70.24
28 -51.532 d28
29 -81.811 1.200 1.80440 39.58
30 52.281 8.800 1.67270 32.10
31 -50.135 1.920
32 -62.128 1.200 1.65160 58.55
33 501.405 -
fn: -115.857
θgFn: 0.5729
(Table 22)
Various data zoom ratios (magnification ratios) when focused on a subject at infinity (shooting magnification = 0) 2.00
Short focal length end Intermediate focal length Long focal length end
FNO. 4.00 4.78 5.85
f 199.850 300.509 399.850
W 6.2 4.1 3.1
Y 21.64 21.64 21.64
fB 37.600 64.084 95.259
L 230.000 268.818 297.352
d5 7.167 29.997 36.596
d10 2.848 2.787 3.860
d20 18.370 36.866 43.957
d28 47.517 18.586 1.181
(Table 23)
Lens group data group Starting surface Focal length
1 1 173.972
2 (subsequent, n) 6 -240.999
3 (subsequent) 11 -371.001
4 (subsequent) 21 81.393
5 (subsequent) 29 -94.481
(Table 24)
Distance between various data objects when focused on a subject at a finite distance 9000.0 9000.0 9000.0
Magnification -0.023 -0.033 -0.044
d5 7.167 29.997 36.596
d10 2.848 2.787 3.860
d20 16.235 33.099 38.816
d28 49.652 22.353 6.322
fB 37.600 64.084 95.259
Object-image distance 5000.0 5000.0 5000.0
Magnification -0.042 -0.060 -0.079
d5 7.167 29.997 36.596
d10 2.848 2.787 3.860
d20 14.467 30.160 35.008
d28 51.420 25.291 10.130
fB 37.600 64.084 95.259

[Numerical Example 7]
31 to 35 and Tables 25 to 28 show Numerical Example 7 of the zoom lens system according to the present invention. Fig. 31 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 32(A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 34A to 34D and FIGS. 35A to 35D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 25 is surface data, Table 26 is various data when focusing on an object at infinity (magnification = 0), Table 27 is lens group data, and Table 28 is when focusing on a finite distance object. Various data.

The zoom lens system of Numerical Example 7 comprises, in order from the object side, a first lens group G1C with positive refractive power, a second lens group (subsequent lens group) G2C with positive refractive power, and a lens group G2C with negative refractive power. The third lens group (subsequent lens group, n-th lens group) G3C, the fourth lens group (subsequent lens group) G4C with positive refractive power, and the fifth lens group (subsequent lens group) G5C with negative refractive power consists of The fourth lens group G4C includes a diaphragm S that moves integrally with the fourth lens group G4C.

The first lens group G1C is composed of, in order from the object side, a positive meniscus lens 11C convex to the object side, a negative meniscus lens 12C convex to the object side, and a positive meniscus lens 13C convex to the object side. The negative meniscus lens 12C and the positive meniscus lens 13C are cemented together.

The second lens group G2C is composed of, in order from the object side, a negative meniscus lens 21C convex to the object side and a biconvex positive lens 22C. The negative meniscus lens 21C and the biconvex positive lens 22C are cemented together.

The third lens group G3C consists of, in order from the object side, a biconcave negative lens 31C, a positive meniscus lens 32C convex to the object side, and a biconcave negative lens 33C. The biconcave negative lens 31C and the positive meniscus lens 32C are cemented together.

The fourth lens group G4C includes, in order from the object side, a biconvex positive lens 41C, a biconvex positive lens 42C, a biconcave negative lens 43C, a diaphragm S, a negative meniscus lens 44C convex to the object side, and a biconvex lens. It consists of a positive lens 45C and a positive meniscus lens 46C convex to the object side. The biconvex positive lens 42C and the biconcave negative lens 43C are cemented together.

The fifth lens group G5C is composed of, in order from the object side, a positive meniscus lens 51C convex to the image side and a biconcave negative lens 52C.

(Table 25)
Surface data surface number R d N(d) ν(d)
1 69.128 6.401 1.51633 64.14
2 525.186 0.150
3 100.847 1.700 1.79952 42.22
4 43.884 7.527 1.48749 70.24
5 321.688 d5
6 107.759 1.700 1.74400 44.79
7 51.867 4.850 1.48749 70.24
8-615.486d8
9 -175.204 1.200 1.77250 49.60
10 22.413 3.290 1.84666 23.78
11 64.808 2.000
12 -52.204 1.100 1.77250 49.60
13 552.401 d13
14 62.895 3.220 1.77250 49.60
15 -218.483 5.000
16 36.531 4.920 1.49700 81.55
17 -57.196 1.200 1.85026 32.27
18 82.066 2.700
19 stop ∞ 14.387
20 84.372 1.100 1.83400 37.34
21 37.252 1.020
22 195.080 4.540 1.59522 67.73
23 -49.305 0.200
24 28.817 3.730 1.61800 63.33
25 294.452 d25
26 -132.364 2.110 1.78472 25.68
27 -43.004 1.970
28 -40.156 1.000 1.69680 55.53
29 39.612 -
fn: -98.480
θgFn: 0.5672
(Table 26)
Various data zoom ratios (magnification ratios) when focused on a subject at infinity (shooting magnification = 0) 5.30
Short focal length end Intermediate focal length Long focal length end
FNO. 4.00 4.86 5.85
f54.95 139.85 291.09
W 15.1 5.7 2.8
Y 14.24 14.24 14.24
fB 52.820 67.339 89.121
L 190.757 215.212 239.996
d5 2.000 26.455 51.240
d8 2.452 15.849 15.519
d13 51.451 22.194 3.000
d25 5.020 6.361 4.102
(Table 27)
Lens group data group Starting surface Focal length
1 1 166.266
2 (subsequent) 6 360.538
3 (successor, n) 9 -32.278
4 (subsequent) 14 39.406
5 (subsequent) 26 -45.597
(Table 28)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.011 -0.028 -0.058
d5 2.000 26.455 51.240
d8 2.452 15.849 15.519
d13 51.451 22.194 3.000
d25 5.192 7.147 6.361
fB 52.648 66.553 86.862
Object-image distance 2000.0 2000.0 2000.0
Magnification -0.029 -0.071 -0.145
d5 2.000 26.455 51.240
d8 2.452 15.849 15.519
d13 51.451 22.194 3.000
d25 5.469 8.377 9.915
fB 52.371 65.323 83.308

[Numerical Example 8]
36 to 40 and Tables 29 to 32 show Numerical Example 8 of the zoom lens system according to the present invention. Fig. 36 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 37(A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 39A to 39D and FIGS. 40A to 40D are various aberration diagrams and lateral aberration diagrams when focusing on infinity at the long focal length extremity. Table 29 is surface data, Table 30 is various data when a subject is focused at infinity (magnification=0), Table 31 is lens group data, and Table 32 is when a subject is focused at a finite distance. Various data.

