JP6504189B2 - Variable power optical system, optical device, manufacturing method of variable power optical system - Google Patents

Description

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

  Heretofore, many variable magnification optical systems suitable for interchangeable lenses for cameras, digital cameras, video cameras and the like have been proposed in which the lens group on the most object side has positive refractive power (for example, Patent Document 1) reference.).

JP, 2010-237455, A

  However, in the conventional variable magnification optical system as described above, there is a problem that it is difficult to obtain sufficiently high optical performance if attempting to miniaturize.

  Accordingly, the present invention has been made in view of the above problems, and has an object to provide a variable magnification optical system having a small size and high optical performance, an optical device, and a method of manufacturing the variable magnification optical system.

In order to solve the above problems, the present invention is
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side And a cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a plano-convex positive lens convex on the object side.
The present invention provides a variable magnification optical system characterized by satisfying the following conditional expression.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes at least one lens that satisfies the following conditional expression,
0.450 <| fh / f1 | <1.400
However,
fh: focal length f1 of the lens in the first lens group: focal length of the first lens group The first lens group is a negative meniscus lens having a convex surface facing the object side and a biconvex shape in order from the object side And a positive meniscus lens having a convex surface facing the object side, or a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens in order from the object side. A variable power optical system comprising a plano-convex positive lens with a convex surface facing the object side.
The present invention
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group has a positive lens satisfying the following conditional expression,
75.00 <dpdp1
However,
dp dp1: Abbe number of d-line (wavelength 587.6 nm) of the positive lens in the first lens group The first lens group has a negative meniscus lens with a convex surface facing the object side and a biconvex shape in order from the object side And a positive meniscus lens having a convex surface facing the object side, or a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens in order from the object side. A variable power optical system comprising a plano-convex positive lens with a convex surface facing the object side.
The present invention
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side And a cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a plano-convex positive lens convex on the object side.
The variable power optical system is characterized in that the rear lens group has a positive lens satisfying the following conditional expression.
75.00 <d dpr
However,
d dpr: Abbe number of d-line (wavelength 587.6 nm) of the positive lens in the rear lens group
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
A variable magnification optical system is provided, wherein the rear lens group includes at least one lens satisfying the following conditional expression .
31.60 <d dhr
However,
d dhr: Abbe number of d-line (wavelength 587.6 nm) of the lens in the back lens group
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dh dh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens Have one,
31.60 <d dhr
However,
d dhr: A variable magnification optical system characterized by satisfying a conditional expression less than or equal to the Abbe number for the d-line (wavelength 587.6 nm) of the lens in the rear lens group.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group
From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dh dh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens Have one,
31.60 <d dhr
However,
d dhr: Abbe number of the lens in the rear lens group with respect to d-line (wavelength 587.6 nm) The rear lens group has a positive lens satisfying the following conditional expression. provide.
75.00 <d dpr
However,
d dpr: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the rear lens group

The present invention
An optical apparatus comprising the variable magnification optical system is provided.

The present invention
A manufacturing method of a variable power optical system having, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a rear lens group having positive refractive power. There,
The rear lens group includes a plurality of lens groups;
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups is changed,
Have at least one lens that satisfies the following condition:
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens
Making the first lens group have at least one lens,
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side From the cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a planoconvex positive lens convex on the object side,
A manufacturing method of a variable magnification optical system characterized by satisfying the following conditional expression is provided.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group
f2: focal length of the second lens group

  According to the present invention, it is possible to provide a variable magnification optical system having a small size and high optical performance, an optical device, and a method of manufacturing the variable magnification optical system.

(A), (b), and (c) are respectively sectional drawings in the wide-angle end state, an intermediate focal length state, and a telephoto end state of the variable magnification optical system according to the first example of the present application. (A), (b) and (c) show various items at the time of focusing on an object at infinity 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 embodiment of the present application. FIG. (A), (b), and (c) are respectively sectional views in the wide-angle end state, an intermediate focal length state, and a telephoto end state of a variable magnification optical system according to a second example of the present application. (A), (b), and (c) show various items 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 of the variable magnification optical system according to the second embodiment of the present application, respectively. FIG. (A), (b), and (c) are respectively sectional views 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 of the present application. (A), (b) and (c) show various items 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 of the variable magnification optical system according to the third embodiment of the present application. FIG. (A), (b), and (c) are respectively sectional views in the wide-angle end state, an intermediate focal length state, and a telephoto end state of a variable magnification optical system according to a fourth example of the present application. (A), (b) and (c) show various items 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 of the variable magnification optical system according to the fourth embodiment of the present application. FIG. (A), (b), and (c) are respectively sectional views in the wide-angle end state, an intermediate focal length state, and a telephoto end state of a variable magnification optical system according to a fifth example of the present application. (A), (b) and (c) show various items 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 of the variable magnification optical system according to the fifth example of the present application. FIG. (A), (b), and (c) are respectively sectional views in the wide-angle end state, an intermediate focal length state, and a telephoto end state of the variable magnification optical system according to the sixth example of the present application. (A), (b) and (c) show various items 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 of the variable magnification optical system according to the sixth embodiment of the present application. FIG. It is a figure which shows the structure of the camera provided with the variable magnification optical system of this application. It is a figure which shows the outline of the manufacturing method of the variable magnification optical system of this application.

The variable magnification optical system, the optical apparatus, and the method of manufacturing the variable magnification optical system according to the present application will be described below.
The variable magnification optical system of the present application includes, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a rear lens group having positive refractive power. Between the wide-angle end state and the telephoto end state, the distance between the first lens group and the second lens group and the distance between the second lens group and the rear lens group are changed. And With this configuration, the variable magnification optical system according to the present application realizes zooming from the wide-angle end state to the telephoto end state, and can suppress the fluctuation of distortion due to the zooming.

The variable magnification optical system of the present invention is characterized by having at least one lens satisfying the following conditional expressions (1) and (2).
(1) 1.928 <ndh
(2) 28.60 <dhdh
However,
ndh: refractive index dhdh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens

Conditional expression (1) defines the optimum refractive index of the lens. By satisfying the conditional expression (1), the variable magnification optical system according to the present application can achieve downsizing while suppressing fluctuations of spherical aberration and astigmatism during zooming.
When the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress the variation of spherical aberration and the variation of astigmatism at the time of zooming and realizes high optical performance. Will not be able to In order to further ensure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (1) to 1.940.
In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit value of the conditional expression (1) to 2.800. When the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application is smaller than 2.800, the visible light transmittance of the material of the lens can be sufficiently secured.

Conditional expression (2) defines an optimal Abbe number of the lens. By satisfying the conditional expression (2), the variable magnification optical system according to the present application can achieve downsizing while suppressing fluctuation of axial chromatic aberration and fluctuation of lateral chromatic aberration during zooming.
When the corresponding value of the conditional expression (2) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress fluctuation of axial chromatic aberration and magnification chromatic aberration during zooming, and realizes high optical performance. Will not be able to In order to further ensure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (2) to 29.00. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the lower limit of conditional expression (2) to 30.00. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the lower limit of conditional expression (2) to 32.00.
In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit of conditional expression (2) to 50.00. When the corresponding value of the conditional expression (2) of the variable magnification optical system of the present application is smaller than 50.00, it is possible to suppress the fluctuation of axial chromatic aberration and the fluctuation of lateral chromatic aberration which occur in lenses other than the lens during zooming. It is possible to realize high optical performance.
With the above configuration, it is possible to realize a compact variable power optical system having high optical performance.

