JP2020030396A - Zoom lens and image capturing device - Google Patents

Abstract

To provide a downsized zoom lens capable of nicely suppressing variation of axial chromatic aberration from the wide-angle end to a middle zoom range and providing superior optical performance, and to provide an image capturing device having the same.SOLUTION: A zoom lens provided herein consists of, in order from the object side, a positive first lens group configured to be stationary while zooming, an intermediate group comprised of two or more movable lens groups configured to move while zooming, and a subsequent group having a lens group with an aperture stop disposed on the most object side. The intermediate group has at least two negative movable lens groups. The subsequent group includes at least one positive lens LA that satisfies predefined conditional expressions regarding its refractive index, Abbe number, and partial dispersion ratio.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, as a zoom lens used for a broadcast camera, a movie camera, a digital camera, and the like, a lens group having a positive refractive power and a moving lens group that moves during zooming in order from the most object side. There is known a type in which a rear group including a stop is arranged, and the entire length of the lens system remains unchanged during zooming. For example, Patent Literature 1 and Patent Literature 2 described below describe a zoom lens having a five-group or six-group configuration of the above type.

JP-A-2006-71141 JP-A-2006-109952

  The zoom lens used for the camera is required to be small and high-performance. In order to achieve a compact and high-performance configuration, it is important to correct the various aberrations while keeping the zoom space of the lens group that moves during zooming as short as possible, while minimizing the space for the subsequent unit. It is. At that time, in order to favorably correct the axial chromatic aberration on the wide-angle side, the arrangement of the refractive power and the material selection of the lens of the succeeding group are particularly important. If axial chromatic aberration is insufficiently corrected in the subsequent lens group, if axial chromatic aberration is corrected by the moving lens group on the object side of the subsequent lens group, fluctuation of axial chromatic aberration from the wide-angle end to the middle zoom range is suppressed. It becomes difficult to do.

  The lens system described in Patent Literature 1 has room for improvement in suppressing fluctuation of axial chromatic aberration from the wide-angle end to the middle zoom range. The lens system described in Patent Literature 2 also does not sufficiently suppress the fluctuation of the axial chromatic aberration from the wide-angle end to the middle zoom range, and the size of the entire system is also insufficient.

  The present disclosure has been made in view of the above circumstances. The problem to be solved by one embodiment of the present invention is to provide a zoom lens having high optical performance in which fluctuations in axial chromatic aberration are favorably suppressed from a wide-angle end to a middle zoom range while achieving miniaturization, and this zoom lens An object of the present invention is to provide an imaging device including

Specific means for solving the above problems include the following aspects.
<1> In order from the object side to the image side, the distance between the first lens group having a positive refractive power fixed to the image plane during zooming and an adjacent group during zooming , And an intermediate group consisting of two or more moving lens groups that move along the optical axis by changing the optical axis, and a subsequent group having a lens group including a stop closest to the object side, and at least two moving lenses in the intermediate group. The group has a negative refractive power, the subsequent group includes at least one positive lens, that is, an LA lens, and the refractive index at the d-line of the LA lens is NdA, the Abbe number of the LA lens based on the d-line is νdA, LA Assuming that the partial dispersion ratio between the g-line and the F-line of the lens is θgFA, the LA lens has 1.72 <NdA <1.84 (1)
43 <νdA <57 (2)
0.62 <θgFA + 0.001625 × νdA <0.66 (3)
2.21 <NdA + 0.01 × νdA (4)
A zoom lens satisfying conditional expressions (1), (2), (3), and (4) represented by:

<2> When the succeeding group includes at least one LA lens on the image side of the stop, and the LA lens located closest to the object side among the LA lenses on the image side of the stop is the most object side LA lens, When the distance on the optical axis between the diaphragm and the LA lens closest to the object side is LDW, and the distance on the optical axis between the diaphragm at the wide-angle end and the lens surface closest to the image is SDW,
0.005 <LDW / SDW <0.45 (5)
The zoom lens according to <1>, which satisfies conditional expression (5) represented by:

<3> The succeeding lens group includes at least one LB lens, which is at least one positive lens, on the image side of the most object side LA lens. The d-line-based Abbe number of the LB lens is νdB, and the LB lens is between the g line and the F line. When the partial dispersion ratio is set to θgFB, the LB lens has 65 <νdB <105 (6)
0.6355 <θgFB + 0.001625 × νdB <0.7 (7)
The zoom lens according to <2>, which satisfies conditional expressions (6) and (7) represented by:

<4> The focal length of the most object side LA lens is fA, the total number of LB lenses arranged on the image side of the most object side LA lens is k, and the focal length of the LB lens arranged on the image side of the most object side LA lens is the object side. Where i is the number assigned in order from, and fBi is the focal length of the ith LB lens from the object side among the LB lenses arranged on the image side of the most object side LA lens.

<3> is a zoom lens satisfying conditional expression (8).

<5> The zoom lens according to any one of <1> to <4>, wherein the lens disposed closest to the object side in the subsequent group is an LA lens.

<6> The zoom lens according to any one of <1> to <5>, wherein the object-side surface of at least one LA lens included in the subsequent group is a convex surface.

<7> The zoom lens according to any one of <1> to <6>, wherein focusing is performed by moving at least a part of the lenses in the first lens group along the optical axis.

<8> The zoom lens according to any one of <1> to <7>, wherein the most image-side moving lens group in the intermediate group has negative refractive power.

<9> The intermediate group consists of two moving lens groups having negative refractive power, and the succeeding group consists of lens groups having positive refractive power fixed to the image plane during zooming. 8> Zoom lens.

<10> The intermediate group is composed of two moving lens groups having negative refractive power, and the succeeding group changes the distance between adjacent groups during zooming in order from the object side to the image side. <8> The zoom lens according to <8>, comprising a lens group having a positive refractive power that moves along the optical axis and a lens group having a positive refractive power fixed to an image plane during zooming.

<11> The intermediate group consists of three moving lens groups having negative refractive power, and the succeeding group consists of lens groups having refractive power fixed to the image plane during zooming. <8> Zoom lens.

<12> The intermediate group consists of four moving lens groups having negative refractive power, and the succeeding group consists of lens groups having positive refractive power fixed to the image plane during zooming. 8> Zoom lens.

