JP7548685B2 - Zoom lens and imaging device - Google Patents

Description

The present invention relates to a zoom lens and an imaging device equipped with the same.

In recent years, imaging devices using solid-state imaging elements, such as digital cameras and video cameras, have become increasingly high-resolution, and imaging optical systems are required to have even higher performance than before. In addition, as imaging devices become more compact, there is also a growing demand for more compact imaging optical systems.

In this situation, the following zoom lens is disclosed in a known document.
Patent Document 1 discloses a zoom lens for so-called digital single-lens reflex cameras and video cameras. In the zoom lens of Patent Document 1, the entire second lens group moves on the optical axis during focusing. However, because the diameter of the second lens group is large and the number of lenses constituting the second lens group is large, the drive mechanism for the focus lens group becomes large, and it is not possible to sufficiently achieve miniaturization of the imaging device.

Patent document 2 discloses a zoom lens for a so-called mirrorless camera. In the zoom lens of Patent document 2, the fourth lens group moves on the optical axis during focusing. However, the fourth lens group contains a large number of lenses, and the drive mechanism for the focus lens group is large, making it difficult to sufficiently achieve a compact imaging device.

JP 2008-003195 A JP 2016-109719 A

The above-mentioned conventional technologies have not realized a zoom lens that is small and has good optical performance, and an imaging device equipped with the same. In particular, the drive mechanism for the focus lens group is large, and the demand for miniaturization is not fully realized.

The present invention was made in consideration of the above-mentioned problems with conventional zoom lenses and imaging devices equipped with the same, and its main objective is to provide a zoom lens that is small and has good optical performance, and an imaging device equipped with the same.

A zoom lens according to one aspect of the present invention includes, in order from the object side, a positive first lens group, a negative second lens group, and a Gr group that is positive as a whole,
the first lens group includes a concave lens,
the Gr group includes, in order from the object side, a Grf group, a negative Grm group including a single lens , and a Grr group,
During magnification change, a distance between the first lens group and the second lens group and a distance between the second lens group and the Gr group change,
a distance between the Grf group and the Grm group, and a distance between the Grm group and the Grr group, are changed at least during either a magnification change or a focusing operation;
the Grf group includes a Grf convex lens disposed closest to the object side of the Grf group, and at least one Grf concave lens;
The zoom lens satisfies the following conditional expressions:
1.70 < ndGrfp < 2.50 ・ ・ ・ ・ ・ ・ (1)
1.82 < ndGrfn < 2.50 ・ ・ ・ ・ ・ ・ (2)
Where:
ndGrfp: the refractive index of the Grf convex lens at the d line
ndGrfn: the refractive index of the Grf concave lens at the d line

In this specification, the distance between the Grf group and the Grm group refers to the distance between the most image-side surface of the Grf group and the most object-side surface of the Grm group. The distance between the Grm group and the Grr group refers to the distance between the most image-side surface of the Grm group and the most object-side surface of the Grr group.

An imaging device according to one aspect of the present invention is characterized by comprising the zoom lens described above and an imaging element provided on the image side of the zoom lens, which converts an optical image formed by the zoom lens into an electrical signal.

The present invention can provide a small zoom lens with good optical performance, and an imaging device equipped with the same.

FIG. 2 is a cross-sectional view showing a lens configuration of a zoom lens according to a first numerical embodiment of the present invention. 4A to 4C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of the zoom lens according to Numerical Example 1 of the present invention when focused on an object at infinity at the wide-angle end. 4A to 4C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration when the zoom lens according to Numerical Example 1 of the present invention is focused on infinity at an intermediate focal length. 4A to 4C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration when the zoom lens according to Numerical Example 1 of the present invention is focused on infinity at the telephoto end. FIG. 11 is a cross-sectional view showing a lens configuration of a zoom lens according to a second numerical embodiment of the present invention. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to a second embodiment of the present invention when focused on an object at infinity at the wide-angle end. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration when the zoom lens according to Numerical Example 2 of the present invention is focused on infinity at an intermediate focal length. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration when the zoom lens according to Numerical Example 2 of the present invention is focused on an object at infinity at the telephoto end. FIG. 11 is a cross-sectional view showing a lens configuration of a zoom lens according to a third numerical embodiment of the present invention. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to a third embodiment of the present invention when focused on an object at infinity at the wide-angle end. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration when the zoom lens according to Numerical Example 3 of the present invention is focused on infinity at an intermediate focal length. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to a third embodiment of the present invention when focused on an object at infinity at the telephoto end. FIG. 11 is a cross-sectional view showing a lens configuration of a zoom lens according to a fourth numerical embodiment of the present invention. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 4 of the present invention when focused on an object at infinity at the wide-angle end. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 4 of the present invention when focused on infinity at an intermediate focal length. 11A to 11C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 4 of the present invention when focused on an object at infinity at the telephoto end. FIG. 11 is a cross-sectional view showing a lens configuration of a zoom lens according to a fifth embodiment of the present invention. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 5 of the present invention when focused on an object at infinity at the wide-angle end. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 5 of the present invention when focused on infinity at an intermediate focal length. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 5 of the present invention when focused on an object at infinity at the telephoto end. FIG. 13 is a cross-sectional view showing a lens configuration of a zoom lens according to a sixth numerical embodiment of the present invention. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 6 of the present invention when focused on an object at infinity at the wide-angle end. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 6 of the present invention when focused on infinity at an intermediate focal length. 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion aberration of a zoom lens according to Numerical Example 6 of the present invention when focused on an object at infinity at the telephoto end. FIG. 1 is a diagram illustrating the configuration of an imaging apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a zoom lens and an image pickup apparatus according to the present invention will be described.
(Zoom lens configuration)
The zoom lens according to the present invention comprises a positive first lens group, a negative second lens group, and a Gr group which is positive overall. The Gr group comprises, in order from the object side, a Grf group, a negative Grm group, and a Grr group. Magnification is varied by changing the distance between the first lens group and the second lens group, and the distance between the second lens group and the Gr group. At least one of magnification and focusing is performed by changing the distance between the Grf group and the Grm group, and the distance between the Grm group and the Grr group.

The first lens group is the lens group that is arranged closest to the object among the lens groups that make up the zoom lens. As long as the first lens group has positive refractive power, the specific lens configuration is not particularly limited. For example, in order to perform good aberration correction and obtain a high-performance zoom lens, it is preferable that the first lens group has at least one concave lens. Furthermore, it is even more preferable that the first lens group has a concave lens closest to the object.

The distance between the first lens group and the second lens group changes when the magnification is changed. More preferably, when the magnification is changed from the wide-angle end to the telephoto end, the first lens group moves toward the object side, thereby making it possible to reduce the overall length of the zoom lens at the wide-angle end.

The second lens group is disposed on the image side of the first lens group, and the distance between the second lens group and the adjacent lens group changes during zooming. As long as the second lens group has negative refractive power, the specific lens configuration is not particularly limited. For example, in order to provide good aberration correction and obtain a high-performance zoom lens, it is preferable that the second lens group has at least one convex lens.

