WO2019097717A1

WO2019097717A1 - Variable magnification optical system, optical device, and manufacturing method of variable magnification optical system

Info

Publication number: WO2019097717A1
Application number: PCT/JP2017/041637
Authority: WO
Inventors: 幸介町田
Original assignee: 株式会社ニコン
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2019-05-23
Also published as: JP2023164939A; JPWO2019097717A1; JP7351390B2; JP2022174298A

Abstract

This variable magnification optical system comprises multiple lens groups, and the intervals between the lens groups change during variable magnification. The multiple lens groups include an object-side focusing lens group which moves during focusing, and at least one image-side focusing lens group which is arranged on the image side of the object-side focusing lens group and which during focusing moves on a trajectory different from that of the object-side focusing lens group. By satisfying a prescribed conditional expression, the variable magnification optical system favorably suppresses aberration fluctuation when changing magnification from a wide-angle end state to a telephoto end state and aberration fluctuation when focusing from an object at infinity to an object at close range.

Description

Variable power optical system, optical device, and method of manufacturing variable power optical system

The present invention relates to a variable magnification optical system, an optical device, and a method of manufacturing the variable magnification optical system.

Heretofore, there have been proposed variable magnification optical systems suitable for photographic cameras, electronic still cameras, video cameras and the like. See, for example, Japanese Patent Laid-Open No. 2004-198529. However, in the conventional variable magnification optical system, it is not sufficient to suppress the fluctuation of various aberrations at the time of focusing.

Unexamined-Japanese-Patent No. 2004-198529

The first aspect of the present invention is
Have multiple lens groups,
During zooming, the distance between the lens units changes,
The plurality of lens units are disposed on the image side of the object-side focusing lens unit that moves when focusing and the object-side focusing lens unit, and a locus that is different from the object-side focusing lens unit when focusing And at least one image-side focusing lens group that moves
It is a variable power optical system that satisfies the following conditional expression.
MTF1 / MTF2 <5.0
0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system

Further, according to a second aspect of the present invention,
A method of manufacturing a variable magnification optical system having a plurality of lens groups, comprising:
The distance between the lens units is changed during zooming.
The plurality of lens units are disposed on the image side of the object-side focusing lens unit moving in focusing and the image-side focusing lens unit, and a locus different from the object-side focusing lens unit in focusing And at least one image-side focusing lens group that moves at
This is a manufacturing method of a variable magnification optical system configured to satisfy the following conditional expression.
MTF1 / MTF2 <5.0
0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system

FIG. 1 is a cross-sectional view of the variable magnification optical system according to the first example. FIGS. 2A, 2B, and 2C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the first example, respectively. FIGS. 3A, 3B, and 3C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the first example. FIG. 4 is a cross-sectional view of a variable magnification optical system according to a second example. FIGS. 5A, 5B, and 5C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the second example, respectively. FIGS. 6A, 6B, and 6C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the second example. FIG. 7 is a cross-sectional view of the variable magnification optical system according to the third example. FIGS. 8A, 8B, and 8C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the third example, respectively. FIGS. 9A, 9B, and 9C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the third example. FIG. 10 is a cross-sectional view of the variable magnification optical system according to the fourth example. FIGS. 11A, 11B, and 11C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fourth example. 12A, 12B, and 12C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fourth example. FIG. 13 is a cross-sectional view of the variable magnification optical system according to the fifth example. FIG. 14A, FIG. 14B, and FIG. 14C are various aberration diagrams at the time of infinity object focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fifth example. FIG. 15A, FIG. 15B, and FIG. 15C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fifth example. FIG. 16 is a cross-sectional view of the variable magnification optical system according to the sixth example. FIGS. 17A, 17B, and 17C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the sixth example. 18A, 18B, and 18C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the sixth example. FIG. 19 is a cross-sectional view of a variable magnification optical system according to a seventh example. FIGS. 20A, 20B, and 20C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively, of the zoom optical system according to the seventh example. FIGS. 21A, 21B, and 21C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the seventh example. FIG. 22 is a cross-sectional view of a variable magnification optical system according to an eighth example. FIGS. 23A, 23B, and 23C show various aberrations of the variable magnification optical system of the eighth embodiment at the wide-angle end state, at the intermediate focal length state, and at the telephoto end state when focusing on infinity. FIGS. 24A, 24B, and 24C show various aberrations of the variable magnification optical system according to Example 8 at the wide-angle end, at the intermediate focal length, and at the telephoto end when focusing on short-distance objects. FIG. 25 is a cross-sectional view of the variable magnification optical system according to the ninth example. FIGS. 26A, 26B, and 26C are aberration diagrams at the time of focusing on an infinite object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively, of the variable magnification optical system according to the ninth example. FIGS. 27A, 27B, and 27C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the ninth example. FIG. 28 is a cross-sectional view of the variable magnification optical system according to the tenth example. FIGS. 29A, 29B, and 29C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the tenth example. FIGS. 30A, 30B, and 30C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the tenth example. FIG. 31 is a cross-sectional view of a variable magnification optical system according to an eleventh example. FIGS. 32A, 32B, and 32C are aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to Example 11. FIGS. 33A, 33B, and 33C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to Example 11. FIG. 34 is a view showing the configuration of a camera provided with a variable magnification optical system. FIG. 35 is a flowchart schematically showing a method of manufacturing a variable magnification optical system.

Hereinafter, a variable magnification optical system, an optical device, and a method of manufacturing the variable magnification optical system according to the present embodiment will be described.
The variable magnification optical system according to the present embodiment has a plurality of lens units, and the distance between the lens units changes at the time of zooming, and the plurality of lens units move at the time of focusing. And at least one image-side focusing lens group disposed on the image side of the object-side focusing lens group and moving along a locus different from that of the object-side focusing lens group at the time of focusing; It is comprised so that conditional expression (1) and (2) may be satisfied.
(1) MTF1 / MTF2 <5.0
(2) 0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system

The variable magnification optical system of the present embodiment has a plurality of lens groups, and changes the distance between the lens groups at the time of zooming from the wide-angle end state to the telephoto end state, thereby achieving good aberration correction at the time of zooming. Can be Further, in the variable magnification optical system of the present embodiment, an object side focusing lens group in which a plurality of lens groups move when focusing from an infinite distance object to a near distance object and an image side from the object side focusing lens group And at least one image-side focusing lens group that moves on a different trajectory from the object-side focusing lens group at the time of focusing, whereby focusing from an infinite distance object to a near distance object is performed. Variations of various aberrations including spherical aberration can be effectively suppressed.
The lens group refers to a portion having at least one lens separated by an air gap. The lens component means a single lens or a cemented lens.

Conditional expression (1) is an absolute value of the amount of movement of the object-side focusing lens unit in focusing from an infinite distance object to a close distance object in the telephoto end state, and an infinite distance object to the near distance object in the telephoto end state This defines the ratio to the absolute value of the movement amount of the focusing lens unit disposed closest to the object side in the image side focusing lens unit at the time of focusing. By satisfying the conditional expression (1), the variable magnification optical system according to the present embodiment can effectively suppress the fluctuation of spherical aberration at the time of focusing from an infinite distance object to a close distance object.

When the corresponding value of the conditional expression (1) of the variable magnification optical system according to the present embodiment exceeds the upper limit value, object side focusing with respect to the focusing lens group disposed closest to the object among the image side focusing lens groups. The amount of movement of the lens unit becomes too large, and it becomes difficult to correct the variation of the spherical aberration at the time of focusing from an infinite distance object to a close distance object. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (1) to 4.7. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the upper limit of conditional expression (1) to 4.5. Further, it is preferable to set the upper limit value of conditional expression (1) to 4.0, further 3.5, further 2.8, and further 2.4.

Moreover, in order to secure the effect of the present embodiment, the conditional expression (1) is
2.0 <MTF1 / MTF2 <5.0
It is preferable to By setting the lower limit value of the conditional expression (1) to 2.0 as described above, it is possible to more effectively suppress the variation of the spherical aberration at the time of focusing.

Conditional expression (2) defines the ratio between the back focus of the variable magnification optical system in the wide angle end state and the focal length of the variable magnification optical system in the wide angle end state. By satisfying the conditional expression (2), the variable magnification optical system according to the present embodiment can effectively correct various aberrations including coma aberration in the wide-angle end state.
The back focus is the distance on the optical axis from the lens surface closest to the image to the image plane.

When the corresponding value of the conditional expression (2) of the variable magnification optical system according to this embodiment exceeds the upper limit value, the back focus in the wide angle end state becomes large with respect to the focal length in the wide angle end state. It will be difficult to correct the initial aberrations. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (2) to 1.70. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (2) to 1.40. Further, it is preferable to set the upper limit value of conditional expression (2) to 1.20, further 1.00, and further 0.80.

On the other hand, when the corresponding value of the conditional expression (2) of the variable magnification optical system of the present embodiment falls below the lower limit, the back focus in the wide angle end becomes smaller than the focal length in the wide angle end. It is difficult to correct various aberrations including the aberration. In addition, it becomes difficult to arrange the mechanical members of the lens barrel. In addition, the effect of this embodiment can be made more reliable by setting the lower limit of conditional expression (2) to 0.30. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (2) to 0.40. Further, it is preferable to set the lower limit value of conditional expression (2) to 0.45, further 0.50, further 0.55, and further 0.60.
With the above configuration, it is possible to favorably suppress the fluctuation of aberration at the time of zooming from the wide-angle end state to the telephoto end state, and the fluctuation of various aberrations at the time of focusing from an infinity object to a near distance object System can be realized.

In the zoom lens system of the present embodiment, at least one focusing lens group of the object-side focusing lens group and the image-side focusing lens group has a lens having at least one negative refractive power, and It is desirable to satisfy conditional expression (3) of
(3) 0.45 <(-fFN) / | fF | <1.70
However,
fFN: Of the lenses in the object-side focusing lens group and the image-side focusing lens group, the focal length fF of the lens having the strongest negative refractive power: the object-side focusing lens group and the image-side focusing Of the lens units, the focal length of the focusing lens unit with the highest refractive power

In the zoom lens system of the present embodiment, at least one focusing lens group of the object-side focusing lens group and the image-side focusing lens group has a lens having at least one negative refractive power, thereby achieving infinite distance. It is possible to suppress the variation of spherical aberration and chromatic aberration at the time of focusing from an object to a near distance object.
The conditional expression (3) shows the focal length of the lens having the strongest negative refractive power among the lenses in the object side focusing lens group and the image side focusing lens group, the object side focusing lens group and the image side Among the focusing lens groups, the ratio to the focal length of the focusing lens group having the strongest refractive power is defined. By satisfying the conditional expression (3), the variable magnification optical system according to the present embodiment can suppress fluctuations of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object. it can.

When the corresponding value of the conditional expression (3) of the variable magnification optical system of the present embodiment exceeds the upper limit value, the focusing lens group having the strongest refractive power among the object side focusing lens group and the image side focusing lens group The refractive power becomes too strong, and it becomes difficult to suppress fluctuations of various aberrations including spherical aberration when focusing from an infinite distance object to a close distance object. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (3) to 1.60. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the upper limit of conditional expression (3) to 1.50. Further, it is preferable to set the upper limit value of conditional expression (3) to 1.40, further 1.30, and further 1.25.