  In the zoom lens system according to the present application, it is preferable that the first lens group has at least one lens. With this configuration, it is possible to suppress the respective variations of spherical aberration, astigmatism, axial chromatic aberration, and lateral chromatic aberration that occur in the first lens unit during zooming.

Further, it is desirable that the variable magnification optical system of the present application satisfy the following conditional expression (3).
(3) 5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group

Conditional expression (3) defines an appropriate range of the focal length ratio of the first lens group and the second lens group. By satisfying the conditional expression (3), the variable magnification optical system according to the present application can suppress variation in astigmatism at the time of variable power while maintaining a high zoom ratio.
When the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application falls below the lower limit value, astigmatism largely occurs in the wide-angle end state, and high optical performance can not be realized. In order to further ensure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (3) to 5.60. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the lower limit of conditional expression (3) to 5.90.
On the other hand, when the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application exceeds the upper limit value, it becomes difficult to suppress the fluctuation of astigmatism generated in the second lens unit at the time of zooming. In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit value of the conditional expression (3) to 11.50. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the upper limit of conditional expression (3) to 10.20.

Further, it is desirable that the variable magnification optical system of the present application satisfy the following conditional expression (4).
(4) 0.160 <(-f2) / fR <0.550
However,
f2: focal length of the second lens group fR: focal length of the rear lens group

Conditional expression (4) defines an appropriate range of the focal length ratio of the second lens unit to the rear lens unit. By satisfying the conditional expression (4), the variable magnification optical system according to the present application can suppress the fluctuation of spherical aberration and the fluctuation of astigmatism during zooming while maintaining a high magnification ratio.
When the corresponding value of the conditional expression (4) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress the fluctuation of astigmatism generated in the second lens unit at the time of zooming. In order to make the effect of the present invention more reliable, it is more preferable to set the lower limit value of the conditional expression (4) to 0.240. Furthermore, in order to make the effect of the present invention more reliable, it is more preferable to set the lower limit value of conditional expression (4) to 0.340.
On the other hand, when the corresponding value of the conditional expression (4) of the variable magnification optical system of the present application exceeds the upper limit value, it becomes difficult to suppress the variation of the spherical aberration generated in the rear lens unit during zooming.

In the zoom lens system according to the present application, it is preferable that the first lens group includes at least one lens satisfying the following conditional expression (5).
(5) 0.450 <| fh / f1 | <1.400
However,
fh: focal length of the lens in the first lens group f1: focal length of the first lens group

  Conditional expression (5) defines the optimum focal length range of the lens in the first lens group. When the lens is cemented with another lens, fh represents the focal length of the single lens. By satisfying the conditional expression (5), the variable magnification optical system according to the present application can suppress variations in spherical aberration, astigmatism, axial chromatic aberration, and lateral chromatic aberration at the time of zooming.

Here, conditional expression (5) will be described separately for the case where the lens has positive refractive power and the case where the lens has negative refractive power.
When the lens has positive refractive power, if the corresponding value of the conditional expression (5) of the variable magnification optical system of the present application falls below the lower limit value, fluctuation of axial chromatic aberration or magnification chromatic aberration generated at the lens during zooming It becomes difficult to suppress the fluctuation, and it becomes impossible to realize high optical performance. On the other hand, when the corresponding value of conditional expression (5) of the variable magnification optical system of the present application exceeds the upper limit, it becomes difficult to suppress positive spherical aberration generated in the second lens group in the telephoto end state, and high optical performance Can not be realized.

In the case where the lens has negative refractive power, if the value of the conditional expression (5) of the variable magnification optical system of the present application falls below the lower limit value, it is possible to suppress fluctuation of astigmatism generated in the lens at the time of zooming. It becomes difficult and can not realize high optical performance. On the other hand, when the corresponding value of the conditional expression (5) of the variable magnification optical system of the present application exceeds the upper limit value, it is difficult to suppress fluctuations of axial chromatic aberration and magnification chromatic aberration caused by lenses other than the lens during zooming. As a result, high optical performance can not be realized.
In order to make the effect of the present invention more reliable, it is more preferable to set the lower limit value of the conditional expression (5) to 0.620. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the upper limit of conditional expression (5) to 1.290.

  In the zoom lens system according to the present application, it is preferable that the rear lens group have at least one lens. With this configuration, it is possible to suppress the respective variations of the spherical aberration, the astigmatism, the axial chromatic aberration, and the lateral chromatic aberration that occur in the rear lens group from the wide-angle end state to the telephoto end state.

  In the variable magnification optical system of the present application, it is preferable that the second lens group has at least one lens. With this configuration, it is possible to suppress the respective variations of the spherical aberration, the astigmatism, the axial chromatic aberration, and the lateral chromatic aberration generated in the second lens group from the wide-angle end state to the telephoto end state.

  In the zoom lens system according to the present application, it is preferable that the first lens group includes at least one lens having negative refractive power. With this configuration, it is possible to suppress the fluctuation of the magnification chromatic aberration generated in the first lens group at the time of zooming, in particular, the fluctuation of the secondary chromatic aberration, and it is possible to realize high optical performance.

  In the zoom lens system of the present application, it is preferable that the rear lens group have at least one lens having negative refractive power. With this configuration, it is possible to suppress axial chromatic aberration, particularly secondary chromatic aberration, generated in the rear lens group, and high optical performance can be realized.

In the zoom lens system of the present application, it is preferable that the rear lens group include at least one lens satisfying the following conditional expression (6).
(6) 31.60 <d dhr
However,
d dhr: Abbe number for d-line (wavelength 587.6 nm) of the lens in the rear lens group

Conditional expression (6) defines the optimum Abbe number of the lens in the rear lens unit. The variable magnification optical system according to the present application can suppress axial chromatic aberration and lateral chromatic aberration by satisfying the conditional expression (6).
When the corresponding value of the conditional expression (6) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress axial chromatic aberration and lateral chromatic aberration generated in lenses other than the lens in the rear lens group. It will not be possible to realize high optical performance.

  In the zoom lens system according to the present application, it is preferable that the second lens group includes at least one lens having negative refractive power. With this configuration, it is possible to suppress the variation of the spherical aberration and the variation of the astigmatism generated in the second lens unit at the time of zooming, and to realize high optical performance.

In the zoom lens system of the present application, it is preferable that the first lens group have a positive lens that satisfies the following conditional expression (7).
(7) 75.00 <dpdp1
However,
dpdp1: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the first lens group

Conditional expression (7) defines the optimum Abbe number of the positive lens in the first lens group. By satisfying the conditional expression (7), the variable magnification optical system according to the present application can suppress fluctuation of axial chromatic aberration and fluctuation of lateral chromatic aberration at the time of magnification change.
When the corresponding value of the conditional expression (7) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress fluctuations of axial chromatic aberration and magnification chromatic aberration during zooming, and realizes high optical performance. Will not be able to
In order to further ensure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (7) to 99.00. Since the corresponding value of the conditional expression (7) of the variable magnification optical system according to the present application is smaller than 99.00, the fluctuation of axial chromatic aberration and the fluctuation of lateral chromatic aberration caused by lenses other than the positive lens during zooming are suppressed. And high optical performance can be realized.