The Gr group is a general term for lenses that include at least one lens group whose spacing with the adjacent lens group changes when the magnification is changed, and that are arranged closer to the image side than the second lens group in the zoom lens. The Gr group may include two or more lens groups that change the magnification by changing the spacing when the magnification is changed, and as long as it has positive refractive power overall and is composed of the Grf group, Grm group, and Grr group described below, there are no particular limitations on the specific lens configuration or the number of lens groups included.

The Gr group is composed of a Grf group, a negative Grm group, and a Grr group. The spacing between the Grf group and the Grm group and the spacing between the Grm group and the Grr group change during either or both of the magnification change and the focusing. The Grf group refers to all lenses in the Gr group that are arranged on the object side of the object side spacing of the negative Grm group that changes during at least one of the magnification change and the focusing, and the Grr group refers to all lenses in the Gr group that are arranged on the image side of the image side spacing of the negative Grm group that changes during at least one of the magnification change and the focusing. The Grf group and the Grr group may include two or more lens groups that change the spacing during the magnification change, and there are no particular limitations on the specific lens configuration or the number of groups included.

It is preferable that the Grf group has a Grf convex lens arranged closest to the object side in the Grf group, and at least one Grf concave lens.
By arranging the Grf convex lens on the most object side of the Grf group, the diameter of the lens on the image side can be made small, which is effective in making the zoom lens compact.
Furthermore, disposing the Grf concave lens in the Grf group is effective in correcting spherical aberration, coma aberration, and curvature of field, making it possible to obtain good optical performance over the entire zoom range.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (1))
1.60 < ndGrfp < 2.50 ・・・・・・(1)
Where:
ndGrfp: the refractive index of the Grf convex lens at the d line

Conditional expression (1) defines the refractive index at the d-line of the Grf convex lens included in the zoom lens. By satisfying the range defined by conditional expression (1), it is possible to achieve a compact zoom lens.
If the lower limit of conditional expression (1) is exceeded, the refractive index at the d-line of the Grf convex lens becomes smaller than the appropriate value, the necessary refractive power cannot be obtained, and it becomes difficult to reduce the diameter of the lens placed on the image side, which is undesirable.
If the upper limit of condition (1) is exceeded, performance degradation due to surface quirks and decentering will increase, and it will become difficult to ensure good optical performance over the entire zoom range due to the effects of manufacturing errors, which is undesirable.

To obtain the above effect, in conditional formula (1), the lower limit is preferably 1.70, more preferably 1.80, and even more preferably 1.85. The upper limit is preferably 2.10, more preferably 2.00, and even more preferably 1.94.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (2))
1.82 < ndGrfn < 2.50 ・・・・・・(2)
Where:
ndGrfn: the refractive index of the Grf concave lens at the d line

Conditional expression (2) defines the refractive index at the d-line of the Grf concave lens included in the Grf group. By satisfying the range defined by conditional expression (2), it is possible to effectively correct spherical aberration, coma aberration, and curvature of field that occur due to positive refractive power, and to obtain good optical performance over the entire zoom range.
If the lower limit of the conditional expression (2) is exceeded, the refractive index of the Grf concave lens at the d-line becomes smaller than the appropriate value, and the spherical aberration, coma aberration, and curvature of field generated by the positive refractive power component are insufficiently corrected. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.
If the upper limit of the conditional expression (2) is exceeded, the refractive index of the Grf concave lens at the d-line becomes larger than the appropriate value, and the spherical aberration, coma aberration, and curvature of field generated by the positive refractive power component are overcorrected. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

To obtain the above effect, in conditional formula (2), the lower limit is preferably 1.85, and more preferably 1.90. The upper limit is preferably 2.10, more preferably 2.00, and even more preferably 1.94.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (3))
42 < vdGrmn < 100 ・・・・・・(3)
Where:
vdGrmn: the minimum Abbe number at the d line of a concave lens included in the Grm group

Conditional expression (3) defines the concave lens in the Grm group that has the smallest Abbe number at the d-line. By satisfying the range defined by conditional expression (3), it is possible to suppress the fluctuation of axial chromatic aberration that occurs during zooming or focusing, and to obtain good optical performance over the entire zoom range.
If the lower limit of the conditional expression (3) is exceeded, the minimum Abbe number at the d-line of the concave lens included in the Grm group becomes smaller than the appropriate value, the glass becomes higher dispersion than the appropriate one for the concave lens included in the Grm group, and the under-axial chromatic aberration generated by the positive refractive power of the zoom lens is overcorrected. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

If the upper limit of conditional expression (3) is exceeded, the minimum Abbe number at the d-line of the concave lens included in the Grm group becomes larger than the appropriate value, resulting in a glass with lower dispersion than that appropriate for a concave lens included in the Grm group, and undercorrection of the on-axis chromatic aberration occurring due to the positive refractive power component in the zoom lens. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

To obtain the above effect, in conditional formula (3), the upper limit value is preferably 80.0, more preferably 70.0, and even more preferably 60.0.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (4))
10.0 < vdGrfp < 35.0 ・・・・・・(4)
where
vdGrfp: Abbe number at d line of the Grf convex lens

Conditional expression (4) defines the Abbe number at the d-line of the Grf convex lens. By satisfying the range defined by conditional expression (4), it is possible to correct the over-axial chromatic aberration generated by the negative refractive power component at the telephoto end to an under-axial chromatic aberration, minimize the secondary spectrum, and obtain good chromatic aberration performance over the entire zoom range.
If the lower limit of the conditional expression (4) is exceeded, the Abbe number at the d-line of the Grf convex lens becomes smaller than the appropriate value, and the glass becomes more highly dispersed than the glass properly selected for the Grf convex lens, resulting in overcorrection of the over-axial chromatic aberration generated by the negative refractive power component in the zoom lens. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.
If the upper limit of the conditional expression (4) is exceeded, the Abbe number at the d-line of the Grf convex lens becomes larger than the appropriate value, the glass becomes lower dispersion than the glass properly selected for the Grf convex lens, and the over-axial chromatic aberration generated by the negative refractive power component in the zoom lens is undercorrected. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

To obtain the above effect, in conditional formula (4), the lower limit is preferably 15.0, and more preferably 17.5. The upper limit is preferably 33.0, more preferably 30.0, and even more preferably 25.0.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (5))
10.0 < vdGrfn < 40.0 ・・・・・・(5)
where
vdGrfn: Abbe number of the Grf concave lens at the d line

Conditional expression (5) defines the Abbe number at the d-line of the Grf concave lens. By satisfying the range defined by conditional expression (5), it is possible to correct the under-axial chromatic aberration generated by the positive refractive power component at the telephoto end to an over-axial chromatic aberration, minimize the secondary spectrum, and obtain good chromatic aberration performance over the entire zoom range.
If the lower limit of the conditional expression (5) is exceeded, the Abbe number at the d-line of the Grf concave lens becomes smaller than the appropriate value, and the glass becomes more highly dispersed than the glass properly selected for the Grf concave lens, resulting in overcorrection of the under-axial chromatic aberration generated by the positive refractive power component in the zoom lens. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

If the upper limit of conditional expression (5) is exceeded, the Abbe number at the d-line of the Grf concave lens becomes larger than the appropriate value, and the glass becomes lower dispersion than the glass appropriately selected for the Grf concave lens, resulting in insufficient correction of the under-axial chromatic aberration generated by the positive refractive power component in the zoom lens. As a result, it becomes difficult to correct aberrations in the entire optical system, which is undesirable.

