WO2013111602A1

WO2013111602A1 - Zoom lens system, image capturing device and camera

Info

Publication number: WO2013111602A1
Application number: PCT/JP2013/000386
Authority: WO
Inventors: 健一惠美; 朴　一武; 恭一美藤
Original assignee: パナソニック株式会社
Priority date: 2012-01-27
Filing date: 2013-01-25
Publication date: 2013-08-01

Abstract

A zoom lens system is provided with, in order from the object side to the image side, at least a first lens group having positive power, and a second lens group having negative power, increases the distance between the first lens group and the second lens group during zooming from a wide angle end to a telephoto end when an image is captured, and satisfies conditions: D1>D2 and D3>D2 at the same time, where D1 is the effective diameter of an aperture stop at the wide angle end, D2 is the effective diameter of the aperture stop at an intermediate position, and D3 is the effective diameter of the aperture stop at the telephoto end.

Description

Zoom lens system, imaging device and camera

The present disclosure relates to a zoom lens system, an imaging device, and a camera.

Demand for downsizing and high performance of a camera having an image sensor that performs photoelectric conversion (hereinafter simply referred to as a digital camera) such as a digital still camera or a digital video camera is extremely strong. In particular, a compact digital camera equipped with a zoom lens system having a high zooming ratio is strongly demanded for its convenience. As such a zoom lens system, for example, a positive lead type in which at least a first lens group having a positive power and a second lens group having a negative power are arranged in order from the object side to the image side. Various zoom lens systems have been proposed.

Patent Documents 1 and 4 disclose a zoom lens having the positive lead type and a positive, negative, positive, and positive five-group configuration.

Patent Document 2 discloses a zoom lens of the positive lead type and having a positive, negative, positive four-group configuration.

Patent Document 3 discloses a zoom lens of the positive lead type and having a five-group configuration of positive, negative, positive and positive.

Patent Document 5 discloses a variable magnification optical system of the positive lead type and having at least a positive and negative three-group configuration.

Patent Document 6 discloses an imaging optical system of the positive lead type and having a positive / negative two-group configuration and at least two subsequent lens groups.

JP 2009-282429 A JP 2009-115875 A JP 2009-086437 A JP 2008-304708 A JP 2008-281927 A JP 2007-047538 A

(I) The present disclosure not only has an extremely high zooming ratio, but also reduces the burden of correcting aberrations of lens elements in the vicinity of the aperture stop in zooming, particularly in the middle position. Provided is a zoom lens system having high resolution with reduced aberrations in position. The present disclosure also provides an imaging apparatus including the zoom lens system and a thin and compact camera including the imaging apparatus.

(II) The present disclosure provides a zoom lens system that not only has an extremely high zooming ratio but also has improved optical performance especially at the telephoto end and excellent optical characteristics. The present disclosure also provides an imaging apparatus including the zoom lens system and a thin and compact camera including the imaging apparatus.

(I) A zoom lens system according to the present disclosure includes:
Having a plurality of lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having positive power and a second lens group having negative power are provided,
During zooming from the wide-angle end to the telephoto end during imaging, the interval between the first lens group and the second lens group is increased,
The following conditions (I-1) and (I-2):
D1> D2 (I-1)
D3> D2 (I-2)
(here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D2: effective diameter (mm) of the aperture stop at the intermediate position,
D3: Effective diameter of aperture stop at telephoto end (mm)
Is)
Is satisfied at the same time.

An imaging apparatus according to the present disclosure
An optical image of an object can be output as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
Having a plurality of lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having positive power and a second lens group having negative power are provided,
During zooming from the wide-angle end to the telephoto end during imaging, the interval between the first lens group and the second lens group is increased,
The following conditions (I-1) and (I-2):
D1> D2 (I-1)
D3> D2 (I-2)
(here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D2: effective diameter (mm) of the aperture stop at the intermediate position,
D3: Effective diameter of aperture stop at telephoto end (mm)
Is)
It is a zoom lens system that satisfies the above.

The camera in the present disclosure is
Converting an optical image of an object into an electrical image signal, displaying and storing the converted image signal, and
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
Having a plurality of lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having positive power and a second lens group having negative power are provided,
During zooming from the wide-angle end to the telephoto end during imaging, the interval between the first lens group and the second lens group is increased,
The following conditions (I-1) and (I-2):
D1> D2 (I-1)
D3> D2 (I-2)
(here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D2: effective diameter (mm) of the aperture stop at the intermediate position,
D3: Effective diameter of aperture stop at telephoto end (mm)
Is)
It is a zoom lens system that satisfies the above.

(II) The zoom lens system in the present disclosure is:
Having at least five lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power are provided.
The first lens group has the following condition (II-1):
νd ₁ ≧ 65 (II-1)
(here,
νd ₁ : Abbe number with respect to d-line of lens elements included in the first lens group)
And at least two lens elements satisfying the following condition (II-2):
νd ₃ ≧ 65 (II-2)
(here,
νd ₃ : Abbe number for the d-line of the lens elements included in the third lens group)
It includes at least one lens element that satisfies the above.

An imaging apparatus according to the present disclosure
An optical image of an object can be output as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
Having at least five lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power are provided.
The first lens group has the following condition (II-1):
νd ₁ ≧ 65 (II-1)
(here,
νd ₁ : Abbe number with respect to d-line of lens elements included in the first lens group)
And at least two lens elements satisfying the following condition (II-2):
νd ₃ ≧ 65 (II-2)
(here,
νd ₃ : Abbe number for the d-line of the lens elements included in the third lens group)
The zoom lens system includes at least one lens element satisfying the above.

The camera in the present disclosure is
Converting an optical image of an object into an electrical image signal, displaying and storing the converted image signal, and
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
Having at least five lens groups composed of at least one lens element;
In order from the object side to the image side, at least a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power are provided.
The first lens group has the following condition (II-1):
νd ₁ ≧ 65 (II-1)
(here,
νd ₁ : Abbe number with respect to d-line of lens elements included in the first lens group)
And at least two lens elements satisfying the following condition (II-2):
νd ₃ ≧ 65 (II-2)
(here,
νd ₃ : Abbe number for the d-line of the lens elements included in the third lens group)
The zoom lens system includes at least one lens element satisfying the above.

(I) The zoom lens system according to the present disclosure not only has an extremely high zooming ratio, but also reduces the burden of correcting aberrations of the lens elements in the vicinity of the aperture stop, particularly at an intermediate position during zooming, thereby achieving downsizing. In addition, particularly, aberration at an intermediate position is reduced, and high resolution is achieved.

(II) The zoom lens system according to the present disclosure not only has an extremely high zooming ratio, but also has excellent optical characteristics with improved imaging performance particularly at the telephoto end.