In the zoom lens system of the present invention, it is preferable that the rear lens group have a positive lens that satisfies the following conditional expression (8).
(8) 75.00 <d dpr
However,
d dpr: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the rear lens group

Conditional expression (8) defines the optimum Abbe number of the positive lens in the rear lens unit. By satisfying the conditional expression (8), the variable magnification optical system according to the present application can suppress fluctuation of axial chromatic aberration and fluctuation of lateral chromatic aberration at the time of zooming.
When the corresponding value of the conditional expression (8) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress fluctuation of axial chromatic aberration during zooming, and high optical performance can not be realized. .
In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit of conditional expression (8) to 99.00. By making the correspondence value of the conditional expression (8) of the variable magnification optical system of the present application smaller than 99.00, it is possible to suppress axial chromatic aberration generated by lenses other than the positive lens and realize high optical performance. Can.

  Further, in the variable magnification optical system of the present application, it is desirable that an interval between the first lens group and the second lens group be increased at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, the magnification of the second lens unit is increased during zooming from the wide-angle end state to the telephoto end state, and the focal length of the first lens group and the focal length of the second lens group are made appropriate. it can. Further, it is possible to suppress spherical aberration and astigmatism generated in each lens unit, and to suppress variation of spherical aberration and variation of astigmatism during zooming.

  Further, in the variable magnification optical system of the present application, it is desirable that the distance between the second lens unit and the rear lens unit be reduced at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, the magnification of the rear lens unit is increased during zooming from the wide-angle end state to the telephoto end state, and the focal length of the second lens group and the focal length of the rear lens group are made appropriate. it can. Further, it is possible to suppress spherical aberration and astigmatism generated in each lens unit, and to suppress variation of spherical aberration and variation of astigmatism during zooming.

  In the variable magnification optical system according to the present application, it is preferable that the rear side lens unit has a plurality of lens units, and the interval between the plurality of lens units changes during zooming from the wide-angle end state to the telephoto end state. . According to this configuration, it is possible to suppress the variation of the spherical aberration and the variation of the astigmatism generated in the rear lens unit at the time of zooming.

  The optical apparatus of the present application is characterized by including the variable magnification optical system having the above-described configuration. As a result, it is possible to realize an optical device that is compact and has high optical performance.

In the method of manufacturing a variable magnification optical system according to the present application, a first lens group having positive refractive power, a second lens group having negative refractive power, and a rear lens group having positive refractive power are arranged in order from the object side And at least one lens satisfying the following conditional expressions (1) and (2), and at the time of zooming from the wide-angle end state to the telephoto end state: The distance between the first lens group and the second lens group and the distance between the second lens group and the rear lens group may be changed. As a result, it is possible to manufacture a compact variable power optical system having high optical performance.
(1) 1.928 <ndh
(2) 28.60 <dhdh
However,
ndh: refractive index dhdh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens

Hereinafter, a variable magnification optical system according to a numerical example of the present application will be described based on the attached drawings.
(First embodiment)
1 (a), 1 (b), and 1 (c) are cross-sectional views 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 first embodiment of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 includes, in order from the object side, a 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 Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a concave surface facing the object It consists of a negative meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.
The rear lens group GR includes, in order from the object side, a first partial group GR1 having positive refractive power, a second partial group GR2 having negative refractive power, and a third partial group GR3 having positive refractive power. It consists of An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302.
The second partial group GR2 is, in order from the object side, a cemented lens of a biconvex positive lens L303 and a biconcave negative lens L304, and a positive meniscus with a biconcave negative lens L305 and a convex surface facing the object side And a cemented lens with the lens L306. The negative lens L305 is a glass mold aspheric lens having an aspheric lens surface on the object side.
The third partial group GR3 includes, in order from the object side, a biconvex positive lens L307, a cemented lens of a biconvex positive lens L308 and a negative meniscus lens L309 having a concave surface facing the object side, and a convex surface facing the object side The cemented lens of a negative meniscus lens L310 with a double convex shape and a biconvex positive lens L311, and a negative meniscus lens L312 with a convex surface facing the image side. The negative meniscus lens L312 is a glass mold aspheric lens having an aspheric lens surface on the image side.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

  Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. In detail, the first lens group G1 moves to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the intermediate focal length state, and moves to the image side from the intermediate focal length state to the telephoto end state. In the rear lens group GR, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the aperture stop S and the first partial group GR1 decreases, and the first partial group GR1 and the second partial group GR2 The first partial group GR1, the second partial group GR2, and the third partial group GR3 are aligned with the optical axis so that the air interval between the second partial group GR2 and the third partial group GR3 decreases. Moving along, the aperture stop S moves integrally with the second partial group GR2. In detail, the first partial group GR1 moves to the object side at the time of zooming. The second partial group GR2 and the third partial group GR3 move to the object side from the wide-angle end state to the intermediate focal length state, and move to the image side from the intermediate focal length state to the telephoto end state.

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 (the distance between the most image side lens surface and the image plane I on the optical axis).
In [Surface Data], the surface number is the order of the optical surface counted from the object side, r is the radius of curvature, d is the surface distance (the distance between the nth surface (n is an integer) and the n + 1th surface), nd is The refractive index for the d-line (wavelength 587.6 nm) and ν d indicate the Abbe number for the d-line (wavelength 587.6 nm). The object plane indicates the object plane, the variable plane spacing is variable, the stop S indicates the aperture stop S, and the image plane indicates the image plane I. The radius of curvature r = ∞ indicates a plane. In the aspheric surface, the surface number is marked with *, and the value of the paraxial radius of curvature is shown in the column of radius of curvature r. The description of the refractive index nd = 1.000000 of air is omitted.

[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-κ (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 (sag amount), and κ is the conical constant , A4, A6, A8 and A10 are aspheric coefficients, and r is the radius of curvature (paraxial radius of curvature) of the reference spherical surface. Incidentally, "E-n" (n is an integer) indicates "× 10 ^-n", for example "1.234E-05" denotes "1.234 × 10 ^-5". The second-order aspheric coefficient A2 is 0, and the description is omitted.

In [Various data], FNO is F number, ω is half angle of view (unit: “°”), Y is image height, TL is total length of variable magnification optical system (image from first surface at infinity object focusing The distance on the optical axis to the surface I), dn represents a variable distance between the nth surface and the n + 1th surface, and φ represents the diameter of the aperture stop S. W indicates the wide-angle end state, M indicates the intermediate focal length state, and T indicates the telephoto end state.
[Lens group data] indicates the starting surface of each lens group and the focal length.
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
[Plane data]
Face number r d nd d d
Object ∞

1 104.5118 1.6000 2.003300 28.27
2 39.3751 7.4000 1.497820 82.57
3-463.5701 0.1000
4 40.3116 5.4000 1.834810 42.73
5 241.9089 Variable

* 6 79.9711 1.0000 1.851350 40.10
7 8.1252 4.8500
8 -14.2116 1.0000 1.883000 40.66
9 124.9279 0.1000
10 30.8124 3.3500 1.808090 22.74
11-15.1873 0.3000
12-13.2221 1.0000 1.883000 40.66
13-23.0302 Variable

14 (stop S) ∞ variable

15 26.1923 1.0000 1.954000 33.46
16 12.2483 2.8500 1.719990 50.27
17 -43.5073 Variable

18 14.5527 2.8500 1.497820 82.57
19-40.3301 1.0000 1.950000 29.37
20 173.4596 2.1500
* 21 -105.0156 1.0000 1.806100 40.71
22 10.9037 2.2000 1.808090 22.74
23 28.6084 Variable

24 30.6882 2.8500 1.579570 53.74
25-18.3.905 0.1000
26 18.8919 3.6000 1.518230 58.82
27-13.1344 1.0000 2.000690 25.46
28 -2198.5412 0.7500
29 412.2295 1.0000 1.954000 33.46
30 12.8823 3.5000 1.755200 27.57
31-23.7185 1.1500
32-16.1296 1.0000 1.806100 40.71
* 33-97.3104 BF

