JP7400483B2 - Zoom lens system, lens barrel and imaging device - Google Patents

Description

The present invention relates to a zoom lens system, a lens barrel, and an imaging device.

2. Description of the Related Art Conventionally, various types of zoom lens systems have been known to be mounted on a digital camera (for example, a digital single-lens reflex camera) that is an imaging device. In particular, for zoom lens systems with a longer focal length on the telephoto side (long focal length end), a positive lead zoom type is generally used, with the positive, negative, and rear groups in order from the closest to the object. Therefore, there is a need for a compact optical system with high optical performance over the entire zoom and shooting distance range. Furthermore, in order to achieve high-speed automatic focusing and to reduce the weight of the focusing lens group, an inner focus method is already generally known in which the inner lens group is moved rather than the heavier front lens.

Patent Document 1 describes a zoom lens system having a four-group zoom configuration of positive, negative, and positive. In this zoom lens system, focusing is performed by moving the positive first lens group toward the object side (the positive first lens group constitutes the focusing lens group). In the zoom lens system disclosed in Patent Document 1, a reduction in photographing magnification is unlikely to occur, but the weight of the focusing lens increases, making it difficult to achieve high-speed AF.

Patent Document 2 describes a zoom lens system having a four-group zoom configuration of positive, negative, positive, and positive. In this zoom lens system, the positive first lens group is divided into a first A sub-lens group and a first B sub-lens group. Therefore, it is conceivable to perform focusing by moving either the first A sub-lens group or the first B sub-lens group toward the object side. Compared to the zoom lens system of Patent Document 1, the zoom lens system of Patent Document 2 can reduce the number of focusing lenses to achieve weight reduction. On the other hand, since the outer diameter of the lens does not change much, the focusing lens is still heavy, making it difficult to achieve high-speed AF.

Patent Document 3 describes a zoom lens system having a four-group zoom configuration of positive, negative, positive, and positive. In this zoom lens system, focusing is performed by moving the negative second lens group toward the object side (the negative second lens group constitutes the focusing lens group). Although the zoom lens system of Patent Document 3 can have a smaller lens outer diameter than the zoom lens systems of Patent Documents 1 and 2, it is inevitable that the zoom lens system will be heavier to some extent because it includes a large number of focusing lenses. Further, in the infinity shooting state at the telephoto end (long focal length end), the second lens group, which is the focusing lens group, and the positive third lens group, which is disposed on the image side thereof, are located close to each other. Since the second and third lens groups that are close to each other have a certain degree of strong refractive power, changing the distance between the second and third lens groups during focusing increases the effect of variable power. Shooting magnification tends to decrease.

Patent Document 4 describes a zoom lens system having a five-group zoom configuration with positive, negative, positive, negative, or a six-group zoom configuration with positive, negative, positive, negative, and positive. In this zoom lens system, focusing is performed by moving the negative fifth lens group toward the image side (the negative fifth lens group constitutes the focusing lens group). Since the fifth lens group, which is a focusing lens group, is located on the image side, the weight of the focusing lens group can be reduced compared to the zoom lens systems of Patent Documents 1 and 2, and it is also suitable for high-speed AF. .

Japanese Patent Application Publication No. 2010-217838 Japanese Patent Application Publication No. 2011-158630 Patent No. 4914991 JP2017-015930A

However, in conventional zoom lens systems, when an inner focus method is adopted, in order to reduce the amount of lens movement during focusing and achieve high-speed autofocus, the refractive power of the focusing lens group and the adjacent lens group must be It has a refractive power opposite in sign to that of the focusing lens group and is (necessarily) to have a relatively strong refractive power. As a result, when focusing with the inner focus method, zooming occurs in addition to focusing, and especially at the telephoto end, the focal length becomes shorter when photographing a subject at a close distance than when photographing a distant view. Put it away. For this reason, the inner focus method has a problem in that the photographing magnification becomes small when photographing at short distances.

Further, in the zoom lens system of Patent Document 4, in the infinity shooting state, the negative fifth lens group, which is the focusing lens group, and the positive fourth lens group, which is disposed on the object side, are located close to each other. Both have a certain degree of strong refractive power. For this reason, there is a problem in that the distance between the fourth lens group and the fifth lens group changes during focusing, which increases the influence of the variable power effect, resulting in a reduction in photographic magnification.

The present invention was completed based on the awareness of the above problems, and aims to appropriately perform focusing, reduce the size and weight of the focusing lens group, and even the entire lens system, and suppress the decrease in imaging magnification during close-range photography. An object of the present invention is to provide a zoom lens system, a lens barrel, and an imaging device.

The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b-th lens group and the 2c-th lens group changes, and the following conditional expression (1) is satisfied .
(1) 0.3<D2bc/(-f2)<1.0
however,
D2bc: distance between the 2b lens group and the 2c lens group when focusing on infinity;
f2: focal length of the second lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b lens group and the 2c lens group changes, and the following conditional expression (2) is satisfied.
(2) 0.3<D2bc/D2<1.0
however,
D2bc: distance between the 2b lens group and the 2c lens group when focusing on infinity;
D2: thickness of the second lens group on the optical axis,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , when the distance between the 2b lens group and the 2c lens group changes and the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group, the following conditional expression (3) is satisfied. , is characterized by.
(3) 0.3<H2_2bc/(-f2bc)
however,
H2_2bc: distance on the optical axis from the most image-side surface of the second bc lens group to the rear principal point position of the second bc lens group,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , when the distance between the 2B lens group and the 2C lens group changes and the combined optical system of the 2B lens group and the 2C lens group is defined as the 2Bc lens group, the following conditional expression (4) is satisfied. , is characterized by.
(4) 0.2<HH_2bc/(-f2bc)
however,
HH_2bc: Principal point interval of the second bc lens group, distance on the optical axis from the front principal point position to the rear principal point position,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b lens group and the 2c lens group changes, and the following conditional expression (5A) is satisfied.
(5A) 0<H1_2/D2≦0.640
however,
H1_2: Distance on the optical axis from the most object-side surface of the second lens group to the front principal point position,
D2: thickness of the second lens group on the optical axis,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , when the distance between the 2B lens group and the 2C lens group changes and the combined optical system of the 2A lens group and the 2B lens group is defined as the 2AB lens group, the following conditional expression (6A) is satisfied. , is characterized by.
(6A) 0<H1_2ab/D2≦0.409
however,
H1_2ab: distance on the optical axis from the most object-side surface of the second ab lens group to the front principal point position,
D2: thickness of the second lens group on the optical axis,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b-th lens group and the 2c-th lens group changes, and the following conditional expression (7) is satisfied.
(7) 1.5<f2a/(-f2b)<6.5
however,
f2a: focal length of the second a lens group,
f2b: focal length of the second b lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b-th lens group and the 2c-th lens group changes, and the following conditional expression (8A) is satisfied.
(8A) 0.5<f2b/f2c≦1.522
however,
f2b: focal length of the second b lens group,
f2c: focal length of the second c lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , when the distance between the 2B lens group and the 2C lens group changes and the combined optical system of the 2B lens group and the 2C lens group is defined as the 2Bc lens group, the following conditional expression (9) is satisfied. , is characterized by.
(9) 4<f2a/(-f2bc)<20
however,
f2a: focal length of the second a lens group,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b lens group and the 2c lens group changes, and the following conditional expression (10) is satisfied.
(10) 0.4<(R2_2a-R1_2a)/(R2_2a+R1_2a)<3.0
however,
R1_2a: paraxial radius of curvature of the surface closest to the object side of the second a lens group,
R2_2a: Paraxial radius of curvature of the most image-side surface of the second a lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b-th lens group and the 2c-th lens group changes, and the following conditional expression (11) is satisfied.
(11) 0.40<|R2_2a|/f2a
however,
R2_2a: Paraxial radius of curvature of the most image-side surface of the second a lens group,
f2a: focal length of the second a lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2B lens group and the 2C lens group changes, the 2A lens group has at least one positive lens, and satisfies the following conditional expression (12). .
(12) 45<2apMAX_νd
however,
2apMAX_νd: Abbe number of the positive lens with the largest Abbe number among the positive lenses in the 2a lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2B lens group and the 2C lens group changes, the 2A lens group has at least one negative lens, and satisfies the following conditional expression (13). .
(13) 0.2<(-f2anMAX)/f2a
however,
f2anMAX: Focal length of the negative lens with the largest refractive power among the negative lenses of the 2a-th lens group,
f2a: focal length of the second a lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b-th lens group and the 2c-th lens group changes, and the following conditional expression (14') is satisfied.
(14') 0.5<(R1_2b-R2_2b)/(R1_2b+R2_2b)<2.0
however,
R1_2b: Paraxial radius of curvature of the surface closest to the object side of the second b lens group,
R2_2b: Paraxial radius of curvature of the most image-side surface of the second b lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the succeeding lens group decreases, and the distance between the succeeding lens group increases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b lens group and the 2c lens group changes, and the 2b lens group is composed of one negative lens and one positive lens located in order from the object side, and the following conditional expression ( 17A).
(17A) 24.6≦2bn_νd−2bp_νd
however,
2bn_νd: Abbe number of the negative lens of the 2b lens group,
2bp_νd: Abbe number of the positive lens of the 2b lens group,
It is.
The zoom lens system of this embodiment includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups. Therefore, when changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the second lens group and the subsequent lens group decreases. The distance between adjacent lens groups among the plurality of lens groups changes, and the second lens group includes, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group changes. , the distance between the 2b lens group and the 2c lens group changes, and the following conditional expression (19'') is satisfied.
(19”) (1-M_2bt ² )・M_2bRt ² <-8.0
however,
M_2bt: Lateral magnification of the 2b lens group when focusing at infinity at the long focal length end,
M_2bRt: Combined lateral magnification of all lens groups on the image side from the 2b lens group when focusing at infinity at the long focal length end,
It is.

In the zoom lens system of this embodiment, the combined optical system of the 2a lens group and the 2b lens group is defined as the 2nd ab lens group, and the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group. When defined, it is preferable that at least one of the following conditional expressions (1), (2), (3), (4), (5), and (6) be satisfied.
(1) 0.3<D2bc/(-f2)<1.0
(2) 0.3<D2bc/D2<1.0
(3) 0.3<H2_2bc/(-f2bc)
(4) 0.2<HH_2bc/(-f2bc)
(5) 0<H1_2/D2<0.9
(6) 0<H1_2ab/D2<1.0
however,
D2bc: distance between the 2b lens group and the 2c lens group when focusing on infinity;
f2: focal length of the second lens group,
D2: thickness of the second lens group on the optical axis,
H2_2bc: distance on the optical axis from the most image-side surface of the second bc lens group to the rear principal point position of the second bc lens group,
f2bc: focal length of the second bc lens group when focusing on infinity;
HH_2bc: Principal point interval of the second bc lens group, distance on the optical axis from the front principal point position to the rear principal point position,
H1_2: Distance on the optical axis from the most object-side surface of the second lens group to the front principal point position,
H1_2ab: distance on the optical axis from the most object-side surface of the second ab lens group to the front principal point position,
It is.

Each of conditional expressions (1), (2), (3), (4), (5), and (6) will be explained below.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (1).
(1) 0.3<D2bc/(-f2)<1.0
however,
D2bc: Distance between the 2B lens group and the 2C lens group when focusing on infinity (distance on the optical axis from the surface vertex of the 2B lens group closest to the image side to the surface vertex of the 2C lens group closest to the object side ),
f2: focal length of the second lens group,
It is.

Within the range of conditional expression (1), it is more preferable to satisfy the following conditional expression (1').
(1')0.4<D2bc/(-f2)<1.0

The zoom lens system of this embodiment preferably satisfies the following conditional expression (2).
(2) 0.3<D2bc/D2<1.0
however,
D2bc: Distance between the 2B lens group and the 2C lens group when focusing on infinity (distance on the optical axis from the surface vertex of the 2B lens group closest to the image side to the surface vertex of the 2C lens group closest to the object side ),
D2: thickness of the second lens group on the optical axis,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (3) when the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group.
(3) 0.3<H2_2bc/(-f2bc)
however,
H2_2bc: distance on the optical axis from the most image-side surface of the second bc lens group to the rear principal point position of the second bc lens group,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.

Among the range of conditional expression (3), it is more preferable that the following conditional expression (3') is satisfied.
(3')0.4<H2_2bc/(-f2bc)<1.0

The zoom lens system of this embodiment preferably satisfies the following conditional expression (4) when the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group.
(4) 0.2<HH_2bc/(-f2bc)
however,
HH_2bc: Principal point interval of the second bc lens group, distance on the optical axis from the front principal point position to the rear principal point position,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.

Among the range of conditional expression (4), it is more preferable that the following conditional expression (4') is satisfied.
(4')0.3<HH_2bc/(-f2bc)<1.0

The zoom lens system of this embodiment preferably satisfies the following conditional expression (5).
(5) 0<H1_2/D2<0.9
however,
H1_2: Distance on the optical axis from the most object-side surface of the second lens group to the front principal point position,
D2: thickness of the second lens group on the optical axis,
It is.

Within the range of conditional expression (5), it is more preferable that the following conditional expression (5') is satisfied.
(5')0.4<H1_2/D2<0.9

The zoom lens system of this embodiment preferably satisfies the following conditional expression (6) when the combined optical system of the 2a-th lens group and the 2b-th lens group is defined as the 2nd ab lens group.
(6) 0<H1_2ab/D2<1.0
however,
H1_2ab: distance on the optical axis from the most object-side surface of the second ab lens group to the front principal point position,
D2: thickness of the second lens group on the optical axis,
It is.

Among the range of conditional expression (6), it is more preferable that the following conditional expression (6') is satisfied.
(6')0.2<H1_2ab/D2<0.8

The second c lens group may include at least two negative lenses and at least one positive lens.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (7).
(7) 1.5<f2a/(-f2b)<6.5
however,
f2a: focal length of the second a lens group,
f2b: focal length of the second b lens group,
It is.

Among the range of conditional expression (7), it is more preferable that the following conditional expression (7') is satisfied.
(7')2.0<f2a/(-f2b)<6.0

The zoom lens system of this embodiment preferably satisfies the following conditional expression (8).
(8) 0.5<f2b/f2c<2.5
however,
f2b: focal length of the second b lens group,
f2c: focal length of the second c lens group,
It is.

Among the range of conditional expression (8), it is more preferable that the following conditional expression (8') is satisfied.
(8') 0.8<f2b/f2c<2.0

The zoom lens system of this embodiment preferably satisfies the following conditional expression (9) when the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group.
(9) 4<f2a/(-f2bc)<20
however,
f2a: focal length of the second a lens group,
f2bc: focal length of the second bc lens group when focusing on infinity;
It is.

Within the range of conditional expression (9), it is more preferable to satisfy the following conditional expression (9').
(9')5<f2a/(-f2bc)<18

The zoom lens system of this embodiment preferably satisfies the following conditional expression (10).
(10) 0.4<(R2_2a-R1_2a)/(R2_2a+R1_2a)<3.0
however,
R1_2a: paraxial radius of curvature of the surface closest to the object side of the second a lens group,
R2_2a: paraxial radius of curvature of the most image-side surface of the second a lens group,
It is.

Among the range of conditional expression (10), it is more preferable to satisfy the following conditional expression (10').
(10') 0.4<(R2_2a-R1_2a)/(R2_2a+R1_2a)<2.5

The zoom lens system of this embodiment preferably satisfies the following conditional expression (11).
(11) 0.40<|R2_2a|/f2a
however,
R2_2a: paraxial radius of curvature of the most image-side surface of the second a lens group,
f2a: focal length of the second a lens group,
It is.

Within the range of conditional expression (11), it is more preferable to satisfy the following conditional expression (11') and further the following conditional expression (11'').
(11') 1.0<|R2_2a|/f2a<3.0
(11”) 1.2<|R2_2a|/f2a<3.0

The 2a-th lens group preferably has at least one positive lens and satisfies the following conditional expression (12).
(12) 45<2apMAX_νd
however,
2apMAX_νd: Abbe number of the positive lens with the largest Abbe number among the positive lenses in the 2a lens group,
It is.

Within the range of conditional expression (12), it is more preferable to satisfy the following conditional expression (12') and further the following conditional expression (12'').
(12') 50<2apMAX_νd
(12”)55<2apMAX_νd

The second a lens group may include at least one negative lens.

The 2a-th lens group is characterized by having at least one negative lens and satisfying the following conditional expression (13).
(13) 0.2<(-f2anMAX)/f2a
however,
f2anMAX: Focal length of the negative lens with the largest refractive power among the negative lenses of the 2a-th lens group,
f2a: focal length of the second a lens group,
It is.

Within the range of conditional expression (13), it is more preferable to satisfy the following conditional expression (13') and further the following conditional expression (13'').
(13')0.5<(-f2anMAX)/f2a<2.8
(13”)0.7<(-f2anMAX)/f2a<2.5

The zoom lens system of this embodiment preferably satisfies the following conditional expression (14).
(14) 0.4<(R1_2b-R2_2b)/(R1_2b+R2_2b)<2.5
however,
R1_2b: Paraxial radius of curvature of the surface closest to the object side of the second b lens group,
R2_2b: Paraxial radius of curvature of the most image-side surface of the second b lens group,
It is.

Within the range of conditional expression (14), it is more preferable to satisfy the following conditional expression (14') and further the following conditional expression (14'').
(14') 0.5<(R1_2b-R2_2b)/(R1_2b+R2_2b)<2.0
(14”) 0.6<(R1_2b-R2_2b)/(R1_2b+R2_2b)<1.6

The second b lens group has a negative lens located closest to the object side, and preferably satisfies the following conditional expression (15).
(15) 30<2bn_νd
however,
2bn_νd: Abbe number of the negative lens located closest to the object side of the 2b lens group,
It is.

Within the range of conditional expression (15), it is more preferable to satisfy the following conditional expression (15') and further the following conditional expression (15'').
(15')40<2bn_νd
(15”)45<2bn_νd

The second b lens group may include one negative lens and one positive lens positioned in order from the object side.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (16).
(16) 0.1<(-f2bn)/f2bp<0.7
however,
f2bn: focal length of the negative lens of the second b lens group,
f2bp: focal length of the positive lens of the second b lens group,
It is.

Within the range of conditional expression (16), it is more preferable to satisfy the following conditional expression (16') and further the following conditional expression (16'').
(16')0.4<(-f2bn)/f2bp<0.7
(16”)0.4<(-f2bn)/f2bp<0.5

The zoom lens system of this embodiment preferably satisfies the following conditional expression (17).
(17) 20<2bn_νd−2bp_νd
however,
2bn_νd: Abbe number of the negative lens of the 2b lens group,
2bp_νd: Abbe number of the positive lens of the 2b lens group,
It is.

Among the range of conditional expression (17), it is more preferable that the following conditional expression (17') is satisfied.
(17') 24<2bn_νd-2bp_νd

The zoom lens system of this embodiment preferably satisfies the following conditional expression (18).
(18) fW/｜f1-2bW｜<0.5
however,
fW: focal length of the entire system when focusing at infinity at the short focal length end,
f1-2bW: composite focal length from the first lens group to the second b lens group when focusing at infinity at the short focal length end,
It is.

Within the range of conditional expression (18), it is more preferable to satisfy the following conditional expression (18') and further the following conditional expression (18'').
(18')fW/|f1-2bW|<0.4
(18”) fW/｜f1-2bW｜<0.3

The zoom lens system of this embodiment preferably satisfies the following conditional expression (19).
(19) (1-M_2bt ² )・M_2bRt ² <-3.0
however,
M_2bt: Lateral magnification of the 2b lens group when focusing at infinity at the long focal length end,
M_2bRt: Combined lateral magnification of all lens groups on the image side from the 2b lens group when focusing at infinity at the long focal length end,
It is.

Within the range of conditional expression (19), it is more preferable to satisfy the following conditional expression (19') and further the following conditional expression (19'').
(19') (1-M_2bt ² )・M_2bRt ² <-5.0
(19”) (1-M_2bt ² )・M_2bRt ² <-8.0

An anti-vibration lens group may be provided on the image side of the second b lens group, which moves in a direction including a component perpendicular to the optical axis to displace the imaging position.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (20).
(20) 0.9<|(1-M_SRt)・M_SRRt|<3.5
however,
M_SRt: Lateral magnification of the anti-shake lens group when focusing at infinity at the long focal length end,
M_SRRt: Combined lateral magnification of all lens groups on the image side from the anti-vibration lens group when focusing at infinity at the long focal length end,
It is.

