JP2014085496A - Variable magnification optical system, optical device, and manufacturing method for variable magnification optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact variable magnification optical system and an optical device which exhibit a high variable magnification ratio and superior optical performances, and to provide a manufacturing method for the variable magnification optical system.SOLUTION: A variable magnification optical system: comprises a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a positive refractive power in this order from the object side; is configured such that a distance between the first lens group G1 and the second lens group G2, a distance between the second lens group G2 and the aperture stop S, a distance between the aperture stop S and the third lens group G3, and a distance between the third lens group G3 and the fourth lens group G4 are changed while a distance between the aperture stop S and the fourth lens group G4 is kept constant when magnification from a wide-angle end state to a telephoto end state; and fulfills a prescribed formula.

Description

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

  Conventionally, as a variable power optical system suitable for an interchangeable lens for a camera, a digital camera, a video camera, and the like, many lenses having a positive refractive power in the most object side lens group have been proposed (for example, Patent Document 1). reference.).

JP 2008-292562 A

  However, the conventional variable power optical system as described above has a problem that it is difficult to obtain sufficiently high optical performance if an attempt is made to increase the zoom ratio without increasing the size.

  Accordingly, the present invention has been made in view of the above problems, and provides a variable magnification optical system, an optical apparatus, and a variable magnification optical system that are small in size, have a high zoom ratio, and have high optical performance. For the purpose.

In order to solve the above problems, the present invention
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a positive refractive power. A fourth lens group having
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, the distance between the second lens group and the aperture stop, the aperture stop and the third lens group And the distance between the third lens group and the fourth lens group are changed, and the distance between the aperture stop and the fourth lens group is constant,
A variable magnification optical system characterized by satisfying the following conditional expression is provided.
5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group

The present invention also provides
Provided is an optical device comprising the variable magnification optical system.

The present invention also provides
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a positive refractive power. A variable magnification optical system having a fourth lens group,
The first lens group satisfies the following conditional expression:
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, the distance between the second lens group and the aperture stop, the aperture stop and the third lens group And the distance between the third lens group and the fourth lens group are changed so that the distance between the aperture stop and the fourth lens group is constant. A method for manufacturing a system is provided.
5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group

  According to the present invention, it is possible to provide a variable magnification optical system, an optical device, and a variable magnification optical system manufacturing method that are small in size, have a high zoom ratio, and have high optical performance.

(A), (b), and (c) are sectional views in the wide-angle end state, intermediate focal length state, and telephoto end state, respectively, of the variable magnification optical system according to the first example of the present application. (A), (b), and (c) are various figures 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 example of the present application, respectively. It is an aberration diagram. (A), (b), and (c) are sectional views of the variable magnification optical system according to the second example of the present application in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. (A), (b), and (c) are various values 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 second example of the present application, respectively. It is an aberration diagram. (A), (b), and (c) are sectional views of the variable magnification optical system according to the third example of the present application in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. (A), (b), and (c) are various values 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 third example of the present application, respectively. It is an aberration diagram. 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.

Hereinafter, a variable magnification optical system, an optical apparatus, and a method for manufacturing the variable magnification optical system of the present application will be described.
The variable magnification optical system of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, and a third lens having a positive refractive power. And a fourth lens group having a positive refractive power, and a distance between the first lens group and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state, the second lens The distance between the group and the aperture stop, the distance between the aperture stop and the third lens group, and the distance between the third lens group and the fourth lens group are changed. With this configuration, the variable magnification optical system of the present application realizes variable magnification from the wide-angle end state to the telephoto end state, and can suppress each variation of distortion aberration, astigmatism, and spherical aberration associated with variable magnification. .

Further, the zoom optical system of the present application is characterized in that the distance between the aperture stop and the fourth lens group is constant during zooming from the wide-angle end state to the telephoto end state. With this configuration, the variable power optical system of the present application can suppress fluctuations in astigmatism and coma aberration that occur in the third lens group due to zooming.
The variable magnification optical system of the present application is characterized by satisfying the following conditional expression (1).
(1) 5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group

Conditional expression (1) defines an appropriate range of the focal length of the first lens group. By satisfying conditional expression (1), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
If the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress variations in spherical aberration and astigmatism that occur in the first lens group during magnification, It becomes impossible to realize high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1) to 5.900. In order to further secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (1) to 6.135.
On the other hand, when the corresponding value of the conditional expression (1) of the zoom optical system of the present application exceeds the upper limit value, in order to obtain a predetermined zoom ratio, the distance between the first lens group and the second lens group at the time of zooming It is necessary to increase the amount of change. This not only makes it difficult to reduce the size, but also the ratio between the diameter of the axial light beam incident on the first lens group and the diameter of the axial light beam incident on the second lens group changes greatly with zooming. For this reason, the variation of the spherical aberration becomes excessive at the time of zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1) to 6.900.
With the above configuration, a variable power optical system that is small in size, has a high zoom ratio, and has high optical performance can be realized.

