JP2014137409A - Variable power optical system, optical device, and method for manufacturing variable power optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable power optical system having a high variable power ratio, being compact, and achieving high optical performance even during focusing, and to provide an optical device and a method for manufacturing the variable power optical system.SOLUTION: The variable power optical system includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. When varying power from a wide angle end state to a telephoto end state, the distance between the first lens group G1 and the second lens group G2, and the distance between the second lens group G2 and the third lens group G3 are changed. The third lens group G3 includes an F lens group GF having positive refractive power and being moved along the optical axis during focusing from an infinite object to a short distance object.

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 2011-232543 A

  However, it has been difficult to obtain sufficiently high optical performance if the conventional variable power optical system as described above is to be downsized while maintaining a high zoom ratio. Also, it has been difficult to obtain sufficiently high optical performance when focusing from an object at infinity to an object at a short distance.

  Therefore, the present invention has been made in view of the above problems, and has a high zoom ratio, a small size, high optical performance, and a high zoom optical system and optical device that have high optical performance even when focused. An object of the present invention is to provide a method for manufacturing a variable magnification optical system.

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, and a third lens group having a positive refractive power,
During 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 third lens group change,
A variable power optical system characterized in that the third lens group has an F lens group that has a positive refractive power and moves along the optical axis when focusing from an object at infinity to an object at a short distance. provide.

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 variable magnification optical system manufacturing method including a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. There,
The third lens group has a positive refractive power and has an F lens group that moves along the optical axis when focusing from an object at infinity to an object at a short distance;
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 third lens group are changed. A variable magnification optical system manufacturing method is provided.

  According to the present invention, there are provided a variable magnification optical system, an optical apparatus, and a variable magnification optical system manufacturing method having a high zoom ratio, small size, high optical performance, and high optical performance even when focused. can do.

(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 respectively when a short-distance object is focused 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 (shooting). FIG. 6 is a diagram showing various aberrations at a magnification of −0.01. (A), (b), and (c) are respectively prevented 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. FIG. 6 is a meridional lateral aberration diagram when vibration is performed. (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 respectively when a short-distance object is focused in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable magnification optical system according to the second example of the present application (shooting). FIG. 6 is a diagram showing various aberrations at a magnification of −0.01. (A), (b), and (c) are respectively prevented 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. FIG. 6 is a meridional lateral aberration diagram when vibration is performed. 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, and a third lens group having a positive refractive power. When the magnification is changed 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 third lens group change. It is a feature. 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. .

In the variable magnification optical system of the present application, the third lens group has a positive refractive power, and has an F lens group that moves along the optical axis when focusing from an object at infinity to an object at a short distance. It is characterized by that. With this configuration, it is possible to suppress fluctuations in astigmatism and spherical aberration during focusing. In addition, it is possible to suppress a change in the focal length of the variable magnification optical system of the present application, and it is possible to realize a high optical performance by suppressing a change in the angle of view accompanying focusing. Further, in the telephoto end state, the amount of movement of the F lens group during focusing can be suppressed. For this reason, not only can the variable magnification optical system of the present application be made compact, but also fluctuations in astigmatism and distortion can be suppressed during focusing.
With the above configuration, a variable magnification optical system having a high zoom ratio, a small size, high optical performance, and high optical performance even when focused can be realized.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (1).
(1) 0.320 <ff / f3 <5.200
However,
f3: focal length of the third lens group ff: focal length of the F lens group

Conditional expression (1) defines an appropriate focal length ratio range between the third lens group and the F lens group. By satisfying conditional expression (1), the variable magnification optical system of the present application can suppress variations in spherical aberration and astigmatism generated by the F lens group during focusing.
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, the fluctuation of spherical aberration and the fluctuation of astigmatism generated by the F lens group at the time of focusing become excessive. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1) to 0.880. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1) to 1.150.
On the other hand, when the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application exceeds the upper limit value, the moving amount of the F lens group becomes large at the time of focusing. For this reason, the height from the optical axis of the on-axis light beam or off-axis light beam incident on the F lens group at the time of focusing changes greatly, and the fluctuation of spherical aberration and astigmatism generated by the F lens group are excessive. turn into. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1) to 2.600. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1) to 1.900.

  In the variable magnification optical system of the present application, it is desirable that the F lens group is a partial lens group in the third lens group. With this configuration, that is, the F lens group is a part of the third lens group, it is possible to suppress a change in the focal length of the variable magnification optical system of the present application at the time of focusing, and fluctuations in aberrations such as astigmatism during focusing. Can be suppressed.