Within the range of conditional expression (20), it is more preferable to satisfy the following conditional expression (20') and further the following conditional expression (20'').
(20')1.1<|(1-M_SRt)・M_SRRt|<3.0
(20”) 1.2<|(1-M_SRt)・M_SRRt|<2.5

The zoom lens system of this embodiment preferably satisfies the following conditional expression (21).
(21) 0.4<f2b<fSR<2.5
however,
f2b: focal length of the second b lens group,
fSR: Focal length of anti-vibration lens group,
It is.

Within the range of conditional expression (21), it is more preferable to satisfy the following conditional expression (21') and further the following conditional expression (21'').
(21')0.6<f2b<fSR<2.3
(21”) 0.8<f2b<fSR<2.0

The lens group including the anti-vibration lens group does not need to move in the optical axis direction when changing power from the short focal length end to the long focal length end.

The second lens group does not need to move in the optical axis direction when changing power from the short focal length end to the long focal length end.

The first lens group does not need to move in the optical axis direction when changing power from the short focal length end to the long focal length end.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (22).
(22) 0.8<(fT/fW)/(M2T/M2W)<3.5
however,
fT: focal length of the entire system when focusing at infinity at the long focal length end,
fW: focal length of the entire system when focusing at infinity at the short focal length end,
M2T: Lateral magnification of the second lens group when focusing on infinity at the long focal length end,
M2W: Lateral magnification of the second lens group when focusing on infinity at the short focal length end,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (23).
(23) 0.2<(-f2)/fW<0.8
however,
f2: focal length of the second lens group,
fW: focal length of the entire system when focusing at infinity at the short focal length end,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (24).
(24) 0.3<f1/fT<1.1
however,
f1: focal length of the first lens group,
fT: focal length of the entire system when focusing at infinity at the long focal length end,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (25).
(25) 0.3<f1/(fW・fT) ^1/2 <3.0
however,
f1: focal length of the first lens group,
fW: focal length of the entire system when focusing at infinity at the short focal length end,
fT: focal length of the entire system when focusing at infinity at the long focal length end,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (26).
(26) 0.1<(D12T-D12W)/(-f2)<10.0
however,
D12T: Distance between the first lens group and the second lens group when focusing on infinity at the long focal length end (from the most image-side refractive surface of the first lens group to the most object-side refractive surface of the second lens group) distance on the optical axis),
D12W: Distance between the first lens group and the second lens group when focusing on infinity at the short focal length end (from the refractive surface closest to the image side of the first lens group to the refractive surface closest to the object side of the second lens group) distance on the optical axis),
f2: focal length of the second lens group,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (27).
(27) 0.1<(D2RW-D2RT)/(-f2)<10.0
however,
D2RW: Distance between the second lens group and the succeeding lens group when focusing on infinity at the short focal length end (optical axis from the refractive surface closest to the image side of the second lens group to the refractive surface closest to the object side of the succeeding lens group) distance above),
D2RT: Distance between the second lens group and the subsequent lens group when focusing on infinity at the long focal length end (optical axis from the most image-side refractive surface of the second lens group to the most object-side refractive surface of the subsequent lens group) distance above),
f2: focal length of the second lens group,
It is.

The zoom lens system of this embodiment preferably satisfies the following conditional expression (28).
(28) 0.5<(R1_2a)/(R2_2b)<10.0
however,
R1_2a: paraxial radius of curvature of the surface closest to the object side of the second a lens group,
R2_2b: Paraxial radius of curvature of the most image-side surface of the second b lens group,
It is.

Within the range of conditional expression (28), it is more preferable to satisfy the following conditional expression (28') and further the following conditional expression (28'').
(28')0.7<(R1_2a)/(R2_2b)<8.0
(28”) 0.9<(R1_2a)/(R2_2b)<5.0

The lens barrel of this embodiment is composed of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group, and has a short focal length end. When changing the magnification from to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the second lens group increases in order from the object side. , the second lens group has a positive refractive power, the second b lens group has a negative refractive power, and the second c lens group has a negative refractive power.When focusing from infinity to a short distance, the second b lens group A zoom lens system characterized in that as the lens group moves toward the image side, the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change. It is characterized by

The imaging device of this embodiment is composed of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group. When changing the magnification to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the second lens group is arranged in order from the object side. It is composed of a 2A lens group with positive refractive power, a 2B lens group with negative refractive power, and a 2C lens group with negative refractive power.When focusing from infinity to a short distance, the 2B lens group A zoom lens system characterized in that as the group moves toward the image side, the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change. It is a feature.

According to the present invention, a zoom lens system, a lens barrel, and an imaging device are capable of performing focusing appropriately, reducing the size and weight of the focusing lens group and the entire lens system, and suppressing a decrease in photographic magnification during close-range photography. can be provided.

FIG. 3 is a conceptual diagram showing a movement trajectory of the zoom lens system during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 1; FIG. 7 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 2; FIG. 7 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 3. FIG. 7 is a conceptual diagram showing a movement trajectory of a zoom lens system during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 4; FIG. 12 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 5. FIG. 9 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 6. FIG. 12 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 7. FIG. 12 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 8. FIG. 2 is a lens configuration diagram of the zoom lens system according to Numerical Example 1 at the time of infinity focusing at the short focal length end. FIG. 3 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 1 when focusing at infinity at the short focal length end. FIG. 3 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 1 when focused at 1.2 m at the short focal length end. FIG. 3 is a lateral aberration diagram when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 1. FIG. FIG. 3 is a lateral aberration diagram of the zoom lens system according to Numerical Example 1 when focused at 1.2 m at the short focal length end. FIG. 13 is a diagram of lateral aberration during anti-vibration driving in FIG. 12; FIG. 3 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 1; FIG. 3 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 1. FIG. 3 is a lateral aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 1. FIG. 3 is a lateral aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 1. 18 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 17. FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 2 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 2; FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 2 when focused at 1.2 m at the short focal length end. FIG. 7 is a lateral aberration diagram when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 2; FIG. 7 is a lateral aberration diagram of the zoom lens system according to Numerical Example 2 when focused at 1.2 m at the short focal length end. FIG. 24 is a diagram of lateral aberration during anti-vibration driving in FIG. 23; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 2; FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 2. FIG. 7 is a lateral aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 2. FIG. 7 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 2. FIG. 29 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 28; FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 3 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 3; FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 3 when focused at 1.2 m at the short focal length end. FIG. 7 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 3. FIG. 7 is a lateral aberration diagram of the zoom lens system according to Numerical Example 3 when focused at 1.2 m at the short focal length end. FIG. 35 is a diagram of lateral aberration during anti-vibration driving in FIG. 34; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 3; FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 3. FIG. 7 is a lateral aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 3. FIG. 7 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 3. 41 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 40; FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 4 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 4 when focusing at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 4 when focused at 1.2 m at the short focal length end. FIG. 7 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 4. FIG. 7 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 4. FIG. 46 is a diagram of lateral aberration during anti-vibration driving in FIG. 45; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 4. FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 4. FIG. 7 is a diagram of lateral aberrations when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 4. FIG. 7 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 4. 51 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 50; FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 5 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 5 when focusing at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 5 when focused at 1.2 m at the short focal length end. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 5. FIG. 7 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 5. FIG. 57 is a diagram of lateral aberration during anti-vibration driving in FIG. 56; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 5. FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 5. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 5. FIG. 7 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 5. 62 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 61. FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 6 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 6 when focusing at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 6 when focused at 1.2 m at the short focal length end. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 6. FIG. 7 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 6. FIG. 68 is a diagram of lateral aberration during anti-vibration driving in FIG. 67; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 6; FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 6. FIG. 7 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 6. FIG. 7 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 6. FIG. 73 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 72; FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 7 at the time of infinity focusing at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 7 when focusing at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 7 when focused at 1.2 m at the short focal length end. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 7. FIG. 7 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 7. FIG. 79 is a diagram of lateral aberration during anti-vibration driving in FIG. 78; FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 7; FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 7. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 7. FIG. 12 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 7. 84 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 83; FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 8 at the time of focusing at infinity at the short focal length end. FIG. 12 is a longitudinal aberration diagram when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 8. FIG. 12 is a longitudinal aberration diagram when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 8. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 8. FIG. 12 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 8. FIG. 89 is a diagram of lateral aberration during anti-vibration driving in FIG. 89; FIG. 9 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 8; FIG. 12 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 8. FIG. 9 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 8. FIG. 12 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 8. 95 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 94; FIG. FIG. 12 is a conceptual diagram showing a movement trajectory during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 9. FIG. 12 is a conceptual diagram showing a movement trajectory of a zoom lens system during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 10. FIG. 9 is a conceptual diagram showing a movement trajectory of a zoom lens system during zooming, a movement trajectory during focusing, and a movement trajectory during anti-shake driving of the zoom lens system according to Numerical Example 11. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 9 when focusing at infinity at the short focal length end. FIG. 9 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 9 when focusing at infinity at the short focal length end. FIG. 12 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 9 when focused at 1.2 m at the short focal length end. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 9. FIG. 12 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 9. FIG. 104 is a diagram of lateral aberration during anti-vibration driving in FIG. 103; 12 is a diagram of longitudinal aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 9. FIG. FIG. 12 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 9. FIG. 9 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 9. FIG. 9 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 9. 109 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 108. FIG. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 10 when focusing at infinity at the short focal length end. FIG. 12 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 10 when focused at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 10. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 10. FIG. 12 is a diagram of lateral aberration when focusing on 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 10. FIG. 115 is a diagram of lateral aberration during anti-vibration driving in FIG. 114; FIG. 12 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 10. FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 10. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 10. FIG. 12 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 10. 120 is a lateral aberration diagram during anti-vibration driving (±0.3°) in FIG. 119. FIG. 7 is a lens configuration diagram of a zoom lens system according to Numerical Example 11 at the time of focusing at infinity at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 11 when focusing on infinity at the short focal length end. FIG. 12 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 11 when focused at 1.2 m at the short focal length end. FIG. 7 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 11 when focused at 0.9 m at the short focal length end. FIG. 11 is a diagram of lateral aberration when focusing on infinity at the short focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a diagram of lateral aberration when focusing at 1.2 m at the short focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a diagram of lateral aberration when focusing at 0.9 m at the short focal length end of the zoom lens system according to Numerical Example 11. 127 is a diagram of lateral aberration during anti-shake driving in FIG. 126. FIG. FIG. 7 is a longitudinal aberration diagram when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 11. FIG. 7 is a longitudinal aberration diagram when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a longitudinal aberration diagram when focusing on 0.9 m at the long focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a diagram of lateral aberration when focusing on infinity at the long focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a diagram of lateral aberration when focusing on 1.2 m at the long focal length end of the zoom lens system according to Numerical Example 11. FIG. 12 is a diagram of lateral aberration when the zoom lens system according to Numerical Example 11 is focused at 0.9 m at the long focal length end. 134 is a lateral aberration diagram during anti-vibration driving (±0.6°) in FIG. 133. FIG. 1 is a diagram illustrating an example of the external configuration of a lens barrel (imaging device) equipped with a zoom lens system according to the present embodiment.

1 to 8 and 97 to 99 are conceptual diagrams illustrating the movement locus during magnification change, the movement locus during focusing, and the movement locus during anti-shake driving of the zoom lens system according to Numerical Examples 1 to 11. It is a diagram. 1 to 8 and 97 to 99 are drawn based on the lens configuration when focusing on infinity at the short focal length end.

Through Numerical Examples 1 to 8, the zoom lens system according to the present embodiment includes, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group G2 with negative refractive power. It is composed of a lens group GR.
During zooming from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, and the distance between the second lens group G2 and the subsequent lens group GR decreases.
The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
When focusing from infinity to a short distance, the 2b lens group G2b moves toward the image side, and the distance between the 2a lens group G2a and the 2b lens group G2b and the distance between the 2b lens group G2b and the 2c lens group G2c change. The interval changes (the second b lens group G2b constitutes the focus lens group). More specifically, the distance between the 2a lens group G2a and the 2b lens group G2b increases, and the distance between the 2b lens group G2b and the 2c lens group G2c decreases.
A plane parallel plate CG is provided in front of the image plane of an image sensor (not shown) on the image side of the subsequent lens group GR. This parallel plane plate CG can have functions such as a low-pass filter, an infrared cut filter, and a cover glass that protects the imaging surface of the imaging device.

The lens configuration and the like described above are common to Numerical Examples 1 to 8. Below, the individual lens configurations of Numerical Examples 1 to 8 will be explained.

In Numerical Example 1 in FIG. 1, the subsequent lens groups GR include, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fourth lens group G4 with positive refractive power. It is composed of five lens groups G5 (that is, it has a five-group zoom lens configuration of positive, negative, positive, negative, and positive).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and The distance between adjacent lens groups changes such that the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, and the fifth lens group G5 move (extend) toward the object side, and the second lens group G2 and the Four lens groups G4 are fixed relative to the image plane. The third lens group G3 and the fifth lens group G5 move (extend) toward the object side while drawing the same locus. Thereby, the mechanical configuration related to zooming can be simplified.
The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a having a positive refractive power and a 4b-th lens group G4b having a negative refractive power. The fourth b lens group G4b is an anti-vibration lens group that corrects image blur by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In numerical examples 2 and 3 in FIGS. 2 and 3, the subsequent lens group GR includes, in order from the object side, a third lens group G3 with a positive refractive power, a fourth lens group G4 with a negative refractive power, and a negative refractive power. and a fifth lens group G5 having a refractive power of (that is, a five-group zoom lens configuration with positive/negative, positive/negative).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and The distance between adjacent lens groups changes such that the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, and the fifth lens group G5 move (extend) toward the object side with respect to the image plane, and the second lens group Lens group G2 and fourth lens group G4 are fixed with respect to the image plane. The third lens group G3 and the fifth lens group G5 move (extend) toward the object side while drawing the same locus. Thereby, the mechanical configuration related to zooming can be simplified.
The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a having a positive refractive power and a 4b-th lens group G4b having a negative refractive power. The fourth b lens group G4b is an anti-vibration lens group that corrects image blur by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In Numerical Example 4 in FIG. 4, the subsequent lens groups GR include, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fourth lens group G4 with negative refractive power. It is composed of a 5th lens group G5 and a 6th lens group G6 having a negative refractive power (that is, a 6-group zoom lens configuration with positive/negative, positive/negative, positive/negative).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between the third lens group G3 and the fourth lens group G4 changes (increases or decreases), the distance between the fourth lens group G4 and the fifth lens group G5 changes (increases or decreases), and the distance between the fifth lens group G5 and the fifth lens group G5 changes (increases or decreases). The distance between adjacent lens groups changes so that the distance between the six lens groups G6 changes (increases or decreases).
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 move toward the object side. (extended), and the second lens group G2 is fixed relative to the image plane. The fourth lens group G4 and the sixth lens group G6 move (extend) toward the object side while drawing the same locus. Thereby, the mechanical configuration related to zooming can be simplified.
The second c lens group G2c is an anti-vibration lens group that corrects image blur by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In numerical example 5 in FIG. 5, the subsequent lens groups GR include, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fourth lens group G4 with negative refractive power. It is composed of five lens groups G5 (that is, it has a five-group zoom lens configuration of positive, negative, positive, negative, and negative).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and Each adjacent lens group is adjusted such that the distance between the third lens group G3 and the fourth lens group G4 changes (increases or decreases), and the distance between the fourth lens group G4 and the fifth lens group G5 changes (increases or decreases). The interval changes.
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move (extend) toward the object side, and The second lens group G2 is fixed with respect to the image plane. The third lens group G3 and the fifth lens group G5 move (extend) toward the object side while drawing the same locus. Thereby, the mechanical configuration related to zooming can be simplified.
Some of the lens groups of the second c lens group G2c are anti-shake lens groups that correct image shake by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In numerical example 6 in FIG. 6, the subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with positive refractive power (i.e. It has a 4-group zoom lens configuration with positive, negative, and positive elements.)
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between adjacent lens groups changes so that the distance between the third lens group G3 and the fourth lens group G4 changes (increases or decreases).
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane, the second lens group G2 moves toward the image side, and the second lens group G2 moves toward the image side. The third lens group G3 once moves to the image side and then returns to the object side (makes a U-turn).
The fourth lens group G4 is composed of, in order from the object side, a 4a lens group G4a with positive refractive power, a 4b lens group G4b with negative refractive power, and a 4c lens group G4c with positive refractive power. ing. The fourth b lens group G4b is an anti-vibration lens group that corrects image shake by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the third lens group G3 and the fourth lens group G4 (at a position immediately before the fourth lens group G4).

In numerical examples 7 and 8 shown in FIGS. 7 and 8, the subsequent lens group GR includes, in order from the object side, a third lens group G3 with a positive refractive power, a fourth lens group G4 with a positive refractive power, and a negative lens group G3 with a positive refractive power. and a fifth lens group G5 having a refractive power of (that is, a five-group zoom lens configuration with positive/negative, positive/negative, positive/negative).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between adjacent lens groups changes such that the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, and the fifth lens group G5 are fixed to the image plane, and the second lens group G2 is fixed to the image plane. and the fourth lens group G4 moves (extends) toward the object side.
The fifth lens group G5 is composed of, in order from the object side, a 5a lens group G5a with positive refractive power, a 5b lens group G5b with negative refractive power, and a 5c lens group G5c with positive refractive power. ing. The fifth b lens group G5b is an anti-vibration lens group that corrects image blur by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In Numerical Example 9 in FIG. 97, the subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with negative refractive power (i.e. It has a 4-group zoom lens configuration with positive, negative, positive and negative lenses).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between adjacent lens groups changes so that the distance between the third lens group G3 and the fourth lens group G4 changes (in the example of FIG. 97, it increases, but may also decrease).
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 move toward the object side with respect to the image plane ( (rolled out).
The fourth lens group G4 is composed of, in order from the object side, a 4a lens group G4a with positive refractive power, a 4b lens group G4b with negative refractive power, and a 4c lens group G4c with positive refractive power. ing. The fourth b lens group G4b is an anti-vibration lens group that corrects image shake by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In Numerical Example 10 in FIG. 98, the subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with positive refractive power (i.e. (It has a 4-group zoom lens configuration with positive, negative, and positive).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between adjacent lens groups changes so that the distance between the third lens group G3 and the fourth lens group G4 changes (in the example of FIG. 98, it increases, but may also decrease).
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, and the fourth lens group G4 move (extend) toward the object side with respect to the image plane, and the second lens group Lens group G2 is fixed with respect to the image plane.
The fourth lens group G4 is composed of, in order from the object side, a 4a lens group G4a with positive refractive power, a 4b lens group G4b with negative refractive power, and a 4c lens group G4c with positive refractive power. ing. The fourth b lens group G4b is an anti-vibration lens group that corrects image shake by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position.
A diaphragm SP for adjusting the amount of light is provided between the second lens group G2 and the third lens group G3 (at a position immediately before the third lens group G3).

In Numerical Example 11 in FIG. 99, the subsequent lens groups GR include, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fourth lens group G4 with negative refractive power. It is composed of a 5th lens group G5 and a 6th lens group G6 with positive refractive power (a 6-group zoom lens configuration with positive/negative, positive/negative, positive/negative).
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the first lens group G1 and the second lens group G2 decreases, and The distance between the third lens group G3 and the fourth lens group G4 changes, the distance between the fourth lens group G4 and the fifth lens group G5 changes, and the distance between the fifth lens group G5 and the sixth lens group G6 changes. , the distance between adjacent lens groups changes.
When changing the magnification from the short focal length end to the long focal length end, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 are aligned with respect to the image plane. The second lens group G2 is moved (extended) toward the object side and fixed relative to the image plane. The fourth lens group G4 and the sixth lens group G6 move (extend) toward the object side while drawing the same locus. Thereby, the mechanical configuration related to zooming can be simplified.
The second c lens group G2c is an anti-shake lens group (first anti-shake lens group) that corrects image blur by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position. Further, the fifth lens group G5 is an anti-shake lens group (second anti-shake lens group) that corrects image shake by moving in a direction including a component perpendicular to the optical axis and displacing the imaging position. The second c lens group G2c (first anti-vibration lens group) and the fifth lens group G5 (second anti-vibration lens group) may each function independently as an anti-vibration lens group, or they may be used in coordination ( (cooperation) may be used to function as an anti-vibration lens group. By providing two anti-vibration lens groups and driving them in coordination, it is possible to secure a large anti-vibration angle while suppressing aberration fluctuations during image blur correction. Furthermore, when a plurality of anti-vibration lens groups are provided, it is preferable that the above-mentioned conditional expressions (20) and (21) be satisfied.