The zoom lens system of Numerical Example 8 comprises, in order from the object side, a first lens group G1D with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2D with negative refractive power, A third lens group (subsequent lens group) G3D with positive refractive power, a fourth lens group (subsequent lens group) G4D with negative refractive power, and a fifth lens group (subsequent lens group) G5D with positive refractive power. consists of The third lens group G3D includes a diaphragm S that moves integrally with the third lens group G3D.

The first lens group G1D is composed of, in order from the object side, a positive meniscus lens 11D convex to the object side, a negative meniscus lens 12D convex to the object side, and a positive meniscus lens 13D convex to the object side. The negative meniscus lens 12D and the positive meniscus lens 13D are cemented together.

The second lens group G2D is composed of, in order from the object side, a biconcave negative lens 21D, a positive meniscus lens 22D convex to the object side, and a negative meniscus lens 23D convex to the image side. The biconcave negative lens 21D and the positive meniscus lens 22D are cemented together.

The third lens group G3D includes, in order from the object side, a biconvex positive lens 31D, a biconvex positive lens 32D, a biconcave negative lens 33D, an aperture stop S, a negative meniscus lens 34D convex to the object side, and a biconvex lens. It consists of a positive lens 35D and a positive meniscus lens 36D convex to the object side. The biconvex positive lens 32D and the biconcave negative lens 33D are cemented together.

The fourth lens group G4D is composed of, in order from the object side, a positive meniscus lens 41D convex to the image side and a biconcave negative lens 42D.

The fifth lens group G5D consists of a biconvex positive single lens 51D.

(Table 29)
Surface data surface number R d N(d) ν(d)
1 61.765 5.940 1.51633 64.14
2 588.992 0.150
3 97.196 1.700 1.79952 42.22
4 39.169 8.210 1.48749 70.24
5 451.941 d5
6 -172.825 0.900 1.72916 54.68
7 22.024 2.960 1.84666 23.78
8 44.314 2.630
9 -38.158 0.800 1.69680 55.53
10 -136.863 d10
11 85.555 3.220 1.72916 54.68
12 -188.580 1.640
13 34.217 4.920 1.59522 67.73
14 -56.730 1.100 1.80610 33.27
15 136.465 2.851
16 stops ∞ 13.105
17 220.885 1.000 1.83400 37.34
18 30.589 1.664
19 60.865 4.392 1.49700 81.55
20 -53.647 0.510
21 30.636 2.920 1.69680 55.53
22 377.447 d22
23 -121.045 2.109 1.76182 26.52
24 -42.590 2.000
25 -41.378 0.700 1.69680 55.53
26 41.151 d26
27 236.669 2.055 1.54072 47.23
28-380.932-
fn: -83.143
θgFn: 0.5672
(Table 30)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.20
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 5.19 6.43
f55.959 135.025 291.146
W 14.8 6.0 2.8
Y 14.24 14.24 14.24
fB 37.602 47.087 73.429
L 165.236 195.005 234.550
d5 3.201 45.662 69.666
d10 35.478 13.300 2.500
d22 6.994 11.211 2.171
d26 14.486 10.269 19.309
(Table 31)
Lens group data group Starting surface Focal length
1 1 144.940
2 (successor, n) 6 -31.551
3 (subsequent) 11 37.495
4 (subsequent) 23 -46.425
5 (subsequent) 27 270.281
(Table 32)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.011 -0.027 -0.059
d5 3.201 45.662 69.666
d10 35.478 13.300 2.500
d22 7.203 12.286 4.899
d26 14.277 9.194 16.581
fB 37.602 47.087 73.429
Object-image distance 3000.0 3000.0 3000.0
Magnification -0.019 -0.046 -0.098
d5 3.201 45.662 69.666
d10 35.478 13.300 2.500
d22 7.349 13.027 6.791
d26 14.131 8.453 14.689
fB 37.602 47.087 73.429

[Numerical Example 9]
41 to 45 and Tables 33 to 36 show Numerical Example 9 of the zoom lens system according to the present invention. Fig. 41 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 42 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 44A to 44D and FIGS. 45A to 45D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 33 is surface data, Table 34 is various data when the subject is focused at infinity (magnification=0), Table 35 is lens group data, and Table 36 is when the subject is focused at a finite distance. Various data.

The zoom lens system of Numerical Example 9 comprises, in order from the object side, a first lens group G1E with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2E with negative refractive power, a positive refractive power third lens group (subsequent lens group) G3E, a positive refractive power fourth lens group (subsequent lens group) G4E, and a negative refractive power fifth lens group (subsequent lens group) G5E; , and a sixth lens group (subsequent lens group) G6E having a positive refractive power. The third lens group G3E includes a diaphragm S that moves integrally with the third lens group G3E.

The first lens group G1E is composed of, in order from the object side, a positive meniscus lens 11E convex to the object side, a negative meniscus lens 12E convex to the object side, and a positive meniscus lens 13E convex to the object side. The negative meniscus lens 12E and the positive meniscus lens 13E are cemented together.

The second lens group G2E is composed of, in order from the object side, a biconcave negative lens 21E, a positive meniscus lens 22E convex to the object side, and a negative meniscus lens 23E convex to the image side. The biconcave negative lens 21E and the positive meniscus lens 22E are cemented together.

The third lens group G3E consists of, in order from the object side, a biconvex positive lens 31E, a biconvex positive lens 32E, and a biconcave negative lens 33E. The biconvex positive lens 32E and the biconcave negative lens 33E are cemented together.

The fourth lens group G4E is composed of, in order from the object side, a negative meniscus lens 41E convex to the object side, a biconvex positive lens 42E, and a positive meniscus lens 43E convex to the object side.

The fifth lens group G5E is composed of, in order from the object side, a positive meniscus lens 51E convex to the image side and a biconcave negative lens 52E.

The sixth lens group G6E consists of a positive meniscus single lens 61E convex to the object side.