FIG. 1 is a lens arrangement diagram illustrating an infinitely focused state of the zoom lens system according to Embodiment 1 (Numerical Example 1). FIG. 2 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 1 when the zoom lens system is in focus at infinity. FIG. 3 is a lens arrangement diagram illustrating an infinitely focused state of the zoom lens system according to Embodiment 2 (Numerical Example 2). FIG. 4 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 2 when the zoom lens system is in focus at infinity. FIG. 5 is a lens arrangement diagram illustrating an infinitely focused state of the zoom lens system according to Embodiment 3 (Numerical Example 3). FIG. 6 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 3 when the zoom lens system is in focus at infinity. FIG. 7 is a lens arrangement diagram illustrating an infinitely focused state of the zoom lens system according to Embodiment 4 (Numerical Example 4). FIG. 8 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 4 when the zoom lens system is in focus at infinity. FIG. 9 is a lens layout diagram illustrating an infinitely focused state of the zoom lens system according to Embodiment 5 (Numerical Example 5). FIG. 10 is a longitudinal aberration diagram of the zoom lens system according to Numerical Example 5 when the zoom lens system is in focus at infinity. FIG. 11 is a schematic configuration diagram of a digital still camera according to the sixth embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

In addition, the inventors provide the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Absent.

(Embodiments 1 to 5)
1, 3, 5, 7, and 9 are lens arrangement diagrams of the zoom lens systems according to Embodiments 1 to 5, respectively, and all represent the zoom lens system in an infinitely focused state.

In each figure, (a) shows a lens configuration at the wide angle end (shortest focal length state: focal length f _W ), and (b) shows an intermediate position (intermediate focal length state: focal length f _M = √ (f _W * f). The lens configuration of _T )) and (c) show the lens configuration at the telephoto end (longest focal length state: focal length f _T ). Also, in each figure, the broken line arrows provided between FIGS. (A) and (b) are obtained by connecting the positions of the lens groups in the wide-angle end, the intermediate position, and the telephoto end in order from the top. Straight line. The wide-angle end and the intermediate position, and the intermediate position and the telephoto end are simply connected by a straight line, which is different from the actual movement of each lens group.

Further, in each figure, an arrow attached to the lens group represents focusing from an infinitely focused state to a close object focused state. That is, FIGS. 1, 3, 5, 7, and 9 show directions in which a later-described fourth lens group G4 moves during focusing from the infinite focus state to the close object focus state.

The zoom lens system according to each embodiment includes, in order from the object side to the image side, a first lens group G1 having a positive power, a second lens group G2 having a negative power, and a first lens group having a positive power. 3 lens group G3, 4th lens group G4 which has negative power, and 5th lens group G5 which has positive power are provided. During zooming, the distance between the lens groups, that is, the distance between the first lens group G1 and the second lens group G2, the distance between the second lens group G2 and the third lens group G3, and the third lens group G3 and the fourth lens group G4. The first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4, and the distance between the fourth lens group G4 and the fifth lens group G5 are all changed. The lens group G4 moves in the direction along the optical axis. The zoom lens system according to each embodiment can reduce the size of the entire lens system while maintaining high optical performance by arranging these lens groups in a desired power arrangement.

In FIGS. 1, 3, 5, 7, and 9, an asterisk * attached to a specific surface indicates that the surface is aspherical. In each figure, a symbol (+) and a symbol (−) attached to a symbol of each lens group correspond to a power symbol of each lens group. In each drawing, the straight line described on the rightmost side represents the position of the image plane S, and is located on the object side of the image plane S (between the image plane S and the most image side lens surface of the fifth lens group G5). Are provided with a low-pass filter FL and a cover glass CG which are parallel plates in order from the object side to the image side.

Further, in FIGS. 1, 3, 5, 7, and 9, an aperture stop A is provided on the most object side of the third lens group G3, that is, between the second lens group G2 and the third lens group G3.

(Embodiment 1)
As shown in FIG. 1, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a biconvex second lens element L2. And a positive meniscus third lens element L3 having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented, and in the surface data in the corresponding numerical examples described later, the adhesion between the first lens element L1 and the second lens element L2 Surface number 2 is given to the agent layer. The second lens element L2 and the third lens element L3 satisfy a condition (II-1) described later.

The second lens group G2 includes, in order from the object side to the image side, a negative meniscus fourth lens element L4 having a convex surface directed toward the object side, a biconcave fifth lens element L5, and a biconvex second lens element L5. 6 lens elements L6. Among these, the fourth lens element L4 has two aspheric surfaces.

The third lens group G3 includes, in order from the object side to the image side, a biconvex seventh lens element L7, a positive meniscus eighth lens element L8 with a convex surface facing the object side, and a convex surface facing the object side. And a negative meniscus ninth lens element L9 and a biconvex tenth lens element L10. Among these, the eighth lens element L8 and the ninth lens element L9 are cemented, and in the surface data in the corresponding numerical value example described later, the adhesion between the eighth lens element L8 and the ninth lens element L9. Surface number 17 is given to the agent layer. The seventh lens element L7 has two aspheric surfaces. The seventh lens element L7 satisfies the condition (II-2) described later.

The fourth lens group G4 comprises solely a negative meniscus eleventh lens element L11 with the convex surface facing the object side.

The fifth lens group G5 comprises solely a positive meniscus twelfth lens element L12 with the convex surface facing the object side. The twelfth lens element L12 has two aspheric surfaces.

An aperture stop A is provided on the object side of the third lens group G3. The aperture stop A moves on the optical axis integrally with the third lens group G3 during zooming from the wide-angle end to the telephoto end during imaging. As shown in the corresponding numerical examples described later, the aperture stop A has conditions (I-1), (described later) for the effective diameter at the wide-angle end, the effective diameter at the intermediate position, and the effective diameter at the telephoto end. I-2) and (I-3) are satisfied simultaneously.

A low-pass filter FL and a cover glass CG are provided in order from the object side to the image side on the object side of the image plane S, that is, between the image plane S and the twelfth lens element L12.

During zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1 moves toward the object side with a slightly convex locus on the image side, and the second lens group G2 slightly moves toward the image side. The third lens group G3 moves to the object side with a slightly convex locus on the object side, and the fourth lens group G4 has a convex locus on the image side. And the fifth lens group G5 does not move. That is, during zooming, 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 third lens group G3 and the fourth lens. The first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens so that the distance between the group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes. The group G4 moves along the optical axis.

In focusing from the infinitely focused state to the close object focused state, the fourth lens group G4 moves to the image side along the optical axis.

By moving the entire third lens group G3 in a direction perpendicular to the optical axis, it is possible to correct image point movement due to vibration of the entire system. That is, when correcting the image point movement due to the vibration of the entire system, the entire third lens group G3 moves in a direction perpendicular to the optical axis, thereby suppressing the enlargement of the entire zoom lens system and making it compact. However, it is possible to optically correct image blur due to camera shake, vibration, etc. while maintaining excellent imaging characteristics with small decentration coma and decentering astigmatism.

(Embodiment 2)
As shown in FIG. 3, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a biconvex second lens element L2. And a positive meniscus third lens element L3 having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented, and in the surface data in the corresponding numerical examples described later, the adhesion between the first lens element L1 and the second lens element L2 Surface number 2 is given to the agent layer. The second lens element L2 and the third lens element L3 satisfy a condition (II-1) described later.

During zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1 moves toward the object side with a slightly convex locus on the image side, and the second lens group G2 protrudes toward the image side. The third lens group G3 moves toward the object side with a slightly convex locus on the object side, and the fourth lens group G4 draws a locus along the image side. Therefore, the fifth lens group G5 does not move. That is, during zooming, 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 third lens group G3 and the fourth lens. The first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens so that the distance between the group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes. The group G4 moves along the optical axis.