To obtain the above effect, in conditional formula (5), the lower limit is preferably 15.0, and more preferably 17.5. The upper limit is preferably 35.0, and more preferably 32.0, and even more preferably 25.0.

In a zoom lens according to one embodiment of the present invention, it is preferable that the Grm group is a focusing lens group.

By using the Grm group as a focusing lens group, the drive mechanism can be made smaller than when the first lens group or the second lens group is used as a focusing lens group. In addition, by satisfying conditional expressions (1), (2), and (3), it is possible to suppress aberration fluctuations when focusing on an object at a finite distance, and therefore good optical performance can be obtained.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
(Conditional formula (6))
-5 < fGrm/fw < -0.1 ・・・・・・(6)
where
fGrm: focal length of the Grm group
fw: focal length at the wide-angle end of the zoom lens

Conditional formula (6) defines the ratio of the focal length of the Grm group to the focal length at the wide-angle end of the zoom lens. By satisfying the range defined by conditional formula (6), the spherical aberration and coma aberration generated in the Grm group can be suppressed to an appropriate amount. In addition, when attempting to obtain a predetermined zoom magnification, the amount of movement of the Grm group can be made an appropriate amount, and the zoom lens as a whole can be made compact.

If the lower limit of conditional expression (6) is exceeded, the focal length of the Grm group will be longer than the optimum value, in other words, the refractive power of the Grm group will be weaker than the optimum value, and the amount of movement of the Grm group when attempting to obtain a specified zoom magnification will be larger than the optimum amount, which is not preferable since the zoom lens will become larger.
If the upper limit of conditional expression (6) is exceeded, the focal length of the Grm group will be shorter than the optimum value, in other words, the refractive power of the Grm group will be stronger than the optimum value, and the spherical aberration and coma aberration generated in the Grm group will be larger than the optimum amount, making it difficult to correct aberrations in the entire zoom lens, which is not preferable.

To obtain the above effect, in conditional formula (6), the lower limit is preferably -4.0, and more preferably -3.0. The upper limit is preferably -0.5, more preferably -0.6, and even more preferably -0.7.

A zoom lens according to an embodiment of the present invention has an aperture stop, and preferably satisfies the following conditional expression:
(Conditional formula (7))
0.01 < Tsfw/fw < 5.0 ・・・・・・(7)
where
Tsfw: the distance between the aperture stop and the Grm group at the wide-angle end of the zoom lens
fw: focal length at the wide-angle end of the zoom lens

Conditional expression (7) defines the ratio of the distance between the aperture stop and the Grm group at the wide-angle end of the zoom lens to the focal length of the zoom lens at the wide-angle end. By satisfying the range defined by conditional expression (7), the height of the chief ray of the off-axis light passing through the Grm group can be reduced, and the diameter of the Grm group can be reduced and the fluctuation of the curvature of field that occurs during zooming or focusing can be suppressed.
If the lower limit of condition (7) is exceeded, the distance between the aperture stop and the Grm group at the wide-angle end becomes smaller than the appropriate value, which is undesirable because it becomes difficult to arrange lens holding parts and the like.
If the upper limit of conditional expression (7) is exceeded, the distance between the aperture stop and the Grm group at the wide-angle end will be larger than an appropriate value, the height of the chief ray passing through the Grm group will be increased, the diameter of the Grm group will be enlarged, and the variation in field curvature that occurs during zooming or focusing will be large, making it difficult to reduce the size of the zoom lens and to correct aberrations in the entire optical system, which is not preferable.

To obtain the above effect, in conditional formula (7), the lower limit is preferably 0.1, more preferably 0.2, and even more preferably 0.5. The upper limit is preferably 3.0, more preferably 2.5, and even more preferably 2.0.

It is preferable that the zoom lens according to one embodiment of the present invention has at least two of the above-mentioned Grf concave lenses.

This configuration is effective in correcting spherical aberration, coma, curvature of field, and other aberrations that occur with positive refractive power components, and provides good optical performance across the entire zoom range.

In a zoom lens according to one embodiment of the present invention, it is preferable that the Grf concave lens has a concave surface on the image side.

This configuration allows the field curvature to be over-corrected, and aberration correction can be performed well throughout the entire optical system. To achieve the above effect, it is more preferable that at least two of the Grf concave lenses have a concave surface on the image side.

In a zoom lens according to one embodiment of the present invention, it is preferable that the Grf concave lens forms a cemented lens.

In this configuration, the action of the cemented surface of the Grf concave lens allows for excellent correction of spherical aberration and curvature of field. In addition, compared to when the Grf concave lens is constructed from a single lens, the occurrence of on-axis coma aberration caused by decentering during assembly can be suppressed.

In a zoom lens according to one embodiment of the present invention, it is preferable that the Grm group is composed of a single lens.

This configuration reduces the weight of the Grm group, makes it easier to simplify the zoom drive mechanism, and allows the zoom lens to be made more compact.

Here, a single lens refers to a lens (optical element) having one optical surface on the object side and one on the image side, and the single lens also includes lenses on which various coatings such as anti-reflection films and protective films have been applied. The shape of the optical surface of the single lens is not particularly limited, and it may be either spherical or aspherical. One side may be flat. The manufacturing method of the single lens is not particularly limited, and includes various lenses manufactured by polishing, molding, injection molding, etc. On the other hand, a single lens refers to a lens that is composed of one lens, and does not include a cemented lens in which multiple lenses such as positive and negative lenses are bonded or closely attached to each other on their optical surfaces without an air layer between them, and also does not include a lens in which multiple lenses are integrated with an air layer between them.

In a zoom lens according to one embodiment of the present invention, it is preferable that the Gr group has an anti-vibration lens system that moves in a direction perpendicular to the optical axis to change the imaging position.

The Gr group has an anti-vibration lens system that moves perpendicular to the optical axis to change the imaging position, so camera shake caused by the photographer can be effectively corrected without enlarging the drive mechanism, compared to when an anti-vibration lens system is placed in the first lens group or the second lens group.

To achieve the above effect, it is preferable to place the vibration-proof lens system in the Grf group.

In a zoom lens according to one embodiment of the present invention, the vibration-proof lens system preferably has a lens having at least one aspheric surface.

By having the vibration-proof lens system have a lens with at least one aspheric surface, it is possible to suppress the occurrence of on-axis coma aberration and curvature of field during image stabilization, and to obtain good optical performance.

It is preferable for a zoom lens according to an embodiment of the present invention to satisfy the following conditional expression:
-10 < (1-βvc)×βvcr < -0.10 ・・・(8)
where βvc is the lateral magnification of the vibration-proof lens system at the telephoto end, and βvcr is the combined lateral magnification of all lenses disposed on the image side of the vibration-proof lens system at the telephoto end.