The zoom lens system according to this embodiment has the four-group zoom configuration shown in Numerical Examples 1 to 8 in FIGS. 1 to 8 and Numerical Examples 9 to 11 in FIGS. 97 to 99, The present invention is not limited to a 5-group zoom configuration or a 6-group zoom configuration. An aspherical surface or a diffractive surface may be used on any surface of the zoom lens system. Aspherical surfaces include glass molded aspherical surfaces and ground aspherical surfaces that are formed directly on the lens surface, composite aspherical surfaces (hybrid aspherical surfaces) that are made by coating a resin layer on the lens surface and applying an aspherical surface on top, and lenses. A plastic aspherical surface made of resin material or the like can be applied.

The zoom lens system according to the present embodiment is a positive lead type with a particularly extended focal length on the telephoto side, and the second lens group G2 includes, in order from the object side, a second lens group G2a with a positive refractive power and a second lens group G2a with a negative refractive power. It is composed of a second b lens group G2b having a refractive power and a second c lens group G2c having a negative refractive power. When focusing from infinity to a short distance, the 2b lens group G2b moves toward the image side, and the distance between the 2a lens group G2a and the 2b lens group G2b, and the distance between the 2b lens group G2b and the 2c lens group The interval between G2c changes (the second b lens group G2b constitutes a focus lens group). More specifically, the distance between the 2a lens group G2a and the 2b lens group G2b increases, and the distance between the 2b lens group G2b and the 2c lens group G2c decreases.

In the zoom lens system of this embodiment, the second lens group G2a, which is arranged adjacent to the object side of the second lens group G2b, which is a focusing lens group, has an opposite sign (the second lens group G2b has a negative refractive power). In contrast, the second a lens group G2a has a positive refractive power) and a relatively weak refractive power. Thereby, it is possible to suppress the magnification change effect during focusing and to suppress a decrease in the photographing magnification during close-range photography.

By arranging the positive 2nd a lens group G2a on the object side of the negative 2b lens group G2b, the light beam incident on the 2b lens group G2b is converged, thereby reducing the lens outer diameter of the 2b lens group G2b. This makes it possible to reduce the weight of the focusing lens group.

Generally, when zooming, especially at the telephoto end (long focal length end), the distance between the first lens group and the second lens group becomes wider, so the diameter of the axial light beam incident on the second lens group becomes smaller. This may result in loss of focusing sensitivity.

On the other hand, in the zoom lens system of this embodiment, the positive 2a lens group G2a is arranged immediately before the negative 2b lens group G2b, which is the focusing lens group, and the 2a lens group G2a and the 2a lens group G2a The sensitivity of the focus lens group is maintained by maintaining the distance between the 2b lens group G2b and arranging the 2a lens group G2a and the 2b lens group G2b close to each other even at the telephoto end (long focal length end). That's what I do. Thereby, it is possible to prevent the amount of movement of the second b lens group G2b during focusing from increasing more than necessary and thereby increasing the AF time.

Further, a lens group having a positive refractive power (for example, the first lens group G1) disposed closer to the object side than the second lens group G2 has a relatively weak refractive power. Therefore, even if the distance between the second a lens group G2a and the second b lens group G2b is large during focusing, the magnification change effect is relatively small, and it is possible to suppress a decrease in photographing magnification at short distances. Note that although it is possible to use the second a lens group G2a as a focusing lens group, since the lens outer diameter is relatively large, it is not suitable as a group used for high-speed AF.

The second c lens group G2c is arranged on the image side of the second b lens group G2b. Since the 2nd c lens group G2c, whose refractive powers have the same sign (both have negative powers), is located on the image side of the 2b lens group G2b, which is a focus lens group, the 2b lens group G2b has such a strong refractive power. It is possible to obtain focusing sensitivity without any distortion, and since strong refractive power is not required, the number of lenses can be relatively small. Furthermore, by arranging the second c lens group G2c, it is possible to suppress aberration fluctuations due to changes in the photographing distance that occur during focusing, and it is also possible to reduce the weight of the focusing lens group.

Further, by providing the second c lens group G2c, the entire second lens group G2 can have a strong refractive power, and it is possible to secure the refractive power for changing the magnification from wide-angle to telephoto. In addition, the second c lens group G2c is necessary to ensure the necessary amount of back focus (distance from the final lens surface to the image plane in the entire lens system) for the camera system, and is necessary for correction of spherical aberration, chromatic aberration, etc. It also has a role.

Note that it is also possible to use the 2nd c lens group G2c as a focusing lens group, but in focusing from infinity to a short distance, a positive 3rd lens group with an opposite sign and a relatively strong refractive power is used. Since the distance from G3 increases, the magnification change effect is strong, and the reduction in imaging magnification becomes large when shooting at close distances, which is not preferable.

In the zoom lens system of this embodiment, the "lens groups (for example, the first lens group G1 to the sixth lens group G6)" change in relative positional relationship in the optical axis direction with adjacent lens groups during zooming, so that the distance between the front and rear lenses changes. is a unit that changes, and "sub lens groups (for example, 2a lens group G2a to 2c lens group G2c, 4a lens group G4a to 4c lens group G4c, 5a lens group G5a to 5c lens group G5c)" are , means a unit whose relative positional relationship in the optical axis direction with adjacent lens groups does not change during zooming.

In the 2b lens group G2b, which is a focusing lens group, if the distance between the 2a lens group G2a and the 2c lens group G2c which are adjacent to each other changes during zooming, a means for controlling by a cam and a means for controlling by a motor may be used. is possible. However, if an attempt is made to control the second b lens group G2b using a cam, for example, the mechanical configuration becomes complicated and the entire lens becomes large, which is not preferable. Furthermore, if a motor is used to control the zooming operation in synchronization with the zooming operation, it is difficult to achieve sufficient synchronization due to electrical control delays and motor speed limits, resulting in out-of-focus during zooming. Undesirable. Therefore, in this embodiment, the interval between the 2a-th lens group G2a to the 2c-th lens group G2c is fixed during zooming.

In the zoom lens system of this embodiment, the "anti-shake lens group" refers to a unit that moves in a direction perpendicular to the optical axis during image stabilization, and the distance between adjacent lens groups in the optical axis direction during zooming or focusing. There is no limit as to whether or not it changes. That is, the entire lens group or sub-lens group may be used as an anti-vibration lens group, or a part of the lens group or sub-lens group may be used as an anti-vibration lens group.

Conditional expressions (1) and (1') are based on the distance between the 2b lens group G2b and the 2c lens group G2c at infinity focusing (from the vertex of the most image side surface of the 2b lens group G2b to the 2c lens group G2c). (distance on the optical axis to the surface vertex closest to the object side) and the focal length of the second lens group G2. By satisfying conditional expression (1), it is possible to downsize the second lens group G2 and, by extension, the entire lens system, and to satisfactorily correct various aberrations. This effect can be obtained more significantly by satisfying conditional expression (1').
When the upper limits of conditional expressions (1) and (1') are exceeded, the overall thickness of the second lens group G2 increases and the total lens length becomes longer, and the diameter of the front lens increases in order to secure off-axis light. I end up.
If the lower limit of conditional expression (1) is exceeded, the distance between the principal points of the composite optical system of the 2b lens group G2b and the 2c lens group G2c becomes narrower. It is necessary to strengthen the refractive power of at least one of the group G2b and the second c lens group G2c. Therefore, during zooming or focusing, variations in aberrations such as spherical aberration, coma aberration, and astigmatism become large, making correction difficult.

Conditional expression (2) is based on the distance between the 2b lens group G2b and the 2c lens group G2c at infinity focusing (from the vertex of the most image side surface of the 2b lens group G2b to the most object side of the 2c lens group G2c). (distance on the optical axis to the apex of the surface) and the thickness of the second lens group G2 on the optical axis. By satisfying conditional expression (2), it is possible to downsize the second lens group G2 and, by extension, the entire lens system, and to satisfactorily correct various aberrations.
If the upper limit of conditional expression (2) is exceeded, the overall thickness of the second lens group G2 increases, the total lens length becomes longer, and the diameter of the front lens increases in order to secure off-axis light.
If the lower limit of conditional expression (2) is exceeded, the distance between the principal points of the composite optical system of the 2b lens group G2b and the 2c lens group G2c becomes narrower. It is necessary to strengthen the refractive power of at least one of the group G2b and the second c lens group G2c. Therefore, during zooming or focusing, variations in aberrations such as spherical aberration, coma aberration, and astigmatism become large, making correction difficult.

Conditional expressions (3) and (3') are defined as The relationship between the distance on the optical axis to the rear principal point position of the 2bc lens group and the focal length of the 2bc lens group when focusing on infinity is defined. By setting the rear principal point position of the second bc lens group relatively to the object side so as to satisfy conditional expression (3), the second a lens group G2a has the smallest pupil diameter in the second lens group G2. The arrangement and movement amount of the second b lens group G2b, which is the focusing lens group, can be easily secured between the second b lens group G2b and the second b lens group G2b. This effect can be obtained more significantly by satisfying conditional expression (3').
If the upper limit of conditional expression (3') is exceeded, the overall thickness of the second lens group G2 increases, the overall lens length becomes longer, and the diameter of the front lens increases to ensure off-axis light.
If the lower limit of conditional expression (3) is exceeded, the position of the rear principal point of the second bc lens group will be too close to the image side, making it difficult to ensure the amount of focusing movement. If an attempt is made to forcibly secure the amount of focusing movement, it is necessary to increase the refractive power of the second b lens group G2b, which increases aberration fluctuations during focusing.

Conditional expressions (4) and (4') are the principal point spacing of the 2nd bc lens group on the front side when the combined optical system of the 2b lens group G2b and the 2c lens group G2c is defined as the 2nd bc lens group. The relationship between the distance on the optical axis from the principal point position to the rear principal point position and the focal length of the second bc lens group when focusing on infinity is defined. By satisfying conditional expression (4), appropriate focusing sensitivity can be obtained without extremely increasing the refractive powers of the second b lens group G2b and the second c lens group G2c. This effect can be obtained more significantly by satisfying conditional expression (4'). Furthermore, by satisfying conditional expression (4'), it is possible to downsize the second lens group G2 and, by extension, the entire lens system.
If the upper limit of conditional expression (4') is exceeded, the overall thickness of the second lens group G2 increases, the overall lens length becomes longer, and the diameter of the front lens increases in order to secure off-axis light.
If the lower limit of conditional expression (4) is exceeded, the distance between the principal points of the second bc lens group becomes too narrow. It is necessary to strengthen the refractive power of one side. Therefore, during zooming or focusing, variations in aberrations such as spherical aberration, coma aberration, and astigmatism become large, making correction difficult.

Conditional expressions (5) and (5') are the distance on the optical axis from the surface closest to the object side of the second lens group G2 to the front principal point position, and the thickness of the second lens group G2 on the optical axis. It defines the relationship. By satisfying conditional expression (5), the entire lens system can be made smaller and lighter, and fluctuations in spherical aberration depending on the photographing distance at the long focal length end can be suppressed. This effect can be obtained more significantly by satisfying conditional expression (5').
When the upper limits of conditional expressions (5) and (5') are exceeded, the thickness of the second lens group G2 becomes large, and the lens outer diameters of the first lens group G1 and the second a lens group G2a become large. This will lead to an increase in the size of the system.
When the lower limit of conditional expression (5) is exceeded, the second b lens group G2b, which is the focus lens group, is moved closer to the object side and becomes larger, resulting in an increase in the weight of the entire lens system. In particular, at the long focal length end, variations in spherical aberration depending on the photographing distance increase.

Conditional expressions (6) and (6') are expressed as The relationship between the distance on the optical axis to the principal point position and the thickness of the second lens group G2 on the optical axis is defined. By satisfying conditional expression (6), it is possible to reduce the size and weight of the entire lens system, and to suppress fluctuations in spherical aberration due to shooting distance at the long focal length end. This effect can be obtained more significantly by satisfying conditional expression (6').
If the upper limit of conditional expression (6) is exceeded, the thickness of the second lens group G2 becomes large, and the lens outer diameters of the first lens group G1 and the second a lens group G2a become large, resulting in an increase in the size of the entire lens system. I invite you.
When the lower limit of conditional expression (6) is exceeded, the second b lens group G2b, which is the focus lens group, is moved closer to the object side and becomes larger, resulting in an increase in the weight of the entire lens system. In particular, at the long focal length end, variations in spherical aberration depending on the shooting distance increase.

The second c lens group G2c includes at least two negative lenses and at least one positive lens. This makes it possible to effectively correct axial chromatic aberration, magnification chromatic aberration, spherical aberration, coma, etc. that change during zooming or focusing, while maintaining a certain zoom ratio without increasing the size of the lens. . The positive lens and the negative lens in the second c lens group G2c may be arranged in close contact with each other or may be cemented together, or may be arranged with an air gap between them.

Conditional expressions (7) and (7') define the relationship between the focal length of the second a lens group G2a and the focal length of the second b lens group G2b. By satisfying conditional expression (7), it is possible to downsize the second b lens group G2b and, by extension, the entire lens system. Furthermore, the AF speed can be increased by reducing the weight of the second b lens group G2b, which is the focusing lens group. Furthermore, aberration fluctuations such as spherical aberration, coma aberration, astigmatism, axial chromatic aberration, and lateral chromatic aberration during focusing can be favorably corrected. Further, positive distortion (pincushion distortion) at the telephoto end can be favorably corrected. Furthermore, by appropriately setting the focusing sensitivity, the amount of movement during focusing can be suppressed and the AF speed can be increased. This effect can be obtained more significantly by satisfying conditional expression (7').
If the upper limit of conditional expression (7) is exceeded, the refractive power of the second a lens group G2a becomes too weak and the diameter of the light beam incident on the second b lens group G2b becomes large, so that the lens outer diameter of the second b lens group G2b becomes It gets bigger. Furthermore, the weight of the second b lens group G2b, which is the focusing lens group, increases, and the AF speed decreases.
If the lower limit of conditional expression (7) is exceeded, the refractive power of the second a lens group G2a becomes too strong, resulting in large fluctuations in aberrations such as spherical aberration, coma aberration, astigmatism, longitudinal chromatic aberration, and lateral chromatic aberration during focusing. turn into. Furthermore, positive distortion (pincushion distortion) at the telephoto end increases. Furthermore, since the refractive power of the second b lens group G2b is relatively weakened, it becomes difficult to increase the focusing sensitivity, the amount of movement during focusing increases, and the AF speed decreases.

Conditional expressions (8) and (8') define the relationship between the focal length of the second b lens group G2b and the focal length of the second c lens group G2C. By satisfying conditional expression (8), it is possible to shorten the overall lens length, suppress the amount of focusing movement of the second b lens group G2b, increase the AF speed, and suppress aberration fluctuations during focusing. This effect can be obtained more significantly by satisfying conditional expression (8').
If the upper limit of conditional expressions (8) and (8') is exceeded, the refractive power of the second b lens group G2b becomes too weak, resulting in an increase in focusing movement and a decrease in AF speed. Moreover, the total length of the lens becomes large.
If the lower limit of conditional expression (8) is exceeded, the refractive power of the second b lens group G2b becomes too strong, and aberration fluctuations during focusing increase.

Conditional expressions (9) and (9') define the focal length of the 2b lens group G2a and the infinity distance when the composite optical system of the 2b lens group G2b and the 2c lens group G2c is defined as the 2bc lens group. The relationship with the focal length of the second bc lens group at the time of focusing is defined. By satisfying conditional expression (9), the focusing sensitivity of the second b lens group G2b can be appropriately set to suppress the amount of focusing movement, and aberration fluctuations (spherical aberration, comatic aberration) during focusing can be suppressed, especially at the long focal length end. , astigmatism) can be suppressed. This effect can be obtained more significantly by satisfying conditional expression (9').
If the upper limit of conditional expression (9) is exceeded, the refractive power of the second a lens group G2a becomes too weak, and the focusing sensitivity of the second b lens group G2b becomes weak, resulting in an increase in the amount of focusing movement.
If the lower limit of conditional expression (9) is exceeded, the refractive power of the second a lens group G2a becomes too strong, which increases aberration fluctuations (spherical aberration, coma aberration, astigmatism) during focusing, especially on the long focal length end side. Resulting in.

Conditional expressions (10) and (10') express the relationship between the paraxial radius of curvature of the surface closest to the object side of the second lens group G2a and the paraxial radius of curvature of the surface closest to the image side of the second lens group G2a. stipulated. When focusing is performed with the second b lens group G2b, the position (height from the optical axis) of the chief ray passing through the second a lens group G2a changes greatly depending on the photographing distance. Therefore, it is preferable that the object side surface of the second a lens group G2a has a convex shape and the image side surface has a shape close to a flat surface so that changes in aberration caused by the position of the principal ray are reduced. When the paraxial radius of curvature of the surface closest to the image side of the second a lens group G2a is positive (convex shape toward the object side), the image surface changes excessively as the distance becomes short from infinity. When the paraxial radius of curvature of the surface closest to the image side of the second a lens group G2a is negative (convex shape toward the image side), the image surface changes to an underside. By satisfying conditional expression (10), it is possible to suppress fluctuations in spherical aberration during focusing. This effect can be obtained more significantly by satisfying conditional expression (10').
If the upper limit of conditional expression (10) is exceeded, the curvature of the most image-side surface of the second a lens group G2a becomes too strong in a convex shape toward the image side, and spherical aberration fluctuations during focusing become significant.
If the lower limit of conditional expressions (10) and (10') is exceeded, the curvature of the most image-side surface of the second a lens group G2a becomes too strong, and aberration fluctuations due to changes in the image surface during focusing become significant. Put it away.

Conditional expressions (11), (11'), and (11'') define the relationship between the paraxial radius of curvature of the surface closest to the image side of the second a lens group G2a and the focal length of the second a lens group G2a. When focusing is performed using the 2b lens group G2b, the position (height from the optical axis) of the principal ray passing through the 2a lens group G2a changes greatly depending on the shooting distance. Therefore, the 2a lens group G2a It is preferable that the object side surface is a convex surface and the image side surface is close to a flat surface so that changes in aberration caused by the position of G2a are reduced.Paraxial curvature of the surface closest to the image side of the second a lens group G2a When the radius is positive (convex shape toward the object side), the image surface changes excessively as the distance moves from infinity to short distance.The paraxial radius of curvature of the surface closest to the image side of the second a lens group G2a is negative (the radius of curvature is negative) In the case of a convex shape), the image surface changes to an underside.By satisfying conditional expression (11), it is possible to suppress fluctuations in spherical aberration during focusing.This effect can be achieved by satisfying conditional expression (11'). ), (11″) can be obtained more significantly.
When the upper limit of conditional expression (11') is exceeded, the curvature of the most image-side surface of the second a lens group G2a becomes too strong in a convex shape toward the image side, and spherical aberration fluctuations during focusing become significant.
If the lower limit of conditional expression (11) is exceeded, the curvature of the most image-side surface of the second a lens group G2a becomes too strong, and aberration fluctuations due to changes in the image surface during focusing become significant.

The second a lens group G2a includes at least one positive lens and at least one negative lens. This makes it possible to satisfactorily correct aberration fluctuations such as longitudinal chromatic aberration, lateral chromatic aberration, and spherical aberration that occur during focusing. The positive lens and the negative lens in the second a lens group G2a may be arranged in close contact with each other or may be cemented together, or may be arranged with an air gap between them.

Conditional expressions (12), (12'), and (12'') define the Abbe number of the positive lens with the largest Abbe number among the positive lenses in the 2a lens group.Conditional expression (12) is satisfied. By doing so, it is possible to suppress fluctuations in longitudinal chromatic aberration and lateral chromatic aberration mainly during focusing.This effect can be obtained more markedly by satisfying conditional expressions (12') and (12''). I can do it.
If the lower limit of conditional expression (12) is exceeded, fluctuations in longitudinal chromatic aberration and lateral chromatic aberration mainly during focusing will become large.