Image plane ∞

[Aspheric surface data]
Sixth face--8.7294
A4 4.64796E-05
A6-4.09659E-07
A8 2.44519E-09
A10-9.90503E-12

The 21st face--1.5760
A4 1.72590E-05
A6 9.45415E-08
A8-1.00397E-09
A10 0.00000E + 00

The 33rd face -19.8082
A4 -1.67719E-05
A6-2.11776E-07
A8-4.15932E-10
A10-1.15008E-11

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 97.00
FNO 4.09 to 5.81
ω 40.21 to 4.76 °
Y 8.19 to 8.19

W M T
f 10.30000 50.00013 97.00039
ω 40.21337 9.15519 4.75685
FNO 4.09 5.78 5.81
φ 7.68 8.50 9.20
TL 100. 29944 130.25093 139.59967
d5 2.10000 28.50000 39.66696
d13 17.38897 3.31447 2.00000
d14 4.87082 3.98262 1.60000
d17 2.59389 3.48209 5.86471
d23 5.29632 3.42829 3.30000
BF 13.94944 33.44346 33.06800

[Lens group data]
Group front f
1 1 64. 38705
2 6-9.57903
R15 19.60736 (W), 19.90275 (M), 19.45721 (T)
R1 15 29.91408
R2 18 -81.48313
R3 24 28.77173

[Conditional expression corresponding value]
(1) ndh = 1.954 (L301), 1.950 (L304), 1.954 (L310)
(2) dh dh = 33.46 (L301), 29.37 (L304), 33.46 (L310)
(3) f1 / (− f2) = 6.72
(4) (-f2) / fR = 0.489 (W), 0.503 (M), 0.492 (T)
(6) d dhr = 33.46 (L301), 33.46 (L310)
(7) dpdp1 = 82.57 (L12)
(8) d dpr = 82.57 (L 303)

  2 (a), 2 (b) and 2 (c) show infinity of the variable magnification optical system according to the first embodiment of the present invention at the wide-angle end, at the intermediate focal length and at the telephoto end, respectively. FIG. 7 shows various aberrations that occurred when the object was in focus.

  In each of the aberration diagrams, FNO denotes an F number, and A denotes a light beam incident angle, that is, a half angle of view (unit: "°"). d indicates the aberration at the d-line (wavelength 587.6 nm), g indicates the aberration at the g-line (wavelength 435.8 nm), and those without d and g indicate the aberration at the d-line. 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 charts of the examples which will be described later.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Second Embodiment
3 (a), 3 (b), and 3 (c) are cross-sectional views 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 second embodiment of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 includes, in order from the object side, a 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 Become.
The second lens group G2 includes, in order from the object side, a biconcave negative lens L21, a biconcave negative lens L22, a biconvex positive lens L23, and a negative meniscus lens L24 having a concave surface facing the object side. It consists of
The rear lens group GR includes, in order from the object side, a first partial group GR1 having positive refractive power, a second partial group GR2 having negative refractive power, and a third partial group GR3 having positive refractive power. It consists of An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302.
The second partial group GR2 is, in order from the object side, a cemented lens of a biconvex positive lens L303 and a biconcave negative lens L304, and a positive meniscus with a biconcave negative lens L305 and a convex surface facing the object side And a cemented lens with the lens L306. The negative lens L305 is a glass mold aspheric lens having an aspheric lens surface on the object side.
The third partial group GR3 includes, in order from the object side, a double convex positive lens L307, and a cemented lens of a positive meniscus lens L308 concave on the object side and a negative meniscus lens L309 concave on the object side. Become. The positive lens L307 is a glass mold aspheric lens having an aspheric lens surface on the object side.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. In detail, the first lens group G1 moves to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the intermediate focal length state, and moves to the image side from the intermediate focal length state to the telephoto end state. In the rear lens group GR, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the aperture stop S and the first partial group GR1 decreases, and the first partial group GR1 and the second partial group GR2 Of the first partial group GR1, the second partial group GR2 and the third partial group GR3 to the object side so that the air interval between the second partial group GR2 and the third partial group GR3 decreases. The aperture stop S moves integrally with the second part group GR2.
Table 2 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 2) Second embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 251.8446 1.6000 1.950000 29.37
2 36.8495 7.9000 1.497820 82.57
3 -162.8867 0.1000
4 41.6898 5.7500 1.883000 40.66
5 7827.2710 Variable

6-808.8261 1.0000 1.883000 40.66
7 9.5148 3.6000
8-15.5435 1.0000 1.883000 40.66
9 143.0303 0.1000
10 28.6318 3.0500 1.808090 22.74
11-13.3 1 0.2500
12-12.1771 1.0000 1.834810 42.73
13-36.4394 Variable

14 (stop S) ∞ variable

15 27.0772 1.0000 2.000690 25.46
16 15. 7705 2. 5000 1. 744000 44. 80
17-35.2142 Variable

18 12.6941 2.9500 1.497820 82.57
19-24.8876 1.0000 1.846660 23.80
20 775.1758 2.1500
* 21-227.6550 1.0000 1.806100 40.97
22 8.8217 2.2000 1.846660 23.80
23 19.5840 Variable

* 24 15.0000 3.1500 1.583130 59.42
25-23.9888 0.1000
26-509.6518 4.2000 1.581440 40.98
27 -7.8594 1.0000 1.954000 33.46
28 -200.0000 BF

Image plane ∞

[Aspheric surface data]
The 21st face -20.0000
A4 1.61374E-05
A6-2.79 859 E-08
A8-1.22068E-09
A10 0.00000E + 00

The 24th 3.6 3.6281
A4-1.212377 E-04
A6-7. 10924 E-07
A8 1.36403E-08
A10-4.10781E-10

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 97.00
FNO 4.12 to 6.48
ω 43.07-4.70 °
Y 8.19 to 8.19

W M T
f 10.30000 50.00001 96.99995
ω 43.07103 9.11914 4.70123
FNO 4.12 5.81 6.48
φ 6.80 7.90 7.90
TL 90.80323 122.13334 131.09941
d5 2.28937 28.97477 38.62002
d13 13.12572 3.71901 2.00000
d14 6.29895 3.32684 1.40000
d17 2.43367 5.40578 7.33262
d23 6.60623 3.30000 3.30000
BF 13.44928 30.80693 31.84677

[Lens group data]
Group front f
1 1 59.94630
2 6 -8.99248
R15 17.81228 (W), 17.01324 (M), 17.322 228 (T)
R1 15 24.34092
R2 18 -112.21259
R3 24 35.78226

[Conditional expression corresponding value]
(1) ndh = 1.950 (L11), 1.954 (L309)
(2) dhdh = 29.37 (L11), 33.46 (L309)
(3) f1 / (-f2) = 6.67
(4) (-f2) / fR = 0.505 (W), 0.529 (M), 0.519 (T)
(5) | fh / f1 | = 0.761 (L11)
(6) d dhr = 33. 46 (L 309)
(7) dpdp1 = 82.57 (L12)
(8) d dpr = 82.57 (L 303)