Conditional expression (8) defines the ratio between the amount of movement of the image point on the image plane and the vertical direction of the vibration-proof lens system, i.e., the image stabilization coefficient. By satisfying the range defined by conditional expression (8), the image stabilization coefficient can be set within an appropriate range, and the occurrence of axial coma aberration and curvature of field during image stabilization can be suppressed, thereby realizing a large-aperture lens having excellent optical performance even during image stabilization.
If the lower limit of conditional expression (8) is exceeded, the image stabilization coefficient becomes larger than the appropriate value, which requires that the composite refractive power of the image stabilization lens system and all lenses arranged on the image side of the image stabilization lens system be made stronger than the appropriate value. However, this is not preferable because it increases the amount of axial coma aberration and curvature of field that occur during image stabilization.
If the upper limit of conditional expression (8) is exceeded, the image stabilization coefficient will be smaller than the optimum value, the amount of vertical movement of the image stabilization lens system during image stabilization will be larger than the optimum value, and the drive mechanism will become larger, which will lead to an increase in the size of the zoom lens, which is not preferable.

To obtain the above effect, in conditional formula (8), the lower limit is preferably -5.0, and more preferably -4.0. The upper limit is preferably -0.55, and more preferably -1.0.

In a zoom lens according to one embodiment of the present invention, the vibration-proof lens system is preferably a single lens.

This configuration reduces the weight of the anti-vibration lens system, makes it easier to simplify the drive mechanism for the anti-vibration lens system, and allows the zoom lens to be made more compact.

The imaging device according to one embodiment of the present invention is preferably an imaging device including the zoom lens described above and an imaging element provided on the image side of the zoom lens for converting an optical image formed by the zoom lens into an electrical signal. Here, there are no particular limitations on the imaging element, and solid-state imaging elements such as CCD sensors and CMOS sensors can also be used. In other words, the imaging device according to the present invention is preferably an imaging device using such solid-state imaging elements, such as a digital camera or video camera. Furthermore, the imaging device may be a fixed-lens imaging device in which the lens is fixed to the housing, or it may of course be an interchangeable-lens imaging device, such as a single-lens reflex camera or a mirrorless single-lens camera.

<Example>
Next, numerical examples of the present invention will be described with reference to numerical tables and drawings, although the present invention is not limited to the following numerical examples.
The zoom lenses in the following numerical examples are photographic zoom lenses suitable for use in imaging devices (optical devices) such as digital cameras, video cameras, and silver halide film cameras.

For all numerical examples, in the lens cross-sectional views (Figs. 1, 5, 9, 13, 17, and 21), the left side is the object side and the right side is the image side. The arrows at the bottom of the lens cross-sectional views indicate the trajectory of movement of each lens group during magnification change from the wide-angle end (W) to the telephoto end (T) from top to bottom.

(Numerical Example 1)
1 is a lens cross-sectional view showing the configuration of Numerical Example 1. The zoom lens is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power. The Gr lens group Gr is composed of a Grf group, i.e., a third lens group G3, having positive refractive power, a Grm group, i.e., a fourth lens group G4, having negative refractive power, and a Grr group, i.e., a fifth lens group G5, having positive refractive power.

When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once to draw a convex locus toward the image side and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, and the fifth lens group G5 is fixed on the optical axis.
Focusing is performed by moving the fourth lens group G4 along the optical axis.
The Gvc concave lens Gvc in the third lens group G3 is moved in a direction perpendicular to the optical axis to perform camera shake correction during shooting.
In Fig. 1, "S" is an aperture stop, and "I" shown on the image side of the zoom lens is an image plane. On the image plane, the light receiving surface of a solid-state image sensor such as a CCD sensor or a CMOS sensor, the film surface of a silver halide film, etc. are arranged. The same applies to the following examples.

In Table 1 showing the lens data of Numerical Example 1, the surface number No. indicates the order of the lens surface counted from the object side, R indicates the radius of curvature of the lens surface, D indicates the distance on the optical axis of the lens surface, Nd indicates the refractive index for the d-line (wavelength λ=587.6 nm), and ABV indicates the Abbe number for the d-line (wavelength λ=587.6 nm). The aperture stop S is indicated by adding STOP to the surface number. Furthermore, if the lens surface is aspheric, ASPH is added to the surface number, and the paraxial radius of curvature is indicated in the column for radius of curvature R.
Table 2 shows the F-number, half angle of view, and distance between the movable lens group and the adjacent lens group on the image side for each focal length of the zoom lens.
Table 3 shows the aspherical coefficients and conic constants when the shape of the aspherical surface is expressed by the following formula: The aspherical surface is defined by the following formula.
z=ch ² /[1+{1-(1+k)c ² h ² }1/2]+A ₄ h ⁴ +A ₆ h ⁶ +A ₈ h ⁸ +A ₁₀ h ¹⁰ +A ₁₂ h ¹²
(where c is the curvature (1/r), h is the height from the optical axis, k is the cone coefficient, and _A4 , _A6 , _A8 , _A10 , and _A1 are the aspheric coefficients of each order.)
Since these also apply to Tables 3 to 19 relating to Numerical Examples 2 to 6, the explanation thereof will be omitted below.

2 to 4 show longitudinal aberration diagrams of the zoom lens when focused at infinity. From the left, each longitudinal aberration diagram shows spherical aberration, astigmatism, and distortion.
In the diagrams showing spherical aberration, the solid line represents the d-line (587.6 nm), and in the diagrams showing astigmatism, the solid line represents the sagittal direction of the d-line, and the dashed line represents the meridional direction of the d-line.
The order in which these aberrations are displayed, the arrangement thereof, and the solid and wavy lines in each figure are the same as those in FIGS. 6 to 8, 10 to 12, 14 to 16, 18 to 20, and 22 to 24 shown in Examples 2 to 6, and therefore will not be described below.

[Table 1]
No. RD Nd ABV
1 2000.000 1.200 1.92286 20.88
2 251.498 4.474 1.77250 49.62
3 -334.651 0.200
4 41.925 5.956 1.59319 67.90
5 75.902 D(5)
6ASPH 84.620 0.200 1.51460 49.96
7 50.864 1.000 1.87070 40.73
8 14.151 8.695
9 -26.471 0.800 1.61997 63.88
10 20.069 6.749 1.85026 32.35
11 -33.310 0.953
12 -23.718 1.866 1.90366 31.31
13 -46.358 D(13)
14 33.006 3.063 1.80518 25.46
15 -368.354 1.471
16STOP 0.000 1.000
17 616.656 6.909 1.55032 75.50
18 -25.902 0.800 1.92119 23.96
19 151.063 1.000
20 21.429 0.800 2.00100 29.13
21 15.058 7.670 1.59319 67.90
22 -37.466 1.000
23ASPH -61.153 1.000 1.69350 53.20
24ASPH 34.627 0.800
25ASPH 20.773 4.788 1.77377 47.17
26ASPH -84.058D(26)
27 -197.049 1.000 1.62299 58.12
28 19.516 0.150 1.51460 49.96
29ASPH 19.516D(29)
30 53.015 6.000 1.77250 49.62
31 -115.535 18.080
32 inf. 2.500 1.51680 64.20
33 inf. 1.000

[Table 2]
F 16.477 29.656 53.349
Fno 2.903 2.904 2.902
W 42.054 25.047 14.489
D(5) 1.000 18.718 35.468
D(13) 24.375 7.962 1.000
D(26) 1.098 4.854 5.544
D(29) 6.405 7.808 21.553