  In the zoom optical system according to the present application, it is preferable that the first lens unit moves toward the object side when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to suppress a change in height from the optical axis of the off-axis light beam that passes through the first lens group during zooming. Thereby, not only can the diameter of the first lens group be reduced, but also fluctuations in astigmatism can be suppressed during zooming.

  In the zoom optical system of the present application, it is desirable that the distance between the first lens group and the second lens group is increased when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to increase the magnification of the second lens group, and it is possible to suppress fluctuations in spherical aberration and astigmatism during zooming while efficiently realizing a high zoom ratio.

  In the zoom optical system of the present application, it is preferable that the distance between the second lens group and the third lens group is reduced when zooming from the wide-angle end state to the telephoto end state. With this configuration, the combined magnification of the third lens group and the fourth lens group can be increased, and the variation of spherical aberration and astigmatism are suppressed during zooming while efficiently realizing a high zoom ratio. be able to.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (2).
(2) 3.250 <(d1t-d1w) / fw <4.200
However,
fw: focal length of the variable magnification optical system in the wide-angle end state d1w: distance from the most image-side lens surface in the first lens group to the most object-side lens surface in the second lens group in the wide-angle end state d1t: Distance from the most image side lens surface in the first lens group to the most object side lens surface in the second lens group in the telephoto end state

Conditional expression (2) is the distance on the optical axis from the most image side lens surface in the first lens group to the most object side lens surface in the second lens group, that is, the first lens group and the second lens group. The range of an appropriate amount of change at the time of changing the interval between and is specified. By satisfying conditional expression (2), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
When the corresponding value of the conditional expression (2) of the zoom optical system of the present application is below the lower limit value, it is necessary to increase the refractive power of the second lens group in order to obtain a predetermined zoom ratio. As a result, it becomes difficult to suppress variations in spherical aberration and astigmatism that occur in the second lens group during zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2) to 3.450. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2) to 3.510.
On the other hand, when the corresponding value of conditional expression (2) of the variable magnification optical system of the present application exceeds the upper limit value, the diameter of the axial light beam incident on the first lens group and the diameter of the axial light beam incident on the second lens group The ratio changes greatly with zooming. For this reason, the variation of the spherical aberration becomes excessive at the time of zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2) to 4.000. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2) to 3.860.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (3).
(3) 0.160 <(d3t-d3w) / fw <0.550
However,
fw: focal length of the zoom optical system in the wide-angle end state d3w: distance from the most image-side lens surface in the third lens group to the most object-side lens surface in the fourth lens group in the wide-angle end state d3t: Distance from the most image side lens surface in the third lens group to the most object side lens surface in the fourth lens group in the telephoto end state

Conditional expression (3) is the distance on the optical axis from the most image side lens surface in the third lens group to the most object side lens surface in the fourth lens group, that is, the third lens group and the fourth lens group. The range of an appropriate amount of change at the time of changing the interval between and is specified. By satisfying conditional expression (3), the zoom optical system of the present application can suppress fluctuations in coma and astigmatism during zooming.
If the corresponding value of conditional expression (3) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress fluctuations in coma and astigmatism that occur in the third lens group during zooming, It becomes impossible to realize high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3) to 0.172.
On the other hand, if the corresponding value of the conditional expression (3) of the zoom optical system of the present application exceeds the upper limit value, a mechanism for increasing the amount of change at the time of zooming of the distance between the third lens group and the fourth lens group. I need it. This not only makes it difficult to reduce the size, but also tends to cause mutual eccentricity between the third lens group and the fourth lens group. For this reason, eccentric coma and astigmatism are likely to occur due to variations during manufacturing, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3) to 0.450.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (4).
(4) 0.140 <(d2it−d2iw) / fw <0.700
However,
fw: focal length of the variable magnification optical system in the wide-angle end state d2iw: distance from the most image side lens surface to the image plane in the second lens group in the wide-angle end state d2it: the second lens group in the telephoto end state The distance from the lens surface closest to the image side to the image surface

Conditional expression (4) indicates that the distance on the optical axis from the most image-side lens surface in the second lens group to the image surface, that is, the appropriate amount of change when the distance between the second lens group and the image surface is changed The range is defined. By satisfying conditional expression (4), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
If the corresponding value of conditional expression (4) of the zoom optical system of the present application is below the lower limit value, it is necessary to increase the refractive power of the second lens group in order to obtain a predetermined zoom ratio. As a result, it becomes difficult to suppress variations in spherical aberration and astigmatism that occur in the second lens group during zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4) to 0.170. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4) to 0.200.
On the other hand, if the corresponding value of conditional expression (4) of the variable magnification optical system of the present application exceeds the upper limit value, fluctuations in spherical aberration and astigmatism that occur in the first lens group and the second lens group at the time of zooming are reduced. It becomes difficult to suppress, and high optical performance cannot be realized.