<13> The moving lens group having at least one negative refractive power in the intermediate group includes at least one LN lens which is a negative lens, wherein the refractive index at the d-line of the LN lens is Ndn, and the d-line reference of the LN lens is d-line. When the Abbe number of νdn is νdn and the partial dispersion ratio between the g-line and the F-line of the LN lens is θgFn, the LN lens has 1.72 <Ndn <1.8 (9)
43 <νdn <57 (10)
0.6355 <θgFn + 0.001625 × νdn <0.66 (11)
2.21 <Ndn + 0.01 × νdn (12)
The zoom lens according to any one of <1> to <12>, which satisfies conditional expressions (9), (10), (11), and (12).

<14> LA lens is further 45 <νdA <55 (2-1)
The zoom lens according to any one of <1> to <13>, which satisfies conditional expression (2-1) represented by:

<15> LA lens is further 0.637 <θgFA + 0.001625 × νdA <0.65 (3-1)
The zoom lens according to any one of <1> to <14>, which satisfies conditional expression (3-1) represented by:

<16> LA lens is 2.21 <NdA + 0.01 × νdA <2.33 (4-1)
The zoom lens according to any one of <1> to <15>, which satisfies conditional expression (4-1) represented by:

<17> 0.005 <LDW / SDW <0.2 (5-1)
The zoom lens according to <2>, which satisfies conditional expression (5-1) represented by:

<18>

The zoom lens according to <4>, which satisfies the conditional expression (8-1) represented by:

<19> An imaging apparatus including the zoom lens according to any one of <1> to <18>.

  In the present specification, “consisting of” and “consisting of” mean, in addition to the listed components, a lens having substantially no refractive power, and a lens such as a diaphragm, a filter, and a cover glass. It is intended that an optical element other than the above, and a lens flange, a lens barrel, an image sensor, a mechanical portion such as a camera shake correction mechanism, and the like may be included.

  In this specification, “having a positive refractive power to a group” means that the entire group has a positive refractive power. Similarly, “having a negative refractive power to a group” means that the group as a whole has a negative refractive power. “Lens having positive refractive power” and “positive lens” are synonymous. “Lens having negative refractive power” and “negative lens” are synonymous. The “lens group” is not limited to the configuration including a plurality of lenses, and may include a configuration including only one lens. In addition, “one lens group” is a lens group in which the distance in the optical axis direction between adjacent groups changes during zooming. That is, when the lens groups are divided at intervals that change during zooming, the lens groups included in one division are regarded as one lens group.

  A compound aspherical lens (a lens in which a spherical lens and an aspherical film formed on the spherical lens are integrally formed and functions as one aspherical lens as a whole) is regarded as a cemented lens. Instead, treat it as a single lens. The sign of the refractive power and the surface shape of the lens surface of the lens including the aspherical surface will be considered in the paraxial region unless otherwise specified.

  The “focal length” used in the conditional expression is a paraxial focal length. The value used in the conditional expression is a value based on the d-line in a state where an object at infinity is focused. The partial dispersion ratio θgF between the g-line and the F-line of a certain lens is θgF = (Ng−Ng) when the refractive indices of the lens with respect to the g-line, the F-line, and the C-line are Ng, NF, and NC, respectively. NF) / (NF-NC). The “d-line”, “C-line”, “F-line”, and “g-line” described in this specification are bright lines, the wavelength of the d-line is 587.56 nm (nanometers), and the wavelength of the C-line is 656. .27 nm (nanometers), the wavelength of the F line is 486.13 nm (nanometers), and the wavelength of the g line is 435.84 nm (nanometers).

  ADVANTAGE OF THE INVENTION According to one Embodiment of this invention, the zoom lens which has high optical performance by suppressing the fluctuation | variation of an axial chromatic aberration from the wide-angle end to the zoom intermediate | middle region, while miniaturizing, and imaging with this zoom lens An apparatus can be provided.

FIG. 2 is a diagram corresponding to the zoom lens of Example 1 of the present invention and showing a cross-sectional view and a movement locus of the configuration of a zoom lens according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a configuration and a light beam of the zoom lens illustrated in FIG. 1. FIG. 4 is a diagram illustrating a cross-sectional view and a movement locus of a configuration of a zoom lens according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of a configuration of a zoom lens according to a third embodiment of the present invention and a diagram illustrating a movement locus. FIG. 10 is a diagram illustrating a cross-sectional view of a configuration of a zoom lens according to a fourth embodiment of the present invention and a movement locus. It is a figure showing the section of the composition of the zoom lens of Example 5 of the present invention, and a locus of movement. FIG. 14 is a diagram illustrating a cross-sectional view and a movement locus of a configuration of a zoom lens according to a sixth embodiment of the present invention. FIG. 3 is an aberration diagram of the zoom lens according to the first embodiment of the present invention. FIG. 7 is an aberration diagram of the zoom lens according to the second embodiment of the present invention. FIG. 10 is an aberration diagram of the zoom lens according to Embodiment 3 of the present invention. FIG. 10 is an aberration diagram of the zoom lens according to Embodiment 4 of the present invention. It is each aberration figure of the zoom lens of Example 5 of this invention. It is each aberration figure of the zoom lens of Example 6 of this invention. It is a schematic structure figure of an imaging device concerning one embodiment of the present invention.

  Hereinafter, embodiments of the zoom lens of the present disclosure will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a configuration and a movement locus of a zoom lens according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a lens configuration and a light beam in each state of the zoom lens. The examples shown in FIGS. 1 and 2 correspond to a zoom lens of Example 1 described later. FIGS. 1 and 2 show a state in which an object at infinity is in focus. The left side is the object side, and the right side is the image side. FIG. 1 shows a wide-angle end state. In FIG. 2, the upper stage labeled “Wide Angle End” indicates the wide angle end state, the middle stage labeled “Middle” indicates the intermediate focal length state, and the lower stage labeled “Telephoto End” indicates the telephoto end state. In FIG. 2, as the light beam, the on-axis light beam wa and the light beam wb having the maximum angle of view in the wide-angle end state, the on-axis light beam ma and the light beam mb having the maximum angle of view in the intermediate focal length state, and the on-axis light beam ta and the maximum light beam in the telephoto end state. The luminous flux tb at the angle of view is shown.