(Embodiment 3)
As shown in FIG. 5, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a biconvex second lens element L2. And a positive meniscus third lens element L3 having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented, and in the surface data in the corresponding numerical examples described later, the adhesion between the first lens element L1 and the second lens element L2 Surface number 2 is given to the agent layer. The second lens element L2 and the third lens element L3 satisfy the condition (II-1) described later.

(Embodiment 4)
As shown in FIG. 7, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a biconvex second lens element L2. And a positive meniscus third lens element L3 having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented, and in the surface data in the corresponding numerical examples described later, the adhesion between the first lens element L1 and the second lens element L2 Surface number 2 is given to the agent layer. The second lens element L2 and the third lens element L3 satisfy a condition (II-1) described later.

The second lens group G2 includes, in order from the object side to the image side, a biconcave fourth lens element L4, a biconcave fifth lens element L5, and a biconvex sixth lens element L6. . Among these, the fourth lens element L4 has two aspheric surfaces.

The fifth lens group G5 comprises solely a biconvex twelfth lens element L12. The twelfth lens element L12 has two aspheric surfaces.

(Embodiment 5)
As shown in FIG. 9, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a positive meniscus having a convex surface facing the object side. The second lens element L2 having a shape, the third lens element L3 having a positive meniscus shape having a convex surface facing the object side, and the fourth lens element L4 having a positive meniscus shape having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented, and in the surface data in the corresponding numerical examples described later, the adhesion between the first lens element L1 and the second lens element L2 Surface number 2 is given to the agent layer. The second lens element L2, the third lens element L3, and the fourth lens element L4 satisfy a condition (II-1) described later.

The second lens group G2 includes, in order from the object side to the image side, a negative meniscus fifth lens element L5 having a convex surface facing the object side, a biconcave sixth lens element L6, and a biconvex first lens element L6. 7 lens elements L7. Among these, the fifth lens element L5 has two aspheric surfaces.

The third lens group G3 includes, in order from the object side to the image side, a biconvex eighth lens element L8, a positive meniscus ninth lens element L9 with a convex surface facing the object side, and a convex surface facing the object side. And a negative meniscus tenth lens element L10 and a biconvex eleventh lens element L11. Among these, the ninth lens element L9 and the tenth lens element L10 are cemented, and in the surface data in the corresponding numerical value example described later, the adhesion between the ninth lens element L9 and the tenth lens element L10. Surface number 19 is given to the agent layer. The eighth lens element L8 has two aspheric surfaces. The eighth lens element L8 and the eleventh lens element L11 satisfy a condition (II-2) described later.

The fourth lens group G4 comprises solely a bi-concave twelfth lens element L12.

The fifth lens group G5 comprises solely a bi-convex thirteenth lens element L13. The thirteenth lens element L13 has two aspheric surfaces.

A low-pass filter FL and a cover glass CG are provided in order from the object side to the image side on the object side of the image plane S, that is, between the image plane S and the thirteenth lens element L13.

Like the zoom lens systems according to Embodiments 1 to 5, one of the following lens groups arranged on the image side of the second lens group G2, that is, the third lens group G3 and the third lens group By performing focusing with any one of the lens groups disposed on the image side of the lens group G3, the lens outer diameter and the weight of the lens group to be focused can be reduced, and mechanically. Miniaturization of the lens barrel can be achieved.

Although the zoom lens system according to Embodiments 1 to 5 has a five-group configuration, in the case of a zoom lens system having a basic configuration I according to an embodiment described later, a first lens group having a positive power and a negative lens group are used. The number of lens groups constituting the lens system is not particularly limited as long as the configuration includes two or more groups including at least a second lens group having the following power. In the case of a zoom lens system having a basic configuration II according to an embodiment described later, a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power. The number of lens groups constituting the lens system is not particularly limited. Further, in any of the zoom lens system having the basic configuration I of the embodiment and the zoom lens system having the basic configuration II of the embodiment, there is no particular limitation on the power of each lens group constituting the lens system.

As described above, Embodiments 1 to 5 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

Hereinafter, conditions in which it is beneficial for the zoom lens system such as the zoom lens systems according to Embodiments 1 to 5 to be satisfied will be described. A plurality of useful conditions are defined for the zoom lens system according to each embodiment, but the configuration of the zoom lens system that satisfies all of the plurality of conditions is most effective. However, by satisfying individual conditions, it is possible to obtain a zoom lens system that exhibits the corresponding effects.

For example, as in the zoom lens systems according to Embodiments 1 to 5, the first lens has a plurality of lens groups including at least one lens element and has positive power in order from the object side to the image side. And at least a second lens group having a negative power, and the distance between the first lens group and the second lens group is increased during zooming from the wide-angle end to the telephoto end during imaging ( Hereinafter, the zoom lens system (hereinafter referred to as the basic configuration I of the embodiment) satisfies the following conditions (I-1) and (I-2) at the same time.
D1> D2 (I-1)
D3> D2 (I-2)
here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D2: effective diameter (mm) of the aperture stop at the intermediate position,
D3: Effective diameter of aperture stop at telephoto end (mm)
It is.

The condition (I-1) is a condition for reducing the burden of aberration correction of each lens element at an intermediate position during zooming, particularly a lens element arranged near the aperture stop. If the condition (I-1) is not satisfied, the effective diameter of the aperture stop at the intermediate position is larger than or equal to the effective diameter of the aperture stop at the wide-angle end during zooming. The burden of correcting the aberration of the lens element thus made becomes large, and it becomes difficult to obtain good imaging performance over the entire zoom range. Further, if it is attempted to improve the imaging performance over the entire zoom range, it is difficult to reduce the size of the zoom lens system.

The condition (I-2) is a condition for obtaining a small F number at the telephoto end. If the condition (I-2) is not satisfied, the effective diameter of the aperture stop at the telephoto end is smaller than or equal to the effective diameter of the aperture stop at the intermediate position during zooming. It becomes large and it becomes difficult to obtain a bright image.

For example, as in the zoom lens systems according to Embodiments 1 to 5, it is beneficial that the zoom lens system having the basic configuration I further satisfies the following condition (I-3).
D1 = D3 (I-3)
here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D3: Effective diameter of aperture stop at telephoto end (mm)
It is.

The condition (I-3) is a condition for further simplifying the configuration of the zoom lens system. By satisfying the condition (I-3), the effective diameter of the aperture stop at the wide-angle end is equal to the effective diameter of the aperture stop at the telephoto end during zooming. It can be substantially circular, which is advantageous for reducing flare and the like at the wide-angle end and the telephoto end.

For example, as in the zoom lens systems according to Embodiments 1 to 5, the zoom lens system includes at least five lens units each including at least one lens element, and has positive power in order from the object side to the image side. In a zoom lens system including at least one lens group, a second lens group having negative power, and a third lens group having positive power (hereinafter, this lens configuration is referred to as a basic configuration II of the embodiment) The first lens group includes at least two lens elements satisfying the following condition (II-1), and at the same time, the third lens group satisfies the following condition (II-2): Including at least one sheet.
νd ₁ ≧ 65 (II-1)
νd ₃ ≧ 65 (II-2)
here,
νd ₁ : Abbe number for the d-line of the lens elements included in the first lens group,
νd ₃ is an Abbe number with respect to the d-line of the lens elements included in the third lens group.