In the variable magnification optical system of the present application, it is desirable that the third lens group is composed of two lenses. With this configuration, it is possible to suppress spherical aberration, coma aberration, and longitudinal chromatic aberration that occur in the third lens group, as compared to the case where the third lens group is configured by a single lens. In addition, each variation of spherical aberration, coma aberration, and longitudinal chromatic aberration can be suppressed during zooming. Further, as compared with the case where the third lens group is composed of three or more lenses, not only can the size be reduced, but also the mass of the third lens group can be suppressed. For this reason, it is possible to relatively suppress the decentering of the third lens group due to the attitude difference of the optical system in the use state and reduce the occurrence of decentering coma.
It is more preferable that the third lens group is composed of two lenses and the two lenses are joined. With this configuration, it is possible to suppress the decentering of the lenses in the third lens group and reduce the occurrence of decentering coma.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (5).
(5) 0.200 <f3 / f4 <0.650
However,
f3: focal length of the third lens group f4: focal length of the fourth lens group

Conditional expression (5) defines an appropriate focal length ratio range of the third lens group and the fourth lens group. By satisfying conditional expression (5), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
If the corresponding value of conditional expression (5) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress variations in spherical aberration and astigmatism that occur in the third lens group during magnification, It becomes impossible to realize high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5) to 0.400.
On the other hand, if the corresponding value of conditional expression (5) of the variable magnification optical system of the present application exceeds the upper limit value, it becomes difficult to suppress the fluctuation of spherical aberration and the fluctuation of astigmatism that occur in the fourth lens group at the time of zooming. Therefore, high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5) to 0.500.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (6).
(6) 0.780 <f1 / f4 <1.300
However,
f1: Focal length of the first lens group f4: Focal length of the fourth lens group

Conditional expression (6) defines an appropriate focal length ratio range between the first lens group and the fourth lens group. By satisfying conditional expression (6), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
If the corresponding value of conditional expression (6) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress variations in spherical aberration and astigmatism that occur in the first lens group during magnification, It becomes impossible to realize high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6) to 0.820.
On the other hand, if the corresponding value of conditional expression (6) of the variable magnification optical system of the present application exceeds the upper limit, it is difficult to suppress variations in spherical aberration and astigmatism that occur in the fourth lens group during magnification. Therefore, high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6) to 1.100.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (7).
(7) 0.050 <(-f2) / f4 <0.250
However,
f2: focal length of the second lens group f4: focal length of the fourth lens group

Conditional expression (7) defines an appropriate focal length ratio range between the second lens group and the fourth lens group. By satisfying conditional expression (7), the variable magnification optical system of the present application can suppress variations in spherical aberration, astigmatism, and distortion during zooming.
When the corresponding value of conditional expression (7) of the variable magnification optical system of the present application is below the lower limit value, each variation of spherical aberration, astigmatism, and distortion occurring in the second lens group at the time of zooming can be suppressed. This makes it difficult to achieve high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7) to 0.118.
On the other hand, if the corresponding value of conditional expression (7) of the variable magnification optical system of the present application exceeds the upper limit, it is difficult to suppress variations in spherical aberration and astigmatism that occur in the fourth lens group during magnification. Therefore, high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7) to 0.180.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (8).
(8) 0.740 <(− f2) / fw <1.120
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f2: focal length of the second lens group

Conditional expression (8) defines an appropriate range of the focal length of the second lens group. By satisfying conditional expression (8), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism during magnification.
If the corresponding value of conditional expression (8) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress the variation of spherical aberration and astigmatism that occur in the second lens group at the time of zooming, It becomes impossible to realize high optical performance. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8) to 0.860.
On the other hand, when the corresponding value of the conditional expression (8) of the zoom optical system of the present application exceeds the upper limit value, in order to obtain a predetermined zoom ratio, the distance between the first lens group and the second lens group at the time of zooming It is necessary to increase the amount of change. This not only makes it difficult to reduce the size, but also changes the diameter of the on-axis light beam incident from the first lens group to the second lens group with a change in magnification. For this reason, the variation of the spherical aberration becomes excessive at the time of zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8) to 1.040.

  The optical device of the present application is characterized by having the variable magnification optical system having the above-described configuration. Thereby, it is possible to realize an optical device that is small in size, has a high zoom ratio, and has high optical performance.

The variable magnification optical system manufacturing method of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, and a positive refractive power. A variable magnification optical system manufacturing method having a third lens group and a fourth lens group having a positive refractive power, wherein the first lens group satisfies the following conditional expression (1), and a wide angle During zooming from the end state to the telephoto end state, the distance between the first lens group and the second lens group, the distance between the second lens group and the aperture stop, and the aperture stop and the third lens group And the distance between the third lens group and the fourth lens group are changed so that the distance between the aperture stop and the fourth lens group is constant. As a result, it is possible to manufacture a variable magnification optical system that is small in size, has a high variable magnification ratio, and has high optical performance.
(1) 5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group

Hereinafter, a variable magnification optical system according to numerical examples of the present application will be described with reference to the accompanying drawings.
(First embodiment)
1A, 1B, and 1C are cross-sectional views of the zoom optical system according to the first example of the present application in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is.
The variable magnification optical system according to the present example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power.