Conditional expressions (13), (13'), and (13'') represent the relationship between the focal length of the negative lens with the largest refractive power among the negative lenses in the second a lens group G2a and the focal length of the second a lens group G2a. By satisfying conditional expression (13), it is possible to suppress fluctuations in spherical aberration, comatic aberration, longitudinal chromatic aberration, and lateral chromatic aberration mainly during focusing.This effect is achieved by satisfying conditional expression (13). By satisfying (13') and (13''), more significant results can be obtained.
When the upper limit of conditional expression (13') is exceeded, the refractive power of the negative lens included in the second a lens group G2a becomes weaker, and it becomes difficult to correct spherical aberration, coma aberration, and longitudinal chromatic aberration mainly on the telephoto side.
When the lower limit of conditional expression (13) is exceeded, the refractive power of the negative lens included in the second a lens group G2a becomes strong, and fluctuations in spherical aberration, coma aberration, longitudinal chromatic aberration, and lateral chromatic aberration mainly during focusing become large. I end up.

Conditional expressions (14) and (14') express the relationship between the paraxial radius of curvature of the surface closest to the object side of the second lens group G2b and the paraxial radius of curvature of the surface closest to the image side of the second lens group G2b. stipulated.
When focusing is performed using the second b lens group G2b, the position of the chief ray passing through the second b lens group G2b and the pupil diameter vary greatly depending on the photographing distance. Therefore, the second b lens group G2b should have a shape with a weak curvature on the object side and a strong curvature on the image side so that the change in aberration caused by the position of the principal ray is reduced without impairing focusing sensitivity. preferable.
By satisfying conditional expression (14), it is possible to suppress variations in field curvature, spherical aberration, and coma aberration during focusing. This effect can be obtained more significantly by satisfying conditional expression (14').
If the upper limit of conditional expression (14) is exceeded, the curvature of the surface closest to the object of the second b lens group G2b becomes concave toward the object side and becomes too strong, resulting in curvature of field on the wide-angle side and spherical aberration on the telephoto side during focusing. and fluctuations in coma aberration become large.
If the lower limit of conditional expression (14) is exceeded, the curvature of the surface closest to the image side of the second b lens group G2b becomes too strong in a convex shape toward the image side, resulting in excessive curvature of field over the entire zoom range. Alternatively, the focusing sensitivity becomes weaker and the amount of movement during focusing becomes larger.

The second b lens group G2b has a negative lens located closest to the object side. Conditional expressions (15) and (15') define the Abbe number of the negative lens located closest to the object side in the second b lens group. By satisfying conditional expression (15), it is possible to satisfactorily correct lateral chromatic aberration mainly at the long focal length end. This effect can be obtained more significantly by satisfying conditional expression (15').
If the lower limit of conditional expression (15) is exceeded, lateral chromatic aberration will be undercorrected mainly at the long focal length end.

The second b lens group G2b is composed of one negative lens and one positive lens, which are positioned in order from the object side. This makes it possible to reduce the weight of the second b lens group G2b, which is the focus lens group, and to satisfactorily correct axial chromatic aberration, lateral chromatic aberration, spherical aberration, etc. that occur during focusing. The positive lens and the negative lens in the second lens group G2b may be arranged in close contact with each other or may be cemented together, or may be arranged with an air gap between them.

Conditional expressions (16), (16′), and (16″) define the relationship between the focal length of the negative lens of the second b lens group G2b and the focal length of the positive lens of the second b lens group G2b. By satisfying conditional expression (16), it is possible to shorten the overall lens length, increase the AF speed, and suppress fluctuations in spherical aberration and curvature of field during zooming and focusing. can be obtained more clearly by satisfying conditional expressions (16') and (16'').
If the upper limits of conditional expressions (16) and (16') are exceeded, the refractive power of the negative lens of the second b lens group G2b becomes too weak, resulting in weak focusing sensitivity. As a result, the focusing movement amount increases and the AF speed becomes slow. Moreover, the total length of the lens becomes large.
If the lower limit of conditional expression (16) is exceeded, the refractive power of the negative lens of the second b lens group G2b becomes too strong, resulting in large fluctuations in spherical aberration and curvature of field during zooming and focusing.

Conditional expressions (17) and (17') define the relationship between the Abbe number of the negative lens of the second b lens group G2b and the Abbe number of the positive lens of the second b lens group G2b. By satisfying conditional expression (17), it is possible to satisfactorily correct longitudinal chromatic aberration that occurs during focusing. This effect can be obtained more significantly by satisfying conditional expression (17').
If the lower limit of conditional expression (17) is exceeded, the axial chromatic aberration that occurs during focusing will be insufficiently corrected.

Conditional expressions (18), (18'), and (18'') are the combined focal length from the first lens group G1 to the second b lens group G2b when focusing at infinity at the short focal length end, and the short focal length end. This specifies the ratio between the focal length and the focal length when focusing at infinity.
Considering spherical aberration fluctuations during focusing, it is desirable that the axial ray between the 2b lens group G2b and the 2c lens group G2c sub-lens group be as parallel as possible to the optical axis (afocal).
By satisfying conditional expression (18), it is possible to satisfactorily correct aberrations in the subsequent lens group GR and to reduce fluctuations in spherical aberration during focusing.
When the upper limits of conditional expressions (18), (18'), and (18'') are exceeded, it becomes difficult to maintain the parallelism of the light rays between the 2b lens group G2b and the 2c lens group G2c, and this mainly occurs at the wide-angle end. In this case, the divergent light becomes stronger on the image side than the second b lens group G2b.As a result, it becomes difficult to correct aberrations in the succeeding lens group GR, and the spherical aberration fluctuation becomes large especially during focusing.

Conditional expressions (19), (19'), and (19'') are the lateral magnification of the second b lens group G2b when focusing at infinity at the long focal length end, and the lateral magnification of the second b lens group G2b when focusing at infinity at the long focal length end. 2b lens group G2b defines the relationship (focusing sensitivity) with the combined lateral magnification of all lens groups on the image side.By satisfying conditional expression (19), focusing sensitivity can be set appropriately and a long It is possible to secure a minimum shooting distance of More significant effects can be obtained by satisfying conditional expressions (19') and (19'').
If the lower limit of conditional expression (19) is exceeded, the focusing sensitivity becomes too weak, the minimum photographing distance becomes long, and the maximum photographing magnification decreases. Furthermore, the amount of focusing movement increases, and the AF speed slows down. Moreover, the total length of the lens becomes large.

The zoom lens system of this embodiment includes an anti-vibration lens group that moves in a direction including a component perpendicular to the optical axis and displaces the imaging position, closer to the image side than the second b lens group G2b. This anti-vibration lens group can correct image blur that occurs in photographed images due to hand shake or the like. When camera shake occurs at the same angle, the longer the focal length, the greater the image blur, so it is more desirable for a lens with a long focal length on the long focal length side to be able to correct image blur. However, as the weight of the anti-vibration lens group increases, the anti-vibration lens drive unit for driving the anti-vibration lens group becomes larger. Therefore, it is desired that the anti-vibration lens group be small and lightweight. In order to take in the brightness (Fno) of on-axis light and off-axis light, lenses located closer to the object than the second b lens group G2b tend to have larger outer diameters and become heavier. Therefore, by arranging the anti-vibration lens group closer to the image side than the second b lens group G2b, it is possible to reduce the weight of the anti-vibration lens group.

The above-mentioned anti-vibration lens group includes at least one negative lens and at least one positive lens. This makes it possible to satisfactorily correct aberrations due to eccentricity, such as eccentric coma aberration, image plane tilt, and lateral chromatic aberration during image stabilization driving.

Conditional expression (20) is the lateral magnification of the anti-vibration lens group when focusing on infinity at the long focal length end, and all lens groups on the image side of the anti-vibration lens group when focusing on infinity at the long focal length end. This defines the relationship (vibration isolation sensitivity) with the composite lateral magnification. By satisfying conditional expression (20), it becomes easy to manufacture (integrate) the entire lens system including the anti-vibration lens group, and it becomes easier to obtain the desired anti-vibration performance. Further, the outer diameter of the lens (outer diameter of the lens frame) can be made smaller.
If the upper limit of conditional expression (20) is exceeded, the vibration isolation sensitivity becomes too strong, making it difficult to control vibration isolation. Furthermore, decentering comatic aberration and image plane tilt during image stabilization increase, making it difficult to maintain optical performance.
If the lower limit of conditional expression (20) is exceeded, the anti-vibration sensitivity becomes too weak and the desired anti-vibration performance cannot be obtained. Furthermore, since the number of movable frames in the direction perpendicular to the optical axis of the anti-vibration lens group increases, the outer diameter of the lens (outer diameter of the lens frame) increases.

Conditional expressions (21), (21'), and (21'') define the relationship between the focal length of the second b lens group G2b and the focal length of the anti-shake lens group. Conditional expression (21) is satisfied. By doing so, it is possible to satisfactorily correct decentering aberrations during anti-vibration driving and to suppress aberration fluctuations during focusing.This effect can be achieved by satisfying conditional expressions (21') and (21''). can be obtained more noticeably.
If the upper limit of conditional expression (21) is exceeded, the refractive power of the anti-vibration lens group will become too strong, and decentering aberrations during anti-vibration driving will worsen.
If the lower limit of conditional expression (21) is exceeded, the refractive power of the second b lens group G2b becomes too strong, resulting in large aberration fluctuations during focusing.

The lens group including the anti-vibration lens group does not need to move in the optical axis direction (or may be fixed with respect to the image plane) during zooming from the short focal length end to the long focal length end. The anti-vibration lens drive unit is generally provided with a magnet, a coil, a base, etc. in the radial direction (direction perpendicular to the optical axis), and the anti-vibration lens drive unit itself becomes large. When the anti-vibration lens group becomes a group that moves during zooming, parts such as a zoom cam cylinder must be provided around the outer periphery of the unit, which increases the outer diameter. By making the anti-vibration lens group a fixed group, there is no need for a movable frame on the outside of the anti-vibration lens unit during zooming, and the outer diameter of the lens can be made smaller.

The second lens group G2 does not need to move in the optical axis direction (it may be fixed with respect to the image plane) during zooming from the short focal length end to the long focal length end. If the second lens group G2 moves during zooming, it becomes a cause of decentering error during zooming, and causes aberrations such as eccentric coma. By making the second lens group G2 a fixed group that does not move during zooming, eccentricity errors can be easily suppressed.

The first lens group G1 does not need to move in the optical axis direction (it may be fixed with respect to the image plane) when changing the magnification from the short focal length end to the long focal length end. If the first lens group G1 moves during zooming, it becomes a cause of decentering error during zooming, and causes aberrations such as eccentric coma. By making the first lens group G1 a fixed group that does not move during zooming, eccentricity errors can be easily suppressed.

Conditional expression (22) is the focal length of the entire system when focusing at infinity at the long focal length end, the focal length of the entire system when focusing at infinity at the short focal length end, and the focal length of the entire system when focusing at infinity at the long focal length end. The relationship between the lateral magnification of the second lens group during focusing and the lateral magnification of the second lens group when focusing at infinity at the short focal length end is defined. That is, conditional expression (22) defines the ratio of the zooming burden of the second lens group G2 to the zoom ratio. By satisfying conditional expression (22), it is possible to satisfactorily correct spherical aberration, coma aberration, astigmatism fluctuations, etc. during zooming.
When the upper limit of conditional expression (22) is exceeded, the power of the second lens group G2 is reduced, and it is necessary to strengthen the refractive power of the other lens groups in order to obtain the desired zoom ratio. It becomes difficult to correct spherical aberration, coma aberration, astigmatism fluctuations, etc.
If the lower limit of conditional expression (22) is exceeded, the burden of zooming on the second lens group G2 increases, making it difficult to correct spherical aberration, coma aberration, astigmatism fluctuations, etc. during zooming.

Conditional expression (23) defines the relationship between the focal length of the second lens group G2 and the focal length of the entire system when focusing at infinity at the short focal length end. By satisfying conditional expression (23), it is possible to maintain an appropriate variable power ratio, downsize the entire lens system, and effectively correct spherical aberration, coma aberration, astigmatism, etc. during zooming. can.
If the upper limit of conditional expression (23) is exceeded, the refractive power of the second lens group G2 becomes too weak, resulting in a reduction in the variable power ratio and/or an increase in the size of the entire lens system.
If the lower limit of conditional expression (23) is exceeded, the refractive power of the second lens group G2 becomes too strong, making it difficult to correct spherical aberration, coma aberration, astigmatism, etc. during zooming.

Conditional expression (24) defines the relationship between the focal length of the first lens group G1 and the focal length of the entire system when focusing at infinity at the long focal length end. By satisfying conditional expression (24), it is possible to maintain an appropriate zoom ratio and downsize the entire lens system, thereby reducing spherical aberration, coma aberration, astigmatism, axial chromatic aberration, and lateral chromatic aberration, especially at the telephoto end. etc. can be effectively corrected.
If the upper limit of conditional expression (24) is exceeded, the refractive power of the first lens group G1 becomes too weak, resulting in a reduction in the variable power ratio and/or an increase in the size of the entire lens system.
If the lower limit of conditional expression (24) is exceeded, the refractive power of the first lens group G1 becomes too strong, making it difficult to correct spherical aberration, coma aberration, astigmatism, axial chromatic aberration, lateral chromatic aberration, etc., especially at the telephoto end. turn into.

Conditional expression (25) is the focal length of the first lens group G1, the focal length of the entire system when focusing on infinity at the short focal length end, and the focal length of the entire system when focusing on infinity at the long focal length end. It specifies the ratio to the distance. By satisfying conditional expression (25), it is possible to maintain an appropriate zoom ratio and downsize the entire lens system, thereby reducing spherical aberration, coma aberration, astigmatism, axial chromatic aberration, and lateral chromatic aberration, especially at the telephoto end. etc. can be effectively corrected.
If the upper limit of conditional expression (25) is exceeded, the refractive power of the first lens group G1 becomes too weak, resulting in a reduction in the variable power ratio and/or an increase in the size of the entire lens system.
If the lower limit of conditional expression (25) is exceeded, the refractive power of the first lens group G1 becomes too strong, making it difficult to correct spherical aberration, coma aberration, astigmatism, axial chromatic aberration, lateral chromatic aberration, etc., especially at the telephoto end. turn into.

Conditional expression (26) is based on the distance between the first lens group G1 and the second lens group G2 (from the most image-side refractive surface of the first lens group G1 to the second lens group G2 when focusing on infinity at the long focal length end). (distance on the optical axis to the refractive surface closest to the object) and the distance between the first lens group G1 and the second lens group G2 when focusing at infinity at the short focal length end (the distance on the optical axis to the refractive surface closest to the object) The distance on the optical axis from the side refractive surface to the object side refractive surface of the second lens group G2) and the focal length of the second lens group G2 are defined. That is, conditional expression (26) defines the focal length ratio of the second lens group G2 to the amount of change in the distance between the first lens group G1 and the second lens group G2 during zooming. By satisfying conditional expression (26), it is possible to reduce the size of the entire lens system and to suppress fluctuations in various aberrations during zooming.
If the upper limit of conditional expression (26) is exceeded, the distance between the first lens group G1 and the second lens group G2 increases on the telephoto side (long focal length end side), resulting in an increase in the size of the entire lens system.
If the lower limit of conditional expression (26) is exceeded, the refractive power of at least one of the first lens group G1 and the second lens group G2 must be strengthened in order to obtain the desired variable power ratio, which causes various problems during zooming. This results in large aberration fluctuations.

Conditional expression (27) is defined as the distance between the second lens group G2 and the succeeding lens group GR at the time of infinity focusing at the short focal length end (from the most image-side refractive surface of the second lens group G2 to the most image-side refractive surface of the succeeding lens group GR). distance on the optical axis to the refractive surface on the object side) and the distance between the second lens group G2 and the subsequent lens group GR when focusing on infinity at the long focal length end (the distance on the image side of the second lens group G2) The ratio between the distance on the optical axis from the surface to the most object-side refractive surface of the subsequent lens group GR and the focal length of the second lens group G2 is defined. That is, conditional expression (27) defines the focal length ratio of the second lens group G2 to the amount of change in the distance between the first lens group G1 and the second lens group G2 during zooming. By satisfying conditional expression (27), it is possible to downsize the entire lens system and to suppress fluctuations in various aberrations during zooming.
If the upper limit of conditional expression (27) is exceeded, the distance between the second lens group G2 and the succeeding lens group GR increases on the telephoto side (long focal length end side), resulting in an increase in the size of the entire lens system.
If the lower limit of conditional expression (27) is exceeded, the refractive power of at least one of the second lens group G2 and the subsequent lens group GR must be strengthened in order to obtain the desired zoom ratio, and various aberrations during zooming must be increased. The fluctuation becomes large.

Conditional expressions (28), (28'), and (28'') are the paraxial radius of curvature of the surface closest to the object side of the second lens group G2a, and the paraxial curvature of the surface closest to the image side of the second lens group G2b. By satisfying conditional expression (28), the centers of curvature of the surface closest to the object side of the second lens group G2a and the surface closest to the image side of the second lens group G2b can be brought closer to each other. , it becomes possible to satisfactorily suppress fluctuations in spherical aberration during focusing, mainly at the long focal length end.This effect can be obtained more markedly by satisfying conditional expressions (28') and (28''). be able to.
If the upper limit of conditional expression (28) is exceeded, the curvature of the surface closest to the image side of the second b lens group G2b becomes too strong (tight), and spherical aberration fluctuations during focusing become significant.
If the lower limit of conditional expression (28) is exceeded, the curvature of the surface closest to the object side of the second a lens group G2a becomes too strong (tight), and spherical aberration fluctuations during focusing become significant.

[Numerical examples]
Next, specific numerical examples 1-8 will be shown. In longitudinal aberration diagrams, lateral aberration diagrams, and tables, d-line, g-line, and C-line are aberrations for each wavelength, S is sagittal, M is meridional, FNO. is F number, Y is image height, and R is curvature. The radius, D is the lens thickness or lens spacing, N(d) is the refractive index for the d-line, and ν(d) is the Abbe number for the d-line. The back focus is the distance from the surface closest to the image side of the entire lens system to the designed image plane. The total lens length and back focus indicate the value of the air equivalent length that does not include a cover glass or the like between the surface closest to the image side of the entire lens system and the designed image plane. F-number, focal length, object-to-image distance, magnification, half angle of view, image height, back focus, total lens length, and lens distance D, which changes with zooming and focusing, from short focal length end to intermediate focus They are shown in the order of distance - long focal length end. The unit of length is [mm].

A rotationally symmetric aspheric surface is defined by the following equation.
x=cy2/[1+[1-(1+K)c2y2]1/2]+A4y4+A6y6+A8y8 +A10y10+A12y12...
(However, c is the curvature (1/r), y is the height from the optical axis, K is the conic coefficient, A4, A6, A8, etc. are the aspheric coefficients of each order)

[Numerical Example 1]
9 to 19 and Tables 1 to 4 show a zoom lens system according to Numerical Example 1. FIG. 9 is a lens configuration diagram when focusing on infinity at the short focal length end. 10 and 11 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 12 and 13 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 14 is a lateral aberration diagram during the anti-vibration drive of FIG. 12. 15 and 16 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 17 and 18 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 19 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 17. Table 1 is surface data, Table 2 is various data, Table 3 is zoom lens group data, and Table 4 is principal point position data.

The zoom lens system of Numerical Example 1 includes, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with positive refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, and negative elements.)

The first lens group G1 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 13A convex to the object side. The negative meniscus lens 12A and the positive meniscus lens 13A are cemented.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a biconvex positive lens 21A and a biconcave negative lens 22A. The biconvex positive lens 21A and the biconcave negative lens 22A are cemented together.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23A and a positive meniscus lens 24A convex toward the object side.
The second c lens group G2c includes, in order from the object side, a biconcave negative lens 25A, a biconcave negative lens 26A, and a biconvex positive lens 27A. The biconcave negative lens 26A and the biconvex positive lens 27A are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31A, a biconvex positive lens 32A, and a negative meniscus lens 33A convex toward the image side. The biconvex positive lens 32A and the negative meniscus lens 33A are cemented together.

The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a with positive refractive power and a 4b-th lens group G4b with negative refractive power.
The fourth a lens group G4a includes, in order from the object side, a biconcave negative lens 41A, a biconvex positive lens 42A, and a biconvex positive lens 43A.
The fourth b lens group G4b includes, in order from the object side, a positive meniscus lens 44A convex to the image side and a biconcave negative lens 45A.

The fifth lens group G5 includes, in order from the object side, a biconvex positive lens 51A, a negative meniscus lens 52A convex to the image side, a negative meniscus lens 53A convex to the image side, and a biconvex positive lens 54A. ing. The biconvex positive lens 51A and the negative meniscus lens 52A are cemented together.