  1 and 2, an example in which an optical member PP having an incident surface and an exit surface parallel to each other is disposed between the zoom lens and the image surface Sim, assuming that the zoom lens is applied to an imaging apparatus. Is shown. The optical member PP is a member assuming various filters, prisms, and / or cover glass, and the like. The various filters include, for example, a low-pass filter, an infrared cut filter, and a filter that cuts a specific wavelength range. The optical member PP is a member having no refractive power, and a configuration in which the optical member PP is omitted is also possible. Hereinafter, description will be made mainly with reference to FIG.

  The zoom lens according to an embodiment of the present disclosure includes a first lens group G1, an intermediate group Gm, and a subsequent group Gs in order from the object side to the image side along the optical axis Z. The first lens group G1 is a lens group fixed to the image plane Sim at the time of zooming and having a positive refractive power. The intermediate group Gm is composed of two or more moving lens groups that move along the optical axis Z while changing the distance between adjacent groups during zooming. That is, the intermediate group Gm includes two or more moving lens groups that move along the optical axis Z with different trajectories during zooming. At least two moving lens groups in the intermediate group Gm have negative refractive power. The succeeding group Gs has a lens group including the aperture stop St closest to the object side.

  By making the lens group closest to the object side a lens group having a positive refractive power, the overall length of the lens system (the distance on the optical axis from the lens surface closest to the object side to the image plane Sim) can be reduced, and the size can be reduced. This is advantageous. Further, by adopting a configuration in which the lens unit having the most positive refractive power on the object side is fixed at the time of zooming, the overall length of the lens system does not change at the time of zooming, and the fluctuation of the center of gravity of the lens system is reduced. Therefore, the convenience at the time of shooting can be improved. Further, by arranging two or more moving lens groups having negative refractive power on the object side with respect to the lens group including the aperture stop St, it is possible to disperse the refractive power of the negative moving lens group having a variable power operation. In addition, fluctuations in spherical aberration and chromatic aberration during zooming can be suppressed. This is advantageous for achieving both a high magnification and a reduction in the overall length of the lens system.

  The zoom lens of the example shown in FIG. 1 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. And a fourth lens group G4 having refractive power. During zooming, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane Sim. The second lens group G2 and the third lens group G3 are moving lens groups that move along the optical axis Z by changing the distance between adjacent groups during zooming. An aperture stop St is disposed closest to the object side of the fourth lens group G4. The aperture stop St shown in FIG. 1 does not indicate a shape, but indicates a position in the optical axis direction. In the example shown in FIG. 1, a group including the second lens group G2 and the third lens group G3 corresponds to the intermediate group Gm, and the fourth lens group G4 corresponds to the subsequent group Gs. In FIG. 1, the movement locus of each moving lens group when changing the magnification from the wide-angle end to the telephoto end is schematically indicated by an arrow below the moving lens group.

  In the example shown in FIG. 1, the first lens group G1 is composed of eleven lenses L1a to L1k in order from the object side to the image side, and the second lens group G2 is from the object side to the image side. The third lens group G3 is composed of two lenses L3a to L3b in order from the object side to the image side, and the fourth lens group G4 is composed of six lenses L2a to L2f. And an aperture stop St and nine lenses L4a to L4i in order from the object side to the image side. However, in the zoom lens according to the present disclosure, the number of lens groups constituting the intermediate group Gm and the succeeding group Gs, the number of lenses constituting each lens group, and the position of the aperture stop St are different from those in the example shown in FIG. It is also possible.

In the zoom lens of the present disclosure, the succeeding group Gs includes at least one positive lens LA lens LA. When the refractive index at the d-line of the LA lens LA is NdA, the Abbe number based on the d-line of the LA lens LA is νdA, and the partial dispersion ratio between the g-line and the F-line of the LA lens LA is θgFA, the LA lens LA is as follows. This lens satisfies conditional expressions (1), (2), (3), and (4).
1.72 <NdA <1.84 (1)
43 <νdA <57 (2)
0.62 <θgFA + 0.001625 × νdA <0.66 (3)
2.21 <NdA + 0.01 × νdA (4)

  The conditional expressions (1), (2), (3), and (4) are conditional expressions relating to the material of the LA lens LA. If the lower limit of conditional expression (1) is not exceeded, a material having a high refractive index can be selected, so that it is easy to satisfactorily correct spherical aberration on the wide-angle side while achieving downsizing and high magnification. Becomes By making an arrangement such that a value is not more than an upper limit of the conditional expression (1), a material having low dispersion can be selected. Therefore, it is easy to satisfactorily correct the axial chromatic aberration on the wide-angle side, and the axial on-axis extends from the wide-angle end to the middle zoom range. It becomes easy to suppress the fluctuation of the chromatic aberration.

By making sure that the lower limit of conditional expression (2) is not exceeded, it is possible to select a material with low dispersion, so that it is easy to favorably correct axial chromatic aberration on the wide-angle side, and to achieve axial on-axis from the wide-angle end to the middle zoom range. It becomes easy to suppress the fluctuation of the chromatic aberration. By making an arrangement such that a value is not more than an upper limit of the conditional expression (2), a material having a high refractive index can be selected. Therefore, it is easy to satisfactorily correct the spherical aberration on the wide-angle side while achieving downsizing and high magnification. Becomes If the configuration satisfies the following conditional expression (2-1), better characteristics can be obtained.
45 <νdA <55 (2-1)

By satisfying conditional expression (3), it becomes easy to satisfactorily correct the secondary axial chromatic aberration on the wide-angle side. If the configuration satisfies the following conditional expression (3-1), better characteristics can be obtained.
0.637 <θgFA + 0.001625 × νdA <0.65 (3-1)

By satisfying the above-mentioned conditional expressions (1) and (2) and not being below the lower limit of conditional expression (4), spherical aberration and on-axis on the wide-angle side can be achieved while achieving miniaturization and high magnification. It becomes easy to satisfactorily correct chromatic aberration. In order to select a suitable material that satisfies the conditional expressions (1) and (2) from existing optical materials, it is preferable that the following conditional expression (4-1) is satisfied.
2.21 <NdA + 0.01 × νdA <2.33 (4-1)

  For example, in the example shown in FIG. 1, the lens L4a corresponds to the LA lens LA. However, in the zoom lens according to the present disclosure, the LA lens LA may be different from the example shown in FIG.

  The lens disposed closest to the object side of the succeeding group Gs may be configured to be the LA lens LA. In this case, it is easy to satisfactorily correct the spherical aberration and the axial chromatic aberration on the wide-angle side while shortening the space of the succeeding group Gs.