The first lens group G1 includes, 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 positive meniscus lens L13 having 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 directed toward the object side, a negative meniscus lens L22 having a concave surface directed toward the object side, a biconvex positive lens L23, and an object side. And a negative meniscus lens L24 having a concave surface. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.
The third lens group G3 is composed of a cemented lens of a negative meniscus lens L31 having a convex surface directed toward the object side and a biconvex positive lens L32 in order from the object side. An aperture stop S is provided on the object side of the third lens group G3.

The fourth lens group G4 includes, in order from the object side, a cemented lens of a biconvex positive lens L401 and a negative meniscus lens L402 with a convex surface facing the image side, a positive meniscus lens L403 with a concave surface facing the object side, and both A cemented lens of a concave negative lens L404, a biconvex positive lens L405, a cemented lens of a positive meniscus lens L406 having a concave surface facing the object side, and a biconcave negative lens L407, and a convex surface facing the object side Is composed of a negative meniscus lens L408 having a convex surface and a biconvex positive lens L409, and a negative meniscus lens L410 having a concave surface facing the object side. The positive meniscus lens L403 is a glass mold aspheric lens having an aspheric lens surface on the object side, and the negative meniscus lens L410 is a glass mold aspheric lens having an aspheric lens surface on the image side.
In the zoom optical system according to the present embodiment, a low-pass filter, a sensor cover glass, or the like may be disposed between the fourth lens group G4 and the image plane I.

  With the above-described 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 increases when the magnification is changed from the wide-angle end state to the telephoto end state. The air gap between the second lens group G2 and the third lens group G3 decreases, the air gap between the third lens group G3 and the fourth lens group G4 increases, and the air gap between the second lens group G2 and the aperture stop S. Decreases, the air gap between the aperture stop S and the third lens group G3 decreases, and the distance between the aperture stop S and the fourth lens group G4 is constant, so that the first to fourth lens groups G1 to G4 are constant. Moves along the optical axis, and the aperture stop S moves integrally with the fourth lens group G4. Specifically, the first lens group G1, the third lens group G3, and the fourth lens group G4 move to the object side during zooming. The second lens group G2 moves toward the object side from the wide-angle end state to the intermediate focal length state, and moves toward the image side from the intermediate focal length state to the telephoto end state.

Table 1 below lists values of specifications of the variable magnification optical system according to the present example.
In Table 1, f indicates the focal length, and BF indicates the back focus (the distance on the optical axis between the lens surface closest to the image side and the image plane I).
In [Surface data], the surface number is the order of the optical surfaces counted from the object side, r is the radius of curvature, d is the surface interval (the interval between the nth surface (n is an integer) and the n + 1th surface), and nd is The refractive index for d-line (wavelength 587.6 nm) and νd indicate the Abbe number for d-line (wavelength 587.6 nm), respectively. In addition, the object plane indicates the object plane, the variable indicates the variable plane spacing, 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. For the aspherical surface, * is added to the surface number, and the value of the paraxial radius of curvature is indicated in the column of the radius of curvature r. The description of the refractive index of air nd = 1.00000 is omitted.

[Aspherical data] shows an aspherical coefficient and a conic constant when the shape of the aspherical 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 (sag amount) from the tangent plane of the apex of the aspheric surface to the aspheric surface at the height h, and κ is the conic constant. , A4, A6, A8, A10 are aspherical coefficients, and r is the radius of curvature of the reference sphere (paraxial radius of curvature). “E−n” (n is an integer) indicates “× 10 ⁻ⁿ ”, for example “1.234E-05” indicates “1.234 × 10 ⁻⁵ ”. The secondary aspherical coefficient A2 is 0 and is not shown.

In [Various data], FNO is the F number, ω is the half angle of view (unit is “°”), Y is the image height, TL is the total length of the variable magnification optical system (image from the first surface when focusing on an object at infinity) (Distance on the optical axis to the surface I), dn represents the variable distance between the nth surface and the (n + 1) th surface, and φ represents the diameter of the aperture stop S. W represents the wide-angle end state, M represents the intermediate focal length state, and T represents the telephoto end state.
[Lens Group Data] indicates the start surface and focal length of each lens group.
[Conditional Expression Corresponding Value] shows the corresponding value of each conditional expression of the variable magnification optical system according to the present example.