On the other hand, when the corresponding value of the conditional expression (3) of the variable magnification optical system of the present embodiment falls below the lower limit value, the most negative refraction among the lenses in the object side focusing lens group and the image side focusing lens group The refractive power of the lens with strong power becomes too strong, and it becomes difficult to suppress the fluctuation of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object. In addition, the effect of the present embodiment can be made more reliable by setting the lower limit value of the conditional expression (3) to 0.47. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (3) to 0.50. Further, it is preferable to set the lower limit value of conditional expression (3) to 0.54, further preferably 0.60.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the object side focusing lens unit have a positive refractive power. With this configuration, it is possible to suppress fluctuations of various aberrations including spherical aberration when focusing from an infinite distance object to a close distance object.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the focusing lens unit disposed closest to the image side among the image side focusing lens units have positive refractive power. With this configuration, it is possible to suppress fluctuations of various aberrations including spherical aberration when focusing from an infinite distance object to a close distance object.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the object-side focusing lens unit be configured of one or two lens components. With this configuration, the focusing lens unit can be reduced in size and weight.

Further, in the variable magnification optical system according to the present embodiment, it is desirable that the image side focusing lens unit be constituted by one or two lens components. With this configuration, the focusing lens unit can be reduced in size and weight.

Further, it is desirable that the variable magnification optical system of the present embodiment has the first lens group fixed at the time of focusing on the most object side. By this configuration, the enlargement of the lens barrel can be suppressed.

Further, in the zoom lens system of the present embodiment, at least one focusing lens group of the object-side focusing lens group and the image-side focusing lens group has a lens having at least one negative refractive power. It is desirable to satisfy the following conditional expression (4).
(4) 0.65 <nP / nN <1.10
However,
nP: Of the lenses in the object side focusing lens group and the image side focusing lens group, the refractive index nN of the lens having the most positive refractive power: the object side focusing lens group and the image side focusing Of the lenses in the lens group, the refractive index of the lens with the strongest negative refractive power

In the zoom lens system of the present embodiment, at least one focusing lens group of the object-side focusing lens group and the image-side focusing lens group has a lens having at least one negative refractive power, thereby achieving infinite distance. It is possible to suppress the variation of spherical aberration and chromatic aberration at the time of focusing from an object to a near distance object.
The conditional expression (4) shows the refractive index of the lens having the most positive refractive power among the lenses in the object side focusing lens group and the image side focusing lens group, the object side focusing lens group and the image side Among the lenses in the focusing lens group, it defines the ratio to the refractive index of the lens having the strongest negative refractive power. By satisfying the conditional expression (4), the variable magnification optical system according to the present embodiment can suppress fluctuations of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object. it can.

When the corresponding value of the conditional expression (4) of the variable magnification optical system of the present embodiment exceeds the upper limit value, the most positive refractive power of the lenses in the object side focusing lens group and the image side focusing lens group is obtained. The positive refractive power of a strong lens becomes too strong, and it becomes difficult to suppress fluctuations of various aberrations including spherical aberration when focusing from an infinite distance object to a near distance object. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (4) to 1.05. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (4) to 1.03. Further, it is preferable to set the upper limit value of conditional expression (4) to 1.00, and further to 0.95.

On the other hand, when the corresponding value of the conditional expression (4) of the variable magnification optical system of the present embodiment falls below the lower limit value, the most negative refraction among the lenses in the object side focusing lens group and the image side focusing lens group The negative refracting power of the lens with strong power becomes too strong, and it becomes difficult to suppress the fluctuation of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a near distance object. In addition, the effect of the present embodiment can be made more reliable by setting the lower limit value of the conditional expression (4) to 0.67. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (4) to 0.70. Further, it is preferable to set the lower limit value of conditional expression (4) to 0.75, further to 0.80, and further to 0.83.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the following conditional expression (5) be satisfied.
(5) 0.40 <| fF1 | / | f1 | <2.60
However,
fF1: focal length of the object side focusing lens unit f1: focal length of the first lens unit

Conditional expression (5) defines the ratio of the focal length of the object side focusing lens unit to the focal length of the first lens unit. By satisfying the conditional expression (5), the variable magnification optical system according to the present embodiment effectively changes the various aberrations including the spherical aberration when focusing from an infinite distance object to a close distance object. It is possible to suppress fluctuations of various aberrations including spherical aberration at the time of zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (5) of the variable magnification optical system of the present embodiment exceeds the upper limit, the refractive power of the first lens group becomes strong, and the spherical surface at the time of zooming from the wide-angle end state to the telephoto end state. It becomes difficult to suppress the fluctuation of various aberrations including the aberration. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (5) to 2.55. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (5) to 2.50. Further, it is preferable to set the upper limit value of conditional expression (5) to 2.30, and further to 2.10.

On the other hand, when the corresponding value of the conditional expression (5) of the variable magnification optical system of the present embodiment falls below the lower limit, the refractive power of the object side focusing lens unit becomes strong, and focusing from an infinite distance object to a near distance object It is difficult to suppress fluctuations of various aberrations including the spherical aberration at the time of. In addition, the effect of the present embodiment can be made more reliable by setting the lower limit value of the conditional expression (5) to 0.45. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (5) to 0.47. Further, it is preferable to set the lower limit value of conditional expression (5) to 0.50, further 0.55, and further 0.60.

Further, it is desirable that the variable magnification optical system of the present embodiment satisfy the following conditional expression (6).
(6) 0.20 <| fF2 | / | f1 <3.80
However,
fF2: Focal length f1 of the focusing lens group disposed closest to the image side among the image-side focusing lens groups f1: Focal length of the first lens group

Conditional expression (6) defines the ratio of the focal length of the focusing lens unit disposed closest to the image side of the image-side focusing lens unit to the focal length of the first lens unit. By satisfying the conditional expression (6), the variable magnification optical system according to the present embodiment effectively changes the various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object. It is possible to suppress fluctuations of various aberrations including spherical aberration at the time of zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (6) of the variable magnification optical system of the present embodiment exceeds the upper limit, the refractive power of the first lens group becomes strong, and the spherical surface at the time of zooming from the wide-angle end state to the telephoto end state It becomes difficult to suppress the fluctuation of various aberrations including the aberration. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (6) to 3.60. In order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (6) to 3.40. Further, it is preferable to set the upper limit value of conditional expression (6) to 3.00, further 2.50, and further 1.90.

On the other hand, when the corresponding value of the conditional expression (6) of the variable magnification optical system of the present embodiment falls below the lower limit value, the refractive power of the focusing lens unit disposed closest to the image among the image side focusing lens units becomes strong. As a result, it becomes difficult to suppress fluctuations of various aberrations including spherical aberration at the time of focusing from an infinite distance object to a close distance object. In addition, the effect of the present embodiment can be made more reliable by setting the lower limit value of the conditional expression (6) to 0.25. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (6) to 0.28. Further, it is preferable to set the lower limit value of conditional expression (6) to 0.50, further 0.70, further 0.90, and further 1.20.

In the zoom lens system according to the present embodiment, it is preferable that the object-side focusing lens unit be formed of, in order from the object side, a lens having positive refractive power and a lens having negative refractive power. With this configuration, it is possible to effectively suppress the variation of spherical aberration and chromatic aberration at the time of focusing from an infinite distance object to a close distance object.

Further, it is desirable that the variable magnification optical system of the present embodiment has an aperture stop, and the object side focusing lens unit be disposed on the image side of the aperture stop. This configuration can reduce the weight of the focusing lens unit.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the following conditional expression (7) be satisfied.
(7) 0.10 <| fF1 | / ft <3.00
However,
fF1: focal length ft of the object-side focusing lens unit focal length of the variable magnification optical system in the telephoto end state

The conditional expression (7) defines the ratio of the focal length of the object side focusing lens unit to the focal length of the variable magnification optical system in the telephoto end state. By satisfying the conditional expression (7), the variable magnification optical system according to the present embodiment effectively changes the various aberrations including the spherical aberration when focusing from an infinite distance object to a close distance object. It can be suppressed.

When the corresponding value of the conditional expression (7) of the variable magnification optical system of the present embodiment exceeds the upper limit, the focal length of the object side focusing lens unit becomes long, and focusing from an infinite distance object to a near distance object The amount of movement of the object-side focusing lens unit becomes too large, and it becomes difficult to correct fluctuations of various aberrations including spherical aberration when focusing from an infinite distance object to a close distance object. By setting the upper limit value of the conditional expression (7) to 2.80, the effect of the present embodiment can be made more reliable. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the upper limit of conditional expression (7) to 2.60. Further, it is preferable to set the upper limit value of conditional expression (7) to 2.20, further 1.90, and further 1.60.

On the other hand, when the corresponding value of the conditional expression (7) of the variable magnification optical system of the present embodiment falls below the lower limit, the refractive power of the object side focusing lens unit becomes strong, and focusing from an infinite distance object to a near distance object It is difficult to suppress fluctuations of various aberrations including the spherical aberration at the time of. In addition, the effect of this embodiment can be made more reliable by setting the lower limit of conditional expression (7) to 0.12. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (7) to 0.15.

Further, it is desirable that the variable magnification optical system of the present embodiment satisfy the following conditional expression (8).
(8) 0.10 <| fF2 | / ft <3.00
However,
fF2: focal length ft of the focusing lens group disposed closest to the image side among the image-side focusing lens groups ft: focal length of the variable magnification optical system in the telephoto end state

Conditional expression (8) defines the ratio of the focal length of the focusing lens unit disposed closest to the image side among the image-side focusing lens groups to the focal length of the variable magnification optical system in the telephoto end state. is there. By satisfying the conditional expression (8), the variable magnification optical system according to the present embodiment can effectively change the various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object. It can be suppressed.

When the corresponding value of the conditional expression (8) of the variable magnification optical system of the present embodiment exceeds the upper limit value, the focal length of the focusing lens unit disposed closest to the image among the image side focusing lens units becomes long. The amount of movement of the focusing lens unit disposed closest to the image side when focusing from an infinite distance object to a near distance object becomes too large, and spherical aberration when focusing from an infinite distance object to a near distance object It becomes difficult to correct fluctuations of various aberrations including. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (8) to 2.80. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (8) to 2.60.

On the other hand, when the corresponding value of the conditional expression (8) of the variable magnification optical system of the present embodiment falls below the lower limit value, the refractive power of the focusing lens unit disposed closest to the image among the image side focusing lens units becomes strong. As a result, it becomes difficult to suppress fluctuations of various aberrations including spherical aberration at the time of focusing from an infinite distance object to a close distance object. In addition, the effect of this embodiment can be made more reliable by setting the lower limit of conditional expression (8) to 0.12. Moreover, in order to make the effect of this embodiment more reliable, it is preferable to set the lower limit of conditional expression (8) to 0.15.

Further, it is desirable that the variable magnification optical system according to the present embodiment satisfy the following conditional expression (9).
(9) | βWF1 | / | βWF2 | <4.00
However,
βWF1: lateral magnification of the object-side focusing lens unit in the wide-angle end state when focusing on an infinite object βWF2: to the most object side of the image-side focusing lens units in the wide-angle end state when focusing on an infinite object Lateral magnification of the focusing lens unit arranged

Conditional expression (9) gives the most magnification among the image-side focusing lens groups in the wide-angle end state at the time of infinity object focusing and the lateral magnification of the object-side focusing lens group at the wide-angle end state at infinity object focusing. It defines the ratio to the lateral magnification of the focusing lens unit disposed on the object side. By satisfying the conditional expression (9), the variable magnification optical system according to the present embodiment causes fluctuations of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object in the wide-angle end state. Can be effectively suppressed.