[Table 3]
No. K A4 A6 A8 A10 A12
6 0.00 1.78265E-05 -3.80659E-08 2.10074E-10 -8.52242E-13 1.58686E-15
23 0.00 -2.36708E-06 -2.68549E-07 2.80258E-09 5.81858E-12 -1.25057E-13
24 0.00 -1.39621E-05 1.45229E-08 -7.53754E-09 1.52158E-10 -8.35097E-13
25 0.00 -1.64474E-05 5.20674E-07 -6.41791E-09 8.49591E-11 -1.75638E-13
26 0.00 3.26460E-05 4.13941E-07 1.91471E-09 -4.60396E-11 6.77568E-13
29 0.00 4.13276E-06 -3.80651E-07 6.12980E-09 -6.18723E-11 2.69244E-13

In Numerical Example 1, the focal length of the first lens group G1 is 111.357, the focal length of the second lens group G2 is -19.444, the focal length of the third lens group G3 is 23.316, the focal length of the fourth lens group G4 is -28.434, and the focal length of the fifth lens group G5 is 47.783.

(Numerical Example 2)
5 is a lens cross-sectional view showing the configuration of a zoom lens according to Numerical Example 2 of the present invention. The zoom lens according to Numerical Example 2 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power. The Gr group Gr is composed of a Grf group Grf having positive refractive power, i.e., a third lens group G3, a Grm group Grm having negative refractive power, i.e., a fourth lens group G4, and a Grr group Grr having positive refractive power, i.e., a fifth lens group G5.

When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once so as to trace a convex locus toward the image side, and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, and the fifth lens group G5 is fixed on the optical axis.
Focusing is performed by moving the fourth lens group G4 along the optical axis.
The Grf concave lens Gvc in the third lens group G3 is moved in a direction perpendicular to the optical axis to perform excellent camera shake correction during shooting.

The lens data etc. of Numerical Example 2 are as follows.
[Table 4]
No. RD Nd ABV
1 688.383 1.200 1.92286 20.88
2 164.125 3.817 1.75500 52.34
3 1017.671 0.200
4 56.238 6.772 1.75500 52.34
5 186.744 D(5)
6ASPH 83.374 0.200 1.51460 49.96
7 51.042 1.000 1.87070 40.73
8 15.031 9.752
9 -29.021 0.800 1.61997 63.88
10 21.625 6.654 1.85026 32.35
11 -31.540 0.676
12 -25.319 1.000 1.80000 29.84
13 -63.814 D(13)
14 27.791 2.786 1.92286 20.88
15 189.515 1.816
16STOP 0.000 1.000
17 61.474 2.751 1.59319 67.90
18 -44.949 0.800 1.96300 24.11
19 28.024 0.200
20 17.999 0.800 2.00100 29.13
21 12.925 6.025 1.59319 67.90
22 -42.097 1.025
23ASPH -44.824 1.000 1.69350 53.20
24ASPH 36.345 0.808
25ASPH 22.574 6.088 1.77250 49.50
26ASPH -48.210 D(26)
27 -120.204 1.000 1.59349 67.00
28 25.406 0.150 1.51460 49.96
29ASPH 25.406 D(29)
30 69.162 6.500 1.61997 63.88
31 -113.620 29.120
32 inf. 2.500 1.51680 64.20
33 inf. 1.000

[Table 5]
F 24.714 40.968 67.899
Fno 4.100 4.100 4.100
W 42.458 27.220 17.161
D(5) 1.000 15.139 30.522
D(13) 20.628 7.362 1.000
D(26) 1.010 4.761 5.697
D(29) 8.241 11.662 26.544

[Table 6]
No. K A4 A6 A8 A10 A12
6 0.00 1.29752E-05 -3.14572E-08 1.62959E-10 -5.19631E-13 7.57582E-16
23 0.00 2.86692E-06 -2.30537E-07 3.22374E-09 -7.11810E-12 -6.17076E-14
24 0.00 -1.52890E-05 6.83680E-08 -4.22634E-09 8.33663E-11 -4.83401E-13
25 0.00 -1.93044E-05 4.39178E-07 -4.47022E-09 5.78013E-11 -1.72393E-13
26 0.00 3.16204E-05 2.34438E-07 2.44475E-09 -2.93199E-11 3.42601E-13
29 0.00 2.77133E-06 -1.26974E-07 1.12597E-09 -6.58648E-12 1.10279E-14

In Numerical Example 2, the focal length of the first lens group G1 is 109.300, the focal length of the second lens group G2 is -21.888, the focal length of the third lens group G3 is 24.886, the focal length of the fourth lens group G4 is -35.228, and the focal length of the fifth lens group G5 is 70.303.

(Numerical Example 3)
9 is a lens cross-sectional view showing the configuration of a zoom lens of Numerical Example 3. The zoom lens of Numerical Example 3 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power. The Gr group Gr is composed of a Grf group Grf having positive refractive power, i.e., a third lens group G3, a fourth lens group G4 having negative refractive power, and a Grr group Grr having positive refractive power, i.e., a fifth lens group G5.
When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once so as to trace a convex locus toward the image side, and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, and the fifth lens group G5 moves toward the object side.
Focusing is performed by moving the fourth lens group G4 along the optical axis.
The Gvc concave lens Gvc in the third lens group is moved in a direction perpendicular to the optical axis to correct camera shake during shooting.

The lens data etc. of Numerical Example 3 are as follows.
[Table 7]
No. RD Nd ABV
1 182.146 1.200 1.92286 20.88
2 109.764 2.687 1.75500 52.34
3 168.071 0.200
4 76.975 5.053 1.75500 52.34
5 370.296 D(5)
6ASPH 82.805 0.200 1.51460 49.96
7 57.642 1.000 1.87070 40.73
8 16.704 10.803
9 -30.171 1.701 1.61997 63.88
10 24.307 6.761 1.85026 32.27
11 -42.477 1.809
12 -25.079 1.000 1.85478 24.80
13 -37.871 D(13)
14 24.331 3.420 1.85478 24.80
15 94.297 2.263
16STOP 0.000 1.002
17 56.891 2.971 1.59319 67.90
18 -68.385 0.800 1.95540 26.44
19 33.635 0.200
20 18.683 1.079 2.00100 29.13
21 11.766 6.488 1.59319 67.90
22 -46.883 1.000
23ASPH -50.612 1.000 1.77250 49.50
24ASPH 31.611 1.100
25ASPH 22.125 6.105 1.77250 49.50
26ASPH -69.424 0.382
27 -70.415 1.702 1.74077 27.76
28 -54.161 D(28)
29ASPH 132.494 0.800 1.59349 67.00
30ASPH 23.566D(30)
31 44.723 2.124 1.66695 35.37
32 69.948 D(32)
33 inf. 2.500 1.51680 64.20
34 inf. 1.000

[Table 8]
F 24.725 40.963 67.911
Fno 4.100 4.100 4.100
W 42.496 27.174 17.167
D(5) 1.000 16.908 33.196
D(13) 24.936 9.908 1.000
D(28) 2.764 3.672 2.393
D(30) 14.606 13.698 14.976
D(32) 18.347 28.368 44.586