Here, the focal length f, the radius of curvature r, and other length units listed in Table 1 are generally “mm”. However, the optical system is not limited to this because an equivalent optical performance can be obtained even when proportionally enlarged or proportionally reduced.
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 Example
[Surface data]
Surface number r d nd νd
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 41.6639 5.5500 1.883000 40.66
5 520.6025 Variable

* 6 2429.7649 1.0000 1.851350 40.10
7 8.6673 5.7500
8 -10.8429 1.0000 1.487490 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 (Aperture 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 13.5564 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 -568.8377 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 ∞

[Aspherical data]
6th surface κ -20.0000
A4 9.19258E-05
A6 -6.71049E-07
A8 3.76181E-09
A10 -1.11659E-11

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

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

[Various data]
Scaling ratio 9.42

W T
f 10.30 to 97.00
FNO 4.08 to 5.83
ω 40.21 〜 4.78 °
Y 8.19-8.19
TL 102.69-142.60

W M T
f 10.30000 50.00021 97.00042
ω 40.21108 9.16962 4.78008
FNO 4.08 5.79 5.83
φ 8.40 9.20 10.10
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 start surface f
1 1 63.95755
2 6 -10.21809
3 15 32.27954
4 18 70.96006

[Conditional expression values]
(1) f1 / fw = 6.209
(2) (d1t-d1w) / fw = 3.667
(3) (d3t−d3w) /fw=0.281
(4) (d2it−d2iw) /fw=0.208
(5) f3 / f4 = 0.455
(6) f1 / f4 = 0.901
(7) (−f2) /f4=0.144
(8) (-f2) / fw = 0.992

  2 (a), 2 (b), and 2 (c) respectively show infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable magnification optical system according to the first example of the present application. It is an aberration diagram at the time of focusing on an object.

  In each aberration diagram, FNO denotes an F number, and A denotes a light 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 the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. Note that the same reference numerals as in this embodiment are used in the aberration diagrams of each embodiment described later.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Second embodiment)
FIGS. 3A, 3B, and 3C are cross-sectional views of the zoom optical system according to the second example of the present application in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is.
The variable magnification optical system according to the present example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power.

The first lens group G1 includes, 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. L13.
In order from the object side, the second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a negative meniscus lens L22 having a concave surface directed toward 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. The negative meniscus lens L21 is a composite aspherical lens formed by forming a resin layer provided on the glass surface on the object side into an aspherical shape.
The third lens group G3 is composed of a cemented lens of a negative meniscus lens L31 having a convex surface directed toward the object side and a biconvex positive lens L32 in order from the object side.

The fourth lens group G4 includes, in order from the object side, a cemented lens of a biconvex positive lens L401 and a negative meniscus lens L402 with a convex surface facing the image side, a positive meniscus lens L403 with a concave surface facing the object side, and both A cemented lens with a concave negative lens L404, a biconvex positive lens L405, a cemented lens with a biconvex positive lens L406 and a biconcave negative lens L407, and a biconvex positive lens L408. It consists of a cemented lens with a negative meniscus lens L409 having a convex surface facing the image side, and a negative meniscus lens L410 with a concave surface facing the object side. The negative lens L404 is a glass mold aspheric lens having an aspheric lens surface on the image side, and the negative meniscus lens L410 is a glass mold aspheric lens having an aspheric lens surface on the image side.
In the zoom optical system according to the present embodiment, a low-pass filter, a sensor cover glass, or the like may be disposed between the fourth lens group G4 and the image plane I.

With the above-described 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 increases when the magnification is changed from the wide-angle end state to the telephoto end state. The air gap between the second lens group G2 and the third lens group G3 is reduced, and the air gap between the third lens group G3 and the fourth lens group G4 is reduced from the wide-angle end state to the intermediate focal length state. It increases to the telephoto end state, the air gap between the second lens group G2 and the aperture stop S decreases, and the air gap between the aperture stop S and the third lens group G3 increases from the wide-angle end state to the intermediate focal length state. The first to fourth lens groups G1 to G4 are each moved toward the object side along the optical axis so that the distance from the focal length state to the telephoto end state is reduced and the distance between the aperture stop S and the fourth lens group G4 is constant. The aperture stop S moves integrally with the fourth lens group G4. .
Table 2 below provides values of specifications of the variable magnification optical system according to the present example.

(Table 2) Second Example
[Surface data]
Surface number r d nd νd
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 ∞ 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 (Aperture 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 1.773770 47.25
* 23 24.1750 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 -9.1997 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 ∞

[Aspherical data]
6th surface κ 20.0000
A4 9.17458E-05
A6 -6.51986E-07
A8 2.69890E-09
A10 -1.23751E-11

23rd surface κ 0.4823
A4 -7.24815E-06
A6 -3.60139E-07
A8 4.05630E-09
A10 0.00000E + 00

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

[Various data]
Scaling ratio 9.42

W T
f 10.30-96.99
FNO 4.12 to 5.81
ω 40.44 〜 4.73 °
Y 8.19-8.19
TL 103.03-143.32

W M T
f 10.30260 30.00000 96.99284
ω 40.44283 14.85841 4.72723
FNO 4.12 5.48 5.81
φ 8.12 8.12 9.70
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 start surface f
1 1 64.09778
2 6 -10.16794
3 15 31.06055
4 18 67.05869