When the corresponding value of the conditional expression (9) of the variable magnification optical system of the present embodiment exceeds the upper limit value, it is disposed closest to the object side in the image side focusing lens group in the wide angle end state at the time of focusing on an infinite distance object. The lateral magnification of the object-side focusing lens group in the wide-angle end state at the time of infinity object focusing increases with respect to the lateral magnification of the focusing lens group, and focusing from an infinite distance object to a near distance object in the wide angle end state It becomes difficult to suppress fluctuations of various aberrations including spherical aberration at the time of focusing. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (9) to 3.50. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (9) to 3.00. Further, it is preferable to set the upper limit value of conditional expression (9) to 2.50, further 2.00, further 1.50, and further 1.20.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the following conditional expression (10) be satisfied.
(10) | βRw | / | βRt | <4.00
However,
βRw: composite lateral magnification from the object-side focusing lens unit to the image plane in the wide-angle end state at the time of infinity object focusing βRt: an image from the object-side focusing lens group in the telephoto end state at infinity object focusing Composite lateral magnification up to surface

Conditional expression (10) shows the combined lateral magnification from the object-side focusing lens unit to the image plane in the wide-angle end state at the time of infinity object focusing and the object-side focusing lens in the telephoto end state at infinity object focusing It defines the ratio to the combined lateral magnification from the group to the image plane. By satisfying the conditional expression (10), the variable magnification optical system according to the present embodiment causes fluctuations of various aberrations including the spherical aberration at the time of focusing from an infinite distance object to a close distance object in the wide-angle end state. Can be effectively suppressed.

When the corresponding value of the conditional expression (10) of the variable magnification optical system of the present embodiment exceeds the upper limit value, in the combined lateral magnification from the object side focusing lens group to the image plane in the telephoto end state at the time of infinity object focusing On the other hand, the combined lateral magnification from the object-side focusing lens unit to the image plane in the wide-angle end state at the time of infinity object focusing becomes large, and the focusing from the infinity object to the near object in the wide-angle end state It becomes difficult to suppress fluctuations of various aberrations including spherical aberration. In addition, the effect of the present embodiment can be made more reliable by setting the upper limit value of the conditional expression (10) to 3.50. Moreover, in order to make the effect of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (10) to 3.00. Further, it is preferable to set the upper limit value of conditional expression (10) to 2.60, further 2.20, and further 1.90.

Further, in the variable magnification optical system of the present embodiment, it is desirable that the following conditional expression (11) be satisfied.
(11) 15.0 ° <ωw <85.0 °
However,
ω w: half angle of view of the variable magnification optical system in the wide angle end state

Conditional expression (11) defines the optimum value of the angle of view in the wide-angle end state. By satisfying the conditional expression (11), the variable magnification optical system according to the present embodiment can properly correct various aberrations such as coma aberration, distortion aberration, and field curvature while having a wide angle of view. it can.

In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (11) to 80.0 °. Further, it is preferable to set the upper limit value of the conditional expression (11) to 75.0 °, more preferably 70.0 °, further preferably 65.0 °.
In order to secure the effect of the present embodiment, it is preferable to set the lower limit value of the conditional expression (11) to 16.0 °. Further, it is desirable to set the lower limit value of conditional expression (11) to 17.0 °, 35.0 °, 37.0 °, 39.0 °, 40.0 °, 42.0 °. .

The optical device of the present embodiment has the variable magnification optical system having the above-described configuration. As a result, it is possible to realize an optical device capable of favorably suppressing aberration fluctuation at the time of zooming from the wide-angle end state to the telephoto end state, and at the time of focusing from an infinite distance object to a near distance object. .

A method of manufacturing a variable magnification optical system according to the present embodiment is a method of manufacturing a variable magnification optical system having a plurality of lens groups, and is configured such that an interval between the lens groups changes at the time of zooming. The lens unit is disposed on the image side with respect to the object-side focusing lens unit that moves when focusing and the object-side focusing lens unit, and moves along a locus different from that of the object-side focusing lens unit when focusing. This is a manufacturing method of a variable power optical system configured to have at least one image side focusing lens group and configured to satisfy the following conditional expressions (1) and (2).
(1) MTF1 / MTF2 <5.0
(2) 0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system

Accordingly, it is possible to manufacture a variable power optical system capable of favorably suppressing aberration fluctuation at the time of zooming from the wide-angle end state to the telephoto end state, and at the time of focusing from an infinite distance object to a close distance object. Can.

Hereinafter, a variable magnification optical system according to a numerical example of the present embodiment will be described based on the attached drawings.
(First embodiment)
FIG. 1 is a cross-sectional view of the variable magnification optical system according to the first example. Arrows in FIG. 1 and FIGS. 4, 7, 10, 13, 16, 19, 22, 25, 28, and 31 described later indicate the wide-angle end state (W) to the telephoto end. The movement locus of each lens unit at the time of zooming to the state (T) is shown.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. , An aperture stop S, a fourth lens group G4 having negative refracting power, a fifth lens group G5 having positive refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group having negative refracting power It is composed of a lens group G7.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, and a cemented negative lens having a biconcave negative lens L12 and a positive meniscus lens L13 having a convex surface facing the object side It consists of
The second lens group G2 is composed of a positive cemented lens of a double convex positive lens L21 and a negative meniscus lens L22 having a concave surface facing the object side.
The third lens group G3 is composed of a positive cemented lens of a negative meniscus lens L31 with a convex surface facing the object side and a biconvex positive lens L32.

The fourth lens group G4 includes, in order from the object side, a cemented negative lens constructed of a double concave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a positive meniscus lens L43 having a convex surface facing the object side It consists of
The fifth lens group G5 is composed of a positive cemented lens of a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side.
The sixth lens group G6 is composed of a biconvex positive lens L61.
The seventh lens group G7 is composed of a negative meniscus lens L71 with a concave surface facing the object side.

In the variable magnification optical system according to the present embodiment, the distance between the first lens group G1 and the second lens group G2, the second lens group G2, and the third lens group G2 during zooming between the wide angle end state and the telephoto end state. The distance between the lens group G3, the distance between the third lens group G3 and the fourth lens group G4, the distance between the fourth lens group G4 and the fifth lens group G5, the distance between the fifth lens group G5 and the sixth lens group G6 All the lens units from the first lens unit G1 to the seventh lens unit G7 move along the optical axis such that the distance and the distance between the sixth lens unit G6 and the seventh lens unit G7 change.

In the optical system according to the present embodiment, as the focusing lens group, the fifth lens group G5 is moved to the object side along the optical axis, and the sixth lens group G6 has a locus different from that of the fifth lens group G5. By moving to the object side along the axis, focusing from an infinite distance object to a near distance object is performed.

Table 1 below presents values of specifications of the variable magnification optical system according to the present example.
In Table 1, f is the focal length, and BF is the back focus, that is, the distance on the optical axis from the lens surface closest to the image to the image plane I.
In [Plane data], m is the order of the optical surface counted from the object side, r is the radius of curvature, d is the surface distance (distance between the nth surface (n is an integer) and the n + 1th surface), nd is the d line The refractive index with respect to a wavelength of 587.6 nm) and d d respectively indicate Abbe numbers with respect to the d-line (wavelength of 587.6 nm). Further, OP indicates an object plane, variable indicates a variable surface interval, S indicates an aperture stop, and I indicates an image plane. The radius of curvature r = ∞ indicates a plane. The description of the refractive index nd = 1.00000 of air is omitted. When the lens surface is an aspheric surface, the surface number is marked with *, and the paraxial radius of curvature is shown in the column of radius of curvature r.

[Spherical surface data] shows the aspheric surface coefficient and the conical constant when the shape of the aspheric surface shown in [Surface data] is expressed by the following equation.
x = (h ² / r) / [1+ {1-1 (h / r) ² } ^1/2 ]
+ A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰
Here, h is the height in the direction perpendicular to the optical axis, x is the distance along the optical axis direction from the tangent plane of the apex of the aspheric surface at height h to the aspheric surface, κ is the conical constant , A4, A6, A8 and A10 are aspheric coefficients, and r is a paraxial radius of curvature which is a radius of curvature of the reference spherical surface. "E-n" (n: integer) indicates "x 10- ⁿ ", for example, "1.234 E-05" indicates "1.234 x 10 ^-5 ". The second-order aspheric coefficient A2 is 0, and the description is omitted.

In [Various data], f is the focal length of the whole lens system, FNO is the f-number, 2ω is the angle of view (unit: “°”), Ymax is the maximum image height, TL is the variable power optical system according to this embodiment The total length, ie, the distance on the optical axis from the first surface to the image plane I, β is the imaging magnification between the object and the image, d0 is the distance on the optical axis from the object surface OP to the first surface, d0 = 0.000 is infinite When focusing on a distant or infinite distance object, d0 = 641.690, etc. indicate a variable distance between the nth surface and the (n + 1) th surface, respectively, when focusing on a short distance or near distance object. Note that f and β are f at infinity, β at short distance, W at the wide-angle end, M at the intermediate focal length, and T at the telephoto end.
In [Lens group data], the starting surface number ST of each lens group and the focal length f are shown.
In [Conditional Expression Correspondence Value], the correspondence values of the conditional expressions of the variable magnification optical system according to the present embodiment are shown.

Here, the unit of focal length f, radius of curvature r and other lengths listed in Table 1 is generally “mm”. However, the optical system is not limited to this because the same optical performance can be obtained by proportional enlargement or reduction.
In addition, the code | symbol of Table 1 described above shall be similarly used also in the table | surface of each Example mentioned later.

(Table 1) First embodiment [surface data]
m r d nd d d
OP ∞
1 270.0000 2.900 1.74389 49.53
* 2 33.2562 13.215
3 -1900.2102 2.100 1.59349 67.00
4 35.8236 7.700 2.00100 29.12
5 79.6938 Variable

6 271.3181 7.400 1.83481 42.73
7-36.9149 1.500 1.75520 27.57
8 164.0000 variable

9 39.7511 1.500 1.85000 27.03
10 25.6246 10.800 1.59319 67.90
11 -134.6401 Variable

12 (S) ∞ 2.350
13 -65.9523 1.300 1.80100 34.92
14 18.5797 4.700 1.90366 31.27
15 51.607 0.919
16 45.9293 2.500 1.94595 17.98
17 120.0000 Variable

18 47.5350 7.100 1.48749 70.31
19-24.2409 1.300 1.69895 30.13
20 -74.7188 Variable

21 113.0000 4.200 1.5891 13 61.15
* 22 -108.0000 variable

* 23-30.5616 1.500 1.58913 61.15
24-81.9388 BF
I ∞

[Aspheric surface data]
m: 2
κ = 0.0000
A4 = 2.97162E-06
A6 = 1.62510E-09
A8 = 2.42658E-13
A10 = 4.56491E-16
A12 = 8.02650E-19

m: 22
κ = 1.0000
A4 = 8.43912E-06
A6 = 6.68890E-10
A8 = 1.69267E-11
A10 = -5.36609E-14

m: 23
κ = 1.0000
A4 = 8.13845E-06
A6 = -4.05875E-09
A8 = 1.66491E-11
A10 = -5.84964E-14

[Various data]
Magnification 2.99
W M T
f 22.7 50.0 67.9
FNO 2.92 2.92 2.92
2ω 91.10 45.68 33.64
Ymax 19.32 21.60 21.60
TL 188.45 157.95 163.95
BF 11.75 20.19 25.26

W M T W M T
f, β 22.700 50.000 67.900 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 641.690 1469.10 2002.79
d5 639.985 0.9.98 3.100 63.985 10.99.3 100
d8 1.000 1.763 1.000 1.000 1.763 1.000
d11 1.900 12.973 26.707 1.900 12.973 26.707
d17 20.431 12.752 12.052 20.013 11.839 10.654
d20 8.701 16.480 16.780 8.112 16.125 16.831
d22 7.699 9.815 6.069 8.705 11.084 7.415

[Lens group data]
Group ST f
1 1 -46.132
2 6 102.733
3 9 64. 434
4 12-89.031
5 18 92.237
6 21 94.399
7 23 -83.639

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 1.038
(2) BFw / fw = 0.518
(3) (-fFN) / | fF | = 0.563
(4) nP / nN = 0.876
(5) | fF1 | / | f1 | = 1.999
(6) | fF2 | / | f1 | = 2.046
(7) | fF1 | / ft = 1.358
(8) | fF2 | /ft=1.390
(9) | βWF1 | / | βWF2 |
(10) | βRw | / | βRt | = 1.616
(11) ωw = 45.55 °

FIGS. 2A, 2B, and 2C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the first example, respectively.
FIGS. 3A, 3B, and 3C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the first example.