[Table 9]
No. K A4 A6 A8 A10 A12
6 0.00 9.98914E-06 -1.65026E-08 9.10887E-11 -2.78176E-13 3.99209E-16
23 0.00 -6.23788E-07 -2.62926E-07 6.37575E-09 -5.26054E-11 1.56101E-13
24 0.00 -1.19424E-05 -2.30539E-07 3.25711E-09 2.05167E-12 -1.31972E-13
25 0.00 -1.96508E-05 1.80923E-07 -2.43809E-09 3.96828E-11 -1.13302E-13
26 0.00 2.33283E-05 1.85050E-07 -1.03998E-09 6.70391E-12 1.06493E-13
29 0.00 -5.68298E-06 -3.67418E-08 3.42188E-10 1.19122E-11 -1.08488E-13
30 0.00 -6.63961E-06 -1.24517E-07 2.15708E-09 -7.18969E-12 -2.82251E-14

In Numerical Example 3, the focal length of the first lens group G1 is 146.101, the focal length of the second lens group G2 is -25.334, the focal length of the third lens group G3 is 27.737, the focal length of the fourth lens group G4 is -48.429, and the focal length of the fifth lens group G5 is 179.878.

(Numerical Example 4)
(Zoom lens configuration)
13 is a lens cross-sectional view showing the configuration of a zoom lens of Numerical Example 4. The zoom lens of Numerical Example 4 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power. The Gr group Gr is composed of a Grf group, i.e., a third lens group G3, having positive refractive power, a Grm group, i.e., a fourth lens group G4, having negative refractive power, and a Grr group, i.e., a fifth lens group G5, having positive refractive power.
When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once to draw a convex locus toward the image side and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, and the fifth lens group G5 is fixed on the optical axis.
Focusing is performed by moving the fourth lens group G4 along the optical axis.
The Gvc concave lens Gvc in the third lens group G3 is moved in a direction perpendicular to the optical axis to correct camera shake during shooting.

The lens data etc. of Numerical Example 4 are as follows.
[Table 10]
No. RD Nd ABV
1 996.724 1.200 1.92286 20.88
2 203.034 4.724 1.77250 49.62
3 -416.040 0.200
4 49.543 6.521 1.61997 63.88
5 115.082 D(5)
6ASPH 155.318 0.200 1.51460 49.96
7 65.339 1.190 1.87070 40.73
8 15.890 9.678
9 -24.547 0.800 1.61997 63.88
10 24.248 6.563 1.85026 32.35
11 -31.607 1.099
12 -23.095 1.199 1.90366 31.34
13 -37.985 D(13)
14 28.698 2.785 1.92286 20.88
15 75.762 2.392
16STOP 0.000 1.690
17 29.254 3.969 1.59319 67.90
18 -68.399 0.800 1.96300 24.11
19 30.865 1.000
20 21.086 1.748 2.00100 29.13
21 13.365 6.843 1.59319 67.90
22 -57.527 1.000
23ASPH -62.180 1.000 1.69350 53.20
24ASPH 41.625 0.800
25ASPH 21.055 7.114 1.77377 47.17
26ASPH -72.558D(26)
27 -135.045 1.000 1.59349 67.00
28 20.826 0.150 1.51460 49.96
29ASPH 20.826D(29)
30 49.638 5.324 1.75500 52.34
31 -128.013 18.763
32 inf. 2.500 1.51680 64.20
33 inf. 1.000

[Table 11]
F 17.507 34.486 67.899
Fno 2.900 2.900 2.900
W 40.339 21.809 11.484
D(5) 1.000 20.389 40.352
D(13) 28.449 8.314 1.000
D(26) 1.369 5.838 5.451
D(29) 5.930 7.909 23.950

[Table 12]
No. K A4 A6 A8 A10 A12
6 0.00 1.54091E-05 -2.95342E-08 1.42901E-10 -5.18027E-13 9.09923E-16
23 0.00 -5.62744E-06 1.71245E-07 -7.89939E-09 1.11898E-10 -4.89966E-13
24 0.00 -1.59116E-05 4.43181E-07 -1.45801E-08 1.83238E-10 -7.72093E-13
25 0.00 -1.26537E-05 3.56484E-07 -3.60385E-09 3.97646E-11 -9.90564E-14
26 0.00 3.08427E-05 1.97745E-07 2.35779E-09 -2.95500E-11 2.82052E-13
29 0.00 9.23625E-07 -2.51901E-07 3.69382E-09 -3.41158E-11 1.36937E-13

In Numerical Example 4, the focal length of the first lens group G1 is 105.576, the focal length of the second lens group G2 is -21.226, the focal length of the third lens group G3 is 25.471, the focal length of the fourth lens group G4 is -30.311, and the focal length of the fifth lens group G5 is 47.994.

(Numerical Example 5)
17 is a lens cross-sectional view showing the configuration of a zoom lens of Numerical Example 5. The zoom lens of Numerical Example 5 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power. The Gr group is composed of a Grf group having positive refractive power, i.e., a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a Grm group having negative refractive power, i.e., a fifth lens group G5, and a Grr group having positive refractive power, i.e., a sixth lens group G6.
When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once so as to trace a convex path toward the image side, and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.
Focusing is performed by moving the fifth lens group G5 along the optical axis.
The Gvc concave lens Gvc in the fourth lens group is moved in a direction perpendicular to the optical axis to correct camera shake during shooting.

The lens data etc. of Numerical Example 5 are as follows.
[Table 13]
No. RD Nd ABV
1 82.044 1.200 1.92286 20.88
2 64.694 6.488 1.75500 52.34
3 387.277 D(3)
4ASPH 87.363 0.200 1.51460 49.96
5 56.476 1.000 1.87070 40.73
6 16.888 11.178
7 -30.598 1.904 1.61997 63.88
8 25.618 6.832 1.85026 32.27
9 -41.264 1.278
10 -25.947 1.000 1.85478 24.80
11 -41.195 D(11)
12 24.680 3.508 1.85478 24.80
13 116.941 2.737
14STOP 0.000 1.000
15 58.461 2.853 1.59319 67.90
16 -71.228 0.800 1.95816 26.30
17 30.485 0.200
18 17.962 0.800 2.00100 29.13
19 11.698 7.151 1.59319 67.90
20 -40.302 D(20)
21ASPH -46.170 1.000 1.77250 49.50
22ASPH 30.047 1.015
23ASPH 20.282 7.579 1.77250 49.50
24ASPH -68.827D(24)
25ASPH 130.453 0.800 1.59349 67.00
26ASPH 23.296D(26)
27 45.401 2.113 1.78795 24.53
28 71.269 D(28)
29 inf. 2.500 1.51680 64.20
30 inf. 1.000

[Table 14]
F 24.723 40.962 67.903
Fno 4.110 4.112 4.109
W 42.482 27.164 17.165
D(3) 1.000 16.692 33.898
D(11) 24.662 9.853 1.000
D(20) 0.568 0.819 1.000
D(24) 3.248 3.757 2.505
D(26) 14.047 13.702 15.799
D(28) 18.475 28.496 43.307