(Table 33)
Surface data surface number R d N(d) ν(d)
1 74.014 5.940 1.48749 70.24
2 915.456 0.150
3 121.231 1.700 1.78590 44.20
4 47.604 8.210 1.48749 70.24
5 748.965 d5
6 -190.634 0.900 1.74100 52.64
7 23.710 2.960 1.84666 23.78
8 47.887 2.630
9 -37.671 0.800 1.61800 63.33
10 -145.430 d10
11 93.946 3.220 1.72916 54.68
12 -101.424 1.640
13 33.772 4.920 1.59522 67.73
14 -51.804 1.100 1.80610 33.27
15 119.681 2.851
16 stop ∞ d16
17 63.455 1.000 1.83400 37.34
18 24.801 3.719
19 30.359 4.392 1.49700 81.55
20 -87.115 0.510
21 42.618 2.920 1.69680 55.53
22 226.723 d22
23 -126.233 2.109 1.76182 26.52
24 -40.199 2.000
25 -36.365 0.700 1.69680 55.53
26 37.591 d26
27 51.840 2.055 1.51742 52.43
28 87.690 -
fn: -100.761
θgFn: 0.5631
(Table 34)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 5.21
Short focal length end Intermediate focal length Long focal length end
FNO. 4.60 5.60 6.48
f 56.000 123.120 291.999
W 14.8 6.6 2.8
Y 14.24 14.24 14.24
fB 37.600 56.366 70.026
L 165.367 209.909 248.397
d5 3.000 47.542 86.031
d10 36.367 19.174 2.500
d16 14.122 12.549 15.563
d22 2.544 3.685 1.913
d26 15.309 14.168 15.940
(Table 35)
Lens group data group Starting surface Focal length
1 1 173.992
2 (successor, n) 6 -33.596
3 (subsequent) 11 44.294
4 (subsequent) 17 56.311
5 (subsequent) 23 -41.708
6 (subsequent) 27 240.371
(Table 36)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.011 -0.025 -0.058
d5 3.000 47.542 86.031
d10 36.367 19.174 2.500
d16 14.122 12.549 15.563
d22 2.725 4.286 4.509
d26 15.128 13.567 13.344
fB 37.600 56.366 70.026
Object-image distance 3000.0 3000.0 3000.0
Magnification -0.019 -0.042 -0.097
d5 3.000 47.542 86.031
d10 36.367 19.174 2.500
d16 14.122 12.549 15.563
d22 2.850 4.701 6.283
d26 15.003 13.152 11.570
fB 37.600 56.366 70.026

[Numerical Example 10]
46 to 50 and Tables 37 to 40 show Numerical Example 10 of the zoom lens system according to the present invention. Fig. 46 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 47 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 49A to 49D and FIGS. 50A to 50D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 37 is surface data, Table 38 is various data when a subject is focused at infinity (magnification=0), Table 39 is lens group data, and Table 40 is when a subject is focused at a finite distance. Various data.

The zoom lens system of Numerical Example 10 comprises, in order from the object side, a first lens group G1F with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2F with negative refractive power, A third lens group (subsequent lens group) G3F having a positive refractive power. The third lens group G3F includes a diaphragm S that moves integrally with the third lens group G3F.

The first lens group G1F is composed of, in order from the object side, a positive meniscus lens 11F convex to the object side, a negative meniscus lens 12F convex to the object side, and a positive meniscus lens 13F convex to the object side. The negative meniscus lens 12F and the positive meniscus lens 13F are cemented together.

The second lens group G2F is composed of, in order from the object side, a biconcave negative lens 21F, a positive meniscus lens 22F convex to the object side, and a biconcave negative lens 23F. The biconcave negative lens 21F and the positive meniscus lens 22F are cemented together.

The third lens group G3F includes, in order from the object side, a biconvex positive lens 31F, a biconvex positive lens 32F, a biconcave negative lens 33F, a diaphragm S, a biconvex positive lens 34F, and a biconcave negative lens 35F. , a biconvex positive lens 36F, a negative meniscus lens 37F convex to the image side, and a biconvex positive lens 38F. The biconvex positive lens 32F and the biconcave negative lens 33F are cemented together, and the biconvex positive lens 34F and the biconcave negative lens 35F are cemented together.

(Table 37)
Surface data surface number R d N(d) ν(d)
1 73.372 4.737 1.64000 60.08
2 308.552 0.150
3 98.116 1.700 1.83400 37.16
4 45.864 6.874 1.48749 70.24
5 320.457 d5
6 -543.000 1.200 1.69680 55.53
7 20.527 4.200 1.84666 23.78
8 50.126 2.806
9 -56.691 1.500 1.83481 42.72
10 113.676 d10
11 66.417 3.581 1.77250 49.60
12 -89.590 2.000
13 26.536 5.796 1.49700 81.55
14 -33.059 1.200 1.85026 32.27
15 55.548 1.675
16 stops ∞ 7.268
17 125.175 2.873 1.62299 58.17
18 -26.979 1.200 1.66680 33.05
19 61.108 5.654
20 97.439 3.450 1.80518 25.43
21 -37.663 16.060
22 -22.183 1.500 1.91082 35.25
23 -96.715 0.200
24 58.834 2.633 1.69680 55.53
25-310.598-
fn: -104.813
θgFn: 0.5776
(Table 38)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 4.70
Short focal length end Intermediate focal length Long focal length end
FNO. 4.30 5.25 6.47
f 51.601 100.118 242.760
W 16.3 8.2 3.4
Y 14.24 14.24 14.24
fB 42.352 58.425 78.816
L 157.671 192.600 230.307
d5 4.800 36.184 69.535
d10 32.263 19.735 3.700
(Table 39)
Lens group data group Starting surface Focal length
1 1 158.229
2 (successor, n) 6 -30.075
3 (subsequent) 11 38.335
(Table 40)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.010 -0.020 -0.043
d5 4.357 35.232 65.382
d10 32.706 20.687 7.853
fB 42.352 58.425 78.816
Object-image distance 2000.0 2000.0 2000.0
Magnification -0.027 -0.049 -0.096
d5 3.677 33.872 61.529
d10 33.386 22.047 11.706
fB 42.352 58.425 78.816

[Numerical Example 11]
51 to 55 and Tables 41 to 44 show Numerical Example 11 of the zoom lens system according to the present invention. Fig. 51 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 52 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 54(A) to (D) and FIGS. 55(A) to (D) are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 41 is surface data, Table 42 is various data when focusing on an object at infinity (magnification = 0), Table 43 is lens group data, and Table 44 is when focusing on a finite distance object. Various data.

The lens configuration of Numerical Example 11 is the same as the lens configuration of Numerical Example 10 except for the following points.
(1) The third lens group G3F includes, in order from the object side, a diaphragm S, a biconvex positive lens 31F', a biconvex positive lens 32F', a biconcave negative lens 33F', and a positive meniscus convex to the object side. It consists of a lens 34F', a negative meniscus lens 35F' convex to the object side, a biconvex positive lens 36F', a biconcave negative lens 37F', and a biconvex positive lens 38F'. A biconvex positive lens 32F' and a biconcave negative lens 33F' are cemented together, and a positive meniscus lens 34F' and a negative meniscus lens 35F' are cemented together.