[Conditional expression values]
(1) f1 / fw = 6.223
(2) (d1t−d1w) /fw=3.699
(3) (d3t−d3w) /fw=0.241
(4) (d2it−d2iw) /fw=0.213
(5) f3 / f4 = 0.463
(6) f1 / f4 = 0.956
(7) (−f2) /f4=0.152
(8) (-f2) / fw = 0.986

  4 (a), 4 (b), and 4 (c) respectively 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 second example of the present application. It is an aberration diagram at the time of focusing on an object.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Third embodiment)
5A, 5B, and 5C are cross-sectional views of the zoom optical system according to the third example of the present application in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is.
The variable magnification optical system according to the present example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power.

The first lens group G1 includes, 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 positive meniscus lens L13 having 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 directed toward the object side, a negative meniscus lens L22 having a concave surface directed toward the object side, a biconvex positive lens L23, and an object side. And a negative meniscus lens L24 having a concave surface. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.
The third lens group G3 is composed of a cemented lens of a negative meniscus lens L31 having a convex surface directed toward the object side and a biconvex positive lens L32 in order from the object side. An aperture stop S is provided on the object side of the third lens group G3.

The fourth lens group G4 includes, in order from the object side, a cemented lens of a biconvex positive lens L401 and a negative meniscus lens L402 having a convex surface directed to the image side, a negative meniscus lens L403 having a convex surface directed to the object side, and an image. A cemented lens with a positive meniscus lens L404 having a concave surface facing side, a biconvex positive lens L405, a positive meniscus lens L406 with a concave surface facing the object side, and a negative meniscus lens L407 with a concave surface facing the object side It consists of a cemented lens, a cemented lens of a negative meniscus lens L408 having a convex surface facing the object side and a biconvex positive lens L409, and a negative meniscus lens L410 having a concave surface facing the object side. The negative meniscus lens L403 is a glass mold aspheric lens having an aspheric lens surface on the object side, and the negative meniscus lens L410 is a glass mold aspheric lens having an aspheric lens surface on the image side.
In the zoom optical system according to the present embodiment, a low-pass filter, a sensor cover glass, or the like may be disposed between the fourth lens group G4 and the image plane I.

With the above-described 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 increases when the magnification is changed from the wide-angle end state to the telephoto end state. The air gap between the second lens group G2 and the third lens group G3 decreases, the air gap between the third lens group G3 and the fourth lens group G4 increases, and the air gap between the second lens group G2 and the aperture stop S. Decreases, the air gap between the aperture stop S and the third lens group G3 decreases, and the distance between the aperture stop S and the fourth lens group G4 is constant, so that the first to fourth lens groups G1 to G4 are constant. Moves along the optical axis, and the aperture stop S moves integrally with the fourth lens group G4. Specifically, the first lens group G1, the third lens group G3, and the fourth lens group G4 move to the object side during zooming. The second lens group G2 moves toward the object side from the wide-angle end state to the intermediate focal length state, and moves toward the image side from the intermediate focal length state to the telephoto end state.
Table 3 below lists values of specifications of the variable magnification optical system according to the present example.

(Table 3) Third Example
[Surface data]
Surface number r d nd νd
Object ∞

1 100.6708 1.6000 2.003300 28.27
2 38.2945 7.4500 1.497820 82.57
3 -587.4003 0.1000
4 40.2838 5.4500 1.834810 42.73
5 280.5337 Variable

* 6 202.2993 1.0000 1.851350 40.10
7 7.9721 5.1500
8 -9.9586 1.0000 1.883000 40.66
9 -44.8957 0.1000
10 74.4947 3.1500 1.808090 22.74
11 -13.5735 0.6500
12 -10.3252 1.0000 1.883000 40.66
13 -14.1555 Variable

14 (Aperture S) ∞ Variable

15 26.4355 1.0000 1.954000 33.46
16 14.5535 2.9500 1.700000 48.11
17 -46.9949 Variable

18 13.6121 3.5000 1.497820 82.57
19 -26.0652 1.0000 2.000690 25.46
20 -274.8099 2.1500
* 21 1292.9454 1.0000 1.806100 40.71
22 10.6698 2.1500 1.808090 22.74
23 23.0448 2.8000
24 19.2818 3.4500 1.548140 45.51
25 -13.8291 0.1000
26 -32.9399 2.8500 1.620040 36.40
27 -8.0721 1.0000 1.954000 33.46
28 -206.7578 0.1000
29 18.5580 1.0000 2.000690 25.46
30 7.4367 4.2000 1.647690 33.73
31 -21.5339 1.7500
32 -9.9511 1.0000 1.743300 49.32
* 33 -17.6298 BF

Image plane ∞

[Aspherical data]
6th surface κ 20.0000
A4 9.82146E-05
A6 -6.04337E-07
A8 2.59138E-09
A10 1.16839E-11