[Table 15]
No. K A4 A6 A8 A10 A12
4 0.00 9.34445E-06 -1.48253E-08 7.21196E-11 -2.04831E-13 2.80677E-16
21 0.00 5.96329E-07 -3.88332E-07 7.63596E-09 -5.63489E-11 1.56101E-13
22 0.00 -1.17460E-05 -3.87541E-07 5.12724E-09 -5.02839E-12 -1.37730E-13
23 0.00 -2.26569E-05 1.26991E-07 -1.54165E-09 3.35046E-11 -1.22928E-13
24 0.00 2.73118E-05 1.50401E-07 -2.11620E-10 1.51568E-12 1.07210E-13
25 0.00 -1.00968E-05 -6.52017E-09 7.57102E-10 2.83635E-12 -5.91493E-14
26 0.00 -1.35319E-05 -6.29236E-08 2.18641E-09 -1.38061E-11 1.13791E-14

In Numerical Example 5, the focal length of the first lens group G1 is 147.089, the focal length of the second lens group G2 is -25.354, the focal length of the third lens group G3 is 29.303, the focal length of the fourth lens group G4 is 106.916, the focal length of the fifth lens group G5 is -47.918, and the focal length of the sixth lens group G6 is 153.227.

(Numerical Example 6)
21 is a lens cross-sectional view showing the configuration of a zoom lens of Numerical Example 6. The zoom lens of Numerical Example 6 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a Gr group Gr having positive refractive power, i.e., a third lens group G3. The third lens group G3 is composed of a Grf group Grf, a Grm group Grm, and a Grr group Grr which is a positive meniscus lens.
When changing the magnification from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side once so as to trace a convex locus toward the image side, and then moves toward the object side, and the Gr group Gr moves toward the object side.
Focusing is performed by moving the Grm group Grm, which has negative refractive power, along the optical axis.
By moving the Gvc concave lens Gvc in the Grf group Grf in a direction perpendicular to the optical axis, camera shake during shooting can be effectively corrected.

The lens data etc. of Numerical Example 6 are as follows.
[Table 16]
No. RD Nd ABV
1 103.235 1.200 1.92286 20.88
2 76.710 6.556 1.75500 52.34
3 3002.806 D(3)
4ASPH 103.048 0.200 1.51460 49.96
5 64.366 1.408 1.87070 40.73
6 18.409 10.221
7 -29.200 1.014 1.61997 63.88
8 25.410 5.945 1.85026 32.27
9 -48.133 2.183
10 -22.633 1.000 1.85478 24.80
11 -30.852 D(11)
12 23.704 3.790 1.85478 24.80
13 95.620 2.903
14STOP 0.000 1.000
15 60.390 2.994 1.59319 67.90
16 -65.131 0.800 1.95104 25.84
17 33.219 0.200
18 17.897 0.800 2.00100 29.13
19 11.429 8.294 1.59319 67.90
20 -71.986 1.352
21ASPH -44.888 1.000 1.77250 49.50
22ASPH 35.316 1.047
23ASPH 22.008 6.342 1.77250 49.50
24ASPH -42.598 3.152
25ASPH 306.708 0.800 1.59349 67.00
26ASPH 26.242 13.910
27 48.153 4.302 1.92286 20.88
28 60.270 D(28)
29 inf. 2.500 1.51680 64.20
30 inf. 1.000

[Table 17]
F 27.799 43.457 67.905
Fno 4.100 4.100 4.100
W 39.167 25.803 17.162
D(3) 3.897 17.308 26.394
D(11) 21.230 9.864 1.000
D(28) 18.961 29.875 46.649

[Table 18]
No. K A4 A6 A8 A10 A12
4 0.00 6.85022E-06 -9.01762E-09 5.33929E-11 -1.67759E-13 3.03955E-16
21 0.00 6.82104E-06 -3.99441E-07 7.90040E-09 -4.26423E-11 1.72015E-14
22 0.00 3.16978E-06 -5.15549E-07 5.87720E-09 1.37952E-11 -3.10812E-13
23 0.00 -2.50998E-05 -2.86707E-08 -1.11929E-09 2.83851E-11 -8.15037E-14
24 0.00 1.61800E-05 7.59569E-08 -9.24577E-10 -1.82886E-12 1.16079E-13
25 0.00 3.97589E-06 7.16355E-08 -1.06256E-10 -4.38988E-12 4.00442E-14
26 0.00 3.84251E-06 4.53217E-08 6.78497E-10 -1.11994E-11 5.67154E-14

In Numerical Example 6, the focal length of the first lens group G1 is 153.381, the focal length of the second lens group G2 is -25.072, and the focal length of the third lens group G3 is 27.957.

(Imaging device)
25, in an embodiment of the image capturing device 100, a taking lens 110 is supported by a lens barrel 106 attached to an image capturing device housing 102 by a lens mount 104. An image of a subject is formed on an image forming plane I through the taking lens 110 and a cover glass C, and the subject image is displayed on a display 112.

(Numerical values related to conditional expressions)
The values of the conditional expressions in the respective numerical examples are as follows.
[Table 19]
Example 1 Example 2 Example 3 Example 4 Example 5 Example 6
(1)ndpH 1.80518 1.92286 1.92286 1.92286 1.85500 1.85500
(2)ndnH 2.00100 2.00100 2.00100 2.00100 2.00100 2.00100
(3)vdGrmn 58.12 67.00 67.00 67.00 67.00 67.00
(4)vdGrfp 25.45 20.88 20.88 20.88 26.29 26.29
(5)vdGrfn 29.13 29.13 29.13 29.13 29.13 29.13
(6)fGrm/fw -1.726 -1.425 -1.959 -1.731 -1.938 -1.741
(7)Tsfw/fw 1.630 0.870 1.076 1.561 0.541 0.971
(8)(1-βvc)×βvcr -1.532 -2.170 -2.750 -1.417 -2.883 -2.802

G1: first lens group G2: second lens group G3: third lens group G4: fourth lens group G5: fifth lens group G6: sixth lens group 100: photographing device 102: photographing device housing 104: lens mount 106: lens barrel 110: photographing lens

Claims (17)