The condition (II-1) is a condition for reducing chromatic aberration at the telephoto end. When the condition (II-1) is not satisfied, the axial chromatic aberration and the chromatic aberration of magnification particularly when the magnification is increased are lowered, and it is difficult to increase the magnification of the zoom lens system.

The condition (II-2) is a condition for reducing chromatic aberration over the entire zoom range. When the condition (II-2) is not satisfied, the axial chromatic aberration and the chromatic aberration of magnification in the entire zoom range are reduced, and it is difficult to increase the magnification of the zoom lens system.

The first lens group includes at least two lens elements that satisfy the following condition (II-1) ′, or the lens element that the third lens group satisfies the following condition (II-2) ′: In the case where at least one sheet is included or both of them, the above-described effect can be further achieved.
νd ₁ ≧ 68 (II-1) ′
νd ₃ ≧ 68 (II-2) '

Further, when the first lens group includes at least two lens elements that satisfy the following condition (II-1) ″, the above effect can be further achieved.
νd ₁ ≧ 75 (II-1) ″

Each lens group constituting the zoom lens system according to Embodiments 1 to 5 includes a refractive lens element that deflects incident light by refraction (that is, a type in which deflection is performed at an interface between media having different refractive indexes) However, the present invention is not limited to this. For example, a diffractive lens element that deflects incident light by diffraction, a refractive / diffractive hybrid lens element that deflects incident light by a combination of diffraction and refraction, and a refractive index that deflects incident light by the refractive index distribution in the medium Each lens group may be composed of a distributed lens element or the like. In particular, in a refractive / diffractive hybrid lens element, forming a diffractive structure at the interface of media having different refractive indexes is advantageous because the wavelength dependency of diffraction efficiency is improved.

(Embodiment 6)
FIG. 11 is a schematic configuration diagram of a digital still camera according to the sixth embodiment. In FIG. 11, the digital still camera includes an imaging device including a zoom lens system 1 and an imaging device 2 that is a CCD, a liquid crystal monitor 3, and a housing 4. As the zoom lens system 1, the zoom lens system according to Embodiment 1 is used. In FIG. 11, the zoom lens system 1 includes a first lens group G1, a second lens group G2, an aperture stop A, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. It is configured. In the housing 4, the zoom lens system 1 is disposed on the front side, and the imaging element 2 is disposed on the rear side of the zoom lens system 1. A liquid crystal monitor 3 is disposed on the rear side of the housing 4, and an optical image of the subject by the zoom lens system 1 is formed on the image plane S.

The lens barrel is composed of a main lens barrel 5, a movable lens barrel 6, and a cylindrical cam 7. When the cylindrical cam 7 is rotated, the first lens group G1, the second lens group G2, the aperture stop A, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are based on the imaging device 2. Moving to a predetermined position, zooming from the wide-angle end to the telephoto end can be performed. The fourth lens group G4 is movable in the optical axis direction by a focus adjustment motor.

Thus, by using the zoom lens system according to Embodiment 1 for a digital still camera, it is possible to provide a small digital still camera that has a high ability to correct resolution and curvature of field and has a short overall lens length when not in use. it can. In the digital still camera shown in FIG. 11, any of the zoom lens systems according to Embodiments 2 to 5 may be used instead of the zoom lens system according to Embodiment 1. Further, the optical system of the digital still camera shown in FIG. 11 can be used for a digital video camera for moving images. In this case, not only a still image but also a moving image with high resolution can be taken.

In the digital still camera according to the sixth embodiment, the zoom lens system according to the first to fifth embodiments is shown as the zoom lens system 1, but these zoom lens systems do not use the entire zooming area. May be. That is, a range in which the optical performance is ensured may be cut out according to a desired zooming area, and used as a zoom lens system having a lower magnification than the zoom lens system described in the first to fifth embodiments.

Furthermore, in the sixth embodiment, an example in which the zoom lens system is applied to a so-called collapsible lens barrel is shown, but the present invention is not limited to this. For example, a prism having an internal reflection surface or a surface reflection mirror may be disposed at an arbitrary position such as in the first lens group G1, and the zoom lens system may be applied to a so-called bent lens barrel. Further, in Embodiment 6, a zoom lens system including the entire second lens group G2, the entire third lens group G3, a part of the second lens group G2, and a part of the third lens group G3 is configured. The zoom lens system may be applied to a so-called sliding lens barrel in which the lens group of the part is retracted from the optical axis when retracted.

As described above, the sixth embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

In addition, an image pickup apparatus including the zoom lens system according to Embodiments 1 to 5 described above and an image pickup element such as a CCD or a CMOS is used as a camera of a portable information terminal such as a smartphone, a monitor camera in a monitoring system, a Web The present invention can also be applied to cameras, in-vehicle cameras, and the like.

Hereinafter, numerical examples in which the zoom lens systems according to Embodiments 1 to 5 are specifically implemented will be described. In each numerical example, the unit of length in the table is “mm”, and the unit of angle of view is “°”. In each numerical example, r is a radius of curvature, d is a surface interval, nd is a refractive index with respect to the d line, and vd is an Abbe number with respect to the d line. The aperture radius represents the effective diameter of the aperture stop as a radius. In each numerical example, the surface marked with * is an aspherical surface, and the aspherical shape is defined by the following equation.

here,
Z: distance from a point on the aspheric surface having a height h from the optical axis to the tangent plane of the aspheric vertex,
h: height from the optical axis,
r: vertex radius of curvature,
κ: conic constant,
An: n-order aspherical coefficient.

2, 4, 6, 8, and 10 are longitudinal aberration diagrams of the zoom lens systems according to Numerical Examples 1 to 5, respectively.

In each longitudinal aberration diagram, (a) shows the aberration at the wide angle end, (b) shows the intermediate position, and (c) shows the aberration at the telephoto end. Each longitudinal aberration diagram shows spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)) in order from the left side. In the spherical aberration diagram, the vertical axis represents the F number (indicated by F in the figure), the solid line is the d line (d-line), the short broken line is the F line (F-line), and the long broken line is the C line (C- line). In the astigmatism diagram, the vertical axis represents the image height (indicated by H in the figure), the solid line represents the sagittal plane (indicated by s), and the broken line represents the meridional plane (indicated by m in the figure). is there. In the distortion diagram, the vertical axis represents the image height (indicated by H in the figure).

(Numerical example 1)
The zoom lens system of Numerical Example 1 corresponds to Embodiment 1 shown in FIG. Table 1 shows surface data of the zoom lens system of Numerical Example 1, Table 2 shows aspheric data, and Table 3 shows various data.