(Table 1)
Surface data surface number r DN(d) ν(d)
1 109.489 4.050 1.48749 70.2
2 1346.163 0.200
3 84.450 1.950 1.73800 32.3
4 49.769 9.020 1.49700 81.6
5 1342.515 D5
6 124.201 4.000 1.65160 58.5
7 -186.275 1.340 1.53775 74.7
8 362.228 D8
9 -257.022 1.000 1.65160 58.5
10 22.616 1.400
11 22.808 2.600 1.80518 25.4
12 37.531 D12
13 -154.978 1.000 1.95375 32.3
14 96.030 2.000
15 -95.527 1.200 1.80400 46.5
16 37.706 2.400 1.80810 22.8
17 251.929 D17
18 aperture INFINITY 2.000
19 62.420 3.930 1.80400 46.5
20 -78.827 0.200
21 45.402 5.260 1.59522 67.7
22 -41.935 1.200 2.00069 25.5
23 -321.928 D23
24 -93.217 1.000 1.90366 31.3
25 99.821 1.280
26 66.813 3.040 1.59410 60.5
27 -177.060 0.200
28 58.506 3.000 1.80400 46.5
29 -271.111 2.000
30 -315.044 1.800 1.80518 25.4
31 -48.174 1.200
32 -45.134 0.950 1.77250 49.6
33 45.832 D33
34 92.685 6.560 1.60342 38.0
35 -22.387 1.200 1.91082 35.2
36 -58.706 6.561
37 -26.520 1.150 1.83481 42.7
38 -100.411 0.200
39 346.562 3.900 1.64769 33.8
40 -52.470 D40
41 INFINITY 1.500 1.51633 64.1
42 INFINITY -
(Table 2)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.8
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.7 8.9 4.2
Image height 21.64 21.64 21.64
Back focus 40.44 48.63 60.38
Lens total length 193.39 219.82 240.00
D5 2.950 29.380 49.564
D8 3.000 3.000 3.000
D12 16.460 16.460 16.460
D17 21.941 13.751 2.000
D23 4.659 12.849 24.598
D33 25.146 16.957 5.208
D40 38.453 46.644 58.394
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.8
Focal length 81.55 139.07 187.68
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.080 -0.148 -0.313
Half angle of view 13.7 7.0 3.2
Image height 21.64 21.64 21.64
Back focus 40.44 48.63 60.38
Lens total length 193.39 219.82 240.00
D5 2.950 29.380 49.564
D8 11.183 12.567 14.750
D12 8.277 5.893 3.710
D17 21.941 13.751 2.000
D23 4.659 12.849 24.598
D33 25.146 16.957 5.208
D40 38.453 46.644 58.394
(Table 3)
Zoom lens group data group Starting plane Focal length
1 1 130.42
2 6 -21.93
3 19 33.51
4 24 -134.61
5 34 1414.94
2a 6 227.71
2b 9 -59.73
2c 13 -35.47
Anti-vibration 30 -62.40
(Table 4)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 130.419 0.182 5.194 9.844 Group 1
6 17 -21.926 21.421 7.572 7.407 Group 2
18 23 33.505 2.642 4.388 5.560 Group 3
24 33 -134.606 14.365 4.397 -4.292 Group 4
34 40 1414.938 -35.242 5.643 49.170 5th group sub-lens group start surface End surface Focal length Front principal point Principal point spacing Rear principal point
6 8 227.705 -0.776 2.062 4.054 2a sub lens group
9 12 -59.732 1.108 1.649 2.242 2b sub lens group
13 17 -35.465 1.440 2.155 3.004 2c sub lens group
6 12 -85.109 10.854 3.294 -0.809 2ab sub lens group
9 17 -18.367 11.540 7.322 9.198 2bc sub lens group

[Numerical Example 2]
20 to 30 and Tables 5 to 8 show a zoom lens system according to Numerical Example 2. FIG. 20 is a lens configuration diagram when focusing on infinity at the short focal length end. 21 and 22 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 23 and 24 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 25 is a lateral aberration diagram during the anti-vibration drive shown in FIG. 23. 26 and 27 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 28 and 29 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 30 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 28. Table 5 is surface data, Table 6 is various data, Table 7 is zoom lens group data, and Table 8 is principal point position data.

The zoom lens system of Numerical Example 2 includes, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with negative refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, positive, negative, and negative lenses.)

The first lens group G1 includes, in order from the object side, a biconvex positive lens 11B, 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.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21B that is convex toward the object side, and a positive meniscus lens 22B that is convex toward the object side. The negative meniscus lens 21B and the positive meniscus lens 22B are cemented.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23B and a positive meniscus lens 24B convex toward the object side.
The second c lens group G2c is composed of, in order from the object side, a biconcave negative lens 25B, a positive meniscus lens 26B convex to the image side, a biconcave negative lens 27B, and a positive meniscus lens 28B convex to the object side. ing. The positive meniscus lens 26B, the biconcave negative lens 27B, and the positive meniscus lens 28B are cemented.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31B, a biconvex positive lens 32B, and a negative meniscus lens 33B convex toward the image side. The biconvex positive lens 32B and the negative meniscus lens 33B are cemented together.

The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a with positive refractive power and a 4b-th lens group G4b with negative refractive power.
The fourth a lens group G4a includes, in order from the object side, a biconcave negative lens 41B, a biconvex positive lens 42B, and a biconvex positive lens 43B. The biconcave negative lens 41B and the biconvex positive lens 42B are cemented together.
The fourth b lens group G4b includes, in order from the object side, a biconvex positive lens 44B and a biconcave negative lens 45B.

The fifth lens group G5 includes, in order from the object side, a biconvex positive lens 51B, a negative meniscus lens 52B convex to the image side, and a positive meniscus lens 53B convex to the image side.

(Table 5)
Surface data surface number r DN(d) ν(d)
1 139.763 4.500 1.48749 70.2
2 -4443.525 0.200
3 68.823 1.950 1.85883 30.0
4 49.243 8.400 1.49700 81.6
5 688.357 D5
6 81.370 1.340 1.83481 42.7
7 37.593 6.100 1.59410 60.5
8 858.649 D8
9 -236.261 1.000 1.65160 58.5
10 24.526 1.400
11 24.395 2.600 1.75520 27.5
12 38.249 D12
13 -221.191 1.000 1.91082 35.2
14 122.370 2.000
15 -118.823 3.400 1.62004 36.3
16 -37.301 1.200 1.87070 40.7
17 33.219 2.900 1.89286 20.4
18 288.780 D18
19 aperture INFINITY 2.000
20 438.709 3.930 1.80400 46.5
21 -56.933 0.200
22 31.295 6.260 1.53775 74.7
23 -45.961 1.200 1.80810 22.8
24 -390.140 D24
25 -73.691 1.000 2.05090 26.9
26 74.990 3.040 1.49700 81.6
27 -81.076 0.200
28 40.313 3.000 1.80610 33.3
29 -193.599 2.000
30 276.350 1.800 1.84666 23.8
31 -54.629 1.200
32 -46.398 0.950 1.77250 49.6
33 38.565 D33
34 134.664 2.900 1.68893 31.1
35 -51.606 3.280
36 -23.022 1.150 1.95375 32.3
37 -135.545 0.200
38 -460.628 2.900 1.56732 42.8
39 -47.532 D39
40 INFINITY 1.500 1.51633 64.1
41 INFINITY -
(Table 6)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.9
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.3 8.8 4.1
Image height 21.64 21.64 21.64
Back focus 45.01 53.61 65.62
Lens total length 196.27 219.60 237.97
D5 2.950 26.251 44.619
D9 3.000 3.000 3.000
D12 16.460 16.460 16.460
D18 22.612 14.011 2.000
D24 4.607 13.208 25.219
D33 26.459 17.858 5.847
D39 43.018 51.619 63.631
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.9
Focal length 83.46 139.33 182.55
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.082 -0.152 -0.320
Half angle of view 12.9 6.8 3.1
Image height 21.64 21.64 21.64
Back focus 45.01 53.61 65.62
Lens total length 196.27 219.60 237.97
D5 2.950 26.251 44.619
D9 12.486 13.175 14.760
D12 6.975 6.285 4.701
D18 22.612 14.011 2.000
D24 4.607 13.208 25.219
D33 26.459 17.858 5.847
D39 43.018 51.619 63.631
(Table 7)
Zoom lens group data group Starting plane Focal length
1 1 123.06
2 6 -21.14
3 20 33.73
4 25 -149.32
5 34 -318.57
2a 6 309.79
2b 9 -56.84
2c 13 -37.35
Anti-vibration 30 -58.09
(Table 8)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 123.058 0.297 5.237 9.515 Group 1
6 18 -21.137 22.336 10.510 9.553 Group 2
19 24 33.729 3.667 4.531 5.392 Group 3
25 33 -149.315 13.384 4.361 -4.555 Group 4
34 39 -318.572 17.050 1.998 -8.618 5th group sub-lens group starting surface Ending surface Focal length Front principal point Principal point spacing Rear principal point
6 9 309.788 -2.429 2.920 6.950 2a sub lens group
9 12 -56.843 1.207 1.606 2.187 2b sub lens group
13 18 -37.346 2.478 3.838 4.184 2c sub lens group
6 12 -72.829 11.865 4.011 -0.436 2ab sub lens group
9 18 -18.409 11.620 9.315 11.025 2bc sub lens group

[Numerical Example 3]
31 to 41 and Tables 9 to 12 show a zoom lens system according to Numerical Example 3. FIG. 31 is a lens configuration diagram when focusing on infinity at the short focal length end. 32 and 33 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 34 and 35 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 36 is a lateral aberration diagram during the vibration-proof driving shown in FIG. 34. 37 and 38 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 39 and 40 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 41 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 39. Table 9 is surface data, Table 10 is various data, Table 11 is zoom lens group data, and Table 12 is principal point position data.

The zoom lens system of Numerical Example 3 includes, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with negative refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, positive, negative, and negative lenses.)

The first lens group G1 includes, in order from the object side, a biconvex positive lens 11C, a negative meniscus lens 12C convex on the object side, and a positive meniscus lens 13C convex on the object side. The negative meniscus lens 12C and the positive meniscus lens 13C are cemented.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21C that is convex toward the object side, and a biconvex positive lens 22C. The negative meniscus lens 21C and the biconvex positive lens 22C are cemented.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23C and a positive meniscus lens 24C convex toward the object side.
The second c lens group G2c includes, in order from the object side, a biconcave negative lens 25C, a biconcave negative lens 26C, and a positive meniscus lens 27C convex toward the object side. The biconcave negative lens 26C and the positive meniscus lens 27C are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31C, a biconvex positive lens 32C, and a negative meniscus lens 33C convex toward the image side. The biconvex positive lens 32C and the negative meniscus lens 33C are cemented.

The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a with positive refractive power and a 4b-th lens group G4b with negative refractive power.
The fourth a lens group G4a includes, in order from the object side, a biconcave negative lens 41C, a biconvex positive lens 42C, and a biconvex positive lens 43C.
The fourth b lens group G4b includes, in order from the object side, a positive meniscus lens 44C convex toward the image side and a biconcave negative lens 45C.

The fifth lens group G5 includes, in order from the object side, a biconvex positive lens 51C, a negative meniscus lens 52C convex to the image side, a negative meniscus lens 53C convex to the image side, and a biconvex positive lens 54C. ing. The biconvex positive lens 51C and the negative meniscus lens 52C are cemented together.

(Table 9)
Surface data surface number r DN(d) ν(d)
1 186.417 4.050 1.48749 70.2
2 -1822.306 0.200
3 95.344 1.950 1.73800 32.3
4 59.003 7.420 1.49700 81.6
5 4141.382 D5
6 98.011 1.340 1.73800 32.3
7 65.395 4.000 1.65160 58.5
8 -1355.397 D8
9 -209.666 1.000 1.65160 58.5
10 23.388 1.400
11 23.552 2.600 1.80518 25.4
12 37.887 D12
13 -149.496 1.000 1.95375 32.3
14 108.565 2.000
15 -90.953 1.200 1.80400 46.5
16 40.982 2.400 1.80810 22.8
17 853.949 D17
18 aperture INFINITY 2.000
19 63.174 3.930 1.80400 46.5
20 -84.994 0.200
21 48.043 5.260 1.59522 67.7
22 -43.499 1.200 2.00069 25.5
23 -376.671 D23
24 -110.331 1.000 1.90366 31.3
25 110.962 1.280
26 71.711 3.040 1.59410 60.5
27 -224.850 0.200
28 58.111 3.000 1.80400 46.5
29 -261.671 2.000
30 -279.636 1.800 1.80518 25.4
31 -50.194 1.200
32 -46.652 0.950 1.77250 49.6
33 45.680 D33
34 109.803 6.560 1.60342 38.0
35 -22.102 1.200 1.91082 35.2
36 -56.098 2.515
37 -27.654 1.150 1.83481 42.7
38 -93.015 0.200
39 5565.113 3.900 1.64769 33.8
40 -53.577 D40
41 INFINITY 1.500 1.51633 64.1
42 INFINITY -
(Table 10)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.8
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.5 8.8 4.1
Image height 21.64 21.64 21.64
Back focus 40.25 49.59 62.32
Lens total length 193.46 226.53 252.89
D5 2.950 36.022 62.381
D8 3.000 3.000 3.000
D12 16.460 16.460 16.460
D17 24.079 14.732 2.000
D23 4.659 14.007 26.737
D33 28.918 19.570 6.840
D40 38.256 47.605 60.335
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.1 5.8
Focal length 80.18 138.28 189.66
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.079 -0.148 -0.312
Half angle of view 13.7 7.0 3.2
Image height 21.64 21.64 21.64
Back focus 40.25 49.59 62.32
Lens total length 193.46 226.53 252.89
D5 2.950 36.022 62.381
D8 9.840 11.703 14.414
D12 9.622 6.758 4.046
D17 24.079 14.732 2.000
D23 4.659 14.007 26.737
D33 28.918 19.570 6.840
D40 38.256 47.605 60.335
(Table 11)
Zoom lens group data group Starting plane Focal length
1 1 155.21
2 6 -25.78
3 19 35.50
4 24 -151.03
5 34 -6472.48
2a 6 149.55
2b 9 -57.62
2c 13 -39.60
Anti-vibration 30 -50.36
(Table 12)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 155.206 0.910 4.632 8.078 Group 1
6 17 -25.779 22.623 6.738 7.039 Group 2
18 23 35.500 2.530 4.398 5.662 Group 3
24 33 -151.031 17.072 4.071 -6.673 Group 4
34 40 -6472.478 -39.590 4.357 50.758 5th group sub-lens group starting surface Ending surface Focal length Front principal point Principal point spacing Rear principal point
6 8 149.545 0.077 2.143 3.120 2a sub lens group
9 12 -57.617 1.131 1.650 2.219 2b sub lens group
13 17 -39.604 1.219 2.134 3.247 2c sub lens group
6 12 -101.756 12.882 3.172 -2.714 2ab sub lens group
9 17 -19.483 10.920 7.164 9.976 2bc sub lens group

[Numerical Example 4]
42 to 52 and Tables 13 to 16 show a zoom lens system according to Numerical Example 4. FIG. 42 is a lens configuration diagram when focusing on infinity at the short focal length end. 43 and 44 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 45 and 46 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 47 is a lateral aberration diagram during the anti-vibration drive of FIG. 45. 48 and 49 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 50 and 51 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 52 is a diagram of lateral aberration during anti-vibration driving (±0.3°) in FIG. 50. Table 13 is surface data, Table 14 is various data, Table 15 is zoom lens group data, and Table 16 is principal point position data.

The zoom lens system of Numerical Example 4 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR includes, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a negative refractive power. (In other words, it has a positive/negative, positive/negative, positive/negative, 6-group zoom lens configuration).

The first lens group G1 is composed of, in order from the object side, a plano-convex positive 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.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a biconvex positive lens 21D and a negative meniscus lens 22D convex toward the image side. The biconvex positive lens 21D and the negative meniscus lens 22D are cemented.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23D and a positive meniscus lens 24D convex toward the object side.
The second c lens group G2c includes, in order from the object side, a biconcave negative lens 25D, a positive meniscus lens 26D convex toward the object side, and a biconcave negative lens 27D. The biconcave negative lens 25D and the positive meniscus lens 26D are cemented.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31D, a biconvex positive lens 32D, and a negative meniscus lens 33D convex toward the image side. The biconvex positive lens 32D and the negative meniscus lens 33D are cemented.

The fourth lens group G4 includes, in order from the object side, a negative meniscus lens 41D convex to the object side, a biconvex positive lens 42D, and a positive meniscus lens 43D convex to the object side. The negative meniscus lens 41D and the biconvex positive lens 42D are cemented.

The fifth lens group G5 is composed of a negative meniscus lens 51D that is convex toward the object side.

The sixth lens group G6 includes, in order from the object side, a biconcave negative lens 61D and a biconvex positive lens 62D. The biconcave negative lens 61D and the biconvex positive lens 62D are cemented.

(Table 13)
Surface data surface number r DN(d) ν(d)
1 95.549 5.400 1.48749 70.2
2 INFINITY 0.200
3 93.980 1.950 1.83400 37.2
4 54.009 8.100 1.49700 81.6
5 538.374 D5
6 71.512 5.590 1.51823 59.0
7 -98.080 1.380 1.95375 32.3
8 -194.492 D8
9 -230.444 1.000 1.75500 52.3
10 27.962 1.400
11 26.420 2.400 1.84666 23.8
12 41.166 D12
13 -67.460 1.000 1.78800 47.4
14 38.494 2.900 1.85478 24.8
15 427.561 2.000
16 -83.084 1.000 1.83481 42.7
17 873.197 D17
18 aperture INFINITY 2.000
19 127.859 2.930 1.80400 46.5
20 -88.194 0.200
21 51.974 5.170 1.49700 81.6
22 -44.897 1.200 1.90366 31.3
23 -162.261 D23
24 81.995 1.200 2.00100 29.1
25 35.316 5.000 1.48749 70.2
26 -133.881 0.200
27 52.803 2.000 1.90043 37.4
28 336.536 D28
29 111.476 1.000 1.66672 48.3
30 30.261 D30
31 -37.239 1.200 1.48749 70.2
32 70.193 5.550 1.76200 40.1
33 -87.277 D33
34 INFINITY 1.500 1.51633 64.1
35 INFINITY -
(Table 14)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.2 5.7
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 17.2 9.0 4.1
Image height 21.64 21.64 21.64
Back focus 35.96 52.45 60.50
Lens total length 193.71 219.79 248.87
D5 2.950 29.033 58.110
D8 2.000 2.000 2.000
D12 12.183 12.183 12.183
D17 26.445 14.029 2.000
D23 20.007 15.936 19.919
D28 5.000 6.860 2.074
D30 27.189 25.329 30.115
D33 33.975 50.463 58.510
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.2 5.7
Focal length 79.46 137.92 206.36
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.077 -0.145 -0.306
Half angle of view 14.5 7.4 3.3
Image height 21.64 21.64 21.64
Back focus 35.96 52.45 60.50
Lens total length 193.71 219.79 248.87
D5 2.950 29.033 58.110
D8 7.578 9.026 11.976
D12 6.605 5.157 2.207
D17 26.445 14.029 2.000
D23 20.007 15.936 19.919
D28 5.000 6.860 2.074
D30 27.189 25.329 30.115
D33 33.975 50.463 58.510
(Table 15)
Zoom lens group data group Starting plane Focal length
1 1 144.43
2 6 -28.06
3 19 46.42
4 24 63.12
5 29 -62.61
6 31 -15551.99
2a 6 130.08
2b 9 -54.78
2c 13 -42.55
Anti-vibration 13 -42.55
(Table 16)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 144.428 -0.835 5.465 11.019 Group 1
6 17 -28.060 20.760 6.612 5.481 Group 2
18 23 46.415 2.825 3.607 5.068 Group 3
24 28 63.118 4.004 3.161 1.234 Group 4
29 30 -62.608 0.828 0.397 -0.225 Group 5
31 33 -15551.988 -584.947 -20.212 611.909 6th group sub-lens group start surface End surface Focal length Front principal point Principal point spacing Rear principal point
6 8 130.079 0.680 2.551 3.739 2a sub lens group
9 12 -54.776 0.984 1.612 2.205 2b sub lens group
13 17 -42.553 2.095 2.325 2.480 2c sub lens group
6 12 -103.898 13.433 3.503 -3.166 2ab sub lens group
9 17 -20.480 8.917 6.323 8.643 2bc sub lens group

[Numerical Example 5]
53 to 63 and Tables 17 to 20 show a zoom lens system according to Numerical Example 5. FIG. 53 is a lens configuration diagram when focusing on infinity at the short focal length end. 54 and 55 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIGS. 56 and 57 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 58 is a lateral aberration diagram during the anti-vibration drive of FIG. 56. 59 and 60 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 61 and 62 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 63 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 61. Table 17 is surface data, Table 18 is various data, Table 19 is zoom lens group data, and Table 20 is principal point position data.