  FIGS. 4 (a), 4 (b) and 4 (c) show infinity of the variable magnification optical system according to the second embodiment of the present invention at the wide-angle end, at the intermediate focal length and at the telephoto end, respectively. FIG. 7 shows various aberrations that occurred when the object was in focus.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Third Embodiment
5 (a), 5 (b), and 5 (c) are cross-sectional views 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 third embodiment of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 includes, in order from the object side, a 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 Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a concave surface facing the object It consists of a negative meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.
The rear lens group GR includes, in order from the object side, a first partial group GR1 having positive refractive power, a second partial group GR2 having negative refractive power, and a third partial group GR3 having positive refractive power. It consists of An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302.
The second partial group GR2 includes, in order from the object side, a cemented lens of a biconvex positive lens L303 and a negative meniscus lens L304 having a convex surface facing the image side, a biconcave negative lens L305, and a convex surface on the object side And a cemented lens with a positive meniscus lens L306 directed. The negative lens L305 is a glass mold aspheric lens having an aspheric lens surface on the object side.
The third partial group GR3 is composed of, in order from the object side, a double convex positive lens L307, and a cemented lens of a double convex positive lens L308 and a negative meniscus lens L309 having a concave surface facing the object side. The positive lens L307 is a glass mold aspheric lens having an aspheric lens surface on the object side.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. In detail, the first lens group G1 moves to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the intermediate focal length state, and moves to the image side from the intermediate focal length state to the telephoto end state. In the rear lens group GR, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the aperture stop S and the first partial group GR1 decreases, and the first partial group GR1 and the second partial group GR2 Of the first partial group GR1, the second partial group GR2 and the third partial group GR3 to the object side so that the air interval between the second partial group GR2 and the third partial group GR3 decreases. The aperture stop S moves integrally with the second part group GR2.
Table 3 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 3) Third embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 149.8692 1.6000 1.949665 27.56
2 44.3736 6.8398 1 .97820 82.51
3 -243.5058 0.1000
4 45.3756 5.3508 1.867900 41.78
5 311.4136 Variable

* 6 89.0243 1.2000 1.834810 42.73
7 8.4900 3.7581
8-15.7255 1.0000 1.834810 42.73
9 250.0000 0.1000
10 25.2749 3.2925 1.808090 22.74
11-17.4 750 0.5480
12-12.6196 1.0000 1.816000 46.59
13 -33.4252 Variable

14 (stop S) ∞ variable

15 29.1681 1.0000 1.889044 39.77
16 18.2404 3.2071 1.593125 66.16
17-26.5261 Variable

18 14.2857 3.5654 1.497820 82.51
19-21.9776 1.0000 1.902000 25.23
20 -82.8398 2.2052
* 21-52.3071 1.0000 1.848976 43.01
22 9.1414 2.6915 1.950000 29.37
23 25.8642 Variable

* 24 35.4414 3.3350 1.589130 61.22
25-21.3191 0.3000
26 42.3100 4.4029 1.581440 40.98
27 -10.1979 1.2000 1.954000 33.46
28 -300.4717 BF

Image plane ∞

[Aspheric surface data]
Sixth face 1. 1.0000
A4 3.45801E-05
A6-1.38520E-07
A8-5.59965E-11
A10 1.26030E-11

The 21st face 1. 1.0000
A4 1.74477E-06
A6 1.28096E-07
A8 -2.63692E-09
A10 0.00000E + 00

The 24th face 1. 1.0000
A4 -1.22983E-05
A6 1.47314E-07
A8 -5.48742E-10
A10 0.00000E + 00

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 97.00
FNO 3.50 to 5.62
ω 39.90 to 4.69 °
Y 8.19 to 8.19

W M T
f 10.3 0001 49.99 971 96.99 932
ω 39.90076 9.01930 4.68610
FNO 3.50 5.20 5.62
φ 8.99 8.81 9.00
TL 99.25773 129.201001 139.67596
d5 1.99991 30.68218 41.26022
d13 18.53440 4.14191 2.00000
d14 3.76478 2.96318 1.40000
d17 3.54181 4.34341 5.9065
d23 8.01786 3.30678 3.30001
BF 14.70262 35.07621 37.11281

[Lens group data]
Group front f
1 1 66.85483
2 6-9.36043
R15 21.45922 (W), 19.27354 (M), 19.65214 (T)
R1 15 27.88295
R2 18-160.91663
R3 24 33.55859

[Conditional expression corresponding value]
(1) ndh = 1.950 (L306), 1.954 (L309)
(2) dh dh = 29. 37 (L 306), 33. 46 (L 309)
(3) f1 / (-f2) = 7.14
(4) (-f2) / fR = 0.436 (W), 0.486 (M), 0.476 (T)
(6) d dhr = 33. 46 (L 309)
(7) dpdp1 = 82.51 (L12)
(8) d dpr = 82. 51 (L 303)

  6 (a), 6 (b), and 6 (c) show infinity of the variable magnification optical system according to the third embodiment of the present invention at the wide-angle end, at the intermediate focal length, and at the telephoto end, respectively. FIG. 7 shows various aberrations that occurred when the object was in focus.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Fourth Embodiment
FIGS. 7A, 7B, and 7C are cross-sectional views 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 fourth embodiment of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 includes, in order from the object side, a 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 Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a concave surface facing the object side, a biconvex positive lens L23, and the object side It consists of the negative meniscus lens L24 which turned concave surface. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.
The rear lens group GR includes, in order from the object side, a first partial group GR1 having a positive refractive power and a second partial group GR2 having a positive refractive power. An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302.
The second partial group GR2 includes, in order from the object side, a cemented lens of a double convex positive lens L303 and a negative meniscus lens L304 having a convex surface facing the image side, a positive meniscus lens L305 having a concave surface facing the object side, and A cemented lens with a concave negative lens L306, a biconvex positive lens L307, a cemented lens with a positive meniscus lens L308 concave on the object side and a biconcave negative lens L309, and a convex surface on the object side The cemented lens of a negative meniscus lens L310 with a double convex shape and a biconvex positive lens L311, and a negative meniscus lens L312 with a concave surface facing the object side. The positive meniscus lens L305 is a glass mold aspheric lens in which the lens surface on the object side is aspheric, and the negative meniscus lens L312 is a glass mold aspheric lens in which the lens surface on the image side is aspheric.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. In detail, the first lens group G1 moves to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the intermediate focal length state, and moves to the image side from the intermediate focal length state to the telephoto end state. In the rear lens group GR, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the aperture stop S and the first partial group GR1 decreases, and the first partial group GR1 and the second partial group GR2 The first partial group GR1 and the second partial group GR2 move to the object side, and the aperture stop S moves integrally with the second partial group GR2 so that the air gap between
Table 4 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 4) Fourth embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 134.9416 1.6000 2.001000 29.14
2 37.4620 7.6500 1.497820 82.57
3-339.5674 0.1000
4 41.636.35 5.5500 1.883000 40.66
5 520.6025 Variable

* 6 2429.7649 1.0000 1.851350 40.10
7 8.6675 5.7500
8-10.8429 1.0000 1.47490 70.31
9-45.5363 0.8500
10 52.5147 3.1000 1.808090 22.74
11-17. 4657 0.3000
12 -16.1357 1.0000 1.954000 33.46
13-39. 2793 Variable

14 (stop S) ∞ variable

15 29.3843 1.0000 1.902650 35.73
16 14.8567 2.8000 1.719990 50.27
17-55.5590 Variable

18 13.5554 3.3500 1.497820 82.57
19-24.9755 1.0000 1.950000 29.37
20 -183.0794 2.1500
* 21-145.2052 2.2500 1.802440 25.55
22-14.7800 1.0000 1.766840 46.78
23 23.7425 2.8000
24 25.8106 3.0000 1.516800 63.88
25-15.0644 0.1000
26-568.8 377 3.0000 1.568830 56.00
27-9.3137 1.0000 1.954000 33.46
28 98.3635 0.1000
29 15.0059 1.0000 1.950000 29.37
30 7.0809 4.2500 1.647690 33.73
31-21.2496 1.4500
32 -11.4669 1.0000 1.743300 49.32
* 33 -29.8012 BF