In each of the aberration diagrams of FIG. 2 and FIG. 3, FNO indicates an F number, NA indicates a numerical aperture, and Y indicates an image height. In the spherical aberration diagram, the f-number or numerical aperture value corresponding to the maximum aperture is shown, in the astigmatism diagram and the distortion diagram, the maximum value of the image height is shown, and in the coma aberration diagram, the value of each image height is shown. . d is d line (λ = 587.6 nm), g is g line (λ = 435.8 nm). In astigmatism diagrams, a solid line indicates a sagittal image plane, and a broken line indicates a meridional image plane. The same reference numerals as in this example are used also in the aberration diagrams of the examples below.

As shown in the various aberration diagrams, the variable magnification optical system according to the present embodiment has excellent imaging performance with excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and also at the time of near distance focusing. It can be seen that it has excellent imaging performance.

Second Embodiment
FIG. 4 is a view showing a lens configuration of a variable magnification optical system according to a second example.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, an aperture stop S, and negative refractive power. The third lens group G3, the fourth lens group G4 having positive refracting power, the fifth lens group G5 having positive refracting power, and the sixth lens group G6 having negative refracting power.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface on the object side, a negative meniscus lens L12 having a convex surface on the object side, and a positive meniscus lens L13 having a convex surface on the object side It consists of a cemented negative lens.
The second lens group G2 includes, in order from the object side, a double positive lens L21 cemented with a negative meniscus lens L22 having a concave surface facing the object side, and a negative meniscus lens L23 having a convex surface facing the object side And a cemented positive lens with a biconvex positive lens L24.

The third lens group G3 is composed of, in order from the object side, a biconcave negative lens L31, and a cemented positive lens constructed by a biconcave negative lens L32 and a biconvex positive lens L33.
The fourth lens group G4 is composed of a positive cemented lens of a biconvex positive lens L41 and a negative meniscus lens L42 having a concave surface facing the object side.
The fifth lens group G5 is composed of a biconvex positive lens L51.
The sixth lens group G6 is composed of a negative meniscus lens L61 with a concave surface facing the object side.

In the variable magnification optical system according to the present embodiment, the distance between the first lens group G1 and the second lens group G2, the second lens group G2, and the third lens group G2 during zooming between the wide angle end state and the telephoto end state. The distance between the lens group G3, the distance between the third lens group G3 and the fourth lens group G4, the distance between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6 All the lens units from the first lens unit G1 to the sixth lens unit G6 move along the optical axis so that the interval between

In the optical system according to the present embodiment, as the focusing lens group, the fourth lens group G4 is moved to the object side along the optical axis, and the fifth lens group G5 has a locus different from that of the fourth lens group G4. By moving to the object side along the axis, focusing from an infinite distance object to a near distance object is performed.

Table 2 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 2) Second embodiment [surface data]
m r d nd d d
OP ∞
1 217.2239 2.900 1.74389 49.53
* 2 30.2414 13.112
3 1223.5572 2.100 1.59349 67.00
4 35.8181 6.436 2.00069 25.46
5 72.5839 Variable

6 128.9.112 7.447 1.81.600 46.59
7-39.6982 1.500 1.85000 27.03
8 -142.9408 1.000
9 40.8283 1.500 1.80518 25.45
10 25.0719 10.948 1.60300 65.44
11 -92.3055 Variable

12 (S) ∞ 2.486
13-55.5201 1.300 1.90265 35.72
14 121.6217 1.190
15 -124.4061 1.300 1.67270 32.18
16 22.4038 6.400 1.80809 22.74
17-97.2368 Variable

18 62.1388 6.900 1.48749 70.32
19-23.2151 1.300 1.78472 25.64
20-50.9732 Variable

21 186.2633 4.200 1.5891 13 61.15
* 22-79.5614 variable

* 23-33.8149 1.500 1.5891 13 61.15
24 -131.2649 BF
I ∞

[Aspheric surface data]
m: 2
κ = 0.0000
A4 = 3.46899E-06
A6 = 3.81982 E-09
A8 = -6.40834E-12
A10 = 1.09738E-14
A12 = -4.82160E-18

m: 22
κ = 1.0000
A4 = 6.88818E-06
A6 = -6.09818E-10
A8 = 8.44660E-12
A10 = -2.63571E-14

m: 23
κ = 1.0000
A4 = 8.06346E-06
A6 = -8.60497E-09
A8 = 2.28581E-11
A10 = -5.12367E-14

[Various data]
Magnification 2.99
W M T
f 22.7 50.0 67.9
FNO 2.92 2.92 2.92
2ω 91.24 45.92 33.78
Ymax 19.34 21.60 21.60
TL 188.49 155.49 159.75
BF 16.19 19.69 24.21

W M T W M T
f, β 22.700 50.000 67.900 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 643.745 147.35 2002.57
d5 63.857 10.035 2.501 63.857 10.035 2.501
d11 2.202 10.972 22.702 2.202 10.972 22.702
d17 19.524 10.852 10.688 19.122 9.959 9.322
d20 8.007 19.445 19.346 7.507 19.082 19.339
d22 5.193 10.974 6.787 6.095 12.231 8.161

[Lens group data]
Group ST f
1 1-42.007
2 6 36.073
3 12 -74.292
4 18 96.221
5 21 95.186
6 23-77.759

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.995
(2) BFw / fw = 0.713
(3) (-fFN) / | fF | = 0.583
(4) nP / nN = 0.833
(5) | fF1 | / | f1 | = 2.291
(6) | fF2 | / | f1 | = 2.266
(7) | fF1 | / ft = 1.417
(8) | fF2 | / ft = 1.402
(9) | βWF1 | / | βWF2 | = 0.762
(10) | βRw | / | βRt | = 1.663
(11) ωw = 45.62 °

FIGS. 5A, 5B, and 5C are various aberration diagrams at the time of focusing on an infinite distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the second example.
FIGS. 6A, 6B, and 6C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the second example.

As shown in the various aberration diagrams, the variable magnification optical system according to the present embodiment has excellent imaging performance with excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and at the time of focusing on a short distance object. It can also be seen that they have excellent imaging performance.

Third Embodiment
FIG. 7 is a diagram showing the lens configuration of the variable magnification optical system according to the third example.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. , An aperture stop S, a fourth lens group G4 having negative refracting power, a fifth lens group G5 having positive refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group having negative refracting power It is composed of a lens group G7.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface on the object side, a negative meniscus lens L12 having a convex surface on the object side, and a positive meniscus lens L13 having a convex surface on the object side It consists of a cemented negative lens.
The second lens group G2 is composed of a positive cemented lens of a double convex positive lens L21 and a negative meniscus lens L22 having a concave surface facing the object side.
The third lens group G3 is composed of a positive cemented lens of a negative meniscus lens L31 with a convex surface facing the object side and a biconvex positive lens L32.

The fourth lens group G4 is composed of a cemented negative lens constructed by a double concave negative lens L41 and a positive meniscus lens L42 having a convex surface directed to the object side.
The fifth lens group G5 is composed of a positive cemented lens of a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side.
The sixth lens group G6 is composed of a biconvex positive lens L61.
The seventh lens group G7 is composed of a negative meniscus lens L71 with a concave surface facing the object side.

Table 3 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 3) Third Example [Plane Data]
m r d nd d d
OP ∞
1 259.2015 2.900 1.74389 49.53
* 2 30.9799 13.410
Three 1201.6909 2.100 1.59349 66.99
4 36.4155 6.936 2.00100 29.14
5 81.5436 Variable

6 124.3745 6.555 1.80400 46.60
7 -55.7538 1.500 1.72825 28.38
8-633.0468 Variable

9 44.9659 1.500 1.85000 27.03
10 27.3358 10.990 1.59319 67.90
11-89.5168 Variable

12 (S) ∞ 2.562
13-58. 2664 1. 300 1. 68893 31. 16
14 20.8969 4.742 1.80809 22.74
15 201.5296 Variable

16 52.2605 6.900 1.48749 70.31
17-26.1209 1.300 1.69895 30.13
18 -72.7540 variable

19 130.0000 4.200 1.5891 13 61.15
* 20-100.4826 Variable

* 21-44.3630 1.500 1.5891 3 61.15
22-412.9422 BF
I ∞

[Aspheric surface data]
m: 2
κ = 0.0000
A4 = 3.40299E-06
A6 = 1.78453 E-09
A8 = -2.01869E-13
A10 = 1.07948E-15
A12 = 2.74510E-19

m: 20
κ = 1.0000
A4 = 8.80591E-06
A6 = -1.07404E-09
A8 = 1.74456E-11
A10 = -2.66494E-14

m: 21
κ = 1.0000
A4 = 6.66893E-06
A6 = -5.20154E-09
A8 = 5.00802E-12
A10 = -7.75803E-15

[Various data]
Magnification 2.99
W M T
f 22.7 50.0 67.9
FNO 2.92 2.92 2.92
2ω 91.30 45.88 33.64
Ymax 19.36 21.60 21.60
TL 188.49 156.49 165.34
BF 14.19 20.41 24.73

W M T W M T
f, β 22.700 50.000 67.900 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 643.522 1473.82 2010.17
d5 64.909 10.197 2.263 64.909 10.197 2.263
d8 1.000 1.000 1.000 1.000 1.000
d11 2.200 12.573 28.831 2.200 12.573 28.831
d15 22.896 13.304 11.893 22.388 12.281 10.318
d18 8.047 19.430 19.884 7.707 19.294 20.25
d20 6.853 11.181 8.344 7.701 12.340 9.543

[Lens group data]
Group ST f
1 1 -45.334
2 6 112.275
3 9 63.547
4 12 -98.234
5 16 92.914
6 19 96.856
7 21 -84.494

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 1.313
(2) BFw / fw = 0.625
(3) (-fFN) / | fF | = 0.635
(4) nP / nN = 0.876
(5) | fF1 | / | f1 | = 2.050
(6) | fF2 | / | f1 | = 2.137
(7) | fF1 | / ft = 1.368
(8) | fF2 | / ft = 1.426
(9) | βWF1 | / | βWF2 | = 0.723
(10) | βRw | / | βRt | = 2.084
(11) ωw = 45.65 °

FIGS. 8A, 8B, and 8C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the third example.
FIGS. 9A, 9B, and 9C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the third example.

Fourth Embodiment
FIG. 10 is a diagram showing the lens configuration of the variable magnification optical system according to the fourth example.
The variable magnification optical system according to the present embodiment has, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, and positive refractive power. The third lens group G3, the fourth lens group G4 having positive refracting power, the fifth lens group G5 having positive refracting power, and the sixth lens group G6 having negative refracting power.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 with a convex surface facing the object side and a negative cemented lens of a positive meniscus lens L12 with a convex surface facing the object side, and a positive lens It consists of a meniscus lens L13.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object, a biconcave negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. And a cemented negative lens of a biconvex positive lens L25.

The third lens group G3 includes, in order from the object side, a biconvex positive lens L31, a negative meniscus lens L32 with a concave surface facing the object side, a biconvex positive lens L33, and a biconcave negative lens L34. It consists of
The fourth lens group G4 is composed of a positive cemented lens of a biconvex positive lens L41 and a negative meniscus lens L42 having a concave surface facing the object side.
The fifth lens group G5 is composed of a biconvex positive lens L51.
The sixth lens group G6 is composed of, in order from the object side, a biconcave negative lens L61, and a positive meniscus lens L62 having a convex surface facing the object side.