The zoom lens system of Numerical Example 5 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with negative refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, positive, negative, and negative lenses.)

The first lens group G1 is composed of, in order from the object side, a plano-convex positive 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.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a biconvex positive lens 21E and a negative meniscus lens 22E convex toward the image side. The biconvex positive lens 21E and the negative meniscus lens 22E are cemented together.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23E and a positive meniscus lens 24E convex toward the object side.
The second c lens group G2c includes, in order from the object side, a negative meniscus lens 25E convex to the image side, a biconcave negative lens 26E, a positive meniscus lens 27E convex to the object side, and a negative meniscus lens 28E convex to the image side. It is composed of. The biconcave negative lens 26E and the positive meniscus lens 27E are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31E, a biconvex positive lens 32E, a biconcave negative lens 33E, a negative meniscus lens 34E convex to the object side, and a biconvex positive lens 35E. , and a positive meniscus lens 36E convex toward the object side. The biconvex positive lens 32E and the biconcave negative lens 33E are cemented together. The negative meniscus lens 34E and the biconvex positive lens 35E are cemented together.

The fourth lens group G4 includes, in order from the object side, a biconvex positive lens 41E and a biconcave negative lens 42E. The biconvex positive lens 41E and the biconcave negative lens 42E are cemented together.

The fifth lens group G5 is composed of a negative meniscus lens 51E that is convex toward the image side.

(Table 17)
Surface data surface number r DN(d) ν(d)
1 120.884 5.400 1.48749 70.2
2 INFINITY 0.200
3 109.398 1.950 1.73800 32.3
4 58.845 8.100 1.53775 74.7
5 1249.592 D5
6 81.455 5.590 1.59410 60.5
7 -121.229 1.380 1.90366 31.3
8 -288.457 D8
9 -322.128 1.000 1.75500 52.3
10 26.652 1.400
11 25.806 2.400 1.84666 23.8
12 42.918 D12
13 -58.813 1.000 1.61997 63.9
14 -296.883 1.300
15 -187.864 1.000 1.80400 46.5
16 24.516 4.100 1.80000 29.9
17 540.867 1.500
18 -70.350 1.000 1.88300 40.8
19 -1156.493 D19
20 aperture INFINITY 2.000
21 513.556 2.930 1.75500 52.3
22 -57.197 0.200
23 34.940 5.170 1.49700 81.6
24 -52.550 1.200 1.90366 31.3
25 421.282 21.661
26 118.288 1.200 2.00100 29.1
27 39.474 4.500 1.48749 70.2
28 -86.850 0.200
29 58.198 2.500 1.85883 30.0
30 906.824 D30
31 702.226 2.200 1.80810 22.8
32 -52.353 1.000 1.67270 32.1
33 59.484 D33
34 -25.672 1.200 1.48749 70.2
35 -39.726 D35
36 INFINITY 1.500 1.51633 64.1
37 INFINITY -
(Table 18)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.2 5.7
Focal length 72.08 135.00 291.29
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.9 8.9 4.1
Image height 21.64 21.64 21.64
Back focus 38.53 51.59 59.79
Lens total length 194.98 218.62 250.45
D5 2.950 26.597 58.426
D8 2.000 2.000 2.000
D12 12.709 12.709 12.709
D19 23.262 10.198 2.000
D30 5.059 15.969 1.250
D33 27.189 16.279 30.998
D35 36.538 49.603 57.798
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.6 5.3 5.7
Focal length 77.98 132.32 192.60
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.076 -0.144 -0.304
Half angle of view 14.4 7.3 3.2
Image height 21.64 21.64 21.64
Back focus 38.53 51.59 59.79
Lens total length 194.98 218.62 250.45
D5 2.950 26.597 58.426
D8 7.345 8.691 12.004
D12 7.364 6.018 2.705
D19 23.262 10.198 2.000
D30 5.059 15.969 1.250
D33 27.189 16.279 30.998
D35 36.538 49.603 57.798
(Table 19)
Zoom lens group data group Starting plane Focal length
1 1 143.62
2 6 -26.23
3 21 39.27
4 31 -132.72
5 34 -153.14
2a 6 127.44
2b 9 -58.97
2c 13 -36.77
Anti-vibration 15 -55.64
(Table 20)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 143.616 0.678 5.462 9.510 Group 1
6 19 -26.228 22.635 7.803 5.940 Group 2
20 30 39.267 20.743 -5.053 25.871 Group 3
31 33 -132.722 2.303 1.379 -0.482 Group 4
34 35 -153.143 -1.516 0.370 2.346 5th group sub-lens group starting surface Ending surface Focal length Front principal point Principal point spacing Rear principal point
6 8 127.435 0.551 2.716 3.703 2a sub lens group
9 12 -58.971 0.852 1.606 2.342 2b sub lens group
13 19 -36.777 3.239 3.324 3.338 2c sub lens group
6 12 -121.387 14.045 3.627 -3.903 2ab sub lens group
9 19 -19.018 10.310 7.863 9.236 2bc sub lens group

[Numerical Example 6]
64 to 74 and Tables 21 to 24 show a zoom lens system according to Numerical Example 6. FIG. 64 is a lens configuration diagram when focusing on infinity at the short focal length end. 65 and 66 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 67 and 68 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 69 is a lateral aberration diagram during the anti-vibration drive of FIG. 67. 70 and 71 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 72 and 73 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 74 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 72. Table 21 is surface data, Table 22 is various data, Table 23 is zoom lens group data, and Table 24 is principal point position data.

The zoom lens system of Numerical Example 6 includes, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with positive refractive power (that is, a four-group zoom lens configuration with positive, negative, positive, and positive). ).

The first lens group G1 includes, in order from the object side, a negative meniscus lens 11F convex to the object side, a positive biconvex lens 12F, and a positive meniscus lens 13F convex to the object side.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21F that is convex toward the object side, and a positive meniscus lens 22F that is convex toward the object side.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23F and a positive meniscus lens 24F convex toward the object side.
The second c lens group G2c includes a biconcave negative lens 25F, a biconcave negative lens 26F, and a biconvex positive lens 27F. The biconcave negative lens 26F and the biconvex positive lens 27F are cemented.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31F, a positive meniscus lens 32F convex to the image side, and a negative meniscus lens 33F convex to the image side. The positive meniscus lens 32F and the negative meniscus lens 33F are cemented.

The fourth lens group G4 is composed of, in order from the object side, a 4a lens group G4a with positive refractive power, a 4b lens group G4b with negative refractive power, and a 4c lens group G4c with positive refractive power. ing.
The 4th a lens group G4a includes, in order from the object side, a negative meniscus lens 41F convex to the object side, a positive biconvex lens 42F, a positive meniscus lens 43F convex to the object side, and a positive meniscus lens 44F convex to the object side. , a negative meniscus lens 45F convex to the object side, and a biconvex positive lens 46F. The negative meniscus lens 41F and the biconvex positive lens 42F are cemented together. The positive meniscus lens 44F and the negative meniscus lens 45F are cemented.
The fourth b lens group G4b includes, in order from the object side, a biconvex positive lens 47F, a biconcave negative lens 48F, and a negative meniscus lens 49F convex to the image side. The biconvex positive lens 47F and the biconcave negative lens 48F are cemented.
The fourth c lens group G4c includes, in order from the object side, a biconvex positive lens 50F, a positive meniscus lens 51F convex to the image side, and a negative meniscus lens 52F convex to the image side. The positive meniscus lens 51F and the negative meniscus lens 52F are cemented.

(Table 21)
Surface data surface number r DN(d) ν(d)
1 211.989 2.710 1.85478 24.8
2 99.937 0.980
3 119.824 7.800 1.49700 81.6
4 -1695.428 0.200
5 87.128 8.600 1.72916 54.1
6 1485.614 D6
7 74.974 2.070 1.73800 32.3
8 47.595 2.410
9 64.981 8.700 1.61997 63.9
10 595.830 D10
11 -839.107 1.500 1.78800 47.4
12 34.909 2.000
13 35.588 3.500 1.80810 22.8
14 63.361 D14
15 -95.248 1.320 1.80400 46.6
16 111.987 4.500
17 -64.408 1.370 1.61800 63.4
18 149.839 4.600 2.05090 26.9
19 -157.190 D19
20 301.713 3.080 1.90043 37.4
21 -250.285 0.200
22 -565.980 7.160 1.49700 81.6
23 -46.079 1.530 2.00100 29.1
24 -75.606 D24
25 aperture INFINITY 2.400
26 81.830 1.510 1.90366 31.3
27 40.840 7.500 1.49700 81.6
28 -459.366 0.500
29 43.465 4.600 1.85025 30.0
30 81.416 3.620
31 76.442 5.800 1.59410 60.5
32 173.707 1.390 1.90366 31.3
33 53.463 5.990
34 73.105 5.240 1.75500 52.3
35 -158.062 1.800
36 258.881 4.000 1.84666 23.8
37 -114.093 1.230 1.61405 55.0
38 31.643 6.500
39 -59.612 1.140 1.50137 56.4
40 -1064.653 3.600
41 91.538 4.960 1.67003 47.3
42 -118.728 1.580
43 -311.030 6.880 1.64850 53.0
44 -26.359 1.240 2.00100 29.1
45 -91.199 50.757
46 INFINITY 1.500 1.51680 64.2
47 INFINITY -
(Table 22)
Various data zoom ratio (variable magnification ratio) 2.69
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 72.08 100.00 194.00
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.5 11.9 6.1
Image height 21.64 21.64 21.64
Back focus 52.75 52.75 52.75
Lens total length 258.17 258.17 258.17
D6 1.200 17.662 38.546
D10 2.000 2.000 2.000
D14 16.700 16.700 16.700
D19 40.743 31.979 2.000
D24 9.075 1.370 10.472
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 84.38 115.00 179.00
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.084 -0.115 -0.215
Half angle of view 13.1 9.2 4.6
Image height 21.64 21.64 21.64
Back focus 52.75 52.75 52.75
Lens total length 258.17 258.17 258.17
D6 1.200 17.662 38.546
D10 12.164 13.074 15.113
D14 6.536 5.626 3.587
D19 40.743 31.979 2.000
D24 9.075 1.370 10.472
(Table 23)
Zoom lens group data group Starting plane Focal length
1 1 127.16
2 7 -36.87
3 20 125.53
4 26 105.38
2a 6 327.33
2b 9 -76.37
2c 13 -66.08
Anti-vibration 15 -41.25
(Table 24)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 6 127.160 7.591 7.455 5.244 Group 1
7 19 -36.874 24.433 10.644 15.594 Group 2
20 24 125.526 3.790 4.459 3.721 Group 3
25 45 105.382 -7.708 22.230 56.958 4th group sub-lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
7 10 327.330 2.299 4.205 6.676 2a sub lens group
11 14 -76.371 1.057 2.327 3.615 2b sub lens group
15 19 -66.077 -1.240 3.127 9.903 2c sub lens group
7 14 -103.631 15.507 6.139 0.534 2ab sub lens group
11 19 -31.242 10.077 7.707 17.706 2bc sub lens group

[Numerical Example 7]
75 to 85 and Tables 25 to 28 show a zoom lens system according to Numerical Example 7. FIG. 75 is a lens configuration diagram when focusing on infinity at the short focal length end. FIGS. 76 and 77 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 78 and 79 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 80 is a lateral aberration diagram during the vibration-proof driving of FIG. 78. FIGS. 81 and 82 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIGS. 83 and 84 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 85 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 83. Table 25 is surface data, Table 26 is various data, Table 27 is zoom lens group data, and Table 28 is principal point position data.

The zoom lens system of Numerical Example 7 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with negative refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, positive, and negative lenses.)

The first lens group G1 includes, in order from the object side, a negative meniscus lens 11G convex to the object side, a positive biconvex lens 12G, and a positive meniscus lens 13G convex to the object side. The negative meniscus lens 11G and the biconvex positive lens 12G are cemented together.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21G that is convex toward the object side, and a biconvex positive lens 22G.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23G and a positive meniscus lens 24G convex toward the object side. The biconcave negative lens 23G and the positive meniscus lens 24G are cemented together.
The second c lens group G2c includes a biconcave negative lens 25G, a biconcave negative lens 26G, and a biconvex positive lens 27G. The biconcave negative lens 26G and the biconvex positive lens 27G are cemented together.

The third lens group G3 includes, in order from the object side, a positive meniscus lens 31G convex to the image side, a biconvex positive lens 32G, and a negative meniscus lens 33G convex to the image side. The biconvex positive lens 32G and the negative meniscus lens 33G are cemented together.

The fourth lens group G4 includes, in order from the object side, a biconvex positive lens 41G, a negative meniscus lens 42G convex toward the object side, and a biconvex positive lens 43G. The negative meniscus lens 42G and the biconvex positive lens 43G are cemented together.

The fifth lens group G5 is composed of, in order from the object side, a 5a lens group G5a with positive refractive power, a 5b lens group G5b with negative refractive power, and a 5c lens group G5c with positive refractive power. ing.
The fifth a lens group G5a includes, in order from the object side, a biconvex positive lens 51G, a biconcave negative lens 52G, and a biconvex positive lens 53G. The biconvex positive lens 51G and the biconcave negative lens 52G are cemented together.
The fifth b lens group G5b includes, in order from the object side, a biconvex positive lens 54G, a biconcave negative lens 55G, and a negative meniscus lens 56G convex toward the image side.
The 5c lens group G5c includes, in order from the object side, a biconvex positive lens 57G, a positive meniscus lens 58G convex to the image side, and a negative meniscus lens 59G convex to the image side. The positive meniscus lens 58G and the negative meniscus lens 59G are cemented.

(Table 25)
Surface data surface number r DN(d) ν(d)
1 218.592 2.700 1.85478 24.8
2 125.729 10.640 1.49700 81.6
3 -278.494 0.200
4 88.406 6.700 1.53775 74.7
5 254.754 D5
6 89.588 2.070 1.73800 32.3
7 48.571 1.300
8 52.655 8.970 1.61800 63.4
9 -312547.760 D9
10 -425.796 1.370 1.76385 48.5
11 33.583 3.900 1.84666 23.8
12 56.336 D12
13 -118.862 1.330 1.74100 52.7
14 123.460 4.500
15 -63.716 1.430 1.72916 54.1
16 79.097 5.960 1.85478 24.8
17 -159.183 D17
18 aperture INFINITY 2.500
19 -2372.949 4.410 1.90043 37.4
20 -83.332 0.200
21 91.261 9.320 1.49700 81.6
22 -47.098 1.630 2.00100 29.1
23 -258.484 D23
24 72.775 5.380 1.90043 37.4
25 -1116.604 0.200
26 2238.885 1.220 1.91082 35.2
27 52.682 8.590 1.49700 81.6
28 -88.227 D28
29 44.376 7.900 1.49700 81.6
30 -80.836 1.260 1.80440 39.6
31 54.600 3.546
32 85.944 4.300 1.90366 31.3
33 -124.309 1.800
34 100.024 4.980 1.84666 23.8
35 -89.303 0.543
36 -76.657 1.150 1.72000 50.2
37 27.200 6.500
38 -45.000 1.130 1.65160 58.5
39 -88.138 4.223
40 84.857 5.070 1.70154 41.2
41 -166.669 2.000
42 -900.972 8.460 1.65160 58.5
43 -26.886 1.320 2.00100 29.1
44 -448.101 29.621
45 INFINITY 1.500 1.51680 64.2
46 INFINITY -
(Table 26)
Various data zoom ratio (variable magnification ratio) 2.69
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 72.08 100.00 194.01
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.3 11.7 6.0
Image height 21.64 21.64 21.64
Back focus 31.61 31.61 31.61
Lens total length 249.68 249.68 249.68
D5 1.200 14.150 37.750
D9 2.000 2.000 2.000
D12 16.030 16.030 16.030
D17 38.290 25.341 1.740
D23 18.843 12.389 3.680
D28 3.003 9.457 18.166
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 81.37 106.64 148.93
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.083 -0.113 -0.213
Half angle of view 13.0 9.2 4.8
Image height 21.64 21.64 21.64
Back focus 31.61 31.61 31.61
Lens total length 249.68 249.68 249.68
D5 1.200 14.150 37.750
D9 10.850 11.571 13.503
D12 7.180 6.459 4.527
D17 38.290 25.341 1.740
D23 18.843 12.389 3.680
D28 3.003 9.457 18.166
(Table 27)
Zoom lens group data group Starting plane Focal length
1 1 146.21
2 6 -37.54
3 19 102.99
4 24 89.06
5 29 -113.84
2a 6 203.26
2b 9 -69.67
2c 13 -60.65
Anti-vibration 15 -41.25
(Table 28)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 146.210 5.484 7.087 7.670 Group 1
6 17 -37.540 26.228 10.012 12.620 Group 2
18 23 102.991 0.857 6.376 10.827 Group 3
24 28 89.065 2.539 5.634 7.216 Group 4
29 44 -113.837 55.354 6.600 -7.772 5th group sub-lens group starting surface Ending surface Focal length Front principal point Principal point spacing Rear principal point
6 9 203.260 2.324 4.279 5.737 2a sub lens group
10 12 -69.672 2.887 2.385 -0.002 2b sub lens group
13 17 -60.651 0.240 3.700 9.280 2c sub lens group
6 12 -115.167 19.885 5.747 -6.022 2ab sub lens group
10 17 -28.826 10.619 7.891 16.010 2bc sub lens group

[Numerical Example 8]
86 to 96 and Tables 29 to 32 show a zoom lens system according to Numerical Example 8. FIG. 86 is a lens configuration diagram when focusing on infinity at the short focal length end. 87 and 88 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIGS. 89 and 90 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 91 is a lateral aberration diagram during the anti-vibration drive shown in FIG. 89. 92 and 93 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 94 and 95 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 96 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 94. Table 29 is surface data, Table 30 is various data, Table 31 is zoom lens group data, and Table 32 is principal point position data.

The zoom lens system of Numerical Example 8 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with negative refractive power. (In other words, it has a five-group zoom lens configuration with positive, negative, positive, and negative lenses.)

The first lens group G1 includes, in order from the object side, a negative meniscus lens 11H that is convex toward the object side, and a biconvex positive lens 12H. The negative meniscus lens 11H and the biconvex positive lens 12H are cemented together.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a is composed of, in order from the object side, a positive meniscus lens 21H convex to the object side, a negative meniscus lens 22H convex to the object side, and a positive meniscus lens 23H convex to the object side.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 24H and a positive meniscus lens 25H convex toward the object side. The biconcave negative lens 24H and the positive meniscus lens 25H are cemented together.
The second c lens group G2c includes a biconcave negative lens 26H, a biconcave negative lens 27H, and a positive meniscus lens 28H convex toward the object side. The biconcave negative lens 27H and the positive meniscus lens 28H are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31H, a biconvex positive lens 32H, and a negative meniscus lens 33H convex toward the image side. The biconvex positive lens 32H and the negative meniscus lens 33H are cemented together.

The fourth lens group G4 includes, in order from the object side, a biconvex positive lens 41H, a biconcave negative lens 42H, and a biconvex positive lens 43H. The biconcave negative lens 42H and the biconvex positive lens 43H are cemented.

The fifth lens group G5 is composed of, in order from the object side, a 5a lens group G5a with positive refractive power, a 5b lens group G5b with negative refractive power, and a 5c lens group G5c with positive refractive power. ing.
The fifth a lens group G5a includes, in order from the object side, a biconvex positive lens 51H, a biconcave negative lens 52H, and a biconvex positive lens 53H. The biconvex positive lens 51H and the biconcave negative lens 52H are cemented together.
The fifth b lens group G5b includes, in order from the object side, a biconvex positive lens 54H, a biconcave negative lens 55H, and a negative meniscus lens 56H convex toward the image side. The biconvex positive lens 54H and the biconcave negative lens 55H are cemented together.
The 5c lens group G5c includes, in order from the object side, a biconvex positive lens 57H, a biconvex positive lens 58H, and a biconcave negative lens 59H. The biconvex positive lens 58H and the biconcave negative lens 59H are cemented together.