  In the variable magnification optical system of the present application, it is desirable that the F lens group is disposed on the most image side in the third lens group. With this configuration, a change in focal length of the variable magnification optical system of the present application can be further suppressed during focusing, and high optical performance can be realized by suppressing a change in angle of view accompanying focusing. In addition, it is possible to suppress fluctuations in astigmatism and distortions during focusing.

  The zoom optical system of the present application has a fourth lens group having negative refractive power on the image side of the third lens group, and the third lens group has a third lens unit at the time of zooming from the wide-angle end state to the telephoto end state. It is desirable that the distance between the lens group and the fourth lens group changes. With this configuration, the principal point position in the lens group from the first lens group to the third lens group can be moved to the object side, and the variable magnification optical system of the present application can be made compact. In addition, it is possible to suppress distortion in the wide-angle end state, and to suppress variations in spherical aberration and astigmatism during zooming.

  The variable magnification optical system of the present application has a fifth lens group on the image side of the fourth lens group, and the fourth lens group and the fifth lens group at the time of zooming from the wide-angle end state to the telephoto end state. It is desirable that the distance from the lens group changes. With this configuration, it is possible to suppress distortion in the wide-angle end state, and to suppress variations in spherical aberration and astigmatism during zooming.

  Further, it is desirable that the zoom optical system of the present application has an R lens group on the most image side, and the position of the R lens group is fixed when zooming from the wide angle end state to the telephoto end state. With this configuration, the height of the peripheral light beam incident on the R lens group from the optical axis can be changed during zooming, and astigmatism fluctuations can be suppressed.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (2).
(2) 5.500 <f1 / fw <9.0000
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 (2) defines an appropriate focal length range of the first lens group. By satisfying conditional expression (2), 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 (2) of the variable magnification optical system of the present application is less than 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 (2) to 6.700. 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 7.300.
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 distance between the first lens group and the second lens group at the time of zooming is obtained in order to obtain a predetermined zoom ratio. It is necessary to increase the amount of change. This not only makes it difficult to miniaturize the variable magnification optical system of the present application, but also changes the ratio of 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. It changes greatly with it. 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 8.500. 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 8.200.

  In the zoom optical system of the present application, it is desirable that the third lens group has a V lens group that has a negative refractive power and moves so as to include a component in a direction orthogonal to the optical axis. The variable magnification optical system of the present application moves an image by moving the V lens group so as to include a component in a direction orthogonal to the optical axis, and corrects image blur caused by camera shake, that is, performs image stabilization. Can do. In addition, with the above-described configuration, it is possible to suppress decentered coma generated in the V lens group.

  In the variable magnification optical system of the present application, it is desirable that the V lens group is disposed closer to the object side than the F lens group. With this configuration, the ratio of the amount of movement of the image to the amount of movement of the V lens group can be increased in the telephoto end state than in the wide angle end state. For this reason, the movement amount of the V lens group required in the telephoto end state can be suppressed, and the eccentric coma aberration generated in the V lens group can be suppressed.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (3).
(3) 0.240 <ff / (-fv) <4.0000
However,
ff: focal length of the F lens group fv: focal length of the V lens group

Conditional expression (3) defines an appropriate focal length ratio range between the F lens group and the V lens group. By satisfying conditional expression (3), the variable magnification optical system of the present application exhibits the decentration coma aberration when the V lens group is moved so as to include the component in the direction orthogonal to the optical axis and the image stabilization is performed. Can be suppressed. In addition, it is possible to suppress changes in spherical aberration and astigmatism that occur in each lens group during focusing.
If the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application is below the lower limit value, the fluctuation of spherical aberration and the fluctuation of astigmatism occurring in each lens group at the time of focusing become excessive. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3) to 0.490. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3) to 0.630.
On the other hand, if the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application exceeds the upper limit value, the decentration coma aberration at the time of image stabilization becomes excessive. In addition, the amount of movement of the F lens group during focusing increases. For this reason, at the time of focusing, the state of the light beam passing through the F lens group changes greatly, and it becomes impossible to suppress the variation in spherical aberration and the astigmatism generated in the F lens group. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3) to 2.800. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3) to 1.800.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (4).
(4) 0.280 <(− fv) / f3 <5.200
However,
f3: focal length of the third lens group fv: focal length of the V lens group

Conditional expression (4) defines an appropriate focal length ratio range between the third lens group and the V lens group. The variable magnification optical system of the present application can suppress decentering coma during vibration isolation by satisfying conditional expression (4).
If the corresponding value of the conditional expression (4) of the variable magnification optical system of the present application is less than the lower limit value, the decentering coma aberration at the time of image stabilization becomes excessive. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4) to 0.610. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (4) to 0.740.
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, the amount of movement of the V lens group required for image stabilization becomes excessive. For this reason, the eccentric coma aberration generated by the V lens group becomes excessive. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4) to 2.400. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4) to 1.650.