Table 1 (surface data)

Surface number r d nd vd
Object ∞
1 37.37280 0.75000 1.84666 23.8
2 25.83290 0.01000 1.56732 42.8
3 25.83290 3.30000 1.49700 81.6
4 -176.78680 0.15000
5 22.80580 1.95680 1.59282 68.7
6 55.99180 Variable
7 * 108.56210 0.50000 1.80470 41.0
8 * 5.50820 3.55990
9 -8.34990 0.30000 1.80420 46.5
10 949.02850 0.29540
11 28.64210 1.30000 1.94595 18.0
12 -28.64210 variable
13 (Aperture) ∞ 0.30000
14 * 5.68180 2.03000 1.51845 70.0
15 * -19.60350 0.62300
16 10.00060 1.20000 1.51823 59.0
17 26.75760 0.01000 1.56732 42.8
18 26.75760 0.30000 1.90366 31.3
19 5.05870 0.47690
20 8.56960 1.16790 1.52996 55.8
21 -36.91150 Variable
22 12.26960 0.30000 1.83481 42.7
23 7.00680 Variable
24 * 10.04750 2.19000 1.52996 55.8
25 * 76.76380 3.00000
26 ∞ 0.28000 1.51680 64.2
27 ∞ 0.12000
28 ∞ 0.50000 1.51680 64.2
29 ∞ 0.37000
30 ∞ (BF)
Image plane ∞

Table 2 (Aspheric data)

7th surface K = 0.00000E + 00, A4 = -2.50004E-04, A6 = 1.96580E-05, A8 = -3.28001E-07
A10 = 8.55228E-09, A12 = -6.28968E-10, A14 = 1.70366E-11, A16 = -1.51771E-13
8th surface K = 0.00000E + 00, A4 = -3.12612E-04, A6 = -3.48429E-05, A8 = 1.13165E-05
A10 = -1.16801E-06, A12 = 8.03270E-08, A14 = -2.79962E-09, A16 = 3.90303E-11
14th surface K = 0.00000E + 00, A4 = -5.88999E-04, A6 = -1.07484E-06, A8 = -2.17358E-06
A10 = 2.58194E-07, A12 = -1.52854E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
15th surface K = 0.00000E + 00, A4 = 2.48725E-04, A6 = -9.68037E-06, A8 = 1.82750E-06
A10 = -1.07543E-07, A12 = -4.36854E-09, A14 = 0.00000E + 00, A16 = 0.00000E + 00
24th surface K = 0.00000E + 00, A4 = 3.80397E-04, A6 = 6.23300E-05, A8 = -1.82422E-05
A10 = 1.75445E-06, A12 = -7.53639E-08, A14 = 1.18900E-09, A16 = 0.00000E + 00
25th surface K = 0.00000E + 00, A4 = 8.58282E-04, A6 = -3.10506E-05, A8 = -1.35900E-05
A10 = 1.71031E-06, A12 = -8.21376E-08, A14 = 1.39615E-09, A16 = 0.00000E + 00

Table 3 (various data)

Zoom ratio 18.82867
Wide angle Medium telephoto Focal length 4.4160 19.1596 83.1473
F number 3.39736 5.32757 6.11133
Angle of View 41.2756 11.2292 2.6901
Image height 3.3 100 3.8770 3.8770
Total lens length 51.0256 58.0563 67.3844
BF 0.01279 -0.01410 -0.01721
d6 0.3000 12.2349 23.3589
d12 19.1000 6.4789 0.9500
d21 4.4794 11.5183 7.7124
d23 2.1436 2.8485 10.3904
Entrance pupil position 12.0075 42.6174 155.7596
Exit pupil position -18.3774 -29.7585 -102.1355
Front principal point position 15.3631 49.4355 171.22063
Rear principal point position 46.6096 38.8967 -15.7629
Aperture radius 2.537 2.450 2.537

Single lens data Lens Start surface Focal length 1 1 -101.8482
2 3 45.5976
3 5 63.5132
4 7 -7.2265
5 9 -10.2909
6 11 15.3083
7 14 8.7361
8 16 30.0792
9 18 -6.9487
10 20 13.2412
11 22 -20.0890
12 24 21.5690

Zoom lens group data Group Start surface Focal length Lens composition length Front principal point position Rear principal point position 1 1 36.52727 6.16680 1.19246 3.35104
2 7 -5.84472 5.95530 0.54302 1.42818
3 13 10.39941 6.10780 -0.20639 1.58893
4 22 -20.08899 0.30000 0.39134 0.52348
5 24 21.56896 6.09000 -0.21315 0.82729

Zoom lens group magnification group Start surface Wide angle Medium telephoto 1 1 0.00000 0.00000 0.00000
2 7 -0.21628 -0.38735 -1.47413
3 13 -0.51661 -1.22218 -1.11439
4 22 1.46563 1.49827 1.87341
5 24 0.73826 0.73951 0.73965

(Numerical example 2)
The zoom lens system of Numerical Example 2 corresponds to Embodiment 2 shown in FIG. Table 4 shows surface data of the zoom lens system of Numerical Example 2, Table 5 shows aspheric data, and Table 6 shows various data.

Table 4 (surface data)

Surface number r d nd vd
Object ∞
1 33.80380 0.75000 1.84666 23.8
2 24.76800 0.01000 1.56732 42.8
3 24.76800 3.40000 1.49700 81.6
4 -256.85280 0.15000
5 22.15220 2.10000 1.49700 81.6
6 57.08190 Variable
7 * 803.92520 0.50000 1.87872 37.1
8 * 6.26700 3.19500
9 -8.92500 0.30000 1.80420 46.5
10 50.27120 0.39500
11 25.99300 1.27000 1.94595 18.0
12 -25.99300 variable
13 (Aperture) ∞ 0.30000
14 * 5.58170 1.95000 1.51776 69.9
15 * -22.60550 0.20000
16 9.06440 1.47000 1.51823 59.0
17 32.30660 0.01000 1.56732 42.8
18 32.30660 0.30000 1.90366 31.3
19 5.07740 0.41000
20 9.54190 1.15000 1.54310 56.0
21 -20.99820 Variable
22 38.58740 0.30000 1.88300 40.8
23 9.14340 Variable
24 * 7.93810 2.44000 1.54310 56.0
25 * 41.08140 2.13680
26 ∞ 0.28000 1.51680 64.2
27 ∞ 0.12000
28 ∞ 0.50000 1.51680 64.2
29 ∞ 0.37000
30 ∞ (BF)
Image plane ∞

Table 5 (Aspheric data)

7th surface K = 0.00000E + 00, A4 = -1.27031E-04, A6 = 1.74687E-05, A8 = -2.51691E-07
A10 = 1.01251E-08, A12 = -7.61084E-10, A14 = 1.74758E-11, A16 = -1.22170E-13
8th surface K = 0.00000E + 00, A4 = -1.11940E-04, A6 = -1.33043E-05, A8 = 8.97201E-06
A10 = -1.03899E-06, A12 = 8.11223E-08, A14 = -2.90319E-09, A16 = 3.64152E-11
14th surface K = 0.00000E + 00, A4 = -5.19180E-04, A6 = -3.77855E-06, A8 = -1.11172E-06
A10 = 2.48137E-07, A12 = -1.39628E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
15th surface K = 0.00000E + 00, A4 = 3.55926E-04, A6 = -1.86447E-05, A8 = 5.80987E-06
A10 = -5.92858E-07, A12 = 2.45731E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
24th surface K = 0.00000E + 00, A4 = -3.64007E-06, A6 = 6.46331E-05, A8 = -1.26082E-05
A10 = 1.25191E-06, A12 = -6.47131E-08, A14 = 1.65459E-09, A16 = -1.76796E-11
25th surface K = 0.00000E + 00, A4 = 1.19333E-03, A6 = -1.49744E-04, A8 = 6.86248E-06
A10 = 3.73263E-07, A12 = -5.17758E-08, A14 = 1.77675E-09, A16 = -2.04767E-11