  The object-side surface of at least one LA lens LA included in the succeeding group Gs is preferably a convex surface. In this case, it becomes easy to satisfactorily correct the spherical aberration on the wide-angle side while reducing the space of the succeeding group Gs.

  The succeeding group Gs may be configured to include an LA lens LA having at least one aspheric surface. In this case, it becomes easy to satisfactorily correct the spherical aberration on the wide-angle side.

  Further, it is preferable that the succeeding group Gs includes at least one LA lens LA on the image side of the aperture stop St. In this case, it is easy to achieve both the correction of the axial chromatic aberration on the wide-angle side and the correction of the chromatic aberration of magnification.

Hereinafter, the LA lens LA located closest to the object side among the LA lenses LA closer to the image than the aperture stop St will be referred to as the most object side LA lens. When at least one LA lens LA is arranged on the image side of the aperture stop St, the distance between the aperture stop St at the wide angle end and the most object side LA lens on the optical axis is LDW, and the aperture stop St at the wide angle end is When the distance on the optical axis from the lens surface closest to the image is SDW, it is preferable that the following conditional expression (5) is satisfied. By making an arrangement such that the lower limit of conditional expression (5) is not surpassed, it becomes easy to secure a space for providing an aperture stop mechanism for changing the aperture diameter of the aperture stop St in order to make the amount of incident light variable. By including at least one LA lens LA on the image side of the aperture stop St and by making sure that the upper limit of conditional expression (5) is not exceeded, it is easy to achieve both correction of longitudinal chromatic aberration and correction of lateral chromatic aberration on the wide-angle side. Become. If the configuration satisfies the following conditional expression (5-1), better characteristics can be obtained.
0.005 <LDW / SDW <0.45 (5)
0.005 <LDW / SDW <0.2 (5-1)

When at least one LA lens LA is arranged on the image side of the aperture stop St and the conditional expression (5) is satisfied, the succeeding group Gs is at least one positive lens on the image side of the most object side LA lens LA. It is preferable to include an LB lens which is a lens. When the Abbe number based on the d-line of the LB lens LB is νdB, and the partial dispersion ratio between the g-line and the F-line of the LB lens LB is θgFB, the LB lens LB satisfies the following conditional expressions (6) and (7). Lens.
65 <νdB <105 (6)
0.6355 <θgFB + 0.001625 × νdB <0.7 (7)

  The conditional expressions (6) and (7) are conditional expressions relating to the material of the LB lens LB. By satisfying conditional expression (6), it becomes easy to favorably correct primary axial chromatic aberration on the wide-angle side. Further, it is easy to achieve both the correction of the axial chromatic aberration on the wide-angle side and the correction of the chromatic aberration of magnification. By satisfying conditional expression (7), it becomes easy to satisfactorily correct the secondary axial chromatic aberration on the wide-angle side.

  Since the succeeding group Gs includes at least one LB lens LB on the image side of the most object side LA lens LA, the effect of correcting the axial chromatic aberration on the wide angle side by the LA lens LA, the axial chromatic aberration by the LB lens LB, Both effects of correcting lateral chromatic aberration can be obtained.

  For example, in the example shown in FIG. 1, the lens L4g and the lens L4i correspond to the LB lens LB. However, in the zoom lens of the present disclosure, the LB lens LB may be different from the example shown in FIG.

The focal length of the most object side LA lens LA is fA, the total number of LB lenses LB arranged on the image side of the most object side LA lens LA is k, and the total number of LB lenses LB arranged on the image side of the most object side LA lens is Assuming that the number given in order from the object side is i and the focal length of the i-th LB lens LB from the object side among the LB lenses LB arranged on the image side from the most object side LA lens LA is fBi, the following conditional expression It is preferable to satisfy (8). By satisfying conditional expression (8), it becomes easy to favorably correct primary axial chromatic aberration and secondary axial chromatic aberration on the wide-angle side. Further, it is easy to achieve both the axial chromatic aberration and the lateral chromatic aberration on the wide-angle side. If the configuration satisfies the following conditional expression (8-1), better characteristics can be obtained.

Further, it is preferable that at least one moving lens group having a negative refractive power in the intermediate group Gm includes at least one LN lens which is a negative lens. When the refractive index at the d-line of the LN lens LN is Ndn, the Abbe number based on the d-line of the LN lens LN is νdn, and the partial dispersion ratio between the g-line and the F-line of the LN lens LN is θgFn, the LN lens LN is This lens satisfies conditional expressions (9), (10), (11), and (12).
1.72 <Ndn <1.8 (9)
43 <νdn <57 (10)
0.6355 <θgFn + 0.001625 × νdn <0.66 (11)
2.21 <Ndn + 0.01 × νdn (12)

  The conditional expressions (9), (10), (11), and (12) are conditional expressions relating to the material of the LN lens LN. If the lower limit of conditional expression (9) is not exceeded, it is possible to select a material having a high refractive index, so that variations in various aberrations during zooming can be satisfactorily suppressed while achieving miniaturization and high magnification. It becomes easy to do. By making an arrangement such that a value is not more than an upper limit of conditional expression (9), a material having low dispersion can be selected, so that it becomes easy to favorably suppress a change in chromatic aberration during zooming.

By making an arrangement such that a value is not lower than a lower limit of the conditional expression (10), a material having a low dispersion can be selected. Therefore, it becomes easy to favorably suppress a change in chromatic aberration upon zooming. By making an arrangement such that a value is not more than an upper limit value of conditional expression (10), a material having a high refractive index can be selected. It becomes easy to do. If the configuration satisfies the following conditional expression (10-1), better characteristics can be obtained.
45 <νdn <55 (10-1)

By satisfying conditional expression (11), it becomes easy to favorably suppress the fluctuation of the secondary chromatic aberration at the time of zooming. If the configuration satisfies the following conditional expression (11-1), better characteristics can be obtained.
0.637 <θgFn + 0.001625 × νdn <0.65 (11-1)

By satisfying the above-mentioned conditional expressions (9) and (10) and making sure that the lower limit of conditional expression (12) is not surpassed, chromatic aberration during zooming is achieved while achieving miniaturization and high magnification. It becomes easy to favorably suppress fluctuations of various aberrations. In order to select a suitable material that satisfies the conditional expressions (9) and (10) from existing optical materials, it is preferable that the following conditional expression (12-1) is satisfied.
2.21 <Ndn + 0.01 × νdn <2.33 (12-1)

  For example, in the example shown in FIG. 1, the lens L2d corresponds to the LN lens LN. However, in the zoom lens of the present disclosure, the LN lens LN may be different from the example shown in FIG.