In the optical system according to the present embodiment, as the focusing lens group, the fourth lens group G4 is moved to the image side along the optical axis, and the fifth lens group G5 is moved to the object side along the optical axis. By this, focusing from an infinite distance object to a near distance object is performed.

Table 4 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 4) Fourth embodiment [surface data]
m r d nd d d
OP ∞
1 1059.302 1.000 1.84666 23.80
2 88.2318 6.929 1.90265 35.72
3 403.3118 0.200
4 87.3429 6.677 1.81600 46.59
5 899.1448 Variable

* 6 145.1405 1.000 1.81600 46.59
7 21.3498 7.013
8 -93.6005 1.000 1.77250 49.62
9 52.8889 0.200
10 40.8152 5.067 1.80518 25.45
11 -74.9610 1.472
12 -36.2791 1.000 1.80400 46.60
13 404.7262 2.056 2.00069 25.46
14-319.9567 Variable

15 (S) 0.2 0.200
16 88.2548 3.685 1.80400 46.60
17-54.7142 1.284
18 -30.7175 1.000 1.68893 31.16
19-74.0526 0.200
20 56.5407 4.903 1.71999 50.27
21-44. 3610 4. 918
22-36.9664 1.000 1.72342 38.03
23 80.5817 Variable

24 573.8232 6.525 1.59349 67.00
25 -22.0116 1.000 1.71736 29.57
26 -42.4849 Variable

27 50.5370 6.205 1.55332 71.68
* 28-153.3313 Variable

* 29-95.1749 3.228 1.59551 39.21
30 84.3183 7.544
31 40.5660 7.785 1.59551 39.21
32 180.7170 BF
I ∞

[Aspheric surface data]
m: 6
κ = 1.0000
A4 = 1.07708E-06
A6 = -2.41884E-09
A8 = 5.80958E-12
A10 = -5.58700E-15

m: 28
κ = 1.0000
A4 = 2.10709E-06
A6 = 4.40633E-09
A8 = -1.52762E-11
A10 = 2.31569E-14

m: 29
κ = 1.0000
A4 = -6.15448E-06
A6 = 7.32819E-09
A8 = -2.45254E-11
A10 = 3.72863E-14

[Various data]
Magnification 2.99
W M T
f 22.7 50.3 67.9
FNO 2.92 2.92 2.92
2ω 91.78 46.78 34.60
Ymax 19.23 21.60 21.60
TL 155.45 174.13 187.93
BF 13.25 21.65 20.92

W M T W M T
f, β 22.700 50.288 67.900 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 638.473 1426.83 1927.07
d5 2.000 25.012 34.560 2.000 25.012 34.560
d14 29.544 7.040 2.000 29.544 7.040 2.000
d23 6.941 4.850 4.000 8.321 5.940 5.254
d26 12.2.867 12.278 14.712 10.219 9.972.178
d28 7.757 20.212 28.652 9.025 21.422 29.932

[Lens group data]
Group ST f
1 1 131.146
2 6-21.329
3 15 56.760
4 24 81. 373
5 27 69.446
6 29 -1467.881

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.980
(2) BFw / fw = 0.584
(3) (-fFN) / | fF | = 0.936
(4) nP / nN = 0.928
(5) | fF1 | / | f1 |
(6) | fF2 | / | f1 |
(7) | fF1 | / ft = 1.198
(8) | fF2 | / ft = 1.023
(9) | βWF1 | / | βWF2 | = 0.014
(10) | βRw | / | βRt | = 0.005
(11) ωw = 45.89 °

11A, 11B, and 11C are various aberration diagrams at the time of focusing on an infinite distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fourth example.
12A, 12B, and 12C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fourth example.

Fifth Embodiment
FIG. 13 is a diagram showing the lens configuration of the variable magnification optical system according to the fifth example.
The variable magnification optical system according to the present embodiment has, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, and positive refractive power. The third lens group G3, the fourth lens group G4 having negative refractive power, the fifth lens group G5 having positive refractive power, and the sixth lens group G6 having negative refractive power.

The first lens group G1 includes, in order from the object side, a positive cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side It consists of
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface on the object side, a negative meniscus lens L22 having a concave surface on the object side, and a positive meniscus lens L23 having a concave surface on the object side The negative meniscus lens L24 has a concave surface facing the object side.

The third lens group G3 has a concave surface facing the object side, a positive meniscus lens L31 having a convex surface facing the object side, a biconvex positive lens L32, a biconvex positive lens L33, and a convex lens facing the object side in this order from the object side And a cemented positive lens with the negative meniscus lens L34.
The fourth lens group G4 is composed of, in order from the object side, a biconcave negative lens L41 and a biconvex positive lens L42.
The fifth lens group G5 is composed of a biconvex positive lens L51.
The sixth lens group G6 is composed of, in order from the object side, a biconcave negative lens L61, and a positive meniscus lens L62 having a convex surface facing the object side.

Table 5 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 5) Fifth embodiment [surface data]
m r d nd d d
OP ∞
1 3049.4158 2.000 1.84666 23.80
2 109.9340 7.861 1.81600 46.59
3-1409.8119 0.200
4 101.3915 6.059 1.81600 46.59
5 503.4410 Variable

* 6 239.3378 1.300 1.81600 46.59
7 22.0458 9.224
8 -40.1436 1.300 1.77250 49.62
9-121. 495 0.200
10 -196.1454 4.421 1.95000 29.37
11-34.6549 1.015
12-29.7495 1.300 1.59349 67.00
13-185.4662 Variable

14 (S) 0.2 0.200
15 47.0680 3.025 1.88300 40.66
16 271.9137 10.130
17 176.7677 2.592 1.59319 67.90
18 -179.0400 0.200
19 86.4232 5.895 1.59319 67.90
20-27.4209 1.000 1.95000 29.37
21-41.6214 Variable

22-33.9616 1.000 1.72825 28.38
23 151.3178 0.200
24 84.0645 3.506 1.71999 50.27
25 -174.4171 Variable

26 140.7071 4.753 1.54814 45.78
* 27-72.5378 variable

* 28 -60.3860 1.300 1.74950 35.25
29 326.8097 1.986
30 45.0000 7.770 1.64000 60.19
31 459.8861 BF
I ∞

[Aspheric surface data]
m: 6
κ = 1.0000
A4 = 8.90328E-07
A6 = -2.96841E-09
A8 = 5.16084 E-12
A10 = -3.05458E-15

m: 27
κ = 1.0000
A4 = 2.61448E-06
A6 = 8.65353 E-09
A8 = -3.00982E-11
A10 = 4.50822E-14

m: 28
κ = 1.0000
A4 = -6.11667E-06
A6 = 9.18242 E-09
A8 = -3.76607E-11
A10 = 4.75789E-14

[Various data]
Magnification 2.99
W M T
f 22.7 49.7 67.9
FNO 2.92 2.92 2.92
2ω 91.48 45.84 32.90
Ymax 19.18 21.60 21.60
TL 157.45 170.49 182.85
BF 14.08 21.92 17.11

W M T W M T
f, β 22. 701 49. 700 67. 907-0.033-0.033-0.033
d0 0.000 0.000 0.000 640.708 1420.26 1939.82
d5 2.000 24.596 37.406 2.000 24.596 37.406
d13 35.154 8.040 2.000 35.154 8.040 2.000
d21 4.461 8.442 11.773 4.175 8.108 11.453
d25 20.335 18.256 18.682 18.556 15.932 15.718
d27 2.986 10.795 17.440 5.050 13.453 20.723

[Lens group data]
Group ST f
1 1 141.872
2 6-24.424
3 14 30.546
4 22 -75.468
5 26 88.014
6 28-713.321

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.098
(2) BFw / fw = 0.620
(3) (-fFN) / | fF | = 0.504
(4) nP / nN = 0.995
(5) | fF1 | / | f1 | = 0.532
(6) | fF2 | / | f1 |
(7) | fF1 | / ft = 1.111
(8) | fF2 | / ft = 1.296
(9) | βWF1 | / | βWF2 | = 2.449
(10) | βRw | / | βRt | = 1.034
(11) ωw = 45.74 °

FIG. 14A, FIG. 14B, and FIG. 14C are various aberration diagrams at the time of infinity object focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fifth example.
FIG. 15A, FIG. 15B, and FIG. 15C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the fifth example.

Sixth Embodiment
FIG. 16 is a diagram showing the lens configuration of the variable magnification optical system according to the sixth example.
The variable magnification optical system according to this embodiment includes, in order from the object side, a first lens group G1 having positive refracting power, a second lens group G2 having negative refracting power, and a third lens group G3 having positive refracting power. , An aperture stop S, a fourth lens group G4 having positive refracting power, a fifth lens group G5 having negative refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group having negative refracting power It is composed of a lens group G7.

The first lens group G1 is composed of, in order from the object side, a biconvex positive lens L11, and a cemented positive lens of a negative meniscus lens L12 with a convex surface facing the object side and a biconvex positive lens L13.
The second lens group G2 includes, in order from the object side, a biconcave negative lens L21, a positive meniscus lens L22 with a convex surface facing the object side, and a biconcave negative lens L23 with a convex surface facing the object side And a cemented negative lens with the meniscus lens L24.
The third lens group G3 is composed of, in order from the object side, a biconvex positive lens L31, and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33.

The fourth lens group G4 is composed of a positive cemented lens of a biconvex positive lens L41 and a negative meniscus lens L42 having a concave surface facing the object side.
The fifth lens group G5 is composed of a negative meniscus lens L51 having a convex surface facing the object side.
The sixth lens group G6 is composed of a positive meniscus lens L61 having a concave surface facing the object side.
The seventh lens group G7 is composed of, in order from the object side, a negative meniscus lens L71 having a concave surface facing the object side, and a biconvex positive lens L72.

In the optical system according to the present embodiment, as the focusing lens group, the fourth lens group G4 is moved to the object side along the optical axis, and the sixth lens group G6 has a locus different from that of the fourth lens group G4. By moving to the object side along the axis, focusing from an infinite distance object to a near distance object is performed.

Table 6 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 6) Sixth embodiment [surface data]
m r d nd d d
OP ∞
1 829.7998 3.542 1.48749 70.32
2-352.7135 0.200
3 102.3920 1.700 1.67270 32.18
4 65.2892 8.627 1.49700 81.73
5-4480.3970 Variable

6-331.7733 1.000 1.77250 49.62
7 47.4606 2.120
8 45.4437 2.785 1.80518 25.45
9 90.1171 3.854
10 -70.4901 1.000 1.67003 47.14
11 34.7167 3.536 1.75520 27.57
12 116.6754 Variable

13 100.8918 3.650 1.80610 40.97
14 -72.8434 0.200
15 48.3355 4.843 1.49700 81.73
16 -53.3052 1.443 1.85026 32.35
17 226.4472 1 .323
18 (S) ∞ variable

19 56.3197 4.471 1.51680 63.88
20-38.8956 1.000 1.80100 34.92
21 -92.0195 variable

22 513.7755 3.255 1.85026 32.35
23 39.1334 Variable

24 -52.5225 4.182 1.71736 29.57
25-30.1949 Variable

26-25.8031 1.873 1.81600 46.59
27--90.1071 0.200
28 139.7088 3.802 1.79504 28.69
29 -94.4559 BF
I ∞

[Various data]
Magnification ratio 4.05
W M T
f 72.1 100.0 292.0
FNO 4.74 4.81 5.88
2ω 34.32 24.20 8.28
Ymax 21.60 21.60 21.60
TL 193.32 211.66 248.32
BF 38.32 39.78 62.52

W M T W M T
f, β 72.100 99.963 292.002 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 211.07 2908.95 8607.60
d5 2.000 28.621 75.058 2.000 28.621 75.058
d12 43.058 34.009 2.000 43.058 34.009 2.000
d18 21.601 19.944 21.366 21.096 19.010 19.414
d21 2.000 3.657 2.235 2.505 4.591 4.188
d23 11.246 10.437 10.009 10.564 10.137 9.509
d25 16.489 16.614 16.522 17.171 16.914 17.022

[Lens group data]
Group ST f
1 1 167.538
2 6-41.098
3 13 50.455
4 19 95.000
5 22 -49.977
6 24 91.830
7 26-136.049

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 3.903
(2) BFw / fw = 0.531
(3) (-fFN) / | fF | = 0.924
(4) nP / nN = 0.842
(5) | fF1 | / | f1 | = 0.567
(6) | fF2 | / | f1 | = 0.548
(7) | fF1 | / ft = 0.325
(8) | fF2 | / ft = 0.314
(9) | βWF1 | / | βWF2 | = 1.096
(10) | βRw | / | βRt | = 0.934
(11) ωw = 17.16 °

FIGS. 17A, 17B, and 17C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the sixth example.
18A, 18B, and 18C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the sixth example.