21st surface κ 20.0000
A4 1.53849E-05
A6 1.73734E-07
A8 -2.83188E-09
A10 0.00000E + 00

33rd surface κ 2.9454
A4 -6.43442E-05
A6 -1.32869E-06
A8 1.61809E-08
A10 -4.99485E-10

[Various data]
Scaling ratio 9.42

W T
f 10.30 to 97.00
FNO 4.10 to 5.82
ω 40.21 〜 4.80 °
Y 8.19-8.19
TL 100.18-142.60

W M T
f 10.30000 50.00015 97.00042
ω 40.21026 9.21685 4.79788
FNO 4.11 5.79 5.82
φ 8.50 9.50 10.24
d5 2.10000 28.21026 39.06515
d13 18.62936 3.83407 2.00000
d14 3.55190 3.36681 1.60000
d17 3.19885 3.38394 5.15075
BF 14.04944 35.47291 36.13193

[Lens group data]
Group start surface f
1 1 63.38656
2 6 -9.32485
3 15 30.22293
4 18 70.69668

[Conditional expression values]
(1) f1 / fw = 6.154
(2) (d1t-d1w) /fw=3.589
(3) (d3t−d3w) /fw=0.190
(4) (d2it−d2iw) /fw=0.529
(5) f3 / f4 = 0.428
(6) f1 / f4 = 0.897
(7) (−f2) /f4=0.132
(8) (−f2) /fw=0.905

  FIGS. 6A, 6B, and 6C are infinite at 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, respectively. It is an aberration diagram at the time of focusing on an object.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

  According to each of the above embodiments, a variable magnification optical system that is small in size, has a high zoom ratio, and has high optical performance can be realized. In addition, each said Example has shown one specific example of this invention, and this invention is not limited to these. The following contents can be adopted as appropriate as long as the optical performance of the variable magnification optical system of the present application is not impaired.

  Although a four-group configuration is shown as a numerical example of the variable magnification optical system of the present application, the present application is not limited to this, and a variable magnification optical system of another group configuration (for example, five groups, six groups, etc.) is configured. You can also. Specifically, a configuration in which a lens or a lens group is added to the most object side or the most image side of the variable magnification optical system of the present application may be used. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming.

  In addition, the variable magnification optical system of the present application uses a part of a lens group, an entire lens group, or a plurality of lens groups as a focusing lens group for focusing from an object at infinity to a near object. It is good also as a structure moved to an axial direction. In particular, it is preferable that at least part of the second lens group, at least part of the third lens group, or at least part of the fourth lens group be the focusing lens group. Such a focusing lens group can also be applied to autofocus, and is also suitable for driving by an autofocus motor, such as an ultrasonic motor.

  Further, in the variable magnification optical system of the present application, any lens group or a part thereof is moved as a vibration-proof lens group so as to include a component in a direction perpendicular to the optical axis, or a surface including the optical axis A configuration in which image blur caused by camera shake or the like is corrected by rotationally moving (swinging) inward is also possible. In particular, in the variable magnification optical system of the present application, it is preferable that at least a part of the third lens group or at least a part of the fourth lens group is an anti-vibration lens group.

  The lens surface of the lens constituting the variable magnification optical system of the present application may be a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, it is preferable because lens processing and assembly adjustment are easy, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is aspherical, any of aspherical surface by grinding, glass mold aspherical surface in which glass is molded into an aspherical shape, or composite aspherical surface in which resin provided on the glass surface is formed in an aspherical shape Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

In the variable magnification optical system of the present application, the aperture stop is preferably arranged in the third lens group or in the vicinity of the third lens group, and the role of the aperture stop is replaced by a lens frame without providing a member. Also good.
Further, an antireflection film having a high transmittance in a wide wavelength range may be applied to the lens surface of the lens constituting the variable magnification optical system of the present application. Thereby, flare and ghost can be reduced, and high optical performance with high contrast can be achieved.

Next, a camera provided with the variable magnification optical system of the present application will be described with reference to FIG.
FIG. 7 is a diagram illustrating a configuration of a camera including the variable magnification optical system of the present application.
As shown in FIG. 7, the camera 1 is a so-called mirrorless camera of an interchangeable lens provided with the variable magnification optical system according to the first example as the photographing lens 2.
In the camera 1, light from an object (subject) (not shown) is collected by the photographing lens 2 and is on the imaging surface of the imaging unit 3 via an OLPF (Optical low pass filter) (not shown). A subject image is formed on the screen. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate an image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thus, the photographer can observe the subject via the EVF 4.
When the release button (not shown) is pressed by the photographer, the subject image generated by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can shoot the subject with the camera 1.