the first lens group having a positive refractive power, the second lens group having a negative refractive power, and a Gr group having one or more lens groups and being positive as a whole,
the first lens group has a concave lens, the Gr group includes, in order from the object side, a Grf group, a negative Grm group including a single lens, and a Grr group,
During zooming, the first lens group moves toward the object side,
During magnification change, a distance between the first lens group and the second lens group and a distance between the second lens group and the Gr group change,
During focusing, the distance between the first lens group and the second lens group, the distance between the second lens group and the Gr group, and the inside of the Grf group do not change,
During zooming and focusing, the insides of the first lens group, the second lens group, the Grm group, and the Grr group do not change,
When the magnification is changed, the distance between the Grf group and the Grm group and the distance between the Grm group and the Grr group change,
the Grf group includes a Grf convex lens disposed closest to the object side of the Grf group, and at least one Grf concave lens;
A zoom lens that satisfies the following conditions:
1.70 < ndGrfp < 2.50 ・ ・ ・ ・ ・ ・ (1)
1.90 < ndGrfn < 2.50 ・ ・ ・ ・ ・ ・ (2)
10.0 < vdGrfp < 30.0 ・ ・ ・ ・ ・ (4)
where
ndGrfp: the refractive index of the Grf convex lens at the d line
ndGrfn: the refractive index of the Grf concave lens at the d line
vdGrfp: Abbe number at d line of the Grf convex lens the first lens group having a positive refractive power, the second lens group having a negative refractive power, and a Gr group having one or more lens groups and being positive as a whole,
the first lens group has a concave lens, the Gr group includes, in order from the object side, a Grf group, a Grm group which is a focusing group and is composed of a negative single lens, and a Grr group,
During zooming, the first lens group moves toward the object side,
during zooming, a distance between the first lens group and the second lens group, and a distance between the second lens group and the Gr group are changed , and a distance between the Grf group and the Grm group, and a distance between the Grm group and the Grr group are not changed;
During zooming and focusing, the insides of the first lens group, the second lens group, the Grf group, the Grm group, and the Grr group do not change,
When focusing, the interval between the Grf group and the Grm group and the interval between the Grm group and the Grr group change,
the Grf group includes a Grf convex lens disposed closest to the object side of the Grf group, and at least one Grf concave lens;
A zoom lens that satisfies the following conditions:
1.70 < ndGrfp < 2.50 ・ ・ ・ ・ ・ ・ (1)
1.90 < ndGrfn < 2.50 ・ ・ ・ ・ ・ ・ (2)
10.0 < vdGrfp < 30.0 ・ ・ ・ ・ ・ (4)
where
ndGrfp: the refractive index of the Grf convex lens at the d line
ndGrfn: the refractive index of the Grf concave lens at the d line
vdGrfp: Abbe number at d line of the Grf convex lens 3. The zoom lens according to claim 1, wherein the Grf concave lens satisfies the following condition:
10.0 < vdGrfn < 40.0 ・ ・ ・ ・ ・ (5)
where
vdGrfn: Abbe number of the Grf concave lens at the d line The zoom lens according to claim 1, wherein the Grm group is a focusing group. 5. The zoom lens according to claim 1, wherein the Grm group satisfies the following condition:
-5 < fGrm/fw < -0.1 ・ ・ ・ ・ ・ (6)
where
fGrm: focal length of the Grm group
fw: focal length at the wide-angle end of the zoom lens 6. The zoom lens according to claim 1, further comprising an aperture stop, and satisfying the following condition:
0.01 < Tsfw/fw < 5.0 ・ ・ ・ ・ ・ (7)
where
Tsfw: Distance between the aperture stop and the Grm group at the wide-angle end
fw: focal length at the wide-angle end of the zoom lens The zoom lens according to any one of claims 1 to 6, wherein the Grf group has at least two Grf concave lenses. The zoom lens according to any one of claims 1 to 7, wherein the Grf concave lens has a concave surface on the image side. The zoom lens according to any one of claims 1 to 8, wherein the Grf concave lens is a cemented lens. 10. The zoom lens according to claim 1, which satisfies the following condition:
42 < vdGrmn < 100 ・ ・ ・ ・ ・ ・ (3)
where
vdGrmn: the minimum Abbe number at the d line of a concave lens included in the Grm group The zoom lens according to any one of claims 1 to 10, wherein the Gr group has an anti-vibration lens system that moves in a direction perpendicular to the optical axis to change the imaging position. The zoom lens according to claim 11, wherein the vibration-proof lens system has a lens having at least one aspheric surface. 13. The zoom lens according to claim 11, which satisfies the following condition:
-10 < (1-β vc)× β vcr < -0.10 ・ ・ ・ (8)
Here, β vc is the lateral magnification of the vibration-proof lens system at the telephoto end, and β vcr is the combined lateral magnification of all lenses disposed on the image side of the vibration-proof lens system at the telephoto end. The zoom lens according to any one of claims 11 to 13, wherein the vibration-proof lens system is made of a single lens. the first lens group having a positive refractive power, the second lens group having a negative refractive power, and a Gr group having one or more lens groups and being positive as a whole,
the first lens group includes a concave lens,
the Gr group includes, in order from the object side, a Grf group, a negative Grm group, and a Grr group,
During zooming, the first lens group moves toward the object side,
During magnification change, a distance between the first lens group and the second lens group and a distance between the second lens group and the Gr group change,
During focusing, the distance between the first lens group and the second lens group, the distance between the second lens group and the Gr group, and the inside of the Grf group do not change,
During zooming and focusing, the insides of the first lens group, the second lens group, the Grm group, and the Grr group do not change,
When the magnification is changed, the distance between the Grf group and the Grm group and the distance between the Grm group and the Grr group change,
the Grf group includes a Grf convex lens disposed closest to the object side of the Grf group, and at least one Grf concave lens;
A zoom lens that satisfies the following conditions:
1.70 < ndGrfp < 2.50 ・ ・ ・ ・ ・ ・ (1)
1.90 < ndGrfn < 2.50 ・ ・ ・ ・ ・ ・ (2)
58.12 ≦ vdGrmn < 100 ・ ・ ・ ・ ・ ・ (3)
10.0 < vdGrfp < 30.0 ・ ・ ・ ・ ・ (4)
Where:
ndGrfp: the refractive index of the Grf convex lens at the d line
ndGrfn: the refractive index of the Grf concave lens at the d line
vdGrmn: the minimum Abbe number at the d line of a concave lens included in the Grm group
vdGrfp: Abbe number at d line of the Grf convex lens the first lens group having a positive refractive power, the second lens group having a negative refractive power, and a Gr group having one or more lens groups and being positive as a whole,
the first lens group includes a concave lens,
the Gr group includes, in order from the object side, a Grf group, a negative Grm group, and a Grr group,
During zooming, the first lens group moves toward the object side,
during zooming, a distance between the first lens group and the second lens group, and a distance between the second lens group and the Gr group are changed , and a distance between the Grf group and the Grm group, and a distance between the Grm group and the Grr group are not changed;
During zooming and focusing, the insides of the first lens group, the second lens group, the Grf group, the Grm group, and the Grr group do not change,
When focusing, the interval between the Grf group and the Grm group and the interval between the Grm group and the Grr group change,
the Grf group includes a Grf convex lens disposed closest to the object side of the Grf group, and at least one Grf concave lens;
A zoom lens that satisfies the following conditions:
1.70 < ndGrfp < 2.50 ・ ・ ・ ・ ・ ・ (1)
1.90 < ndGrfn < 2.50 ・ ・ ・ ・ ・ ・ (2)
58.12 ≦ vdGrmn < 100 ・ ・ ・ ・ ・ ・ (3)
10.0 < vdGrfp < 30.0 ・ ・ ・ ・ ・ (4)
Where:
ndGrfp: the refractive index of the Grf convex lens at the d line
ndGrfn: the refractive index of the Grf concave lens at the d line
vdGrmn: the minimum Abbe number at the d line of a concave lens included in the Grm group
vdGrfp: Abbe number at d line of the Grf convex lens An imaging device comprising the zoom lens according to any one of claims 1 to 16, and an imaging element provided on the image side of the zoom lens for converting an optical image formed by the zoom lens into an electrical signal.

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