Seventh Embodiment
FIG. 19 is a diagram showing a lens configuration of a variable magnification optical system according to a seventh example.
The variable magnification optical system according to the present embodiment has, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, and positive refractive power. The third lens group G3, the fourth lens group G4 having positive refracting power, the fifth lens group G5 having positive refracting power, the sixth lens group G6 having negative refracting power, and the seventh lens group G6 having positive refracting power It is composed of a lens group G7.

The first lens group G1 includes, in order from the object side, a positive cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side It consists of
The second lens group G2 includes, in order from the object side, a biconcave negative lens L21, a biconcave negative lens L22, and a cemented positive lens constructed by a biconvex positive lens L23 and a biconcave negative lens L24. It consists of

The third lens group G3 is composed of, in order from the object side, a biconvex positive lens L31, and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33.
The fourth lens group G4 is composed of, in order from the object side, a double convex positive lens L41 and a negative meniscus lens L42 having a concave surface facing the object side.
The fifth lens group G5 is composed of a biconvex positive lens L51.
The sixth lens group G6 is composed of a negative cemented lens of a positive meniscus lens L61 having a concave surface facing the object side and a biconcave negative lens L62.
The seventh lens group G7 is composed of a positive meniscus lens L71 having a concave surface facing the object side.

Table 7 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 7) Seventh embodiment [surface data]
m r d nd d d
OP ∞
1 137.2611 2.000 1.85000 27.03
2 66.9538 6.897 1.59319 67.90
3-677.5498 0.200
4 107.1491 4.136 1.61800 63.34
5 9353.1970 Variable

* 6-150.8738 2.000 1.90265 35.72
7 25.5606 4.779
8 -260.6181 1.000 1.81600 46.59
9 86.2883 0.200
10 41.4737 5.687 1.84666 23.78
11-48.7116 1.000 1.81600 46.59
12 54.7043 Variable

13 (S) ∞ 0.200
14 44.1680 2.899 1.77250 49.62
15-280.6415 0.200
16 27.1646 4.022 1.59319 67.90
17-146.4206 1.000 1.95000 29.37
18 51.2305 Variable

19 50.9241 2.999 1.83481 42.73
20 -182.3279 2.176
21 -80.2256 1.000 1.88300 40.66
22 -715.7217 Variable

23 101.2327 2.235 1.83481 42.73
* 24 -257.5032 Variable

* 25-283.1336 4.085 1.58144 40.98
26 -18.4049 1.000 1.90366 31.27
27 87.0702 Variable

28 -136.5964 6.525 1.59319 67.90
29-38.7359
I ∞

[Aspheric surface data]
m: 6
κ = 1.0000
A4 = 1.67289E-07
A6 = -1.03260E-09
A8 = 5.37315E-12
A10 = -4.58982E-15

m: 24
κ = 1.0000
A4 = 4.43454E-06
A6 = 2.09008E-08
A8 =-1.49527E-10
A10 = 8.49155E-13

m: 25
κ = 1.0000
A4 = -2.21915E-05
A6 = 1.15956E-07
A8 = -1.94063E-09
A10 = 9.93961 E-12

[Various data]
Magnification ratio 8.50
W M T
f 24.7 70.0 210.0
FNO 3.47 5.31 6.52
2 ω 85.94 32.52 11.08
Ymax 19.90 21.60 21.60
TL 141.66 173.63 194.45
BF 23.35 32.36 13.26

W M T W M T
f, β 24.700 70.005 209.991 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 706.534 2031.32 6175.90
d5 2.002 22.984 54.077 2.002 22.984 54.077
d12 37.630 16.703 2.000 37.630 16.703 2.000
d18 9.388 7.901 4.000 9.688 8.290 4.039
d22 7.722 6.619 11.160 6.491 5.369 9.139
d24 2.215 7.801 20.136 3.147 8.752 21.938
d27 3.110 22.940 33.576 3.110 22.940 33.576

[Lens group data]
Group ST f
1 1 113.050
2 6-19.624
3 13 42.460
4 19 84.928
5 23 87.292
6 25 -33.119
7 28 88.941

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.022
(2) BFw / fw = 0.945
(3) (-fFN) / | fF | = 1.206
(4) nP / nN = 0.974
(5) | fF1 | / | f1 | = 0.751
(6) | fF2 | / | f1 | = 0.772
(7) | fF1 | / ft = 0.404
(8) | fF2 | / ft = 0.416
(9) | βWF1 | / | βWF2 | = 0.616
(10) | βRw | / | βRt | = 1.858
(11) ωw = 42.97 °

FIGS. 20A, 20B, and 20C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the seventh example.
21A, 21B, and 21C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the seventh example.

Eighth embodiment
FIG. 22 is a diagram showing a lens configuration of a variable magnification optical system according to an eighth example.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, an aperture stop S, and negative refractive power. A third lens group G3, a fourth lens group G4 having positive refracting power, a fifth lens group G5 having negative refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group having negative refracting power It is composed of a lens group G7.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface on the object side, a negative meniscus lens L12 having a convex surface on the object side, and a positive meniscus lens L13 having a convex surface on the object side It consists of a cemented positive lens.
The second lens group G2 includes, in order from the object side, a double positive lens L21 cemented with a negative meniscus lens L22 having a concave surface facing the object side, and a negative meniscus lens L23 having a convex surface facing the object side And a cemented positive lens with a biconvex positive lens L24.

The third lens group G3 includes, in order from the object side, a negative meniscus lens L31 having a concave surface facing the object side, and a cemented positive lens constructed by a biconcave negative lens L32 and a positive meniscus lens L33 having a convex surface facing the object side It consists of
The fourth lens group G4 is composed of a biconvex positive lens L41.
The fifth lens group G5 is composed of a negative meniscus lens L51 having a concave surface facing the object side.
The sixth lens group G6 is composed of a biconvex positive lens L61.
The seventh lens group G7 is composed of a negative meniscus lens L71 with a concave surface facing the object side.

In the optical system according to the present embodiment, as the focusing lens group, the fourth lens group G4 is moved to the object side along the optical axis, and the fifth lens group G5 and the sixth lens group G6 are each configured as a fourth lens. Focusing from an infinite distance object to a near distance object is performed by moving to the object side along the optical axis with a locus different from that of the group G4.

Table 8 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 8) Eighth Example [Plane Data]
m r d nd d d
OP ∞
1 250.0000 2.900 1.74389 49.53
* 2 28.0269 12.424
3 154.1167 2.100 1.59349 67.00
4 32.5416 6.969 2.00069 25.46
5 61.8764 Variable

6 175.0869 5.997 1.81600 46.59
7-52.8034 1.500 1.85000 27.03
8 -204.9882 1.000
9 45.2860 1.500 1.80518 25.45
10 26.6188 11.527 1.60300 65.44
11 -76.6492 Variable

12 (S) ∞ 2.465
13 -64.5009 1.300 1.90265 35.72
14 -217.6883 0.200
15 -214.1041 1.300 1.67270 32.18
16 26.6.878 6.400 1.80809 22.74
17 502.6822 Variable

18 65.6282 5.000 1.48749 70.32
19-65.3105 variable

20-52.0851 1.300 1.84666 23.80
21 -201.9547 variable

22 185.0000 5.300 1.5891 13 61.15
* 23-50.5905 Variable

* 24-27.3977 1.500 1.5891 3 61.15
25-49.4756 BF
I ∞

[Aspheric surface data]
m: 2
κ = 0.0000
A4 = 3.95960E-06
A6 = 3.76748E-09
A8 = -5.23494E-12
A10 = 1.04782E-14
A12 = -4.82160E-18

m: 23
κ = 1.0000
A4 = 6.76320E-06
A6 = -8.33082E-09
A8 = 3.88079E-11
A10 = -7.09278E-14

m: 24
κ = 1.0000
A4 = 5.00393E-06
A6 = -8.92918E-09
A8 = 2.86537E-11
A10 = -5.32582E-14

[Various data]
Magnification 2.99
W M T
f 22.7 50.0 67.9
FNO 3.03 3.00 3.03
2ω 91.04 45.96 33.62
Ymax 19.30 21.60 21.60
TL 188.49 155.49 167.35
BF 16.20 23.37 32.67

W M T W M T
f, β 22.700 49.999 67.899 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 644.489 1474.05 2002.27
d5 64.883 10.266 5.946 64.883 10.266 5.946
d11 2.200 12.775 27.038 2.200 12.775 27.038
d17 20.035 8.462 6.571 19.026 7.439 4.593
d19 2.030 3.706 4.816 1.360 3.164 4.349
d21 4.601 9.046 14.467 4.908 8.936 15.092
d23 7.862 17.178 5.159 9.234 18.853 6.997

[Lens group data]
Group ST f
1 1-42.744
2 6 40.599
3 12 -105.371
4 18 68.000
5 20 -83.229
6 22 68.000
7 24 -106.909

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.809
(2) BFw / fw = 0.713
(3) (-fFN) / | fF | = 1.224
(4) nP / nN = 0.806
(5) | fF1 | / | f1 | = 1.591
(6) | fF2 | / | f1 | = 1.591
(7) | fF1 | / ft = 1.001
(8) | fF2 | / ft = 1.001
(9) | βWF1 | / | βWF2 | = 0.350
(10) | βRw | / | βRt | = 1.387
(11) ωw = 45.52 °

FIGS. 23A, 23B, and 23C are various aberration diagrams at the time of focusing on an infinite distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the eighth example.
FIGS. 24A, 24B, and 24C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the eighth example.

(9th embodiment)
FIG. 25 is a diagram showing a lens configuration of a variable magnification optical system according to a ninth example.
The variable magnification optical system according to the present embodiment has, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, and positive refractive power A third lens group G3, a fourth lens group G4 having negative refractive power, a fifth lens group G5 having positive refractive power, a sixth lens group G6 having positive refractive power, and a seventh lens having negative refractive power It is composed of a lens group G7.

The first lens group G1 includes, in order from the object side, a cemented negative lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side It consists of
The second lens group G2 includes, in order from the object side, a biconcave negative lens L21, a negative meniscus lens L22 with a concave surface facing the object side, a positive meniscus lens L23 with a concave surface facing the object side, and a concave surface with the object side And a cemented negative lens with a negative meniscus lens L24 directed.

The third lens group G3 includes, in order from the object side, a positive meniscus lens L31 having a convex surface facing the object, a negative meniscus lens L32 having a convex surface facing the object, and a positive meniscus lens L33 having a convex surface facing the object It consists of a cemented positive lens and a biconvex positive lens L34.
The fourth lens group G4 is composed of, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side, and a biconcave negative lens L42.
The fifth lens group G5 is composed of a positive cemented lens of a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side.
The sixth lens group G6 is composed of a positive meniscus lens L61 having a concave surface facing the object side.
The seventh lens group G7 is composed of a biconcave negative lens L71.