(Table 29)
Surface data surface number r DN(d) ν(d)
1 101.460 2.700 1.85883 30.0
2 66.915 13.710 1.59410 60.5
3 -1371.819 D3
4 67.496 4.820 1.48749 70.2
5 92.998 0.500
6 85.477 2.070 1.72047 34.7
7 44.079 1.300
8 47.000 10.660 1.59410 60.5
9 30296.049 D9
10 -504.435 1.370 1.77250 49.6
11 33.000 4.300 1.84666 23.8
12 54.479 D12
13 -152.165 1.330 1.90043 37.4
14 69.197 4.500
15 -95.660 1.430 1.49700 81.6
16 61.219 4.560 2.05090 26.9
17 794.082 D17
18 aperture INFINITY 2.500
19 450.007 5.610 1.90366 31.3
20 -83.998 0.200
21 115.169 9.320 1.49700 81.6
22 -51.093 1.630 2.00100 29.1
23 -531.092 D23
24 63.003 5.880 1.91082 35.2
25 -1550.091 0.200
26 -6787.793 1.220 1.90366 31.3
27 41.335 9.690 1.53775 74.7
28 -109.863 D28
29 38.816 6.500 1.49700 81.6
30 -94.506 1.260 1.90366 31.3
31 41.448 4.140
32 53.883 5.770 1.90366 31.3
33 -111.107 1.800
34 258.000 3.600 1.84666 23.8
35 -65.396 1.150 1.65160 58.5
36 27.068 7.500
37 -33.923 1.130 1.65160 58.5
38 -55.833 2.600
39 96.283 4.670 1.75520 27.5
40 -61.974 2.000
41 224.495 5.460 1.51633 64.1
42 -30.520 1.320 2.00100 29.1
43 217.587 29.767
44 INFINITY 1.500 1.51680 64.2
45 INFINITY -
(Table 30)
Various data zoom ratio (variable magnification ratio) 2.69
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 72.08 100.00 194.00
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.4 11.7 6.0
Image height 21.64 21.64 21.64
Back focus 31.76 31.76 31.76
Lens total length 263.38 263.38 263.38
D3 1.200 17.175 42.974
D9 2.000 2.000 2.000
D12 17.000 17.000 17.000
D17 43.514 27.539 1.740
D23 27.812 19.647 2.001
D28 1.700 9.865 27.511
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 2.9 2.9 2.9
Focal length 84.19 110.42 151.76
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.084 -0.115 -0.216
Half angle of view 12.7 8.9 4.6
Image height 21.64 21.64 21.64
Back focus 31.76 31.76 31.76
Lens total length 263.38 263.38 263.38
D3 1.200 17.175 42.974
D9 11.095 12.004 13.942
D12 7.905 6.996 5.058
D17 43.514 27.539 1.740
D23 27.812 19.647 2.001
D28 1.700 9.865 27.511
(Table 31)
Zoom lens group data group Starting plane Focal length
1 1 201.29
2 4 -44.78
3 19 101.01
4 24 91.26
5 29 -140.96
2a 6 146.43
2b 9 -67.50
2c 13 -62.15
Anti-vibration 15 -41.25
(Table 32)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 3 201.293 -0.276 6.322 10.364 Group 1
4 17 -44.781 39.085 8.003 8.752 Group 2
18 23 101.008 -0.089 7.138 12.211 Group 3
24 28 91.258 1.619 6.403 8.968 Group 4
29 43 -140.956 52.991 7.510 -11.601 5th group sub-lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
4 9 146.432 1.991 6.285 11.074 2a sub lens group
10 12 -67.500 3.132 2.571 -0.033 2b sub lens group
13 17 -62.153 -0.554 3.330 9.044 2c sub lens group
4 12 -157.578 39.824 4.669 -17.473 2ab sub lens group
8 17 -73.194 49.462 -0.404 -1.908 2bc sub lens group

[Numerical Example 9]
100 to 110 and Tables 33 to 36 show a zoom lens system according to Numerical Example 9. FIG. 100 is a lens configuration diagram when focusing on infinity at the short focal length end. 101 and 102 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 103 and 104 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 105 is a lateral aberration diagram during the vibration-proof driving shown in FIG. 103. FIGS. 106 and 107 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 108 and 109 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 110 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 108. Table 33 is surface data, Table 34 is various data, Table 35 is zoom lens group data, and Table 36 is principal point position data.

The zoom lens system of Numerical Example 9 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with negative refractive power (that is, a four-group zoom lens configuration with positive, negative, positive, and negative). Become).

The first lens group G1 includes, in order from the object side, a biconvex positive lens 11I, a negative meniscus lens 12I convex on the object side, and a plano-convex positive lens 13I convex on the object side. The negative meniscus lens 12I and the plano-convex positive lens 13I are cemented.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21I that is convex toward the object side, and a biconvex positive lens 22I. The negative meniscus lens 21I and the biconvex positive lens 22I are cemented together.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23I and a positive meniscus lens 24I convex toward the object side.
The second c lens group G2c includes a biconcave negative lens 25I, a biconvex positive lens 26I, and a negative meniscus lens 27I convex toward the image side. The biconcave negative lens 25I and the biconvex positive lens 26I are cemented.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31I, a biconvex positive lens 32I, and a negative meniscus lens 33I convex to the image side. The biconvex positive lens 32I and the negative meniscus lens 33I are cemented together.

The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a, a 4b-th lens group G4b, and a 4c-th lens group C4c.
The fourth a lens group G4a includes, in order from the object side, a biconvex positive lens 41I, a biconcave negative lens 42I, and a biconvex positive lens 43I. The biconvex positive lens 41I and the biconcave negative lens 42I are cemented together.
The fourth b lens group G4b includes, in order from the object side, a biconvex positive lens 44I and a biconcave negative lens 45I. The biconvex positive lens 44I and the biconcave negative lens 45I are cemented together.
The fourth c lens group C4c is composed of, in order from the object side, a biconvex positive lens 46I and a negative meniscus lens 47I convex to the image side.

(Table 33)
Surface data surface number r DN(d) ν(d)
1 117.757 4.000 1.48749 70.2
2 -2773.131 0.200
3 103.049 1.500 1.74950 35.3
4 56.571 7.400 1.49700 81.6
5 INFINITY D5
6 68.207 1.200 1.90043 37.4
7 38.000 7.500 1.58313 59.4
8 -280.407 D8
9 -209.874 1.200 1.77250 49.6
10 26.762 2.000
11 27.082 2.000 1.84666 23.8
12 45.797 D12
13 -55.344 1.200 1.75500 52.3
14 50.834 3.660 1.85478 24.8
15 -300.000 1.820
16 -43.730 1.200 1.62299 58.2
17 -40130.232 D17
18 aperture INFINITY 1.000
19 111.055 4.307 1.88300 40.8
20 -80.378 0.200
21 41.051 5.891 1.48749 70.2
22 -47.843 1.200 2.00100 29.1
23 -418.179 D23
24 47.946 5.070 1.59282 68.6
25 -92.822 1.000 1.90366 31.3
26 37.216 0.300
27 32.262 5.943 1.61405 55.0
28 -84.092 5.000
29 635.248 3.000 1.85025 30.0
30 -25.936 1.000 1.80400 46.5
31 41.076 9.946
32 75.873 3.127 1.83481 42.7
33 -194.544 9.066
34 -21.491 1.200 1.73400 51.5
35 -36.089 D35
36 INFINITY 1.500 1.51633 64.1
37 INFINITY -
(Table 34)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.1 5.0 5.8
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.5 8.8 4.1
Image height 21.64 21.64 21.64
Back focus 47.62 64.39 77.41
Lens total length 186.83 220.27 253.23
D5 2.950 27.582 51.351
D8 2.000 2.000 2.000
D12 16.460 16.460 16.460
D17 21.840 13.521 2.000
D23 3.821 4.188 11.885
D35 45.636 62.401 75.419
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.1 5.0 5.8
Focal length 79.24 136.04 193.55
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.078 -0.147 -0.317
Half angle of view 13.5 7.0 3.1
Image height 21.64 21.64 21.64
Back focus 47.62 64.39 77.41
Lens total length 186.83 220.27 253.23
D5 2.950 27.582 51.351
D8 7.968 9.235 11.314
D12 10.492 9.225 7.146
D17 21.840 13.521 2.000
D23 3.821 4.188 11.885
D35 45.636 62.401 75.419
(Table 35)
Zoom lens group data group Starting plane Focal length
1 1 140.18
2 6 -25.29
3 19 43.16
4 24 -31675.66
2a 6 144.20
2b 9 -52.74
2c 13 -42.31
Anti-vibration 29 -61.05
(Table 36)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 140.178 0.679 4.414 8.007 Group 1
6 17 -25.292 23.165 9.198 7.876 Group 2
18 23 43.165 1.178 4.737 6.683 Group 3
24 35 -31675.664 8206.680 -1673.389 -6488.640 4th group sub-lens group start surface End surface Focal length Front principal point Principal point spacing Rear principal point
6 8 144.201 0.857 3.279 4.564 2a sub lens group
9 12 -52.738 0.188 1.484 3.528 2b sub lens group
13 17 -42.308 2.307 2.794 2.779 2c sub lens group
6 12 -89.774 12.350 4.225 -0.675 2ab sub lens group
9 17 -19.015 10.208 8.514 10.818 2bc sub lens group

[Numerical Example 10]
111 to 121 and Tables 37 to 41 show a zoom lens system according to Numerical Example 10. FIG. 111 is a lens configuration diagram when focusing on infinity at the short focal length end. 112 and 113 are longitudinal aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. 114 and 115 are lateral aberration diagrams at the short focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 116 is a lateral aberration diagram during the vibration-proof driving shown in FIG. 114. FIGS. 117 and 118 are longitudinal aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. 119 and 120 are lateral aberration diagrams at the long focal length end when focusing on infinity and when focusing on 1.2 m. FIG. 121 is a lateral aberration diagram during the anti-vibration drive (±0.3°) in FIG. 119. Table 37 is surface data, Table 38 is various data, Table 39 is zoom lens group data, Table 40 is principal point position data, and Table 41 is aspheric data.

The zoom lens system of Numerical Example 10 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR is composed of, in order from the object side, a third lens group G3 with positive refractive power and a fourth lens group G4 with positive refractive power (that is, a four-group zoom lens configuration with positive, negative, positive, and positive). ).

The first lens group G1 includes, in order from the object side, a biconvex positive lens 11J, a negative meniscus lens 12J convex to the object side, and a positive meniscus lens 13J convex to the object side. The negative meniscus lens 12J and the positive meniscus lens 13J are cemented.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing.
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21J that is convex toward the object side, and a biconvex positive lens 22J. The negative meniscus lens 21J and the biconvex positive lens 22J are cemented together.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23J and a positive meniscus lens 24J that is convex toward the object side.
The second c lens group G2c includes a biconcave negative lens 25J, a positive meniscus lens 26J convex toward the object side, and a negative meniscus lens 27J convex toward the image side. The biconcave negative lens 25J and the positive meniscus lens 26J are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31J, a biconvex positive lens 32J, and a negative meniscus lens 33J convex to the image side. The biconvex positive lens 32J and the negative meniscus lens 33J are cemented together.

The fourth lens group G4 includes, in order from the object side, a 4a-th lens group G4a, a 4b-th lens group G4b, and a 4c-th lens group C4c.
The fourth a lens group G4a includes, in order from the object side, a biconvex positive lens 41J, a biconcave negative lens 42J, and a biconvex positive lens 43J. The biconvex positive lens 41J and the biconcave negative lens 42J are cemented together. The biconvex positive lens 43J has an aspherical surface on the image side.
The fourth b lens group G4b includes, in order from the object side, a biconvex positive lens 44J and a biconcave negative lens 45J. The biconvex positive lens 44J and the biconcave negative lens 45J are cemented together.
The fourth c lens group C4c includes, in order from the object side, a biconvex positive lens 46J and a negative meniscus lens 47J convex toward the image side.

(Table 37)
Surface data surface number r DN(d) ν(d)
1 128.481 5.000 1.48749 70.2
2 -775.463 0.200
3 110.744 1.500 1.68376 37.6
4 56.778 7.400 1.49700 81.6
5 644.825 D5
6 89.500 1.200 1.89190 37.1
7 39.000 6.500 1.69680 55.5
8 -368.248 D8
9 -237.670 1.200 1.77250 49.6
10 27.086 2.000
11 28.096 2.000 1.84666 23.8
12 46.990 D12
13 -99.422 1.200 1.61800 63.4
14 41.496 3.100 1.80000 29.9
15 483.673 2.320
16 -46.483 1.200 1.65160 58.5
17 -1336.266 D17
18 aperture INFINITY 1.000
19 69.313 4.307 1.73400 51.5
20 -98.420 0.200
21 58.658 5.891 1.49700 81.6
22 -48.637 1.200 2.00100 29.1
23 -871.247 D23
24 49.679 4.100 1.51742 52.4
25 -75.433 1.000 1.90043 37.4
26 93.084 1.500
27 56.247 4.500 1.58313 59.4
28* -68.418 15.173
29 245.133 2.300 1.85478 24.8
30 -40.455 1.000 1.80400 46.5
31 31.872 8.068
32 45.430 4.630 1.57099 50.8
33 -45.816 3.344
34 -25.003 1.200 1.88300 40.8
35 -97.584 D35
36 INFINITY 1.500 1.51633 64.1
37 INFINITY -
* is a rotationally symmetric aspherical surface.
(Table 38)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.4 5.1 5.8
Focal length 72.10 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.2 8.6 4.0
Image height 21.64 21.64 21.64
Back focus 38.87 49.31 59.39
Lens total length 188.38 219.10 244.19
D5 2.950 33.664 58.758
D8 2.000 2.000 2.000
D12 16.460 16.460 16.460
D17 29.047 18.583 2.000
D23 4.818 4.845 11.346
D35 36.884 47.322 57.404
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.4 5.1 5.8
Focal length 79.58 133.02 172.39
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.079 -0.148 -0.315
Half angle of view 13.1 6.8 3.1
Image height 21.64 21.64 21.64
Back focus 38.87 49.31 59.39
Lens total length 188.38 219.10 244.19
D5 2.950 33.664 58.758
D8 8.833 10.328 12.488
D12 9.627 8.132 5.972
D17 29.047 18.583 2.000
D23 4.818 4.845 11.346
D35 36.884 47.322 57.404
(Table 39)
Zoom lens group data group Starting plane Focal length
1 1 152.30
2 6 -30.84
3 19 55.35
4 24 974.84
2a 6 146.23
2b 9 -52.87
2c 13 -58.09
Anti-vibration 29 -49.23
(Table 40)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 152.300 0.356 4.753 8.991 Group 1
6 17 -30.838 21.434 9.076 8.670 Group 2
18 23 55.352 0.030 4.668 7.899 Group 3
24 35 974.841 -515.576 198.711 363.680 4th group sub-lens group start surface End surface Focal length Front principal point Principal point spacing Rear principal point
6 8 146.234 0.775 3.203 3.722 2a sub lens group
9 12 -52.873 0.248 1.485 3.466 2b sub lens group
13 17 -58.092 3.782 2.372 1.665 2c sub lens group
6 12 -88.474 10.765 4.281 -0.146 2ab sub lens group
9 17 -22.807 9.556 8.032 11.892 2bc sub lens group (Table 41)
Aspheric data
NO.28 K=0.000 A4=0.2088E-05 A6=-0.1121E-08 A8=0.0000E+00 A10=0.0000E+00 A12=0.0000E+00

[Numerical Example 11]
122 to 136 and Tables 42 to 45 show a zoom lens system according to Numerical Example 11. FIG. 122 is a lens configuration diagram when focusing on infinity at the short focal length end. 123, 124, and 125 are longitudinal aberration diagrams at the short focal length end when focusing on infinity, when focusing on 1.2 m, and when focusing on 0.9 m. 126, 127, and 128 are lateral aberration diagrams at the short focal length end when focusing on infinity, when focusing on 1.2 m, and when focusing on 0.9 m. FIG. 129 is a lateral aberration diagram during the vibration-proof driving of FIG. 126. 130, 131, and 132 are longitudinal aberration diagrams at the long focal length end when focusing on infinity, when focusing on 1.2 m, and when focusing on 0.9 m. 133, 134, and 135 are lateral aberration diagrams at the long focal length end when focusing on infinity, when focusing on 1.2 m, and when focusing on 0.9 m. FIG. 136 is a lateral aberration diagram when the image stabilization is driven (±0.6°) in FIG. 133 (when the two anti-vibration lens groups (first and second anti-vibration lens groups) are driven with anti-vibration). Table 42 is surface data, Table 43 is various data, Table 44 is zoom lens group data, and Table 45 is principal point position data.

The zoom lens system of Numerical Example 11 is composed of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a subsequent lens group GR. The subsequent lens group GR includes, in order from the object side, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a positive refractive power. (In other words, it has a six-group zoom lens configuration with positive, negative, positive, negative, and positive lenses.)

The first lens group G1 is composed of, in order from the object side, a plano-convex positive lens 11K that is convex to the object side, a negative meniscus lens 12K that is convex to the object side, and a positive meniscus lens 13K that is convex to the object side. . The negative meniscus lens 12K and the positive meniscus lens 13K are cemented.

The second lens group G2 is composed of, in order from the object side, a 2a lens group G2a with positive refractive power, a 2b lens group G2b with negative refractive power, and a 2c lens group G2c with negative refractive power. ing. As described above, the second c lens group G2c functions as an anti-vibration lens group (see FIG. 99).
The second a lens group G2a includes, in order from the object side, a negative meniscus lens 21K that is convex toward the object side, and a biconvex positive lens 22K. The negative meniscus lens 21K and the biconvex positive lens 22K are cemented together.
The second b lens group G2b includes, in order from the object side, a biconcave negative lens 23K and a positive meniscus lens 24K convex toward the object side.
The second c lens group G2c includes a biconcave negative lens 25K, a positive meniscus lens 26K convex toward the object side, and a negative meniscus lens 27K convex toward the image side. The biconcave negative lens 25K and the positive meniscus lens 26K are cemented together.

The third lens group G3 includes, in order from the object side, a biconvex positive lens 31K, a biconvex positive lens 32K, and a negative meniscus lens 33K convex toward the image side. The biconvex positive lens 32K and the negative meniscus lens 33K are cemented together.

The fourth lens group G4 includes, in order from the object side, a negative meniscus lens 41K that is convex toward the object side, a positive biconvex lens 42K, and a positive meniscus lens 43K that is convex toward the object side. The negative meniscus lens 41K and the biconvex positive lens 42K are cemented together.

The fifth lens group G5 includes, in order from the object side, a positive meniscus lens 51K convex to the image side and a biconcave negative lens 52. The positive meniscus lens 51K and the biconcave negative lens 52 are cemented together. As described above, the fifth lens group G5 functions as an anti-vibration lens group (see FIG. 99).

The sixth lens group G6 includes, in order from the object side, a biconvex positive lens 61K and a negative meniscus lens 62K convex toward the image side.