(Table 41)
Surface data surface number R d N(d) ν(d)
1 71.592 5.865 1.60300 65.44
2 7024.156 1.966
3 312.454 1.700 1.78800 47.37
4 41.001 7.378 1.60300 65.44
5 425.713 d5
6 -103.502 1.200 1.67790 55.34
7 24.583 4.200 1.84666 23.78
8 74.776 2.806
9 -90.360 1.500 1.83400 37.16
10 114.204 d10
11 stop ∞ 1.700
12 274.288 4.056 1.73400 51.47
13 -103.948 0.100
14 25.754 6.106 1.49700 81.55
15 -52.422 1.200 1.85026 32.27
16 109.204 15.000
17 16.828 3.600 1.61800 63.33
18 25.738 1.200 1.58313 59.37
19 17.186 7.296
20 33.718 3.450 1.69680 55.53
21 -49.965 4.207
22 -18.238 1.500 1.88300 40.76
23 108.501 0.200
24 54.250 2.633 1.74000 28.30
25 -118.278 -
fn: -60.056
θgFn: 0.5559
(Table 42)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 3.79
Short focal length end Intermediate focal length Long focal length end
FNO. 4.20 5.22 5.78
f51.400 99.844 194.569
W 16.4 8.2 4.2
Y 14.24 14.24 14.24
fB 41.257 59.441 69.548
L 154.882 188.869 226.352
d5 4.123 35.391 74.884
d10 30.639 15.174 3.057
(Table 43)
Lens group data group Starting surface Focal length
1 1 192.429
2 (successor, n) 6 -35.398
3 (subsequent) 12 38.171
(Table 44)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.010 -0.020 -0.036
d5 3.540 34.353 71.629
d10 31.221 16.212 6.312
fB 41.257 59.441 69.548
Object-image distance 2000.0 2000.0 2000.0
Magnification -0.026 -0.049 -0.082
d5 2.653 32.853 67.988
d10 32.109 17.712 9.953
fB 41.257 59.441 69.548

[Numerical Example 12]
56 to 60 and Tables 45 to 48 show Numerical Example 12 of the zoom lens system according to the present invention. Fig. 56 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 57 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 59(A) to (D) and FIGS. 60(A) to (D) are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 45 is surface data, Table 46 is various data when a subject is focused at infinity (magnification=0), Table 47 is lens group data, and Table 48 is when a subject is focused at a finite distance. Various data.

The lens configuration of Numerical Example 12 is the same as the lens configuration of Numerical Example 10 except for the following points.
(1) The third lens group G3F comprises, in order from the object side, an aperture stop S, a biconvex positive lens 31F'', a biconvex positive lens 32F'', a biconcave negative lens 33F'', and a biconvex positive lens 34F''. , a negative meniscus lens 35F″ convex to the image side, a biconcave negative lens 36F″, and a biconvex positive lens 37F″. The biconvex positive lens 32F″ and the biconcave negative lens 33F″ are cemented together, The biconvex positive lens 34F'' and the negative meniscus lens 35F'' are cemented together.

(Table 45)
Surface data surface number R d N(d) ν(d)
1 85.329 4.529 1.77250 49.60
2 983.202 0.150
3 107.046 1.700 1.72047 34.71
4 41.690 6.874 1.49700 81.55
5 156.582 d5
6 -541.000 1.200 1.78800 47.37
7 24.160 4.200 1.84666 23.78
8 75.055 2.806
9 -55.520 1.500 1.81600 46.62
10 551.971 d10
11 stop ∞ 1.700
12 109.153 4.056 1.61800 63.33
13 -64.888 0.100
14 23.204 6.106 1.49700 81.55
15 -44.037 1.200 1.85026 32.27
16 58.912 16.952
17 75.831 3.450 1.83400 37.16
18 -27.995 1.200 1.61772 49.81
19 -71.414 9.369
20 -21.513 1.500 1.88300 40.76
21 59.394 0.200
22 51.421 2.633 1.60562 43.70
23-50.348-
fn: -95.821
θgFn: 0.5834
(Table 46)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 4.03
Short focal length end Intermediate focal length Long focal length end
FNO. 4.10 4.60 6.35
f 55.319 99.962 222.785
W 14.9 8.1 3.6
Y 14.24 14.24 14.24
fB 40.231 48.460 77.781
L 156.000 177.008 199.353
d5 4.400 32.812 48.147
d10 39.945 24.312 2.000
(Table 47)
Lens group data group Starting surface Focal length
1 1 147.222
2 (successor, n) 6 -37.110
3 (subsequent) 12 40.191
(Table 48)
Distance between various data objects when focused on a subject at a finite distance 5000.0 5000.0 5000.0
Magnification -0.011 -0.019 -0.039
d5 3.488 30.426 42.368
d10 40.857 26.697 7.780
fB 40.231 48.460 77.781
Object-image distance 2000.0 2000.0 2000.0
Magnification -0.028 -0.046 -0.088
d5 2.145 27.492 37.552
d10 42.200 29.631 12.596
fB 40.231 48.460 77.781

[Numerical Example 13]
61 to 65 and Tables 49 to 52 show Numerical Example 13 of the zoom lens system according to the present invention. Fig. 61 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 62 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 64A to 64D and FIGS. 65A to 65D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 49 is surface data, Table 50 is various data when a subject is focused at infinity (magnification=0), Table 51 is lens group data, and Table 52 is when a subject is focused at a finite distance. Various data.

The zoom lens system of Numerical Example 13 comprises, in order from the object side, a first lens group G1G with positive refractive power, a second lens group (subsequent lens group, n-th lens group) G2G with negative refractive power, It is composed of a third lens group (subsequent lens group) G3G with negative refractive power and a fourth lens group (subsequent lens group) G4G with positive refractive power. The fourth lens group G4G includes a diaphragm S that moves integrally with the fourth lens group G4G.

The first lens group G1G includes, in order from the object side, a positive meniscus lens 11G convex to the object side, a negative meniscus lens 12G convex to the object side, a positive meniscus lens 13G convex to the object side, and a convex meniscus lens 13G to the object side. and a positive meniscus lens 14G. The negative meniscus lens 12G and the positive meniscus lens 13G are cemented together.

The second lens group G2G consists of, in order from the object side, a biconcave negative lens 21G, a biconvex positive lens 22G, and a biconcave negative lens 23G.