Table 9 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 9) Ninth Example [Plane Data]
m r d nd d d
OP ∞
1 3442.9453 2.000 2.00100 29.12
2 67.9723 9.758 1.59319 67.90
3-152.3923 0.200
4 58.4962 5.618 1.81600 46.59
5 401.1678 Variable

* 6-290.9507 1.400 1.88300 40.66
7 23.9500 5.968
8-85.0139 1. 200 1. 83481 42. 73
9-120.7468 5.617 1.84666 23.80
10 -22.1853 1.200 1.81600 46.59
11-285.7763 Variable

12 (S) ∞ 0.200
13 43.782. 3.108 1.69680 55.52
14 471.1855 0.200
15 32.7551 1.000 1.83481 42.73
16 21.7787 4.328 1.59319 67.90
17 90.7958 0.200
18 34.8267 4.022 1.58144 40.98
19-155.1147 Variable

* 20-30.2170 1.817 1.90200 25.26
21-25.8045 0.200
22 -168.2619 1.000 1.90366 31.27
23 32.2596 Variable

24 38.3747 4.859 1.49700 81.73
25-32.4370 1.000 2.00069 25.46
26-70.716 Variable

27 -63.4136 3.063 1.56732 42.58
* 28 -25.4716 Variable

* 29-40.3736 1.500 1.81600 46.59
30 223.1585 BF
I ∞

[Aspheric surface data]
m: 6
κ = 1.0000
A4 = 1.12990E-06
A6 = -1.48448E-09
A8 = 2.59485 E-12
A10 = -2.03608E-15

m: 20
κ = 1.0000
A4 = -1.25538E-05
A6 = 2.1423E-08
A8 = -1.35330E-10
A10 = 4.53472 E-13

m: 28
κ = 1.0000
A4 = 2.57266E-05
A6 = 5.03605E-08
A8 = -2.10329E-10
A10 = 3.98690E-13

m: 29
κ = 1.0000
A4 = 1.23110E-05
A6 = 2.00664E-08
A8 = -1.99371E-10
A10 = 2.96093E-13

[Various data]
Magnification ratio 8.97
W M T
f 24.8 70.0 222.0
FNO 3.69 5.39 6.42
2ω 85.32 33.28 10.80
Ymax 20.30 21.60 21.60
TL 152.38 168.67 204.50
BF 13.25 40.90 75.50

W M T W M T
f, β 24.750 70.000 222.000 -0.033 -0.033 -0.033
d0 0.000 0.000 0.0000 708.545 2047.97 6602.17
d5 2.000 19.489 42.969 2.000 19.489 42.969
d11 40.184 17.902 2.000 40.184 17.902 2.000
d19 2.003 3.971 9.577 2.003 3.971 9.577
d23 10.844 6.751 7.946 10.369 6.22
d26 15.034 12.261 4.050 14.9412 12.499 5.206
d28 9.603 7.938 3.000 10.165 8.452 3.568

[Lens group data]
Group ST f
1 1 93.169
2 6-21.680
3 12 24.825
4 20-35.481
5 24 85.936
6 27 72.909
7 29-41.791

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 3.034
(2) BFw / fw = 0.536
(3) (-fFN) / | fF | = 0.832
(4) nP / nN = 0.786
(5) | fF1 | / | f1 | = 0.922
(6) | fF2 | / | f1 | = 0.783
(7) | fF1 | / ft = 0.387
(8) | fF2 | / ft = 0.328
(9) | βWF1 | / | βWF2 | = 0.607
(10) | βRw | / | βRt | = 0.815
(11) ωw = 42.66 °

FIGS. 26A, 26B, and 26C show various aberrations of the variable magnification optical system of the ninth example when focusing on an infinite object at the wide-angle end, at an intermediate focal length, and at the telephoto end.
FIGS. 27A, 27B, and 27C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the ninth example.

Tenth Example
FIG. 28 is a diagram showing the lens configuration of a variable magnification optical system according to the tenth example.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. An aperture stop S, a fourth lens group G4 having positive refracting power, a fifth lens group G5 having negative refracting power, and a sixth lens group G6 having positive refracting power.

The first lens group G1 is composed of, in order from the object side, a biconvex positive lens L11, and a cemented positive lens of a negative meniscus lens L12 with a convex surface facing the object side and a biconvex positive lens L13.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object, a positive meniscus lens L22 having a convex surface facing the object, a negative biconcave lens L23, and a convex surface And a cemented negative lens with a positive meniscus lens L24 facing the lens.
The third lens group G3 is composed of, in order from the object side, a biconvex positive lens L31, and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33.

The fourth lens group G4 is composed of a negative meniscus lens L41 having a convex surface facing the object side and a positive lens cemented with a biconvex positive lens L42.
The fifth lens group G5 is composed of, in order from the object side, a biconvex positive lens L51 and a biconcave negative lens L52.
The sixth lens group G6 is composed of, in order from the object side, a negative meniscus lens L61 having a concave surface facing the object side, and a biconvex positive lens L62.

In the optical system according to the present embodiment, as the focusing lens group, the fourth lens group G4 is moved to the object side along the optical axis, and the fifth lens group G5 is moved to the image side along the optical axis. By this, focusing from an infinite distance object to a near distance object is performed.

Table 10 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 10) Tenth Example [Plane Data]
m r d nd d d
OP ∞
1 339.1302 3.342 1.48749 70.32
2-1748.804 0.200
3 113.3340 1.700 1.62004 36.40
4 62.3111 8.286 1.49700 81.73
5-790.8224 Variable

6 452.0591 1.300 1.80400 46.60
7 41.1492 4.042
8 41.3304 3.091 1.68893 31.16
9 98.8092 4.158
10 -68.4923 1.000 1.70000 48.10
11 36.0772 3.318 1.80518 25.45
12 117.8747 Variable

13 180.8711 3.540 1.80400 46.60
14 -64.2101 0.200
15 40.7438 5.229 1.49700 81.73
16-52.5435 1.200 1.85026 32.35
17 200.0407 1.376
18 (S) ∞ variable
19 68.3281 1.200 1.71736 29.57
20 20.1023 6.000 1.56732 42.58
21 -61.5874 Variable

22 188.7697 2.905 1.72825 28.38
23-56.4394 0.719
24 -72.6983 1.000 1.80400 46.60
25 30.9300 Variable

26 -22.2025 1.300 1.69680 55.52
27-38.2594 0.200
28 95.0769 3.373 1.80610 40.97
29-205.8129 BF
I ∞

[Various data]
Magnification ratio 4.05
W M T
f 72.1 100.0 292.0
FNO 4.68 4.86 5.88
2ω 33.86 24.02 8.26
Ymax 21.60 21.60 21.60
TL 193.32 209.38 244.81
BF 38.32 41.53 60.32

W M T W M T
f, β 72.100 100.000 292.000 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 2108.51 2898.12 8259.76
d5 2.000 26.301 76.285 2.000 26.301 76.285
d12 45.791 35.345 2.000 45.791 35.345 2.000
d18 29.471 29.387 29.007 28.880 29.181 28.801
d21 2.000 3.362 2.000 2.786 4.328 3.858
d25 16.05 17.780 16.521 15.862 14.01 19 14.868

[Lens group data]
Group ST f
1 1 171.900
2 6 -43.196
3 13 51.979
4 19 82.476
5 22 -51.000
6 26 48383.794

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 0.125
(2) BFw / fw = 0.531
(3) (-fFN) / | fF | = 0.527
(4) nP / nN = 0.913
(5) | fF1 | / | f1 |
(6) | fF2 | / | f1 | = 0.297
(7) | fF 1 | / ft = 0.282
(8) | fF2 | / ft = 0.175
(9) | βWF1 | / | βWF2 | = 0.288
(10) | βRw | / | βRt | = 0.911
(11) ωw = 16.93 °

FIGS. 29A, 29B, and 29C are various aberration diagrams at the time of focusing on an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the tenth example.
FIGS. 30A, 30B, and 30C are various aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to the tenth example.

(Eleventh embodiment)
FIG. 31 shows a lens arrangement of a variable magnification optical system according to an eleventh example.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. , An aperture stop S, a fourth lens group G4 having negative refracting power, a fifth lens group G5 having positive refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group having negative refracting power It is composed of a lens group G7.

The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, and a cemented positive lens having a biconcave negative lens L12 and a positive meniscus lens L13 having a convex surface facing the object side It consists of
The second lens group G2 is composed of a positive cemented lens of a double convex positive lens L21 and a negative meniscus lens L22 having a concave surface facing the object side.
The third lens group G3 is composed of a positive cemented lens of a negative meniscus lens L31 with a convex surface facing the object side and a biconvex positive lens L32.

The fourth lens group G4 is composed of a cemented negative lens constructed by a double concave negative lens L41 and a positive meniscus lens L42 having a convex surface directed to the object side.
The fifth lens group G5 is composed of a biconvex positive lens L51.
The sixth lens group G6 is composed of a biconvex positive lens L61.
The seventh lens group G7 is composed of a negative meniscus lens L71 with a concave surface facing the object side.

Table 11 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 11) Eleventh embodiment [surface data]
m r d nd d d
OP ∞
1 260.0000 2.900 1.74389 49.53
* 2 30.1702 13.784
3-191.6463 2.100 1.59349 67.00
4 33.7055 8.364 2.00100 29.13
5 89.6077 Variable

6 108.4958 8.489 1.80100 34.92
7-30.7757 1.500 1.80518 25.45
8 -204.3062 Variable

9 45.1018 1.500 1.85000 27.03
10 24.0000 9.603 1.59319 67.90
11-88.4112 Variable

12 (S) ∞ 1.733
13 -63.2999 1.300 1.65100 56.24
14 36.0420 2.727 1.90265 35.72
15 90.4648 Variable

16 139.2934 5.000 1.48749 70.32
17-72.7540 variable

18 554.8019 4.200 1.5891 13 61.15
* 19-54.8898 Variable

* 20 -29.0077 1.500 1.84666 23.80
21 -45.1973 BF
I ∞

[Aspheric surface data]
m: 2
κ = 0.0000
A4 = 3.70839E-06
A6 = 7.95920 E-10
A8 = 7.22303 E-12
A10 = -1.14971E-14
A12 = 9.51080 E-18

m: 19
κ = 1.0000
A4 = 5.13891E-06
A6 = -3.95654E-09
A8 = 1.36188E-11
A10 = -1.64821E-14

m: 20
κ = 1.0000
A4 = 4.54393E-06
A6 = -1.30549E-09
A8 = 6.99274E-13
A10 = 4.71450E-15

[Various data]
Magnification 2.99
W M T
f 22.7 50.0 67.9
FNO 4.21 5.58 5.88
2ω 92.68 46.22 33.64
Ymax 19.70 21.60 21.60
TL 188.49 156.49 166.42
BF 14.19 21.35 26.73

W M T W M T
f, β 22.700 50.000 67.900 -0.033 -0.033 -0.033
d0 0.000 0.000 0.000 642.626 1479.20 2020.08
d5 62.024 9.333 2.263 62.024 9.333 2.263
d8 1.536 1.576 1.000 1.536 1.576 1.000
d11 2.200 6.706 19.808 2.200 6.706 19.808
d15 25.740 8.889 12.359 25.733 7.830 10.488
d17 3.523 29.546 31.736 2.523 29.489 32.585
d19 14.577 14.391 7.819 15.584 15.506 8.840

[Lens group data]
Group ST f
1 1 -47.325
2 6 90.647
3 9 68.586
4 12 -74.902
5 16 98.800
6 18 85.000
7 20-99.892

[Conditional expression corresponding value]
(1) MTF1 / MTF2 = 1.831
(2) BFw / fw = 0.625
(5) | fF1 | / | f1 | = 2.088
(6) | fF2 | / | f1 | = 1.796
(7) | fF1 | /ft=1.455
(8) | fF2 | / ft = 1.252
(9) | βWF1 | / | βWF2 | = 0.764
(10) | βRw | / | βRt | = 2.455
(11) ωw = 46.34 °

32A, 32B, and 32C are various aberration diagrams at the time of focusing on an infinite distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to Example 11.
FIGS. 33A, 33B, and 33C are aberration diagrams at the time of focusing on a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system according to Example 11.