Image plane ∞

[Aspheric surface data]
Sixth face -20.0000
A4 9.19258E-05
A6 -6.71049E-07
A8 3.76181E-09
A10-1.11659E-11

The 21st face--13.2727
A4 1.25451E-05
A6 1.56196E-07
A8-2.20815E-09
A10 0.00000E + 00

The 33rd side--0.9208
A4-8.91367E-05
A6-1.72158E-06
A8 2.40673 E-08
A10-6.77013E-10

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 97.00
FNO 4.08 to 5.83
ω 40.21 to 4.78 °
Y 8.19 to 8.19

W M T
f 10.30000 50.0021 97.00042
ω 40.21108 9.16962 4.78008
FNO 4.08 5.79 5.83
φ 8.40 9.20 10.10
TL 102.69006 133.09448 142.59913
d5 2.10000 29.30442 39.87067
d13 19.87565 4.17251 2.00000
d14 4.49060 3.80672 1.60000
d17 3.02442 3.70831 5.91502
BF 14.04941 32.95254 34.06346

[Lens group data]
Group front f
1 1 63.95755
2 6-10.21809
R15 19.97043 (W), 20.09022 (M), 20.48674 (T)
R1 15 32.27954
R2 18 70.96006

[Conditional expression corresponding value]
(1) ndh = 2.001 (L11), 1.954 (L24), 1.950 (L304), 1.954 (L309), 1.950 (L310)
(2) dh dh = 29.14 (L11), 33.46 (L24), 29.37 (L304), 33.46 (L309), 29.37 (L310)
(3) f1 / (-f2) = 6.26
(4) (-f2) / fR = 0.512 (W), 0.509 (M), 0.499 (T)
(5) | fh / f1 | = 0.817 (L11)
(6) d dhr = 33. 46 (L 309)
(7) dpdp1 = 82.57 (L12)
(8) d dpr = 82.57 (L 303)

  8 (a), 8 (b) and 8 (c) show infinity of the variable magnification optical system according to the fourth embodiment of the present invention at the wide-angle end, at the intermediate focal length and at the telephoto end, respectively. FIG. 7 shows various aberrations that occurred when the object was in focus.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Fifth Embodiment
9 (a), 9 (b), and 9 (c) are cross-sectional views 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 fifth example of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 is, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a plano-convex positive lens having a convex surface facing the object side It consists of L13.
The second lens group G2, in order from the object side, is a negative meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a concave surface facing the object side, a biconvex positive lens L23, and a concave surface facing the object side And a cemented lens with a negative meniscus lens L24 facing the lens. The negative meniscus lens L21 is a composite aspheric lens in which a resin layer provided on the glass surface on the object side is aspheric.
The rear lens group GR includes, in order from the object side, a first partial group GR1 having a positive refractive power and a second partial group GR2 having a positive refractive power. An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302.
The second partial group GR2 includes, in order from the object side, a cemented lens of a double convex positive lens L303 and a negative meniscus lens L304 having a convex surface facing the image side, a positive meniscus lens L305 having a concave surface facing the object side, and A cemented lens with a concave negative lens L306, a biconvex positive lens L307, a cemented lens of a biconvex positive lens L308 and a biconcave negative lens L309, and a biconvex positive lens L310 It consists of a cemented lens with a negative meniscus lens L311 having a convex surface facing the image side, and a negative meniscus lens L312 having a concave surface facing the object side. The negative lens L306 is a glass mold aspheric lens in which the lens surface on the image side is aspheric, and the negative meniscus lens L312 is a glass mold aspheric lens in which the lens surface on the image side is aspheric.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. Specifically, the first lens group G1 and the second lens group G2 move to the object side during zooming. In the rear lens group GR, the air gap between the aperture stop S and the first partial group GR1 increases from the wide-angle end state to the intermediate focal length state and decreases from the intermediate focal length state to the telephoto end state during zooming. The first partial group GR1 and the second partial group GR2 such that the air gap between the first partial group GR1 and the second partial group GR2 decreases from the wide-angle end state to the intermediate focal length state and increases from the intermediate focal length state to the telephoto end state. The second partial group GR2 moves to the object side, and the aperture stop S moves integrally with the second partial group GR2.
Table 5 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 5) fifth embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 145.1831 1.7000 2.001000 29.14
2 36.6390 8.1000 1.497820 82.57
3-399.3519 0.1000
4 43.2076 6.0000 1.883000 40.66
5 可 変 variable

* 6 436.5967 0.1000 1.553890 38.09
7 87.0031 1.1000 1.834810 42.73
8 8.3001 5.3500
9-12.6073 1.0000 1.755000 52.34
10 -32.7993 0.8000
11 41.1197 2.9500 1.808090 22.74
12-19.6043 0.9000 1.883000 40.66
13-73.1316 Variable

14 (stop S) ∞ variable

15 22.3725 0.9000 1.902650 35.73
16 12.2299 3.4500 1.670030 47.14
17-59.6992 Variable

18 13.7390 3.6000 1.497820 82.57
19-24.8201 0.9000 2.000690 25.46
20-270.0138 2.2000
21 -117.0547 2.0500 1.846660 23.80
22-15.9850 1.0000 1.77370 47.25
* 23 24.17.50 2.0836
24 66.3654 2.8000 1.568830 56.00
25-15.4473 0.1000
26 44.9939 2.7500 1.517420 52.20
27-15.2012 0.9000 1.903660 31.27
28 29.9926 0.3000
29 14.6093 5.0500 1.672700 32.19
30-9.1 997 0.9000 2.000690 25.46
31-24.3892 1.4000
32 -12.8617 1.0000 1.851350 40.10
* 33-27.4946 BF

Image plane ∞

[Aspheric surface data]
Sixth face 2 20.0000
A4 9.17458E-05
A6 -6.5 1986 E-07
A8 2.69890E-09
A10-1.23751E-11

The 23rd face 0.4 0.4823
A4 -7.24815E-06
A6 -3.60139E-07
A8 4.05630E-09
A10 0.00000E + 00

The 33rd side -20.0000
A4-1.22780E-04
A6 8.28360E-07
A8-6.05245E-09
A10-9.88805E-11

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 96.99
FNO 4.12 to 5.81
ω 40.44 to 4.73 °
Y 8.19 to 8.19

W M T
f 10.30260 30.00000 96.99284
ω 40.42283 14.85841 4.72723
FNO 4.12 5.48 5.81
φ 8.12 8.12 9.70
TL 103.02710 121.37977 143.32397
d5 2.10606 20.13084 40.20889
d13 19.66416 6.24359 1.80000
d14 4.27874 4.97381 1.80000
d17 3.43763 2.74256 5.91637
BF 14.05688 27.80535 34.11509

[Lens group data]
Group front f
1 1 64. 09778
2 6-10.16794
R15 19.76515 (W), 19.63564 (M), 20.24126 (T)
R1 15 31.06055
R2 18 67.05869

[Conditional expression corresponding value]
(1) ndh = 2.001 (L11)
(2) dhdh = 29.14 (L11)
(3) f1 / (-f2) = 6.31
(4) (-f2) / fR = 0.514 (W), 0.517 (M), 0.502 (T)
(5) | fh / f1 | = 0.770 (L11)
(7) dpdp1 = 82.57 (L12)
(8) d dpr = 82.57 (L 303)

  10 (a), 10 (b), and 10 (c) show infinity 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 of the present application, respectively. FIG. 7 shows various aberrations that occurred when the object was in focus.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Sixth Embodiment
11 (a), 11 (b), and 11 (c) are cross-sectional views 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 sixth embodiment of the present application. It is.
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 rear side having a positive refractive power. It is composed of a lens group GR.