The third lens group G3G consists of, in order from the object side, a biconcave negative lens 31G and a positive meniscus lens 32G convex to the object side. The biconcave negative lens 31G and the positive meniscus lens 32G are cemented together.

The fourth lens group G4G includes, in order from the object side, an ND filter 41G, a diaphragm S, a biconvex positive lens 42G, a biconvex positive lens 43G, a biconcave negative lens 44G, and a negative meniscus lens convex to the object side. 45G, a positive meniscus lens 46G convex to the object side, a positive meniscus lens 47G convex to the object side, and a plane-parallel plate 48G. The biconvex positive lens 43G and the biconcave negative lens 44G are cemented together, and the negative meniscus lens 45G and the positive meniscus lens 46G are cemented together.

(Table 49)
Surface data surface number R d N(d) ν(d)
1 138.399 10.386 1.59522 67.73
2 1728.931 0.200
3 367.501 2.650 1.78800 47.37
4 89.949 13.160 1.49700 81.55
5 627.536 0.200
6 131.406 8.105 1.43875 94.94
7 327.171 d7
8 -214.076 2.000 1.83481 42.72
9 90.051 1.231
10 100.764 5.606 1.84666 23.78
11 -485.371 2.209
12 -248.972 2.000 1.58267 46.42
13 126.794 d13
14 -103.184 1.200 1.69680 55.46
15 23.318 3.290 1.85026 32.27
16 52.303 d16
17 ∞ 1.000 1.51680 64.20
18 ∞ 0.900
19 stop ∞ 2.500
20 46.542 4.834 1.59522 67.73
21 -58.878 1.964
22 45.580 5.202 1.43875 94.94
23 -35.837 1.800 1.80440 39.58
24 268.315 40.000
25 26.755 1.800 1.88300 40.76
26 15.507 4.982 1.48749 70.24
27 20.474 0.150
28 47.144 2.939 1.84666 23.78
29 146.953 5.000
30 ∞ 3.500 1.51680 64.20
31 ∞ -
fn: -151.780
θgFn: 0.5559
(Table 50)
Various data zoom ratios (magnification ratios) when focusing on a subject at infinity (shooting magnification = 0) 15.18
Short focal length end Intermediate focal length Long focal length end
FNO. 4.00 4.00 4.75
f 25.034 100.000 380.000
W 13.1 3.1 0.8
Y 5.50 5.50 5.50
fB 16.500 16.500 16.500
L 328.705 328.705 328.705
d7 4.500 114.035 154.368
d13 117.197 16.314 26.113
d16 61.701 53.049 2.916
(Table 51)
Lens group data group Starting surface Focal length
1 1 243.658
2 (successor, n) 8 -99.211
3 (subsequent) 14 -60.684
3 (subsequent) 17 44.157
(Table 52)
Distance between various data objects when focused on a subject at a finite distance 9000.0 9000.0 9000.0
Magnification -0.003 -0.012 -0.045
d7 11.551 121.086 161.419
d13 117.197 16.314 26.113
d16 61.701 53.049 2.916
fB 16.500 16.500 16.500
Object-image distance 5000.0 5000.0 5000.0
Magnification -0.006 -0.023 -0.086
d7 17.950 127.485 167.818
d13 117.197 16.314 26.113
d16 61.701 53.049 2.916
fB 16.500 16.500 16.500

[Numerical Example 14]
66 to 70 and Tables 53 to 56 show Numerical Example 14 of the zoom lens system according to the present invention. Fig. 66 is a lens configuration diagram when focusing on infinity at the short focal length extremity, Figs. 67 (A) to (D) and Figs. Aberration diagrams and lateral aberration diagrams, FIGS. 69A to 69D and FIGS. 70A to 70D are various aberration diagrams and lateral aberration diagrams at the long focal length extremity when focusing on infinity. Table 53 is surface data, Table 54 is various data when the subject is focused at infinity (magnification=0), Table 55 is lens group data, and Table 56 is when the subject is focused at a finite distance. Various data.

The lens configuration of Numerical Example 14 is the same as the lens configuration of Numerical Example 13 except for the following points.
(1) The positive lens 22G of the second lens group G2G is a positive meniscus lens convex to the object side, and the biconcave negative lens 21G and the positive meniscus lens 22G are cemented together.
(2) The fourth lens group G4 includes, in order from the object side, an ND filter 41G', a diaphragm S, a biconvex positive lens 42G', a biconvex positive lens 43G', a biconcave negative lens 44G', and an object. It consists of a negative meniscus lens 45G' convex to the object side, a positive meniscus lens 46G' convex to the object side, and a plane-parallel plate 47G'. The biconvex positive lens 43G' and the biconcave negative lens 44G' are cemented together.

(Table 53)
Surface data surface number R d N(d) ν(d)
1 108.673 10.386 1.59522 67.73
2 1875.591 0.200
3 201.048 2.650 1.80400 46.58
4 65.532 13.160 1.49700 81.55
5 392.524 0.200
6 107.913 8.105 1.43875 94.94
7 188.818 d7
8 -2687.000 2.000 1.85026 32.27
9 67.674 5.086 1.84666 23.78
10 719.029 2.538
11 -1647.553 2.000 1.53775 74.70
12 77.127 d12
13 -96.690 1.200 1.77250 49.60
14 20.418 3.290 1.85026 32.27
15 62.943 d15
16 ∞ 1.000 1.51680 64.20
17 ∞ 0.900
18 stop ∞ 2.500
19 43.459 3.846 1.59522 67.73
20 -81.665 1.964
21 70.139 5.202 1.43875 94.94
22 -37.963 1.800 1.80440 39.58
23 537.025 40.000
24 56.904 4.982 1.59522 67.73
25 19.244 0.802
26 25.611 2.939 1.69680 55.53
27 123.227 5.000
28 ∞ 3.500 1.51680 64.20
29 ∞ -
fn: -121.986
θgFn: 0.5573
(Table 54)
Various data zoom ratios (magnification ratios) 15.00 when focusing on a subject at infinity (shooting magnification = 0)
Short focal length end Intermediate focal length Long focal length end
FNO. 4.50 4.49 5.73
f 30.005 200.000 450.000
W 10.5 1.6 0.7
Y 5.50 5.50 5.50
fB 26.814 26.814 26.814
L 329.593 329.593 329.593
d7 4.160 95.464 95.319
d12 79.558 32.075 79.129
d15 93.811 49.991 3.082
(Table 55)
Lens group data group Starting surface Focal length
1 1 196.166
2 (subsequent, n) 8 -112.321
3 (subsequent) 13 -56.049
3 (subsequent) 16 55.913
(Table 56)
Distance between various data objects when focused on a subject at a finite distance 9000.0 9000.0 9000.0
Magnification -0.004 -0.024 -0.053
d7 8.705 100.009 99.864
d12 79.558 32.075 79.129
d15 93.811 49.991 3.082
fB 26.814 26.814 26.814
Object-image distance 4000.0 4000.0 4000.0
Magnification -0.009 -0.058 -0.130
d7 15.282 106.586 106.441
d12 79.558 32.075 79.129
d15 93.811 49.991 3.082
fB 26.814 26.814 26.814