  It is preferable that the first lens group G1 includes a focus group that is a lens group that moves during focusing. That is, it is preferable that focusing is performed by moving at least a part of the lenses in the first lens group G1 along the optical axis Z. Since the first lens group G1 does not move at the time of zooming, if at least a part of the lenses in the first lens group G1 is used as the focus group, the image point of the focus group will not move at the time of zooming. In addition, it is possible to suppress a focus shift at the time of zooming.

The zoom lens according to an embodiment of the present disclosure preferably includes an image stabilizing group that is a lens group that performs image blur correction by moving in a direction that intersects the optical axis on the image side of the aperture stop St. In the configuration including the image stabilizing group, if the focal length of the image stabilizing group is fas and the focal length of the zoom lens at the telephoto end in a state in which an object at infinity is focused is fT, the following conditional expression (13) is satisfied. Is preferred. By making an arrangement such that the lower limit of conditional expression (13) is not exceeded, it becomes easy to suppress the fluctuation of the spherical aberration and the fluctuation of the axial chromatic aberration from the wide-angle end to the middle zoom range. When an optical vibration isolating mechanism is mounted on the device, the size of the device is easily increased, but it is advantageous to reduce the size of the device by making it not more than the upper limit of conditional expression (13).
0.1 <| fas / fT | <0.2 (13)

In the configuration including the image stabilizing group, if the focal length of the image stabilizing group is fas and the combined focal length of all the lenses on the image side of the longest air interval on the optical axis in the subsequent group Gs is fR, the following condition is satisfied. It is preferable to satisfy the expression (14). By making an arrangement such that the lower limit of conditional expression (14) is not surpassed, it becomes easy to suppress the fluctuation of the spherical aberration and the fluctuation of the axial chromatic aberration from the wide-angle end to the middle zoom range. When an optical vibration isolating mechanism is mounted on the device, the size of the device is likely to be increased. However, if the value does not exceed the upper limit of conditional expression (14), it is advantageous for miniaturization of the device.
0.5 <| fas / fR | <1.2 (14)

  The moving lens group closest to the image side in the intermediate group Gm preferably has a negative refractive power. In this case, when correcting the fluctuation of the image position at the time of zooming, it is possible to move to the image side on the telephoto side, and to secure the zoom stroke of the moving lens group mainly responsible for the zooming action. This facilitates miniaturization and high magnification.

  The intermediate group Gm and the succeeding group Gs can have the following configuration, for example. The intermediate group Gm includes two moving lens groups having negative refractive power, and the succeeding group Gs includes the aperture stop St and has positive refractive power fixed to the image plane Sim during zooming. It can be configured to include a lens group. In this case, the zoom stroke of the moving lens group is reduced, and the overall length of the lens system can be shortened, which is advantageous for miniaturization.

  Alternatively, the intermediate group Gm includes two moving lens groups having negative refractive power, and the succeeding group Gs includes, in order from the object side to the image side, the group including the aperture stop St and adjacent to each other during zooming. And a lens group having a positive refractive power that moves along the optical axis Z while changing the distance between the lens group and a lens group having a positive refractive power that is fixed with respect to the image plane Sim during zooming. Can be configured. In such a case, it is easy to reduce variations in various aberrations during downsizing, high magnification, and zooming. In the middle zoom region where the off-axis light flux is highest, the moving lens group having a positive refractive power including the aperture stop St can be extended toward the object side, so that the lens diameter of the first lens group G1 can be suppressed. This is advantageous for downsizing the first lens group G1.

  Alternatively, the intermediate group Gm includes a moving lens group having three negative refractive powers, and the succeeding group Gs includes the aperture stop St and has a refractive power fixed to the image plane Sim during zooming. It can be configured to include a lens group. In such a case, it is easy to reduce variations in various aberrations during downsizing, high magnification, and zooming. In particular, it is advantageous for suppressing the fluctuation of the curvature of field during zooming.

  Alternatively, the intermediate group Gm includes four moving lens groups having negative refractive power, and the subsequent group Gs includes the aperture stop St and has a positive refractive power fixed to the image plane Sim during zooming. It can be configured to include a lens group having In such a case, it is easy to reduce variations in various aberrations during downsizing, high magnification, and zooming. In particular, it is advantageous for suppressing the fluctuation of the field curvature and the fluctuation of the spherical aberration at the time of zooming.

  The above-described preferable configuration and possible configurations can be arbitrarily combined, and it is preferable that the configuration be selectively adopted as appropriate according to required specifications. According to the technology of the present disclosure, it is possible to achieve a zoom lens having high optical performance in which fluctuations in axial chromatic aberration are satisfactorily suppressed from the wide-angle end to the middle zoom range while reducing the size.

Next, numerical examples of the zoom lens according to the present invention will be described.
[Example 1]
FIG. 1 is a cross-sectional view illustrating the configuration of the zoom lens according to the first exemplary embodiment. The illustration method and configuration are the same as those described above, and a description thereof will be partially omitted. The zoom lens according to the first embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a positive refractive power. The intermediate group Gm includes a second lens group G2 and a third lens group G3. The succeeding group Gs includes a fourth lens group G4. At the time of zooming, the first lens group G1 and the fourth lens group G4 are fixed to the image plane Sim, and the second lens group G2 and the third lens group G3 are It moves along the optical axis Z while changing the interval.

  The first lens group G1 includes eleven lenses L1a to L1k in order from the object side to the image side. The second lens group G2 includes six lenses L2a to L2f in order from the object side to the image side. The third lens group G3 is composed of two lenses L3a and L3b in order from the object side to the image side. The fourth lens group G4 includes, in order from the object side to the image side, an aperture stop St and nine lenses L4a to L4i. The lens L4a corresponds to the LA lens LA. The lens L4g and the lens L4i correspond to the LB lens LB. The lens L2d corresponds to the LN lens LN. The focus group includes a lens L1e.