Table 6 (various data)

Zoom ratio 18.48345
Wide angle Medium telephoto Focal length 4.4349 19.2663 81.9716
F number 3.40796 5.54140 6.68361
Angle of View 41.7412 11.2528 2.6539
Image height 3.3 100 3.8770 3.8770
Total lens length 50.4539 56.0526 67.4770
BF 0.00010 0.00777 -0.03358
d6 0.3380 12.5138 23.1986
d12 19.0000 5.8414 0.9500
d21 4.5353 10.8317 9.0191
d23 2.5737 2.8511 10.3361
Entrance pupil position 12.3056 43.2691 141.1457
Exit pupil position -18.0789 -26.0523 -293.7951
Front principal point position 15.6525 48.2918 200.2439
Rear principal point position 46.0190 36.7864 -14.4946
Aperture radius 2.511 2.273 2.511

Single lens data Lens Start surface Focal length 1 1 -113.7703
2 3 45.6353
3 5 71.4140
4 7 -7.1901
5 9 -9.4035
6 11 13.9043
7 14 8.8547
8 16 23.7988
9 18 -6.7015
10 20 12.2422
11 22 -13.6356
12 24 17.6594

Zoom lens group data Group Start surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 37.62663 6.41000 1.02008 3.18170
2 7 -5.85973 5.66000 0.42747 1.22010
3 13 9.72362 5.79000 0.02662 1.77872
4 22 -13.63565 0.30000 0.20980 0.34971
5 24 17.65943 5.47680 -0.36915 0.79531

Zoom lens group magnification group Start surface Wide angle Medium telephoto 1 1 0.00000 0.00000 0.00000
2 7 -0.21099 -0.37569 -1.19280
3 13 -0.46661 -1.12471 -1.13832
4 22 1.67694 1.69838 2.24138
5 24 0.71394 0.71351 0.71585

(Numerical Example 3)
The zoom lens system of Numerical Example 3 corresponds to Embodiment 3 shown in FIG. Table 7 shows surface data of the zoom lens system of Numerical Example 3, Table 8 shows aspheric data, and Table 9 shows various data.

Table 7 (surface data)

Surface number r d nd vd
Object ∞
1 37.60320 0.75000 1.84666 23.8
2 25.92660 0.01000 1.56732 42.8
3 25.92660 3.40000 1.49700 81.6
4 -191.44060 0.15000
5 22.83060 1.96000 1.59282 68.7
6 55.71460 Variable
7 * 96.96720 0.50000 1.80470 41.0
8 * 5.53510 3.53500
9 -8.61090 0.30000 1.80420 46.5
10 206.59700 0.29330
11 28.50050 1.30000 1.94595 18.0
12 -28.50050 Variable
13 (Aperture) ∞ 0.30000
14 * 5.38110 2.05000 1.49710 81.5
15 * -19.73160 0.60000
16 10.15020 1.20000 1.51823 59.0
17 16.30560 0.01000 1.56732 42.8
18 16.30560 0.30000 1.90366 31.3
19 5.04140 0.46000
20 8.90340 1.10000 1.54410 56.1
21 -60.68850 Variable
22 18.58030 0.30000 1.88300 40.8
23 8.83370 Variable
24 * 9.51960 2.01510 1.54410 56.1
25 * 55.21200 2.88230
26 ∞ 0.28000 1.51680 64.2
27 ∞ 0.12000
28 ∞ 0.50000 1.51680 64.2
29 ∞ 0.37000
30 ∞ (BF)
Image plane ∞

Table 8 (Aspherical data)

7th surface K = 0.00000E + 00, A4 = -2.62456E-04, A6 = 2.00458E-05, A8 = -3.42410E-07
A10 = 8.56348E-09, A12 = -6.33719E-10, A14 = 1.76240E-11, A16 = -1.61220E-13
8th surface K = 0.00000E + 00, A4 = -3.32511E-04, A6 = -3.41151E-05, A8 = 1.08798E-05
A10 = -1.12088E-06, A12 = 7.93803E-08, A14 = -2.93445E-09, A16 = 4.37384E-11
14th surface K = 0.00000E + 00, A4 = -4.85802E-04, A6 = 1.87790E-05, A8 = -1.77069E-06
A10 = 2.69271E-07, A12 = 1.09823E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
15th surface K = 0.00000E + 00, A4 = 5.51548E-04, A6 = 2.34601E-05, A8 = 1.95097E-06
A10 = -1.43378E-07, A12 = 4.06859E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
24th surface K = 0.00000E + 00, A4 = 2.17580E-04, A6 = 7.24324E-05, A8 = -1.73136E-05
A10 = 1.55000E-06, A12 = -6.85016E-08, A14 = 1.34068E-09, A16 = -8.41357E-12
25th surface K = 0.00000E + 00, A4 = 9.54666E-04, A6 = -5.28827E-05, A8 = -6.64665E-06
A10 = 9.78986E-07, A12 = -5.56248E-08, A14 = 1.37481E-09, A16 = -1.20479E-11

Table 9 (various data)

Zoom ratio 17.97515
Wide angle Medium telephoto Focal length 4.4914 19.0533 80.7339
F number 3.36784 5.26017 5.78446
Angle of view 40.6834 11.2735 2.7085
Image height 3.3 100 3.8770 3.8770
Total lens length 50.5705 57.9566 66.4883
BF 0.00829 -0.00771 -0.03122
d6 0.3000 13.0355 23.8041
d12 18.7666 6.6667 0.9500
d21 4.3347 10.5145 7.1671
d23 2.4752 3.0619 9.9126
Entrance pupil position 12.1064 46.1231 159.9667
Exit pupil position -18.7750 -29.2347 -91.9215
Front principal point position 15.5238 52.7554 169.7686
Rear principal point position 46.0791 38.9033 -14.2456
Aperture radius 2.553 2.384 2.553

Single lens data Lens Start surface Focal length 1 1 -101.6072
2 3 46.1841
3 5 63.8337
4 7 -7.3127
5 9 -10.2726
6 11 15.2335
7 14 8.7424
8 16 48.6467
9 18 -8.1792
10 20 14.3500
11 22 -19.3507
12 24 20.8177

Zoom lens group data Group Start surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 37.04845 6.27000 1.22320 3.41520
2 7 -5.91206 5.92830 0.54306 1.42733
3 13 10.22048 6.02000 -0.27921 1.55187
4 22 -19.35066 0.30000 0.30817 0.44651
5 24 20.81768 5.79740 -0.26773 0.72807

Zoom lens group magnification group Start surface Wide angle Medium telephoto 1 1 0.00000 0.00000 0.00000
2 7 -0.21547 -0.40210 -1.50264
3 13 -0.51221 -1.14103 -1.04857
4 22 1.48781 1.51661 1.86842
5 24 0.73832 0.73909 0.74022

(Numerical example 4)
The zoom lens system of Numerical Example 4 corresponds to Embodiment 4 shown in FIG. Table 10 shows surface data of the zoom lens system of Numerical Example 4, Table 11 shows aspheric data, and Table 12 shows various data.