  In the variable magnification optical system of the present application, it is desirable that the third lens group has a 3A lens group having a positive refractive power on the object side of the V lens group. With this configuration, it is possible to suppress the amount of movement of the V lens group that is required during image stabilization, and to suppress decentration coma generated by the V lens group.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (5).
(5) 0.300 <(-fv) / f3A <3.800
However,
f3A: focal length of the 3A lens group fv: focal length of the V lens group

Conditional expression (5) defines an appropriate focal length ratio range of the 3A lens group and the V lens group. The variable magnification optical system of the present application can suppress decentering coma during vibration isolation by satisfying conditional expression (5).
If the corresponding value of the conditional expression (5) of the variable magnification optical system of the present application is less than the lower limit value, the decentering coma aberration at the time of image stabilization becomes excessive. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5) to 0.650. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5) to 0.920.
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, the amount of movement of the V lens group required for image stabilization becomes excessive. For this reason, the eccentric coma aberration generated by the V lens group becomes excessive. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5) to 3.700. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5) to 2.900.

  In the variable power optical system of the present application, it is desirable that the distance between the 3A lens group and the V lens group is unchanged when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to suppress a change in tilt eccentricity between the third lens group and the V lens group, which occurs during manufacturing, from changing during zooming. For this reason, it is possible to suppress the fluctuation of the eccentric coma aberration and the fluctuation of the astigmatism caused by the tilt decentration of the V lens group at the time of zooming.

  In the variable magnification optical system of the present application, it is desirable that the third lens group has an M lens group having a positive refractive power between the V lens group and the F lens group. With this configuration, it is possible to suppress decentration coma aberration generated in the V lens group when the V lens group is moved so as to include a component in a direction orthogonal to the optical axis during image stabilization. In addition, the amount of movement of the F lens group can be suppressed during focusing. For this reason, fluctuations in astigmatism and spherical aberration that occur in the F lens group during focusing can be suppressed.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (6).
(6) 0.110 <(− fv) / fm <2.600
However,
fm: focal length of the M lens group fv: focal length of the V lens group

Conditional expression (6) defines an appropriate focal length ratio range between the V lens group and the F lens group. The variable magnification optical system of the present application satisfies the conditional expression (6), so that a deviation generated in the V lens group in a state in which the V lens group is moved to include a component in a direction orthogonal to the optical axis at the time of image stabilization. Core coma can be suppressed. In addition, fluctuations in astigmatism and spherical aberration that occur in the F lens group during focusing can be suppressed.
When the corresponding value of the conditional expression (6) of the variable magnification optical system of the present application is below the lower limit value, the V lens group is moved in the state in which the V lens group is moved so as to include a component in the direction orthogonal to the optical axis during image stabilization. The generated decentered coma aberration becomes excessive. Further, the amount of movement of the F lens group at the time of focusing becomes excessive. For this reason, it becomes difficult to suppress fluctuations in astigmatism and spherical aberration that occur in the F lens group during focusing. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6) to 0.230.
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 value, the amount of movement of the V lens group required for image stabilization becomes excessive. For this reason, the eccentric coma aberration generated by the V lens group becomes excessive. In addition, it becomes difficult to suppress fluctuations in astigmatism and spherical aberration that occur in the F lens group during focusing. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6) to 1.300. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6) to 0.880.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (7).
(7) 0.080 <ff / fm <1.700
However,
ff: focal length of the F lens group fm: focal length of the M lens group

Conditional expression (7) defines an appropriate focal length ratio range between the F lens group and the M lens group. By satisfying conditional expression (7), the variable magnification optical system of the present application can suppress fluctuations in astigmatism and spherical aberration that occur in the F lens group during focusing.
When the corresponding value of the conditional expression (7) of the variable magnification optical system of the present application is below the lower limit value, the fluctuation of astigmatism and the spherical aberration that occur in the F lens group at the time of focusing become excessive. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7) to 0.200.
On the other hand, when the corresponding value of conditional expression (7) of the zoom optical system of the present application exceeds the upper limit value, the amount of movement of the F lens group at the time of focusing increases. For this reason, during focusing, the on-axis light beam and off-axis light beam incident on the F lens group change greatly, and astigmatism variation and spherical aberration variation become excessive. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7) to 1.200. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7) to 0.950.