  Tables 1A and 1B show basic lens data of the zoom lens of Example 1, Table 2 shows specifications and variable surface spacing, and Table 3 shows aspheric coefficients. Tables 1A and 1B show basic lens data divided into two tables in order to avoid lengthening of one table. In Tables 1A and 1B, the column of Sn shows the surface number when the surface closest to the object side is the first surface and the number is increased one by one toward the image side, and the column of R is the column of each surface. The radius of curvature is shown, and the column of D shows the surface interval on the optical axis between each surface and the surface adjacent to the image side. The column of Nd shows the refractive index of each component with respect to the d-line, the column of νd shows the Abbe number of each component with respect to the d-line, and the column of θgF shows the g-line and F of each component. The partial dispersion ratio between lines is shown.

  In Tables 1A and 1B, the sign of the radius of curvature of the surface having the convex surface facing the object side is positive, and the sign of the radius of curvature of the surface having the convex surface facing the image side is negative. Table 1B also shows the aperture stop St and the optical member PP, and the field of the surface number corresponding to the aperture stop St describes the surface number and the term (St). The value in the lowermost column of D in Table 1B is the distance between the most image-side surface in the table and the image surface Sim. In Tables 1A and 1B, the variable surface spacing at the time of zooming is represented by the symbol DD [], and the number of the surface on the object side of this spacing is given in [] and entered in the D column. .

  Table 2 shows the zoom magnification Zr, focal length f, F number FNo. , The maximum total angle of view 2ω, and the value of the variable surface interval are shown on a d-line basis. (°) in the column of 2ω means that the unit is degree. In Table 2, the values of the wide-angle end state, the intermediate focal length state, and the telephoto end state are shown in columns labeled wide-angle end, middle, and telephoto end, respectively.

In Tables 1A and 1B, an asterisk (*) is attached to the surface number of the aspherical surface, and the numerical value of the paraxial radius of curvature is described in the column of the radius of curvature of the aspherical surface. In Table 3, the column of Sn shows the surface number of the aspherical surface, and the column of KA and Am (m is an integer of 3 or more) shows the numerical value of the aspherical coefficient for each aspherical surface. “E ± n” (n: integer) of the numerical values of the aspherical coefficients in Table 3 means “× 10 ^{± n} ”. KA and Am are aspherical coefficients in an aspherical surface expression represented by the following expression.
^{Zd = C × h 2 / {} 1+ (1-KA × C 2 × h 2) 1/2} + ΣAm × h m
However,
Zd: Aspherical depth (length of a perpendicular drawn from a point on the aspherical surface at height h to a plane perpendicular to the optical axis where the aspherical vertex contacts)
h: Height (distance from optical axis to lens surface)
C: reciprocal KA of the paraxial radius of curvature, Am: aspherical coefficient, and Σ in the aspherical expression means the sum of m.

  In the data of each table, degrees are used as the unit of angle, and mm (millimeter) is used as the unit of length. However, since the optical system can be used even if it is proportionally enlarged or reduced, other appropriate Units can also be used. Further, in the following tables, numerical values rounded by predetermined digits are described.

  FIG. 8 shows aberration diagrams of the zoom lens according to the first embodiment in a state where the zoom lens is focused on an object at infinity. FIG. 8 shows, from the left, spherical aberration, astigmatism, distortion, and chromatic aberration of magnification. In FIG. 8, the upper part labeled with the wide angle end shows the wide angle end state, the middle part with the middle part shows the intermediate focal length state, and the lower part with the telephoto end shows the telephoto end state. In the spherical aberration diagram, aberrations at the d-line, C-line, F-line, and g-line are indicated by a solid line, a long broken line, a short broken line, and a two-dot chain line, respectively. In the astigmatism diagram, the aberration at the d-line in the sagittal direction is indicated by a solid line, and the aberration at the d-line in the tangential direction is indicated by a short broken line. In the distortion diagram, the aberration at the d-line is indicated by a solid line. In the magnification chromatic aberration diagram, aberrations at the C line, the F line, and the g line are indicated by long dashed lines, short dashed lines, and two-dot chain lines, respectively. FNo. Denotes the F-number, and ω in the other aberration diagrams denotes the half angle of view.

  The symbols, meanings, description methods, and illustration methods of the respective data relating to the above-described first embodiment are the same in the following embodiments unless otherwise specified.

[Example 2]
FIG. 3 is a cross-sectional view illustrating the configuration of the zoom lens according to the second embodiment. The zoom lens according to the second embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a negative refractive power. The intermediate group Gm includes a second lens group G2, a third lens group G3, and a fourth lens group G4. The succeeding group Gs includes a fifth lens group G5. At the time of zooming, the first lens group G1 and the fifth lens group G5 are fixed with respect to the image plane Sim, and the second lens group G2, the third lens group G3, and the fourth lens group G4 Moves along the optical axis Z while changing the distance between adjacent lens groups.

  The first lens group G1 includes five lenses L1a to L1e in order from the object side to the image side. The second lens group G2 includes one lens of the lens L2a. The third lens group G3 includes five lenses L3a to L3e in order from the object side to the image side. The fourth lens group G4 includes, in order from the object side to the image side, three lenses L4a to L4c. The fifth lens group G5 includes, in order from the object side to the image side, an aperture stop St and 13 lenses L5a to L5m. The lens L5a corresponds to the LA lens LA. The lens L5d, the lens L5k, and the lens L5m correspond to the LB lens LB. The lens L3b corresponds to the LN lens LN. The focus group includes lenses L1c to L1e. The image stabilizing group includes lenses L5f to L5g.

  Table 4A and Table 4B show the basic lens data of the zoom lens of Example 2, Table 5 shows the specifications and the variable surface spacing, Table 6 shows the aspheric coefficients, and each aberration diagram in a state in which the zoom lens is focused on an object at infinity. As shown in FIG.

[Example 3]
FIG. 4 is a cross-sectional view illustrating the configuration of the zoom lens according to the third embodiment. The zoom lens according to the third embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. The intermediate group Gm includes a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. The succeeding group Gs includes a sixth lens group G6. During zooming, the first lens group G1 and the sixth lens group G6 are fixed with respect to the image plane Sim, and the second lens group G2, the third lens group G3, and the fourth lens group G4 The fifth lens group G5 moves along the optical axis Z while changing the distance between adjacent lens groups.