The first lens group G1 includes, in order from the object side, a 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 Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a concave surface facing the object side, a biconvex positive lens L23, and the object side It consists of the negative meniscus lens L24 which turned concave surface. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the image side.
The rear lens group GR includes, in order from the object side, a first partial group GR1 having positive refractive power, a second partial group GR2 having negative refractive power, and a third partial group GR3 having negative refractive power. It consists of An aperture stop S is provided on the object side of the rear lens group GR.

The first partial group GR1 includes, in order from the object side, a cemented lens of a negative meniscus lens L301 having a convex surface facing the object side and a biconvex positive lens L302, and a positive meniscus lens L303 having a convex surface facing the object side. It consists of a cemented lens of a double convex positive lens L304 and a negative meniscus lens L305 having a convex surface facing the image side.
The second partial group GR2 includes, in order from the object side, a cemented lens of a biconcave negative lens L306 and a biconvex positive lens L307. The negative lens L306 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.
The third partial group GR3 includes, in order from the object side, a positive meniscus lens L308 having a convex surface facing the object side, and a cemented lens of a biconvex positive lens L309 and a negative meniscus lens L310 having a convex surface facing the image side. Become. The positive meniscus lens L308 is a glass mold aspheric lens having an aspheric lens surface on the object side.
In the variable magnification optical system according to the present embodiment, a low pass filter, a sensor cover glass, or the like may be disposed between the rear lens group GR and the image plane I.

Under the above configuration, in the variable magnification optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 is increased at the time of zooming from the wide angle end state to the telephoto end state. The first lens group G1, the second lens group G2, and the rear lens group GR move along the optical axis such that the air gap between the second lens group G2 and the rear lens group GR decreases. In detail, the first lens group G1 moves to the object side during zooming. The second lens group G2 moves to the image side from the wide angle end state to the intermediate focal length state, and moves to the object side from the intermediate focal length state to the telephoto end state. In the rear lens group GR, during zooming, the air gap between the first partial group GR1 and the second partial group GR2 increases from the wide-angle end state to the intermediate focal length state, and from the intermediate focal length state to the telephoto end state As the air distance between the second partial group GR2 and the third partial group GR3 decreases from the wide-angle end state to the intermediate focal length state and increases from the intermediate focal length state to the telephoto end state, GR1, the second partial group GR2 and the third partial group GR3 move to the object side. At this time, the first portion group GR1, the third portion group GR3, and the aperture stop S move integrally.
Table 6 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 6) Sixth embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 149.4765 1.4000 1.950000 29.37
2 38.6411 6.6000 1.497820 82.57
3-351.6316 0.1000
4 41.7750 4.6000 1.883000 40.66
5 328.2384 Variable

6 72. 4 89 1. 0000 1. 806 100 40. 97
* 7 7.7391 5.8500
8-13.9505 1.0000 1.883000 40.66
9 -103.9877 0.1000
10 40.8028 3.4000 1.808090 22.74
11 -18.8169 0.6000
12-13.4665 1.0000 1.883000 40.66
13-18.2633 variable

14 (stop S)) 1.4000

15 28.0065 1.5000 2.000690 25.46
16 17.4484 2.9000 1.497820 82.57
17 -29.2004 2.0000
18 28.1447 1.6000 1.795040 28.69
19 53.0274 0.1000
20 27.5255 4.2000 1.497820 82.57
21 -13.902 2.1800 2.000690 25.46
22-20.5898 variable

* 23-13.2794 1.0000 1.806100 40.97
24 24.2300 3.5000 1.728250 28.38
25-18.1038 variable

* 26 47.8180 1.6500 1.583130 59.42
27 100.8528 0.2000
28 38.0626 3.8000 1.516800 63.88
29 -8.1478 1.0000 1.954000 33.46
30-52.2418 BF

Image plane ∞

[Aspheric surface data]
Seventh face κ 0.9456
A4 -7.24873E-05
A6 -1.38772E-06
A8 3.49795E-08
A10-9.90184 E-10

The 23rd face--5.0310
A4-2.13400E-04
A6 3.25281E-06
A8-4.07563E-08
A10 2.36604E-10

Twenty-sixth surface 15 -15.0179
A4 1.31767E-05
A6 1.09725E-06
A8 -1.09512E-08
A10 4.81750E-10

[Various data]
Magnification ratio 9.42

W T
f 10.30 to 97.00
FNO 4.12 to 5.80
ω 40.14 to 4.66 °
Y 8.19 to 8.19

W M T
f 10.30000 50.00000 97.00000
ω 39.34094 8.74331 4.54414
FNO 4.12 5.51 5.80
φ 9.00 9.50 9.80
TL 104.60927 125.18124 137.98082
d5 2.00000 30.95696 41.68937
d13 26.10451 4.99096 2.00000
d22 2.34607 5.18708 2.50149
d25 7.92894 5.08793 7.77351
BF 13.54976 26.27832 31.33645

[Lens group data]
Group front f
1 1 66.37666
2 6-11. 22172
R15 20.98751 (W), 19.21893 (M), 20.87995 (T)
R1 15 16.67848
R2 23-58.03866
R3 26 -77.03015

[Conditional expression corresponding value]
(1) ndh = 1.950 (L11), 1.954 (L310)
(2) dhdh = 29.37 (L11), 33.46 (L310)
(3) f1 / (− f2) = 5.92
(4) (-f2) / fR = 0.535 (W), 0.584 (M), 0.537 (T)
(5) | fh / f1 | = 0.832 (L11)
(6) d dhr = 33.46 (L310)
(7) dpdp1 = 82.57 (L12)
(8) d dpr = 82.57 (L302), 82.57 (L304)

  FIGS. 12 (a), 12 (b) and 12 (c) show infinity 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 sixth embodiment of the present invention. FIG. 7 shows various aberrations that occurred when the object was in focus.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

  According to each of the above embodiments, it is possible to realize a compact variable power optical system having high optical performance. 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 suitably adopted within the range that does not impair the optical performance of the variable magnification optical system of the present application.

  Although the numerical example of the variable magnification optical system according to the present invention is shown as having three groups, the present invention is not limited to this, and variable magnification optical systems of other group configurations (for example, four groups, five groups, etc.) It can also be done. Specifically, a lens or lens group may be added to the most object side or most image side of the variable magnification optical system of the present application. The lens group indicates a portion having at least one lens separated by an air gap that changes at the time of zooming.

  Further, in the variable magnification optical system according to the present invention, in order to focus from an infinite distance object to a close distance object, a part of the lens group, an entire lens group, or a plurality of lens groups is used as a focusing lens group. It may be configured to move in the axial direction. In particular, it is preferable to set at least a part of the second lens group or at least a part of the rear lens group as a focusing lens group. Further, 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.

  Further, in the variable magnification optical system according to the present application, all or part of any lens group is moved as a vibration reduction lens group so as to include a component in a direction perpendicular to the optical axis, or a surface including the optical axis It is also possible to correct image blurring caused by camera shake or the like by rotating (swinging) inward. In particular, in the variable magnification optical system of the present application, it is preferable that at least a part of the rear lens group be a vibration reduction lens group.