Table 57 shows values for each conditional expression in each numerical example.
(Table 57)
Example 1 Example 2 Example 3 Example 4
Conditional expression (1) -2.009 -2.398 -1.711 -1.510
Conditional expression (2) 67.19 72.85 65.46 75.90
Conditional expression (3) -4.914 -4.443 -4.743 -1.102
Conditional expression (4) 1.78590 1.77250 1.65412 1.79952
Conditional expression (5) 2.514 3.050 2.694 2.586
Conditional expression (6) 2.077 2.240 1.746 3.596
Conditional expression (7) -1.649 -1.446 -1.738 -3.528
Conditional expression (8) 46.58 47.82 37.16 31.31
Conditional expression (9) -0.0066 -0.0086 -0.0036 -0.0058
Conditional expression (10) 44.20 49.60 39.68 42.22
Conditional expression (11) 3.972 5.092 3.609 4.447
Conditional expression (12) 10.366 11.097 12.477 10.985
Conditional expression (13) 2.946 3.311 3.444 1.467
Conditional expression (14) 1.298 1.458 1.519 0.957
Example 5 Example 6 Example 7 Example 8
Conditional expression (1) -1.605 -1.502 -1.688 -1.743
Conditional expression (2) 77.78 72.85 67.19 67.19
Conditional expression (3) -4.410 -0.722 -5.151 -4.594
Conditional expression (4) 1.79952 1.80440 1.79952 1.79952
Conditional expression (5) 1.426 2.145 2.405 2.347
Conditional expression (6) 3.002 2.497 2.541 2.350
Conditional expression (7) -1.420 -2.539 -1.440 -1.433
Conditional expression (8) 37.16 29.52 49.60 55.53
Conditional expression (9) -0.0058 -0.0045 -0.0058 -0.0058
Conditional expression (10) 42.22 39.58 42.22 42.22
Conditional expression (11) 4.083 3.306 3.789 3.700
Conditional expression (12) 6.702 6.971 10.538 9.059
Conditional expression (13) 3.352 0.871 3.025 2.590
Conditional expression (14) 1.477 0.615 1.315 1.136
Example 9 Example 10 Example 11 Example 12
Conditional expression (1) -1.727 -1.510 -3.204 -1.536
Conditional expression (2) 70.24 65.16 65.44 65.58
Conditional expression (3) -5.179 -5.261 -5.436 -3.967
Conditional expression (4) 1.78590 1.83400 1.78800 1.72047
Conditional expression (5) 2.351 2.157 2.688 1.725
Conditional expression (6) 2.293 2.755 1.302 2.276
Conditional expression (7) -1.417 -1.465 -1.440 -1.536
Conditional expression (8) 63.33 42.72 37.16 46.62
Conditional expression (9) -0.0066 -0.0039 -0.0084 -0.0022
Conditional expression (10) 44.20 37.16 47.37 34.71
Conditional expression (11) 3.655 3.450 4.693 3.531
Conditional expression (12) 10.875 11.755 11.380 11.109
Conditional expression (13) 3.107 3.066 3.744 2.661
Conditional expression (14) 1.361 1.414 1.924 1.326
Example 13 Example 14
Conditional expression (1) -1.605 -1.608
Conditional expression (2) 81.41 81.41
Conditional expression (3) -2.456 -1.746
Conditional expression (4) 1.78800 1.80400
Conditional expression (5) 1.761 1.805
Conditional expression (6) 1.648 1.967
Conditional expression (7) -1.102 -1.660
Conditional expression (8) 46.42 74.70
Conditional expression (9) -0.0084 -0.0084
Conditional expression (10) 47.37 46.58
Conditional expression (11) 2.709 2.993
Conditional expression (12) 7.022 5.653
Conditional expression (13) 9.733 6.538
Conditional expression (14) 2.498 1.688

As is clear from Table 57, Numerical Examples 1 to 14 satisfy Conditional Expressions (1) to (14). and lateral aberration are relatively well corrected.

Even if a lens or lens group having no substantial power is added to the zoom lens system included in the claims of the present invention, it is included in the technical scope of the present invention. not avoided).

G1A: first lens group with positive refractive power G2A: second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3A Third lens group with positive refractive power (subsequent lens group)
G4A Negative refractive power 4th lens group (subsequent lens group)
G1B: first lens group with positive refractive power G2B: second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3B Negative refractive power third lens group (subsequent lens group)
G4B 4th lens group with positive refractive power (subsequent lens group)
G5B Negative refractive power fifth lens group (subsequent lens group)
G1C First lens group with positive refractive power G2C Second lens group with positive refractive power (subsequent lens group)
G3C 3rd lens group with negative refractive power (subsequent lens group, n-th lens group)
G4C 4th lens group with positive refractive power (subsequent lens group)
G5C 5th lens group with negative refractive power (subsequent lens group)
G1D: first lens group with positive refractive power G2D: second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3D Third lens group with positive refractive power (subsequent lens group)
G4D Negative refractive power fourth lens group (subsequent lens group)
G5D Fifth lens group with positive refractive power (subsequent lens group)
G1E First lens group with positive refractive power G2E Second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3E Third lens group with positive refractive power (subsequent lens group)
G4E 4th lens group with positive refractive power (subsequent lens group)
G5E Negative refractive power fifth lens group (subsequent lens group)
G6E 6th lens group with positive refractive power (subsequent lens group)
G1F First lens group with positive refractive power G2F Second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3F Third lens group with positive refractive power (subsequent lens group)
G1G First lens group with positive refractive power G2G Second lens group with negative refractive power (subsequent lens group, n-th lens group)
G3G Negative refractive power third lens group (subsequent lens group)
G4G 4th lens group with positive refractive power (subsequent lens group)
S aperture I image plane