  The first lens group G1 includes five lenses L1a to L1e in order from the object side to the image side. The second lens group G2 includes one lens of the lens L2a. The third lens group G3 includes four lenses L3a to L3d in order from the object side to the image side. The fourth lens group G4 is composed of two lenses L4a and L4b in order from the object side to the image side. The fifth lens group G5 includes, in order from the object side to the image side, two lenses L5a and L5b. The sixth lens group G6 includes, in order from the object side to the image side, an aperture stop St and ten lenses L6a to L6j. The lens L6a corresponds to the LA lens LA. The lens L6b and the lens L6h correspond to the LB lens LB. The lens L4a corresponds to the LN lens LN. The focus group includes lenses L1c to L1e. The image stabilizing group includes lenses L6d to L6e.

  Table 7 shows the basic lens data of the zoom lens of Example 3, Table 8 shows the specifications and the variable surface spacing, Table 9 shows the aspherical coefficients, and FIG. 10 shows the aberration charts when focusing on an object at infinity. Show.

[Example 4]
FIG. 5 is a sectional view showing the configuration of the zoom lens according to the fourth embodiment. The zoom lens according to the fourth embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power. The intermediate group Gm includes a second lens group G2 and a third lens group G3. The succeeding group Gs includes a fourth lens group G4 and a fifth lens group G5. At the time of zooming, the first lens group G1 and the fifth lens group G5 are fixed with respect to the image plane Sim, and the second lens group G2, the third lens group G3, and the fourth lens group G4 Moves along the optical axis Z while changing the distance between adjacent lens groups.

  The first lens group G1 includes six lenses L1a to L1f in order from the object side to the image side. The second lens group G2 includes six lenses L2a to L2f in order from the object side to the image side. The third lens group G3 is composed of two lenses L3a and L3b in order from the object side to the image side. The fourth lens group G4 includes, in order from the object side to the image side, an aperture stop St and four lenses L4a to L4d. The fifth lens group G5 includes six lenses L5a to L5f in order from the object side to the image side. The lens L4b corresponds to the LA lens LA. The lens L5b corresponds to the LB lens LB. The first focus group includes lenses L1d to L1e, and the second focus group includes lenses L1f. During focusing, the first focus group and the second focus group have different trajectories along the optical axis Z. Move along.

  Table 10 shows basic lens data of the zoom lens of Example 4, Table 11 shows specifications and variable surface spacing, Table 12 shows aspherical coefficients, and FIG. 11 shows aberration diagrams when focusing on an object at infinity. Show.

[Example 5]
FIG. 6 is a cross-sectional view illustrating the configuration of the zoom lens according to the fifth embodiment. The zoom lens according to the fifth embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a positive refractive power. The intermediate group Gm includes a second lens group G2 and a third lens group G3. The succeeding group Gs includes a fourth lens group G4. At the time of zooming, the first lens group G1 and the fourth lens group G4 are fixed to the image plane Sim, and the second lens group G2 and the third lens group G3 are It moves along the optical axis Z while changing the interval.

  The first lens group G1 includes eight lenses L1a to L1h in order from the object side to the image side. The second lens group G2 includes four lenses L2a to L2d in order from the object side to the image side. The third lens group G3 is composed of two lenses L3a and L3b in order from the object side to the image side. The fourth lens group G4 includes, in order from the object side to the image side, an aperture stop St and nine lenses L4a to L4i. The lens L4f corresponds to the LA lens LA. The lens L4g corresponds to the LB lens LB. The focus group includes lenses L1d to L1e.

  Table 13 shows the basic lens data of the zoom lens of Example 5, Table 14 shows the specifications and the variable surface spacing, Table 15 shows the aspherical coefficients, and FIG. 12 shows the aberration diagrams when the object is focused on an object at infinity. Show.

[Example 6]
FIG. 7 is a sectional view showing the configuration of the zoom lens according to the sixth embodiment. The zoom lens according to the sixth embodiment has, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a negative refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. The intermediate group Gm includes a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. The succeeding group Gs includes a sixth lens group G6. During zooming, the first lens group G1 and the sixth lens group G6 are fixed with respect to the image plane Sim, and the second lens group G2, the third lens group G3, and the fourth lens group G4 The fifth lens group G5 moves along the optical axis Z while changing the distance between adjacent lens groups.

  The first lens group G1 includes five lenses L1a to L1e in order from the object side to the image side. The second lens group G2 includes one lens of the lens L2a. The third lens group G3 includes four lenses L3a to L3d in order from the object side to the image side. The fourth lens group G4 is composed of two lenses L4a and L4b in order from the object side to the image side. The fifth lens group G5 includes, in order from the object side to the image side, two lenses L5a and L5b. The sixth lens group G6 includes, in order from the object side to the image side, an aperture stop St and twelve lenses L6a to L61. The lens L6a corresponds to the LA lens LA. The lens L6b and the lens L6c correspond to the LB lens LB. The lens L4a corresponds to the LN lens LN. The focus group includes lenses L1c to L1e. The image stabilizing group includes lenses L6e to L6f.

  Table 16A and Table 16B show the basic lens data of the zoom lens of Example 6, Table 17 shows the specifications and the variable surface spacing, Table 18 shows the aspherical coefficients, and each aberration diagram in a state of focusing on an object at infinity. As shown in FIG.

  Table 19 shows corresponding values of the conditional expressions (1) to (12) of the zoom lenses of Examples 1 to 6. Examples 1 to 6 are based on the d-line. Table 19 shows the values based on the d-line. In addition, below the corresponding values of the conditional expressions (6) and (7), the sign of the corresponding LB lens LB is written in parentheses.

  As can be seen from the above data, the zoom lenses of Examples 1 to 6 are reduced in size, have a magnification of 5 times or more, have relatively high magnification, and vary in axial chromatic aberration from the wide-angle end to the middle zoom range. Is suppressed well to realize high optical performance.

  Next, an imaging device according to an embodiment of the present invention will be described. FIG. 14 is a schematic configuration diagram of an imaging device 100 using the zoom lens 1 according to the embodiment of the present invention as an example of the imaging device of the embodiment of the present invention. Examples of the imaging device 100 include a broadcast camera, a movie shooting camera, a video camera, and a surveillance camera.

  The imaging device 100 includes a zoom lens 1, a filter 2 disposed on the image side of the zoom lens 1, and an image sensor 3 disposed on the image side of the filter 2. In FIG. 14, a plurality of lenses included in the zoom lens 1 are schematically illustrated.

  The imaging element 3 converts an optical image formed by the zoom lens 1 into an electric signal, and for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) can be used. The image sensor 3 is arranged so that its image plane coincides with the image plane of the zoom lens 1.