(Table 42)
Surface data surface number r DN(d) ν(d)
1 96.809 4.900 1.51823 59.0
2 INFINITY 0.200
3 120.285 1.950 1.65412 39.7
4 52.000 7.500 1.43875 95.0
5 654.604 D5
6 67.375 1.380 1.89190 37.1
7 33.851 7.000 1.69680 55.5
8 -497.901 D8
9 -200.377 1.000 1.80400 46.5
10 26.188 1.400
11 26.808 2.400 1.84666 23.8
12 50.000 D12
13 -97.764 1.000 1.72916 54.1
14 38.712 2.900 1.85478 24.8
15 207.147 2.000
16 -60.093 1.000 1.77250 49.6
17 -36895.611 D17
18 aperture INFINITY 2.000
19 96.048 2.430 1.80400 46.5
20 -128.585 0.200
21 47.142 5.170 1.53775 74.7
22 -58.053 1.200 2.00100 29.1
23 -309.281 D23
24 79.885 1.200 2.00100 29.1
25 30.245 4.400 1.49700 81.6
26 -96.418 0.200
27 47.399 3.000 1.83481 42.7
28 154.412 D28
29 -183.762 2.500 1.85478 24.8
30 -27.067 1.000 1.80400 46.5
31 37.271 D31
32 145.885 3.400 1.80518 25.4
33 -108.356 3.871
34 -37.830 1.200 1.98613 16.5
35 -52.287 D35
36 INFINITY 1.500 1.51633 64.1
37 INFINITY -
(Table 43)
Various data zoom ratio (variable magnification ratio) 4.04
Focusing at infinity
Short focal length end Intermediate focal length Long focal length end F number 4.5 5.2 5.8
Focal length 72.08 135.00 291.30
Object-image distance INFINITY INFINITY INFINITY
Magnification 0.000 0.000 0.000
Half angle of view 16.6 8.7 4.0
Image height 21.64 21.64 21.64
Back focus 40.62 53.74 60.62
Lens total length 193.29 221.83 254.83
D5 2.950 31.491 64.491
D8 2.000 2.000 2.000
D12 16.460 16.460 16.460
D17 27.294 14.657 2.000
D23 18.502 18.026 23.794
D28 12.000 15.039 13.714
D31 7.062 4.023 5.348
D35 38.634 51.746 58.635
When focusing at 1.2m
Short focal length end Intermediate focal length Long focal length end F number 4.9 5.2 5.7
Focal length 79.15 134.18 187.15
Object-image distance 1200.00 1200.00 1200.00
Magnification -0.077 -0.146 -0.309
Half angle of view 13.2 7.1 3.2
Image height 21.64 21.64 21.64
Back focus 40.62 53.74 60.62
Lens total length 193.29 221.83 254.83
D5 2.950 31.491 64.491
D8 7.355 8.756 11.558
D12 11.105 9.704 6.902
D17 27.294 14.657 2.000
D23 18.502 18.026 23.794
D28 12.000 15.039 13.714
D31 7.062 4.023 5.348
D35 38.634 51.746 58.635
When focused at 0.9m
Short focal length end Intermediate focal length Long focal length end F number 4.5 5.2 5.7
Focal length 82.31 132.20 158.11
Object-image distance 900.00 900.00 900.00
Magnification -0.114 -0.215 -0.453
Half angle of view 12.6 6.4 2.9
Image height 21.64 21.64 21.64
Back focus 40.62 53.74 60.62
Lens total length 193.29 221.83 254.83
D5 2.950 31.491 64.491
D8 9.851 11.987 16.240
D12 8.609 6.473 2.220
D17 27.294 14.657 2.000
D23 18.502 18.026 23.794
D28 12.000 15.039 13.714
D31 7.062 4.023 5.348
D35 38.634 51.746 58.635
(Table 44)
Zoom lens group data group Starting plane Focal length
1 1 165.24
2 6 -29.44
3 19 46.52
4 24 73.58
5 (Anti-vibration 2) 29 -40.81
6 32 160.47
2a 6 112.71
2b 9 -51.49
2c (anti-vibration 1) 13 -46.38
(Table 45)
Principal point position data Zoom lens group start plane End plane Focal length Front principal point Principal point spacing Rear principal point
1 5 165.242 -1.143 4.826 10.867 Group 1
6 17 -29.440 24.671 7.825 6.044 Group 2
18 23 46.517 2.240 3.546 5.214 Group 3
24 28 73.581 3.399 3.429 1.971 Group 4
29 31 -40.810 1.570 1.611 0.318 Group 5
32 35 160.466 -2.273 2.206 8.538 6th group sub-lens group starting surface End surface Focal length Front principal point Principal point spacing Rear principal point
6 8 112.709 0.295 3.496 4.590 2a sub lens group
9 12 -51.488 0.466 1.606 2.728 2b sub lens group
13 17 -46.384 2.794 2.260 1.846 2c sub lens group
6 12 -107.136 14.976 4.183 -3.978 2ab sub lens group
9 17 -19.926 9.909 7.898 10.353 2bc sub lens group

FIG. 137 is a diagram showing an example of the external configuration of a lens barrel (imaging device) LX equipped with a zoom lens system according to this embodiment. The lens barrel LX is configured, for example, as a zoom interchangeable lens for a single-lens reflex camera. The lens barrel LX includes a fixed barrel 10, and a lens mount 100 is fixed to the rear side of the fixed barrel 10. A zoom ring 11 is fitted on the circumferential surface of the fixed barrel 10 in the front region in the optical axis direction, and a focus ring 12 is fitted in the rear region. Rubber rings ZG and FG are fixed to the respective circumferential surfaces of the zoom ring 11 and the focus ring 12, which improves the feel during operation.

The lens barrel LX can be attached to and detached from a camera body (not shown) using a lens mount 100 provided on a fixed barrel 10, and can be moved to a long focus (tele) side or a short focus (wide) side by rotating the zoom ring 11. Can be zoomed. Further, by operating the zoom ring 11 further toward the short focus side while pressing the collapsible button B provided on the circumference, the lens barrel LX can be set to a collapsible state in which the length of the lens barrel LX is minimized. Focusing is automatically performed by a built-in motor, but manual focusing is also possible by rotating the focus ring 12.

Inside the fixed cylinder 10, an outer translational cylinder 13 and an inner translational cylinder (not shown) are arranged coaxially with a required gap in the cylinder diameter direction. These linear motion barrels are integrated with each other at their respective rear ends, and are driven by cam engagement between a straight groove in the optical axis direction provided on the fixed barrel 10 and a cam groove provided on the zoom ring 11. , are integrally moved linearly in the optical axis direction inside the fixed barrel 10 as the zoom ring 11 rotates.

Although not shown in the drawings, a helicoid tube having a helicoid groove formed on the outer circumferential surface is fitted onto the outer periphery of the inner linear motion tube. This helicoid cylinder is moved integrally with the inner translational cylinder in the direction of the cylinder axis, but is linked to the zoom ring 11, and as the zoom ring 11 rotates, it moves around the cylinder axis on the circumferential surface of the inner translational cylinder. is rotated to . Further, a front translation tube 16 is fitted between the helicoid tube and the outer translation tube 13 in the radial direction. The front translation tube 16 is fitted into a helicoid groove of the helicoid tube, and is moved in the optical axis direction by rotation of the helicoid tube. A lens L1 is supported at the front end of the front translational cylinder 16. The lens L1 depicted in FIG. 137 is, for example, the lens (11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H) located closest to the object side of the first lens group G1 of the zoom lens system of this embodiment. , 11I, 11J, 11K). Further, the lens barrel LX is provided with a component (for example, an ON/OFF switch for anti-vibration drive) for demonstrating and assisting the functions of the zoom lens system of this embodiment.

Movement amount of each anti-vibration lens group during anti-vibration driving (±0.3°) in Numerical Examples 1 to 10 and anti-vibration lens group during anti-vibration driving (±0.3°) in Numerical Example 11 is shown in Table 46. The unit of this amount of movement is millimeter [mm].
(Table 46)
Short focal length end Intermediate focal length Long focal length end Example 1 ±0.246 ±0.457 ±0.973
Example 2 ±0.264 ±0.494 ±1.078
Example 3 ±0.239 ±0.448 ±0.964
Example 4 ±0.272 ±0.359 ±0.561
Example 5 ±0.344 ±0.444 ±0.730
Example 6 ±0.254 ±0.353 ±0.685
Example 7 ±0.299 ±0.415 ±0.804
Example 8 ±0.291 ±0.404 ±0.784
Example 9 ±0.322 ±0.481 ±0.896
Example 10 ±0.327 ±0.509 ±0.944
Example 11
G2C ±0.285 ±0.372 ±0.571
G5 ±0.292 ±0.454 ±0.874

Table 47 shows the values for each conditional expression in Numerical Examples 1 to 11.
(Table 47)
Example 1 Example 2 Example 3 Example 4
Conditional expression (1) 0.751 0.779 0.638 0.434
Conditional expression (2) 0.452 0.388 0.452 0.371
Conditional expression (3) 0.501 0.599 0.512 0.422
Conditional expression (4) 0.399 0.506 0.368 0.309
Conditional expression (5) 0.588 0.527 0.622 0.632
Conditional expression (6) 0.298 0.280 0.354 0.409
Conditional expression (7) 3.812 5.450 2.596 2.375
Conditional expression (8) 1.684 1.522 1.455 1.287
Conditional expression (9) 12.398 16.828 7.676 6.351
Conditional expression (10) 0.489 0.827 1.156 2.163
Conditional expression (11) 1.591 2.772 9.063 1.495
Conditional expression (12) 58.5 60.5 58.5 59.0
Conditional expression (13) 1.004 0.274 1.812 1.606
Conditional expression (14) 1.342 1.386 1.441 1.435
Conditional expression (15) 58.5 58.5 58.5 52.3
Conditional expression (16) 0.476 0.413 0.451 0.407
Conditional expression (17) 33.1 31.0 33.1 28.5
Conditional expression (18) 0.141 0.208 0.135 0.063
Conditional expression (19) -8.203 -8.233 -8.336 -9.409
Conditional expression (20) 1.568 1.415 1.572 2.719
Conditional expression (21) 1.153 0.979 1.144 1.287
Conditional expression (22) 1.503 1.532 1.540 1.312
Conditional expression (23) 0.304 0.293 0.358 0.389
Conditional expression (24) 0.448 0.422 0.533 0.496
Conditional expression (25) 0.900 0.849 1.071 0.997
Conditional expression (26) 2.126 1.971 2.305 1.966
Conditional expression (27) 0.909 0.975 0.856 0.871
Conditional expression (28) 3.309 2.127 2.587 1.737
Example 5 Example 6 Example 7 Example 8
Conditional expression (1) 0.485 0.453 0.427 0.380
Conditional expression (2) 0.349 0.330 0.328 0.304
Conditional expression (3) 0.486 0.567 0.555 0.558
Conditional expression (4) 0.413 0.247 0.274 0.270
Conditional expression (5) 0.622 0.482 0.537 0.700
Conditional expression (6) 0.386 0.306 0.407 0.713
Conditional expression (7) 2.161 4.286 2.917 2.169
Conditional expression (8) 1.603 1.156 1.149 1.086
Conditional expression (9) 6.701 10.477 7.051 5.098
Conditional expression (10) 1.787 0.776 1.001 0.996
Conditional expression (11) 2.264 1.820 1537.675 206.895
Conditional expression (12) 60.5 63.9 63.4 70.2
Conditional expression (13) 1.823 0.557 0.723 0.881
Conditional expression (14) 1.307 1.163 1.305 1.242
Conditional expression (15) 52.3 47.4 48.5 49.6
Conditional expression (16) 0.453 0.447 0.447 0.442
Conditional expression (17) 28.5 24.6 24.7 25.8
Conditional expression (18) 0.018 0.009 0.010 0.017
Conditional expression (19) -9.398 -3.346 -3.724 -3.611
Conditional expression (20) 2.090 1.482 1.263 1.298
Conditional expression (21) 1.060 1.715 1.689 1.735
Conditional expression (22) 1.318 1.000 1.354 1.629
Conditional expression (23) 0.364 0.512 0.521 0.621
Conditional expression (24) 0.493 0.655 0.754 1.038
Conditional expression (25) 0.991 1.075 1.236 1.702
Conditional expression (26) 2.115 1.013 0.974 0.933
Conditional expression (27) 0.811 1.051 0.974 0.933
Conditional expression (28) 1.898 1.183 1.590 1.239
Example 9 Example 10 Example 11
Conditional expression (1) 0.651 0.534 0.559
Conditional expression (2) 0.409 0.420 0.427
Conditional expression (3) 0.569 0.521 0.520
Conditional expression (4) 0.448 0.352 0.396
Conditional expression (5) 0.576 0.547 0.640
Conditional expression (6) 0.307 0.275 0.389
Conditional expression (7) 2.734 2.766 2.189
Conditional expression (8) 1.247 0.910 1.110
Conditional expression (9) 7.584 6.412 5.656
Conditional expression (10) 1.643 1.642 1.313
Conditional expression (11) 1.945 2.518 4.418
Conditional expression (12) 59.370 55.530 55.530
Conditional expression (13) 0.674 0.536 0.690
Conditional expression (14) 1.558 1.493 1.665
Conditional expression (15) 49.600 49.600 46.530
Conditional expression (16) 0.411 0.399 0.441
Conditional expression (17) 25.820 25.820 22.750
Conditional expression (18) 0.155 0.220 0.119
Conditional expression (19) -10.188 -8.975 -9.721
Conditional expression (20) 1.702 1.616 2.673 (G2c standard) 1.742 (G5 standard)
Conditional expression (21) 0.864 1.074 1.110 (G2c standard) 1.262 (G5 standard)
Conditional expression (22) 1.618 1.481 1.488
Conditional expression (23) 0.351 0.428 0.408
Conditional expression (24) 0.481 0.523 0.567
Conditional expression (25) 0.967 1.051 1.140
Conditional expression (26) 1.914 1.810 2.090
Conditional expression (27) 0.784 0.877 0.859
Conditional expression (28) 1.489 1.905 1.348

As is clear from Table 47, Numerical Examples 1 to 11 satisfy conditional expressions (1) to (28), and as is clear from the longitudinal and lateral aberration diagrams, various aberrations are relatively well controlled. It has been corrected. Furthermore, despite the small number of focusing lens elements, aberration fluctuations due to changes in shooting distance are suppressed at both the short focal length end and long focal length end, and aberration fluctuations during image stabilization drive are well corrected. ing.

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 still within the technical scope of the present invention (the technical scope of the present invention is not limited to (This does not mean that it has been avoided.)

G1 First lens group G2 with positive refractive power Second lens group G2a with negative refractive power Second a lens group G2b with positive refractive power Second b lens group (focus lens group) with negative refractive power
G2c 2nd c lens group with negative refractive power (anti-vibration lens group)
GR Subsequent lens group G3 Third lens group G4 with positive refractive power Fourth lens group with positive refractive power, fourth lens group G4a with negative refractive power Fourth a lens group G4b with positive refractive power 4b lens group (anti-vibration lens group)
G4c 4th c lens group with positive refractive power G5 5th lens group with positive refractive power, 5th lens group with negative refractive power G5a 5th a lens group with positive refractive power G5b 5th lens group with negative refractive power (Anti-vibration lens group)
G5c 5th lens group with positive refractive power G6 6th lens group with positive refractive power, 6th lens group CG with negative refractive power Plane parallel plate SP Aperture

Claims (24)

Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (1) is satisfied,
A zoom lens system characterized by
(1) 0.3<D2bc/(-f2)<1.0
however,
D2bc: distance between the 2b lens group and the 2c lens group when focusing on infinity;
f2: Focal length of the second lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (2) is satisfied,
A zoom lens system characterized by
(2) 0.3<D2bc/D2<1.0
however,
D2bc: distance between the 2b lens group and the 2c lens group when focusing on infinity;
D2: Thickness of the second lens group on the optical axis. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
When the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group,
The following conditional expression (3) is satisfied,
A zoom lens system characterized by
(3) 0.3<H2_2bc/(-f2bc)
however,
H2_2bc: distance on the optical axis from the most image-side surface of the second bc lens group to the rear principal point position of the second bc lens group,
f2bc: Focal length of the second bc lens group when focusing on infinity. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
When the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group,
The following conditional expression (4) is satisfied,
A zoom lens system characterized by
(4) 0.2<HH_2bc/(-f2bc)
however,
HH_2bc: Principal point interval of the second bc lens group, distance on the optical axis from the front principal point position to the rear principal point position,
f2bc: Focal length of the second bc lens group when focusing on infinity. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (5A) is satisfied,
A zoom lens system characterized by
(5A) 0<H1_2/D2≦0.640
however,
H1_2: Distance on the optical axis from the most object-side surface of the second lens group to the front principal point position,
D2: Thickness of the second lens group on the optical axis. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
When the combined optical system of the 2a lens group and the 2b lens group is defined as the 2ab lens group,
The following conditional expression (6A) is satisfied,
A zoom lens system characterized by
(6A) 0<H1_2ab/D2≦0.409
however,
H1_2ab: distance on the optical axis from the most object-side surface of the second ab lens group to the front principal point position,
D2: Thickness of the second lens group on the optical axis. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (7) is satisfied,
A zoom lens system characterized by
(7) 1.5<f2a/(-f2b)<6.5
however,
f2a: focal length of the second a lens group,
f2b: Focal length of the second b lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (8A) is satisfied,
A zoom lens system characterized by
(8A) 0.5<f2b/f2c≦1.522
however,
f2b: focal length of the second b lens group,
f2c: Focal length of the second c lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
When the combined optical system of the 2b lens group and the 2c lens group is defined as the 2bc lens group,
The following conditional expression (9) is satisfied,
A zoom lens system characterized by
(9) 4<f2a/(-f2bc)<20
however,
f2a: focal length of the second a lens group,
f2bc: Focal length of the second bc lens group when focusing on infinity. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (10) is satisfied,
A zoom lens system characterized by
(10) 0.4<(R2_2a-R1_2a)/(R2_2a+R1_2a)<3.0
however,
R1_2a: paraxial radius of curvature of the surface closest to the object side of the second a lens group,
R2_2a: Paraxial radius of curvature of the most image-side surface of the second a lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (11) is satisfied,
A zoom lens system characterized by
(11) 0.40<|R2_2a|/f2a
however,
R2_2a: paraxial radius of curvature of the most image-side surface of the second a lens group,
f2a: Focal length of the second a lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The second a lens group has at least one positive lens,
The following conditional expression (12) is satisfied,
A zoom lens system characterized by
(12) 45<2apMAX_νd
however,
2apMAX_νd: Abbe number of the positive lens with the largest Abbe number among the positive lenses in the 2a-th lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The second a lens group has at least one negative lens,
The following conditional expression (13) is satisfied,
A zoom lens system characterized by
(13) 0.2<(-f2anMAX)/f2a
however,
f2anMAX: Focal length of the negative lens with the largest refractive power among the negative lenses of the 2a-th lens group,
f2a: Focal length of the second a lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (14') is satisfied,
A zoom lens system characterized by
(14') 0.5<(R1_2b-R2_2b)/(R1_2b+R2_2b)<2.0
however,
R1_2b: Paraxial radius of curvature of the surface closest to the object side of the second b lens group,
R2_2b: Paraxial radius of curvature of the most image-side surface of the second b lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The second b lens group is composed of one negative lens and one positive lens located in order from the object side,
The following conditional expression (17A) is satisfied,
A zoom lens system characterized by
(17A) 24.6≦2bn_νd−2bp_νd
however,
2bn_νd: Abbe number of the negative lens of the 2b lens group,
2bp_νd: Abbe number of the positive lens of the 2b lens group. Consisting of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent lens group having a plurality of lens groups,
When changing the power from the short focal length end to the long focal length end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the subsequent lens group decreases, and the distance between the multiple lenses in the subsequent lens group increases. The distance between adjacent lens groups changes,
The second lens group is composed of, in order from the object side, a 2a lens group with positive refractive power, a 2b lens group with negative refractive power, and a 2c lens group with negative refractive power,
When focusing from infinity to a short distance, the 2b lens group moves toward the image side, and the distance between the 2a lens group and the 2b lens group and the distance between the 2b lens group and the 2c lens group change,
The following conditional expression (19”) is satisfied,
A zoom lens system characterized by
(19”) (1-M_2bt ² )・M_2bRt ² <-8.0
however,
M_2bt: Lateral magnification of the 2b lens group when focusing at infinity at the long focal length end,
M_2bRt: Combined lateral magnification of all lens groups on the image side from the 2b lens group when focusing on infinity at the long focal length end. 17. The zoom lens system according to claim 1, wherein the second c lens group includes at least two negative lenses and at least one positive lens. 18. The zoom lens system according to claim 1, wherein the second a lens group includes at least one negative lens. The zoom lens according to any one of claims 1 to 18 , wherein the second b lens group has a negative lens located closest to the object side, and satisfies the following conditional expression (15). system.
(15) 30<2bn_νd
however,
2bn_νd: Abbe number of the negative lens located closest to the object side in the second b lens group. Any one of claims 1 to 14 and 16 to 19, wherein the second b lens group is composed of one negative lens and one positive lens positioned in order from the object side. A zoom lens system described in Crab. The zoom lens system according to claim 20 , characterized in that the following conditional expression (16) is satisfied.
(16) 0.1<(-f2bn)/f2bp<0.7
however,
f2bn: focal length of the negative lens of the second b lens group,
f2bp: Focal length of the positive lens of the second b lens group. The zoom lens system according to any one of claims 1 to 21 , characterized in that the following conditional expression (18) is satisfied.
(18) fW/｜f1-2bW｜<0.5
however,
fW: focal length of the entire system when focusing at infinity at the short focal length end,
f1-2bW: Composite focal length from the first lens group to the second b lens group when focusing at infinity at the short focal length end. A lens barrel comprising the zoom lens system according to any one of claims 1 to 22 . An imaging device comprising the zoom lens system according to any one of claims 1 to 22 .

Images