  Here, the zoom optical system according to the first embodiment mounted as the photographing lens 2 on the camera 1 is a zoom optical system that is small in size, has a high zoom ratio, and has high optical performance. Therefore, the camera 1 can achieve high optical performance while achieving downsizing and a high zoom ratio. Even if a camera equipped with the variable magnification optical system according to the second and third examples as the photographing lens 2 is configured, the same effect as the camera 1 can be obtained. Further, even when the variable magnification optical system according to each of the above embodiments is mounted on a single-lens reflex camera that has a quick return mirror and observes a subject with a finder optical system, the same effect as the camera 1 can be obtained. it can.

Finally, the outline of the manufacturing method of the variable magnification optical system of this application is demonstrated based on FIG.
The variable power optical system manufacturing method shown in FIG. 8 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, and a positive aperture. A variable magnification optical system manufacturing method having a third lens group having a refractive power and a fourth lens group having a positive refractive power, and includes the following steps S1 and S2.

Step S1: The first lens group is made to satisfy the following conditional expression (1), and the first to fourth lens groups are sequentially arranged in the lens barrel from the object side.
(1) 5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens unit

  Step S2: By providing a known moving mechanism in the lens barrel, the distance between the first lens group and the second lens group, the second lens group and the aperture at the time of zooming from the wide-angle end state to the telephoto end state. The distance between the aperture stop, the distance between the aperture stop and the third lens group, and the distance between the third lens group and the fourth lens group are changed so that the distance between the aperture stop and the fourth lens group becomes constant. .

  According to the method for manufacturing a variable power optical system of the present application, it is possible to manufacture a variable power optical system that is small in size, has a high zoom ratio, and has high optical performance.

G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group S Aperture stop I Image plane

Claims (14)

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a positive refractive power. A fourth lens group having
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, the distance between the second lens group and the aperture stop, the aperture stop and the third lens group And the distance between the third lens group and the fourth lens group are changed, and the distance between the aperture stop and the fourth lens group is constant,
A zoom optical system characterized by satisfying the following conditional expression:
5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group   The zoom optical system according to claim 1, wherein the first lens unit moves toward the object side during zooming from the wide-angle end state to the telephoto end state.   3. The zoom optical system according to claim 1, wherein an interval between the first lens unit and the second lens unit is increased at the time of zooming from the wide-angle end state to the telephoto end state.   4. The space between the second lens group and the third lens group decreases during zooming from the wide-angle end state to the telephoto end state. 5. Variable magnification optical system. The zoom lens system according to claim 1, wherein the following conditional expression is satisfied.
3.250 <(d1t-d1w) / fw <4.200
However,
fw: focal length of the variable magnification optical system in the wide-angle end state d1w: distance from the most image-side lens surface in the first lens group to the most object-side lens surface in the second lens group in the wide-angle end state d1t: Distance from the most image side lens surface in the first lens group to the most object side lens surface in the second lens group in the telephoto end state The zoom lens system according to any one of claims 1 to 5, wherein the following conditional expression is satisfied.
0.160 <(d3t−d3w) / fw <0.550
However,
fw: focal length of the zoom optical system in the wide-angle end state d3w: distance from the most image-side lens surface in the third lens group to the most object-side lens surface in the fourth lens group in the wide-angle end state d3t: Distance from the most image side lens surface in the third lens group to the most object side lens surface in the fourth lens group in the telephoto end state The zoom lens system according to any one of claims 1 to 6, wherein the following conditional expression is satisfied.
0.140 <(d2it−d2iw) / fw <0.700
However,
fw: focal length of the variable magnification optical system in the wide-angle end state d2iw: distance from the most image side lens surface to the image plane in the second lens group in the wide-angle end state d2it: the second lens group in the telephoto end state The distance from the lens surface closest to the image side to the image surface   The variable power optical system according to any one of claims 1 to 7, wherein the third lens group includes two lenses. The variable magnification optical system according to claim 1, wherein the following conditional expression is satisfied.
0.200 <f3 / f4 <0.650
However,
f3: focal length of the third lens group f4: focal length of the fourth lens group The variable magnification optical system according to any one of claims 1 to 9, wherein the following conditional expression is satisfied.
0.780 <f1 / f4 <1.300
However,
f1: Focal length of the first lens group f4: Focal length of the fourth lens group The zoom lens system according to any one of claims 1 to 10, wherein the following conditional expression is satisfied.
0.050 <(− f2) / f4 <0.250
However,
f2: focal length of the second lens group f4: focal length of the fourth lens group The zoom lens system according to any one of claims 1 to 11, wherein the following conditional expression is satisfied.
0.740 <(− f2) / fw <1.120
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f2: focal length of the second lens group   An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 12. In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a positive refractive power. A variable magnification optical system having a fourth lens group,
The first lens group satisfies the following conditional expression:
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, the distance between the second lens group and the aperture stop, the aperture stop and the third lens group And the distance between the third lens group and the fourth lens group are changed so that the distance between the aperture stop and the fourth lens group is constant. Manufacturing method.
5.300 <f1 / fw <8.0000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state f1: focal length of the first lens group

Images