According to each of the above-described embodiments, high optical performance is provided to well suppress aberration fluctuation during zooming from the wide-angle end state to the telephoto end state, and when focusing from an infinity object to a near distance object. A variable magnification optical system can be realized. Further, according to each of the above-described embodiments, since the weight reduction and size reduction of the focusing lens group can be realized, the drive mechanism of the focusing lens group can be miniaturized and the lens barrel can be made quiet at high speed without increasing the size of the lens barrel. It is possible to realize high-quality focusing operation.

The above-described embodiments show one specific example of the present invention, and the present invention is not limited thereto. The following contents can be adopted appropriately as long as the optical performance of the variable magnification optical system of this embodiment is not impaired.

Although a six-group configuration or a seven-group configuration is shown as a numerical example of the variable magnification optical system according to the present embodiment, the present embodiment is not limited to this, and the magnification variation of other group configurations (for example, eight groups etc.) An optical system can also be configured. Specifically, a lens or lens group may be added to the most object side or the most image side of the variable magnification optical system of each of the above embodiments. Alternatively, a lens or a lens group may be added between the adjacent lens group and the lens group.

In each of the above embodiments, two or three lens groups are used as focusing lens groups. However, a part of the lens groups or four or more lens groups may be used as focusing lens groups. In addition, each focusing lens group may be configured of one or two lens components, and a configuration including one lens component is more preferable. Such a focusing lens group can also be applied to auto focusing, and is also suitable for driving by a motor for auto focusing, such as an ultrasonic motor, a stepping motor, a VCM motor or the like.

Further, in the variable magnification optical system of each of the above-described embodiments, the entire lens group or a part thereof is moved as a vibration reduction group so as to include a component in a direction perpendicular to the optical axis, or It is also possible to adopt a configuration in which vibration isolation is performed by rotational movement (swinging) in the in-plane direction including.

The lens surface of the lens constituting the variable magnification optical system of each of the above embodiments may be a spherical surface, a flat surface, or an aspheric surface. When the lens surface is spherical or flat, it is preferable because lens processing and assembly adjustment can be facilitated, and deterioration of optical performance due to lens processing and assembly adjustment errors can be prevented. In addition, even when the image plane shifts, it is preferable because the deterioration of the imaging performance is small. When the lens surface is aspheric, any of aspheric aspheric surfaces by grinding, a glass mold aspheric surface formed by shaping a glass into aspheric surface shape, or a composite aspheric surface formed by forming a resin on a glass surface into an aspheric surface shape Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

In the variable magnification optical system of each of the above embodiments, the aperture stop S is disposed between the second lens group G2 and the third lens group G3 or between the third lens group G3 and the fourth lens group G4. However, the lens frame may substitute for the role without providing a member as the aperture stop.

Further, an antireflective film having high transmittance over a wide wavelength range may be provided on the lens surface of the lens constituting the variable magnification optical system of each of the above embodiments. This can reduce flare and ghost and achieve high contrast and high optical performance.

Next, a camera provided with the variable magnification optical system of the present embodiment will be described based on FIG.
FIG. 34 is a view showing the configuration of a camera provided with the variable magnification optical system of the present embodiment.
As shown in FIG. 34, the camera 1 is a so-called mirrorless camera of a lens interchangeable type provided with the variable magnification optical system according to the first embodiment as the photographing lens 2.

In the present camera 1, light from an object (not shown) from the object (not shown) is collected by the photographing lens 2 and passes through an OLPF (Optical Low Pass Filter) (not shown) on the imaging surface of the imaging unit 3 Form an image of the subject. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate the image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thereby, the photographer can observe the subject via the EVF 4.
When the photographer presses a release button (not shown), the image of the subject generated by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can shoot a subject with the main camera 1.

Here, the variable magnification optical system according to the first embodiment mounted as the photographing lens 2 in the present camera 1 has good optical performance as described above, and weight reduction and downsizing of the focusing lens group are achieved. ing. That is, the camera 1 realizes high optical performance that well suppresses aberration fluctuation during zooming from the wide-angle end state to the telephoto end state, and when focusing from an infinite distance object to a near distance object. By reducing the size and weight of the focusing lens unit, it is possible to realize high-speed focusing operation. Even if a camera mounted with the variable magnification optical system according to the second to eleventh examples as the taking lens 2 is configured, the same effect as the camera 1 can be obtained. Even when the variable magnification optical system according to each of the above embodiments is mounted on a single-lens reflex camera having a quick return mirror and observing a subject by a finder optical system, the same effect as that of the camera 1 can be obtained. it can.

Next, an outline of a method of manufacturing the variable magnification optical system of the present embodiment will be described based on FIG.
FIG. 35 is a flowchart showing an outline of a method of manufacturing a variable magnification optical system according to this embodiment.

The method of manufacturing a variable magnification optical system according to this embodiment shown in FIG. 35 is a method of manufacturing a variable magnification optical system having a plurality of lens groups, and includes the following steps S1 to S3.

Step S1: A plurality of lens groups are prepared, and the intervals between the lens groups are changed at the time of zooming.
Step S2: A plurality of lens units are disposed on the image side of the object-side focusing lens unit that moves during focusing and the object-side focusing lens unit, and a locus different from the object-side focusing lens unit during focusing And at least one image-side focusing lens group that moves in
Step S3: A variable magnification optical system is made to satisfy the following conditional expressions (1) and (2).
(1) MTF1 / MTF2 <5.0
(2) 0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system

According to the manufacturing method of the variable magnification optical system of the present embodiment, aberration fluctuation at the time of zooming from the wide-angle end state to the telephoto end state, and aberration fluctuation at the time of focusing from an infinite distance object to a near distance object As a result of realizing high optical performance that well suppresses the lens size and reducing the size and weight of the focusing lens group, it is possible to manufacture a variable power optical system that realizes speeding up of the focusing operation.

G1 first lens group G2 second lens group G3 third lens group G4 fourth lens group G5 fifth lens group G6 sixth lens group G7 seventh lens group S aperture stop I image plane 1 camera 2 photographing lens

Claims

Have multiple lens groups,
During zooming, the distance between the lens units changes,
The plurality of lens units are disposed on the image side of the object-side focusing lens unit that moves when focusing and the object-side focusing lens unit, and a locus that is different from the object-side focusing lens unit when focusing And at least one image-side focusing lens group that moves
Variable-magnification optical system that satisfies the following conditional expressions.
MTF1 / MTF2 <5.0
0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system
The at least one focusing lens group of the object side focusing lens group and the image side focusing lens group has a lens having at least one negative refractive power,
Variable-magnification optical system that satisfies the following conditional expressions.
0.45 <(-fFN) / | fF | <1.70
However,
fFN: Of the lenses in the object-side focusing lens group and the image-side focusing lens group, the focal length fF of the lens having the strongest negative refractive power: the object-side focusing lens group and the image-side focusing Of the lens units, the focal length of the focusing lens unit with the highest refractive power
The variable magnification optical system according to claim 1, wherein the object side focusing lens group has positive refractive power.
The variable magnification optical system according to any one of claims 1 to 3, wherein a focusing lens group disposed closest to the image among the image side focusing lens groups has positive refractive power.
The variable magnification optical system according to any one of claims 1 to 4, wherein the object side focusing lens group is configured of one or two lens components.
The variable magnification optical system according to any one of claims 1 to 5, wherein the image side focusing lens group is configured of one or two lens components.
The variable magnification optical system according to any one of claims 1 to 6, further comprising a first lens unit which is fixed at the time of focusing on the most object side.
The at least one focusing lens group of the object side focusing lens group and the image side focusing lens group has a lens having at least one negative refractive power,
The variable magnification optical system according to any one of claims 1 to 7, which satisfies the following conditional expression.
0.65 <nP / nN <1.10
However,
nP: Of the lenses in the object side focusing lens group and the image side focusing lens group, the refractive index nN of the lens having the most positive refractive power: the object side focusing lens group and the image side focusing Of the lenses in the lens group, the refractive index of the lens with the strongest negative refractive power
The variable magnification optical system according to any one of claims 7 and 8, wherein the following conditional expression is satisfied.
0.40 <| fF1 | / | f1 | <2.60
However,
fF1: focal length of the object side focusing lens unit f1: focal length of the first lens unit
The variable magnification optical system according to any one of claims 7 to 9, which satisfies the following conditional expression.
0.20 <| fF2 | / | f1 | <3.80
However,
fF2: Focal length f1 of the focusing lens group disposed closest to the image side among the image-side focusing lens groups f1: Focal length of the first lens group
The variable magnification optical system according to any one of claims 1 to 10, wherein the object side focusing lens group comprises, in order from the object side, a lens having a positive refractive power and a lens having a negative refractive power. system.
With an aperture stop,
The variable magnification optical system according to any one of claims 1 to 11, wherein the object side focusing lens group is disposed on the image side of the aperture stop.
The variable magnification optical system according to any one of claims 1 to 12, which satisfies the following conditional expression.
0.10 <| fF1 | / ft <3.00
However,
fF1: focal length ft of the object-side focusing lens unit focal length of the variable magnification optical system in the telephoto end state
The variable magnification optical system according to any one of claims 1 to 13, which satisfies the following conditional expression.
0.10 <| fF2 | / ft <3.00
However,
fF2: focal length ft of the focusing lens group disposed closest to the image side among the image-side focusing lens groups ft: focal length of the variable magnification optical system in the telephoto end state
The variable magnification optical system according to any one of claims 1 to 14, wherein the following conditional expressions are satisfied.
| ΒWF1 | / | βWF2 | <4.00
However,
βWF1: lateral magnification of the object-side focusing lens unit in the wide-angle end state when focusing on an infinite object βWF2: to the most object side of the image-side focusing lens units in the wide-angle end state when focusing on an infinite object Lateral magnification of the focusing lens unit arranged
The variable magnification optical system according to any one of claims 1 to 15, which satisfies the following conditional expression.
| ΒRw | / | βRt | <4.00
However,
βRw: composite lateral magnification from the object-side focusing lens unit to the image plane in the wide-angle end state at the time of infinity object focusing βRt: an image from the object-side focusing lens group in the telephoto end state at infinity object focusing Composite lateral magnification up to surface
The variable magnification optical system according to any one of claims 1 to 16, which satisfies the following conditional expression.
15.0 ° <ωw <85.0 °
However,
ω w: half angle of view of the variable magnification optical system in the wide angle end state
An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 17.
A method of manufacturing a variable magnification optical system having a plurality of lens groups, comprising:
The distance between the lens units is changed during zooming.
The plurality of lens units are disposed on the image side of the object-side focusing lens unit moving in focusing and the image-side focusing lens unit, and a locus different from the object-side focusing lens unit in focusing And at least one image-side focusing lens group that moves at
A manufacturing method of a variable magnification optical system configured to satisfy the following conditional expression.
MTF1 / MTF2 <5.0
0.2 <BFw / fw <2.0
However,
MTF1: absolute value of the amount of movement of the object-side focusing lens unit when focusing from an infinite distance object to a close distance object in the telephoto end state MTF2: focusing from an infinity object to a close object in the telephoto end state The absolute value BFw of the movement amount of the focusing lens unit disposed closest to the object side among the image-side focusing lens units at the time of: back focus fw of the variable magnification optical system in the wide angle end state: in the wide angle end state Focal length of the variable magnification optical system