A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length When zooming to the end, the first lens group moves toward the object side and the distance between the first lens group and the succeeding lens group increases; When zooming from the focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; and the following conditional expressions (1) and (2) are satisfied; and
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of at least one positive single lens, one negative meniscus lens with a convex surface facing the object side, and two or more positive lenses in order from the side; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1) and (2) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one lens group with negative refractive power; and the following conditional expression (1), (2) and (3″) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(3″) fG1/fGn≦−3.967
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: the focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (4') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(4′) 1.650<nn<1.835
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
nn: refractive index for the d-line of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (5'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(5″) 2.347≦fG1/R1p<3.30
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1p: paraxial radius of curvature of the most object side surface of the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (6'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(6″) 1.30<(R1n+R2n)/(R1n−R2n)≦2.293
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; when the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one negative refractive power lens group, and the negative refractive power included in the subsequent lens group Of the power lens groups, the n-th lens group with negative refractive power located closest to the object side has a negative lens closest to the object side; and the following conditional expressions (1) and (2), (7) is satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(7) fGn/R2Gn<−1.10
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: focal length of the n-th lens group,
R2Gn: the paraxial radius of curvature of the image-side surface of the most object-side negative lens in the n-th lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; when the distance between the lens groups constituting the subsequent lens group changes; the subsequent lens group includes at least one negative refractive power lens group, and the negative refractive power included in the subsequent lens group Of the power lens groups, the n-th lens group with negative refractive power located closest to the object side has a negative lens closest to the image side; and the following conditional expressions (1) and (2): satisfying;
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (11'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(11″) 3.50<fG1/R2n
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (12'') are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(12″) 4.00<fG1/1Gd≦7.022
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
1Gd: the distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (13X) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(13X)2.50<fG1/fw
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; short focal length end to long focal length increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1), (2), and (14X) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
(14×)1.10<fG1/(fw×ft) ^1/2
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
ft: focal length of the entire system at the long focal length end,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups and the distance between each lens group changes; the subsequent lens group has at least one and that the following conditional expressions (1) and (2″) are satisfied:
(1) fG1/fn<−1.50
(2″) 72.85≦νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups and the distance between each lens group changes; the subsequent lens group has at least one and that the following conditional expressions (1), (2), and (3A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(3A) -2.456≤fG1/fGn<-0.70
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: the focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (5A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(5A) 1.40<fG1/R1p≦1.805
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1p: paraxial radius of curvature of the most object side surface of the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (6A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(6A) 3.002≦(R1n+R2n)/(R1n−R2n)
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (10″) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(10″) 44.20≦νn
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (11A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(11A) 2.40<fG1/R2n≦2.993
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R2n: the paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (12A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(12A) 10.366≦fG1/1Gd<13.00
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
1Gd: the distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group;
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, one or more positive single lenses, a negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The distance between the first lens group and the subsequent lens group increases upon zooming; the subsequent lens group has a plurality of lens groups, and the distance between each lens group changes; and the following conditional expression (1): , (2) and (13A) are satisfied;
(1) fG1/fn<−1.50
(2) 65<νpave
(13A) 0.80<fG1/fw≦1.467
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
is.
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; composed of, in order from the side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; The negative meniscus lens is arranged with an air gap between each positive lens adjacent to the object side and the image side; The distance between the group and the subsequent lens group is increased; the subsequent lens group has a plurality of lens groups, and the lens that constitutes the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity. It is characterized by that the intervals between the groups are changed; and that the following conditional expressions (1) and (2) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.
Here, "the negative meniscus lens in the first lens group is arranged with an air gap between each positive lens adjacent to the object side and the image side" means, for example, "the above The negative meniscus lens in the first lens group forms an air lens between each positive lens adjacent to the object side and the image side", "The negative meniscus lens in the first lens group is , not cemented with the positive lenses adjacent to the object side and the image side (being a non-cemented lens)" (same meaning).
A zoom lens system of the present invention has, in order from the object side, a first lens group having a positive refractive power and a subsequent lens group succeeding the first lens group; Composed of, in order from the side, two or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses; increasing the distance between the first lens group and the succeeding lens group when zooming to the extreme; the succeeding lens group having a plurality of lens groups for zooming from the short focal length extremity to the long focal length extremity; In this case, the distance between the lens groups constituting the subsequent lens group is changed; and the following conditional expressions (1) and (2) are satisfied.
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
is.

Claims (31)

Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens having a convex surface facing the object side, and one or more positive lenses;
When zooming from the short focal length extremity to the long focal length extremity, the first lens group moves toward the object side and the distance between the first lens group and the subsequent lens group increases;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; satisfy conditional expressions (1) and (2);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and two or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; satisfy conditional expressions (1) and (2);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes;
The subsequent lens group includes at least one negative refractive power lens group; and satisfying the following conditional expressions (1), (2), and (3″);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(3″) fG1/fGn≦−3.967
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: The focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; Satisfying conditional expressions (1), (2) and (4′);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(4′) 1.650<nn<1.835
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
nn: refractive index for the d-line of the negative meniscus lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; satisfying conditional expressions (1), (2) and (5″);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(5″) 2.347≦fG1/R1p<3.30
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1p: paraxial radius of curvature of the most object side surface of the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; Satisfying conditional expressions (1), (2), (6″);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(6″) 1.30<(R1n+R2n)/(R1n−R2n)≦2.293
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R1n: paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group when zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes;
The subsequent lens group includes at least one negative refractive power lens group, and the lens group having the negative refractive power located closest to the object side among the negative refractive power lens groups included in the subsequent lens group. The n lens group has a negative lens closest to the object; and satisfies the following conditional expressions (1), (2), and (7);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(7) fGn/R2Gn<−1.10
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fGn: focal length of the n-th lens group,
R2Gn: paraxial radius of curvature of the image-side surface of the negative lens closest to the object in the n-th lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes;
The subsequent lens group includes at least one negative refractive power lens group, and the lens group having the negative refractive power located closest to the object side among the negative refractive power lens groups included in the subsequent lens group. The n lens group has a negative lens closest to the image side; and satisfies the following conditional expressions (1) and (2);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; Satisfying conditional expressions (1), (2), (11″);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(11″) 3.50<fG1/R2n
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; Satisfying conditional expressions (1), (2), (12″);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(12″) 4.00<fG1/1Gd≦7.022
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
1Gd: Distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; satisfying conditional expressions (1), (2), (13X);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(13X)2.50<fG1/fw
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length extremity. Having, in order from the object side, a first lens group with positive refractive power and a subsequent lens group succeeding the first lens group;
The first lens group is composed of, in order from the object side, one or more positive single lenses, one negative meniscus lens with a convex surface facing the object side, and one or more positive lenses;
increasing the distance between the first lens group and the subsequent lens group during zooming from the short focal length extremity to the long focal length extremity;
The succeeding lens group has a plurality of lens groups, and when zooming from the short focal length extremity to the long focal length extremity, the distance between the lens groups constituting the succeeding lens group changes; satisfying conditional expressions (1), (2), (14X);
A zoom lens system characterized by
(1) fG1/fn<−1.50
(2) 65<νpave
(14×)1.10<fG1/(fw×ft) ^1/2
however,
fG1: focal length of the first lens group;
fn: focal length of the negative meniscus lens in the first lens group;
νpave: Average Abbe number for the d-line of the positive lens in the first lens group,
fw: focal length of the entire system at the short focal length end,
ft: focal length of the entire system at the long focal length extremity. The zoom lens system according to any one of claims 1 to 6 and 8 to 12,
The subsequent lens group includes at least one lens group with negative refractive power, and of the lens groups with negative refractive power included in the subsequent lens group, the n-th lens with negative refractive power located closest to the object side. A zoom lens system in which the group has a negative lens closest to the object side. In the zoom lens system according to any one of claims 1, 2, and 4 to 13,
A zoom lens system in which the subsequent lens group includes at least one lens group with negative refractive power and satisfies the following conditional expression (3).
(3) fG1/fGn<−0.70
however,
fG1: focal length of the first lens group;
fGn: The focal length of the n-th lens group with negative refractive power located closest to the object side among the lens groups with negative refractive power included in the subsequent lens group. The zoom lens system according to any one of claims 1 to 3 and 5 to 14,
A zoom lens system that satisfies the following conditional expression (4).
(4) 1.650<nn
however,
nn: refractive index for the d-line of the negative meniscus lens in the first lens group. The zoom lens system according to any one of claims 1 to 4 and 6 to 15,
A zoom lens system that satisfies the following conditional expression (5).
(5) 1.40<fG1/R1p<3.30
however,
fG1: focal length of the first lens group;
R1p: paraxial radius of curvature of the most object side surface of the first lens group. The zoom lens system according to any one of claims 1 to 5 and 7 to 16,
A zoom lens system that satisfies the following conditional expression (6).
(6) 1.30<(R1n+R2n)/(R1n−R2n)
however,
R1n: the paraxial radius of curvature of the object-side surface of the negative meniscus lens in the first lens group;
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group. The zoom lens system according to any one of claims 1 to 6 and 8 to 17,
The subsequent lens group includes at least one lens group with negative refractive power, and of the lens groups with negative refractive power included in the subsequent lens group, the n-th lens with negative refractive power located closest to the object side. A zoom lens system in which the group has a negative lens closest to the object side and satisfies the following conditional expression (7).
(7) fGn/R2Gn<−1.10
however,
fGn: focal length of the n-th lens group,
R2Gn: paraxial radius of curvature of the image-side surface of the negative lens closest to the object in the n-th lens group. In the zoom lens system according to any one of claims 1 to 18,
The subsequent lens group includes at least one lens group with negative refractive power, and of the lens groups with negative refractive power included in the subsequent lens group, the n-th lens with negative refractive power located closest to the object side. A zoom lens system in which a group includes, in order from the object side, a negative lens and a positive lens. The zoom lens system according to any one of claims 1 to 7 and 9 to 19,
The subsequent lens group includes at least one lens group with negative refractive power, and of the lens groups with negative refractive power included in the subsequent lens group, the n-th lens with negative refractive power located closest to the object side. A zoom lens system in which the group has a negative lens closest to the image side. In the zoom lens system according to claim 8 or claim 20,
A zoom lens system in which the negative lens closest to the image side in the n-th lens group has a concave surface facing the object side and satisfies the following conditional expression (8).
(8) 29<νGn
however,
νGn: Abbe number for the d-line of the negative lens closest to the image side in the n-th lens group. In the zoom lens system according to any one of claims 1 to 21,
The subsequent lens group includes at least one lens group with negative refractive power, and of the lens groups with negative refractive power included in the subsequent lens group, the n-th lens with negative refractive power located closest to the object side. A zoom lens system in which the group is the second lens group of negative refractive power positioned immediately after the image side of the first lens group. In the zoom lens system according to any one of claims 1 to 22,
A zoom lens system that satisfies the following conditional expression (9).
(9) θgFn−(0.6440−0.001682×νn)<0
however,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group;
θgFn: partial dispersion ratio on the short wavelength side of the negative meniscus lens in the first lens group;
θgF = (ng-nF)/(nF-nC)
ng: refractive index for g-line,
nF: refractive index for F line,
nC: Refractive index for C-line. The zoom lens system according to any one of claims 1 to 23,
A zoom lens system that satisfies the following conditional expression (10).
(10) 34<νn
however,
νn: Abbe number for the d-line of the negative meniscus lens in the first lens group. The zoom lens system according to any one of claims 1 to 8 and 10 to 24,
A zoom lens system that satisfies the following conditional expression (11).
(11) 2.40<fG1/R2n
however,
fG1: focal length of the first lens group;
R2n: paraxial radius of curvature of the image-side surface of the negative meniscus lens in the first lens group. In the zoom lens system according to any one of claims 1 to 9 and 11 to 25,
A zoom lens system that satisfies the following conditional expression (12).
(12) 4.00<fG1/1Gd<13.00
however,
fG1: focal length of the first lens group;
1Gd: Distance on the optical axis from the surface closest to the object side to the surface closest to the image side in the first lens group. In the zoom lens system according to any one of claims 1 to 10 and 12 to 26,
A zoom lens system that satisfies the following conditional expression (13).
(13) 0.80<fG1/fw
however,
fG1: focal length of the first lens group;
fw: focal length of the entire system at the short focal length extremity. In the zoom lens system according to any one of claims 1 to 11 and 13 to 27,
A zoom lens system that satisfies the following conditional expression (14).
(14) 0.60<fG1/(fw×ft) ^1/2
however,
fG1: focal length of the first lens group;
fw: focal length of the entire system at the short focal length end,
ft: focal length of the entire system at the long focal length extremity. In the zoom lens system according to any one of claims 1 to 28,
A zoom lens system in which a positive meniscus lens having a convex surface facing the object side is positioned immediately before the object side of the negative meniscus lens in the first lens group. In the zoom lens system according to any one of claims 1 to 29,
A zoom lens system in which one or two positive lenses are positioned on the image side of the negative meniscus lens in the first lens group. In the zoom lens system according to any one of claims 2 to 30,
A zoom lens system in which the first lens group moves toward the object side during zooming from the short focal length extremity to the long focal length extremity.

Images