  The imaging device 100 also includes a signal processing unit 5 that performs arithmetic processing on an output signal from the imaging element 3, a display unit 6 that displays an image formed by the signal processing unit 5, and a zoom unit that controls zooming of the zoom lens 1. And a double control unit 7. In FIG. 14, only one image sensor 3 is shown, but a so-called three-plate image sensor having three image sensors may be used.

  As described above, the technology of the present disclosure has been described with reference to the embodiments and the examples. However, the technology of the present disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, the surface interval, the refractive index, the Abbe number, the aspheric coefficient, and the like of each lens are not limited to the values shown in each of the numerical examples, and may take other values.

REFERENCE SIGNS LIST 1 zoom lens 2 filter 3 imaging element 5 signal processing unit 6 display unit 7 variable power control unit 100 imaging device G1 first lens group G2 second lens group G3 third lens group G4 fourth lens group G5 fifth lens group G6 Six-lens group Gm Intermediate group Gs Subsequent groups L1a to L61 Lens LA LA lens LB LB lens LN LN Lens ma, ta, wa On-axis light flux mb, tb, wb Light flux PP with maximum field angle PP Optical member Sim Image surface St Aperture stop Z optical axis

Claims (19)

In order from the object side to the image side, the distance between the first lens group having a positive refractive power fixed to the image plane during zooming and an adjacent group during zooming is changed. An intermediate group consisting of two or more moving lens groups moving along the optical axis, and a subsequent group having a lens group including a diaphragm closest to the object side,
At least two of the moving lens groups in the intermediate group have negative refractive power;
The subsequent group includes at least one positive lens, an LA lens;
The refractive index at the d-line of the LA lens is NdA;
The d-line-based Abbe number of the LA lens is νdA,
When the partial dispersion ratio between the g-line and the F-line of the LA lens is θgFA,
1.72 <NdA <1.84 (1)
43 <νdA <57 (2)
0.62 <θgFA + 0.001625 × νdA <0.66 (3)
2.21 <NdA + 0.01 × νdA (4)
A zoom lens satisfying conditional expressions (1), (2), (3), and (4) represented by: The subsequent group includes at least one LA lens on the image side of the stop;
When the LA lens located closest to the object side among the LA lenses closer to the image side than the aperture is the most object side LA lens,
The distance on the optical axis between the stop and the most object side LA lens at the wide angle end is LDW,
When the distance on the optical axis between the stop and the lens surface closest to the image at the wide-angle end is SDW,
0.005 <LDW / SDW <0.45 (5)
The zoom lens according to claim 1, wherein conditional expression (5) is satisfied. The subsequent group includes an LB lens that is at least one positive lens closer to the image side than the most object side LA lens;
The d-line based Abbe number of the LB lens is νdB,
When the partial dispersion ratio between the g-line and the F-line of the LB lens is θgFB,
The LB lens is 65 <νdB <105 (6)
0.6355 <θgFB + 0.001625 × νdB <0.7 (7)
The zoom lens according to claim 2, satisfying conditional expressions (6) and (7) represented by the following expressions. The focal length of the most object side LA lens is fA,
The total number of the LB lenses arranged on the image side of the most object side LA lens is k,
The numbers assigned in order from the object side to the LB lens arranged on the image side from the most object side LA lens are i,
When the focal length of the i-th LB lens from the object side among the LB lenses disposed on the image side of the most object side LA lens is fBi,

The zoom lens according to claim 3, wherein conditional expression (8) represented by the following expression is satisfied.   The zoom lens according to any one of claims 1 to 4, wherein a lens disposed closest to the object side of the subsequent group is the LA lens.   The zoom lens according to claim 1, wherein an object-side surface of at least one of the LA lenses included in the subsequent group is a convex surface.   The zoom lens according to any one of claims 1 to 6, wherein focusing is performed by moving at least a part of the lenses in the first lens group along an optical axis.   The zoom lens according to any one of claims 1 to 7, wherein the movable lens group closest to the image in the intermediate group has a negative refractive power. The intermediate group comprises the moving lens group having two negative refractive powers,
9. The zoom lens according to claim 8, wherein the subsequent group comprises a lens group having a positive refractive power fixed to an image plane during zooming. The intermediate group comprises the moving lens group having two negative refractive powers,
The subsequent group is a lens group having a positive refractive power that moves along the optical axis by changing the interval between adjacent groups at the time of zooming, in order from the object side to the image side, 9. The zoom lens according to claim 8, comprising a lens group having a positive refractive power fixed to an image plane. The intermediate group comprises the moving lens group having three negative refractive powers,
9. The zoom lens according to claim 8, wherein the subsequent group comprises a lens group having a refractive power fixed to an image plane during zooming. The intermediate group comprises the moving lens group having four negative refractive powers,
9. The zoom lens according to claim 8, wherein the subsequent group comprises a lens group having a positive refractive power fixed to an image plane during zooming. The moving lens group having at least one negative refractive power in the intermediate group includes an LN lens that is at least one negative lens;
The refractive index at the d-line of the LN lens is Ndn,
The d-line-based Abbe number of the LN lens is νdn,
When the partial dispersion ratio between the g-line and the F-line of the LN lens is θgFn,
The LN lens is 1.72 <Ndn <1.8 (9)
43 <νdn <57 (10)
0.6355 <θgFn + 0.001625 × νdn <0.66 (11)
2.21 <Ndn + 0.01 × νdn (12)
The zoom lens according to any one of claims 1 to 12, which satisfies conditional expressions (9), (10), (11), and (12) represented by the following expressions. The LA lens may further satisfy 45 <νdA <55 (2-1)
The zoom lens according to any one of claims 1 to 13, which satisfies conditional expression (2-1) represented by the following expression. 0.637 <θgFA + 0.001625 × νdA <0.65 (3-1)
The zoom lens according to any one of claims 1 to 14, which satisfies conditional expression (3-1) represented by: The LA lens further satisfies 2.21 <NdA + 0.01 × νdA <2.33 (4-1)
The zoom lens according to any one of claims 1 to 15, which satisfies conditional expression (4-1) represented by: 0.005 <LDW / SDW <0.2 (5-1)
The zoom lens according to claim 2, wherein conditional expression (5-1) represented by the following expression is satisfied.
The zoom lens according to claim 4, wherein conditional expression (8-1) represented by the following expression is satisfied.   An imaging apparatus comprising the zoom lens according to claim 1.