Table 10 (surface data)

Surface number r d nd vd
Object ∞
1 36.74400 0.75000 1.84666 23.8
2 26.10030 0.01000 1.56732 42.8
3 26.10030 3.30000 1.45860 90.3
4 -142.56620 0.15000
5 22.91800 1.92000 1.59282 68.7
6 55.51700 Variable
7 * -211.61750 0.30000 1.80470 41.0
8 * 5.93290 3.53570
9 -8.92280 0.30000 1.80420 46.5
10 127.00340 0.32180
11 28.84840 1.08600 1.94595 18.0
12 -28.84840 Variable
13 (Aperture) ∞ 0.30000
14 * 5.91700 2.06250 1.59240 68.4
15 * -22.51650 0.70000
16 12.94680 1.20000 1.51742 52.1
17 81.42570 0.01000 1.56732 42.8
18 81.42570 0.30000 1.90366 31.3
19 5.30460 0.48370
20 8.91230 1.20000 1.52996 55.8
21 -26.13570 Variable
22 14.30230 0.30000 1.88300 40.8
23 7.83530 Variable
24 * 11.28200 2.39500 1.52996 55.8
25 * -151.39700 3.00000
26 ∞ 0.28000 1.51680 64.2
27 ∞ 0.12000
28 ∞ 0.50000 1.51680 64.2
29 ∞ 0.37000
30 ∞ (BF)
Image plane ∞

Table 11 (Aspheric data)

7th surface K = 0.00000E + 00, A4 = 5.07056E-05, A6 = 1.63975E-05, A8 = -3.56375E-07
A10 = 7.90942E-09, A12 = -6.22041E-10, A14 = 1.76933E-11, A16 = -1.59606E-13
8th surface K = 0.00000E + 00, A4 = 3.04819E-05, A6 = -3.30219E-05, A8 = 1.17854E-05
A10 = -1.18441E-06, A12 = 8.21892E-08, A14 = -2.87156E-09, A16 = 3.67498E-11
14th surface K = 0.00000E + 00, A4 = -3.89111E-04, A6 = -7.16833E-07, A8 = -1.24467E-06
A10 = 4.03670E-07, A12 = -2.10270E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
15th surface K = 0.00000E + 00, A4 = 3.94371E-04, A6 = -3.97003E-06, A8 = 2.19321E-06
A10 = 6.61118E-08, A12 = -9.97575E-09, A14 = 0.00000E + 00, A16 = 0.00000E + 00
24th surface K = 0.00000E + 00, A4 = -6.00404E-06, A6 = 1.78207E-05, A8 = -1.36323E-05
A10 = 1.37231E-06, A12 = -5.92619E-08, A14 = 9.26073E-10, A16 = 0.00000E + 00
25th surface K = 0.00000E + 00, A4 = 6.05442E-04, A6 = -1.55789E-04, A8 = 3.03155E-06
A10 = 3.83567E-07, A12 = -2.58096E-08, A14 = 4.56893E-10, A16 = 0.00000E + 00

Table 12 (various data)

Zoom ratio 18.90289
Wide angle Medium telephoto Focal length 4.4130 19.1811 83.4190
F number 3.35162 5.14442 6.12555
Angle of View 41.2912 11.2216 2.6394
Image height 3.3 100 3.8770 3.8770
Total lens length 51.1297 58.6917 69.0494
BF 0.00232 -0.02602 -0.04245
d6 0.3000 12.7541 24.1980
d12 19.1630 6.5555 1.2368
d21 3.8424 11.5189 8.5748
d23 2.9273 2.9945 10.1877
Entrance pupil position 11.6823 42.9360 157.3740
Exit pupil position -21.4337 -35.0005 -205.5068
Front principal point position 15.1868 51.5976 206.9247
Rear principal point position 46.7167 39.5106 -14.3696
Aperture radius 2.622 2.578 2.622

Single lens data Lens Start surface Focal length 1 1 -109.9742
2 3 48.4038
3 5 64.4256
4 7 -7.1673
5 9 -10.3567
6 11 15.3893
7 14 8.1290
8 16 29.5758
9 18 -6.2910
10 20 12.6911
11 22 -20.0609
12 24 19.9136

Zoom lens group data Group Start surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 37.53278 6.13000 1.26865 3.35266
2 7 -5.78886 5.54350 0.42748 1.14687
3 13 10.35410 6.25620 -0.31241 1.55045
4 22 -20.06086 0.30000 0.36019 0.49732
5 24 19.91357 6.29500 0.10912 1.19645

Zoom lens group magnification group Start surface Wide angle Medium telephoto 1 1 0.00000 0.00000 0.00000
2 7 -0.20499 -0.36673 -1.33349
3 13 -0.52113 -1.26308 -1.22170
4 22 1.51754 1.51821 1.87523
5 24 0.72527 0.72669 0.72752

(Numerical example 5)
The zoom lens system of Numerical Example 5 corresponds to Embodiment 5 shown in FIG. Table 13 shows surface data of the zoom lens system of Numerical Example 5, Table 14 shows aspheric data, and Table 15 shows various data.

Table 13 (surface data)

Surface number r d nd vd
Object ∞
1 41.82520 0.75000 1.84666 23.8
2 29.43770 0.01000 1.56732 42.8
3 29.43770 2.69270 1.49700 81.6
4 1024.46400 0.15000
5 27.18500 1.40000 1.45860 90.3
6 43.21930 0.15000
7 29.03590 1.40000 1.49700 81.6
8 83.95680 Variable
9 * 1000.00000 0.30000 1.80470 41.0
10 * 6.21940 3.53570
11 -9.38370 0.30000 1.77250 49.6
12 60.91170 0.32180
13 29.92930 1.08600 1.94595 18.0
14 -29.92930 Variable
15 (Aperture) ∞ 0.30000
16 * 6.23220 2.06250 1.51845 70.0
17 * -18.68700 0.70000
18 6.94310 1.20660 1.51742 52.1
19 23.91590 0.01000 1.56732 42.8
20 23.91590 0.30000 1.90366 31.3
21 5.04860 0.48370
22 12.91690 1.19610 1.59282 68.7
23 -46.93350 Variable
24 -332.78670 0.30000 1.83481 42.7
25 13.42790 Variable
26 * 9.88220 2.39500 1.54310 56.0
27 * -59.84640 2.79520
28 ∞ 0.28000 1.51680 64.2
29 ∞ 0.12000
30 ∞ 0.50000 1.51680 64.2
31 ∞ 0.37000
32 ∞ (BF)
Image plane ∞

Table 14 (Aspherical data)