  Further, the lens surface of the lens constituting the variable magnification optical system of the present invention may be a spherical surface or a plane, or may be 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 according to the present invention, the aperture stop is preferably disposed in the rear lens group or in the vicinity of the rear lens group, and the lens frame substitutes for the role without providing a member as the aperture stop. It is also good.
In addition, an anti-reflection 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 the present application. 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 application will be described based on FIG.
FIG. 13 is a diagram showing a configuration of a camera provided with the variable magnification optical system of the present application.
As shown in FIG. 13, the camera 1 is a so-called mirrorless camera of an interchangeable lens 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 on the present camera 1 as the photographing lens 2 is a small sized variable magnification optical system having high optical performance. Therefore, the camera 1 can achieve high optical performance while achieving downsizing. Even if a camera mounted with the variable magnification optical system according to the second to sixth examples as the taking lens 2 can be 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.

Finally, an outline of a method of manufacturing a variable magnification optical system according to the present application will be described based on FIG.
The manufacturing method of the variable magnification optical system of the present application shown in FIG. 14 has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power in order from the object side. A manufacturing method of a variable magnification optical system having a rear lens group, which includes the following steps S1 and S2.

Step S1: A variable magnification optical system has at least one lens satisfying the following conditional expressions (1) and (2), and the respective lens units are arranged in order from the object side in the lens barrel.
(1) 1.928 <ndh
(2) 28.60 <dhdh
However,
ndh: refractive index dhdh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens

  Step S2: The distance between the first lens unit and the second lens unit, the second lens unit, and the like during zooming from the wide-angle end state to the telephoto end state by providing a known moving mechanism in the lens barrel or the like. The distance to the side lens group is made to change.

  According to the manufacturing method of such a variable power optical system of the present application, it is possible to manufacture a compact variable power optical system having high optical performance.

G1 first lens group G2 second lens group GR rear side lens group GR1 first partial group GR2 second partial group GR3 third partial group S aperture stop I image plane

Claims (23)

From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side And a cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a plano-convex positive lens convex on the object side.
A variable magnification optical system characterized by satisfying the following conditional expression.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes at least one lens that satisfies the following conditional expression,
0.450 <| fh / f1 | <1.400
However,
fh: focal length f1 of the lens in the first lens group: focal length of the first lens group The first lens group is a negative meniscus lens having a convex surface facing the object side and a biconvex shape in order from the object side And a positive meniscus lens having a convex surface facing the object side, or a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens in order from the object side. 1. A variable power optical system comprising: a plano-convex positive lens having a convex surface facing the object side. From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group has a positive lens satisfying the following conditional expression,
75.00 <dpdp1
However,
dp dp1: Abbe number of d-line (wavelength 587.6 nm) of the positive lens in the first lens group The first lens group has a negative meniscus lens with a convex surface facing the object side and a biconvex shape in order from the object side And a positive meniscus lens having a convex surface facing the object side, or a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens in order from the object side. 1. A variable power optical system comprising: a plano-convex positive lens having a convex surface facing the object side. From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side And a cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a plano-convex positive lens convex on the object side.
The variable magnification optical system characterized in that the rear lens group has a positive lens satisfying the following conditional expression.
75.00 <d dpr
However,
d dpr: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the rear lens group From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d line (wavelength 587.6 nm) of the lens: Abbe number for d line (wavelength 587.6 nm) of the lens The first lens group has at least one lens
The variable magnification optical system, wherein the rear lens group includes at least one lens satisfying the following conditional expression .
31.60 <d dhr
However,
d dhr: Abbe number for d-line (wavelength 587.6 nm) of the lens in the rear lens group From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dh dh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens at least one of the lenses of which the rear lens group satisfies the following conditional expression Have one,
31.60 <d dhr
However,
d dhr: Variable power optical system characterized by satisfying the conditional expression less than the Abbe number for the d-line (wavelength 587.6 nm) of the lens in the rear lens group.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group From the object side, it has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group having a positive refractive power,
The rear lens group has a plurality of lens groups,
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups changes,
Have at least one lens that satisfies the following conditional expression,
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dh dh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens at least one of the lenses of which the rear lens group satisfies the following conditional expression Have one,
31.60 <d dhr
However,
d dhr: Abbe number of d-line (wavelength 587.6 nm) of the lens in the rear lens group The rear lens group has a positive lens satisfying the following conditional expression.
75.00 <d dpr
However,
d dpr: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the rear lens group   The variable magnification optical system according to claim 6, wherein the first lens group includes at least one lens. The variable magnification optical system according to any one of claims 2 to 5, wherein any one of the following conditional expressions is satisfied.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group The variable magnification optical system according to any one of claims 3 to 7, wherein the first lens group includes at least one of the lenses satisfying the following conditional expression.
0.450 <| fh / f1 | <1.400
However,
fh: focal length of the lens in the first lens group f1: focal length of the first lens group   8. The variable magnification optical system according to claim 6, wherein the rear lens group includes at least one lens. The variable magnification optical system according to any one of claims 2 to 4 , wherein the rear lens group includes at least one lens satisfying the following conditional expression.
31.60 <d dhr
However,
d dhr: Abbe number for d-line (wavelength 587.6 nm) of the lens in the rear lens group The variable magnification optical system according to any one of claims 4 to 7, wherein the first lens group has a positive lens satisfying the following conditional expression.
75.00 <dpdp1
However,
dpdp1: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the first lens group 7. The variable magnification optical system according to claim 5, wherein said rear lens group has a positive lens satisfying the following conditional expression.
75.00 <d dpr
However,
d dpr: Abbe number for d-line (wavelength 587.6 nm) of the positive lens in the rear lens group The variable magnification optical system according to any one of claims 1 to 14, wherein the following conditional expressions are satisfied.
0.160 <(− f2) / fR <0.550
However,
f2: focal length fR of the second lens group: focal length of the rear lens group in the wide-angle end state and the telephoto end state   The variable magnification optical system according to any one of claims 1 to 15, wherein the second lens group includes at least one lens.   The variable power optical system according to any one of claims 1 to 16, wherein the first lens group includes at least one lens having negative refractive power.   The variable magnification optical system according to any one of claims 1 to 17, wherein the rear lens group includes at least one lens having a negative refractive power.   The variable power optical system according to any one of claims 1 to 18, wherein the second lens group includes at least one lens having a negative refractive power.   The distance between the first lens group and the second lens group is increased at the time of zooming from the wide-angle end state to the telephoto end state, as described in any one of claims 1 to 19. Variable magnification optical system.   The distance between the second lens unit and the rear lens unit is reduced at the time of zooming from the wide-angle end state to the telephoto end state. Variable magnification optical system.   An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 21. A manufacturing method of a variable power optical system having, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a rear lens group having positive refractive power. There,
The rear lens group includes a plurality of lens groups;
During zooming from the wide-angle end state to the telephoto end state, the distance between adjacent lens groups is changed,
Have at least one lens that satisfies the following condition:
1.928 <ndh
28.60 <dhdh
However,
ndh: refractive index dhdh for d-line (wavelength 587.6 nm) of the lens: Abbe number for d-line (wavelength 587.6 nm) of the lens such that the first lens group has at least one lens
The first lens group includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, or the object side From the cemented lens of a negative meniscus lens convex on the object side and a positive biconvex lens, and a planoconvex positive lens convex on the object side,
A manufacturing method of a variable magnification optical system characterized by satisfying the following conditional expression.
5.50 <f1 / (− f2) <15.00
However,
f1: focal length of the first lens group f2: focal length of the second lens group

Images