9th surface K = 0.00000E + 00, A4 = -8.37698E-04, A6 = 9.56321E-05, A8 = -3.15143E-06
A10 = 3.26656E-08, A12 = 1.04819E-10, A14 = 2.44038E-12, A16 = -1.00850E-13
10th surface K = 0.00000E + 00, A4 = -9.46241E-04, A6 = 5.25326E-05, A8 = 7.92795E-06
A10 = -1.24531E-06, A12 = 1.27717E-07, A14 = -6.65174E-09, A16 = 1.28631E-10
16th surface K = 0.00000E + 00, A4 = -4.24751E-04, A6 = -2.18713E-05, A8 = 6.91679E-07
A10 = -1.55348E-07, A12 = 2.70789E-09, A14 = 0.00000E + 00, A16 = 0.00000E + 00
17th surface K = 0.00000E + 00, A4 = 2.48331E-04, A6 = -3.07182E-05, A8 = 4.61417E-06
A10 = -7.37912E-07, A12 = 3.27787E-08, A14 = 0.00000E + 00, A16 = 0.00000E + 00
26th surface K = 0.00000E + 00, A4 = 9.21633E-04, A6 = -2.48365E-05, A8 = -7.18193E-06
A10 = 8.89764E-07, A12 = -4.02139E-08, A14 = 6.32545E-10, A16 = 0.00000E + 00
Surface 27 K = 0.00000E + 00, A4 = 2.29051E-03, A6 = -1.63248E-04, A8 = -2.33278E-06
A10 = 1.05403E-06, A12 = -5.86972E-08, A14 = 1.02817E-09, A16 = 0.00000E + 00

Table 15 (various data)

Zoom ratio 18.69556
Wide angle Medium telephoto Focal length 4.4759 17.7712 83.6795
F number 3.43039 5.34096 6.09213
Angle of View 41.6856 12.1922 2.5892
Image height 3.3 100 3.8770 3.8770
Total lens length 51.1399 57.9762 68.4472
BF 0.01252 0.02195 -0.01928
d8 0.3000 12.6591 25.5535
d14 19.2960 6.9896 0.7276
d23 4.4193 10.4268 8.9345
d25 1.9968 2.7636 8.1355
Entrance pupil position 12.5747 42.5828 163.6601
Exit pupil position -20.7828 -37.0684 -910.0970
Front principal point position 16.0872 51.8392 239.6455
Rear principal point position 46.6640 40.2051 -15.2324
Aperture radius 2.476 2.338 2.476

Single lens data Lens Start surface Focal length 1 1 -120.7462
2 3 60.9287
3 5 155.5111
4 7 88.5604
5 9 -7.7783
6 11 -10.5061
7 13 15.9606
8 16 9.2766
9 18 18.4604
10 20 -7.1357
11 22 17.2145
12 24 -15.4550
13 26 15.8082

Zoom lens group data Group Start surface Focal length Lens composition length Front principal point position Rear principal point position 1 1 39.76996 6.55270 1.29166 3.41342
2 9 -6.11947 5.54350 0.49060 1.23716
3 15 10.15852 6.25890 -0.29682 1.67901
4 24 -15.45503 0.30000 0.15710 0.29366
5 26 15.80822 6.09020 0.22266 1.31235

Zoom lens group magnification group Start surface Wide angle Medium telephoto 1 1 0.00000 0.00000 0.00000
2 9 -0.20590 -0.35247 -1.36991
3 15 -0.49490 -1.11424 -1.11863
4 24 1.63973 1.69069 2.03241
5 26 0.67356 0.67297 0.67558

Tables 16 and 17 below show the corresponding values for each condition in the zoom lens system of each numerical example.

Table 16 (corresponding values of conditions)

Table 17 (corresponding values of conditions)

As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

In addition, since the above-described embodiments are for illustrating the technique in the present disclosure, various modifications, replacements, additions, omissions, and the like can be made within the scope of the claims and the equivalents thereof.

The present disclosure can be applied to digital input devices such as digital cameras, cameras of portable information terminals such as smartphones, surveillance cameras in surveillance systems, Web cameras, and in-vehicle cameras. In particular, the present disclosure can be applied to a photographing optical system that requires high image quality, such as a digital camera.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group L1 1st lens element L2 2nd lens element L3 3rd lens element L4 4th lens element L5 5th lens element L6 6th lens element L7 7th lens element L8 8th lens element L9 9th lens element L10 10th lens element L11 11th lens element L12 12th lens element L13 13th lens element A Aperture stop FL Low pass filter CG Cover glass S Image plane 1 Zoom lens system 2 Image sensor 3 Liquid crystal monitor 4 Case 5 Main barrel 6 Moving barrel 7 Cylindrical cam

Claims

A zoom lens system having a plurality of lens groups each composed of at least one lens element,
In order from the object side to the image side, at least a first lens group having positive power and a second lens group having negative power are provided,
During zooming from the wide-angle end to the telephoto end during imaging, the interval between the first lens group and the second lens group is increased,
A zoom lens system characterized by simultaneously satisfying the following conditions (I-1) and (I-2):
D1> D2 (I-1)
D3> D2 (I-2)
here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D2: effective diameter (mm) of the aperture stop at the intermediate position,
D3: Effective diameter of aperture stop at telephoto end (mm)
It is.
The zoom lens system according to claim 1, further satisfying the following condition (I-3):
D1 = D3 (I-3)
here,
D1: Effective diameter (mm) of the aperture stop at the wide angle end,
D3: Effective diameter of aperture stop at telephoto end (mm)
It is.
3. The zoom lens system according to claim 1, wherein at least one subsequent lens group is provided on the image side of the second lens group, and focusing is performed by any one of the subsequent lens groups.
An imaging apparatus capable of outputting an optical image of an object as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
An imaging apparatus, wherein the zoom lens system is the zoom lens system according to claim 1.
A camera that converts an optical image of an object into an electrical image signal, and displays and stores the converted image signal;
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The camera according to claim 1, wherein the zoom lens system is the zoom lens system according to claim 1.
A zoom lens system having at least five lens groups each composed of at least one lens element,
In order from the object side to the image side, at least a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power are provided.
The first lens group includes at least two lens elements that satisfy the following condition (II-1). At the same time, the third lens group includes at least lens elements that satisfy the following condition (II-2): A zoom lens system characterized by including one lens:
νd 1 ≧ 65 (II-1)
νd 3 ≧ 65 (II-2)
here,
νd 1 : Abbe number for the d-line of the lens elements included in the first lens group,
νd 3 is an Abbe number with respect to the d-line of the lens elements included in the third lens group.
The zoom lens system according to claim 6, wherein the first lens group includes at least two lens elements that satisfy the following condition (II-1) '':
νd 1 ≧ 75 (II-1) ″
here,
νd 1 : Abbe number for the d-line of the lens elements included in the first lens group.
The zoom lens system according to claim 6 or 7, wherein focusing is performed by any one of the third lens group and the lens group disposed closer to the image side than the third lens group.
An imaging apparatus capable of outputting an optical image of an object as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
An imaging apparatus, wherein the zoom lens system is the zoom lens system according to claim 6.
A camera that converts an optical image of an object into an electrical image signal, and displays and stores the converted image signal;
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
A camera, wherein the zoom lens system is the zoom lens system according to claim 6.