  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 composite magnification from the third lens group to the lens group located closest to the image side can be increased, and the variation in spherical aberration and astigmatism during zooming can be achieved while efficiently achieving a high zoom ratio. Variations in aberrations can be suppressed.

  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 passing through the first lens unit at the time of zooming, and it is possible not only to reduce the diameter of the first lens unit, but also to astigmatism at the time of zooming. It is also possible to suppress fluctuations.

  In the zoom optical system of the present application, it is preferable that the third lens group 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 increase the magnification of the third lens group, and it is possible to suppress changes in spherical aberration and astigmatism that occur in the third lens group during zooming.

  In the zoom optical system of the present application, it is preferable that the second lens group moves along the optical axis when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to suppress fluctuations in astigmatism that occur in the first lens group and the third lens group during zooming, particularly in the intermediate focal length state.

  In the variable magnification optical system of the present application, the second lens group has, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, and a negative refractive power. It is desirable that the lens is composed of a third lens. With this configuration, it is possible to suppress fluctuations in coma, spherical aberration, and astigmatism that occur in the second lens group during zooming. Further, the thickness of the second lens group can be suppressed as compared with the case where the second lens group is composed of four or more lenses, and the off-axis luminous flux of the first lens group in the wide-angle end state is increased from the optical axis. The first lens group can be reduced in size while suppressing this.

  In the variable magnification optical system of the present application, it is desirable that the second lens and the third lens are cemented. With this configuration, it is possible to suppress coma aberration fluctuations that occur in the second lens during zooming.

  In the zoom optical system of the present application, it is desirable that the object-side lens surface of the first lens and the image-side lens surface of the third lens are aspherical surfaces. With this configuration, each variation of astigmatism, coma, and distortion can be suppressed during zooming.

  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 having a high zoom ratio, a small size, high optical performance, and high optical performance even when focused.

  The variable magnification optical system manufacturing method 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, and a third lens group having a positive refractive power. The third lens group has a positive refractive power and moves along the optical axis when focusing from an object at infinity to a near object. The zoom lens has a lens group, 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 third lens group It is characterized by changing. Thereby, it is possible to manufacture a variable power optical system having a high zoom ratio, a small size, high optical performance, and high optical performance even when focused.

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 negative refractive power and a fifth lens group G5 having a positive refractive power which is an R lens group.

  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 facing the object side that is the first lens, a positive meniscus lens L22 having a concave surface facing the object side that is the second lens, and a third lens. And a cemented lens with a negative meniscus lens L23 having a concave surface facing the object side. The negative meniscus lens L21 is a composite aspheric lens formed by forming a resin layer provided on the glass surface on the object side into an aspherical shape, and the negative meniscus lens L23 has an aspherical surface on the image side. This is a glass mold aspheric lens.

The third lens group G3 includes, in order from the object side, a 3A lens group G3A having a positive refractive power, a V lens group GV having a negative refractive power, an M lens group GM having a positive refractive power, and a positive It consists of an F lens group GF having refractive power.
The 3A lens group G3A includes, in order from the object side, a positive meniscus lens L31 having a convex surface directed toward the object side, and a biconvex positive lens L32.
The V lens group GV includes, in order from the object side, a cemented lens of a positive meniscus lens L33 having a concave surface facing the object side and a biconcave negative lens L34. The negative lens L34 is a glass mold aspheric lens having an aspheric lens surface on the image side.
The M lens group GM includes, in order from the object side, a cemented lens of a biconvex positive lens L35 and a negative meniscus lens L36 having a concave surface facing the object side, and a negative meniscus lens L37 having a concave surface facing the object side. . The negative meniscus lens L37 is a glass mold aspheric lens having an aspheric lens surface on the image side.
The F lens group GF includes, in order from the object side, a cemented lens of a negative meniscus lens L38 having a convex surface facing the object side and a biconvex positive lens L39.
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 biconcave negative lens L41, a negative meniscus lens L42 having a concave surface directed toward the object side, and a biconvex positive lens L43.

  The fifth lens group G5 includes a positive meniscus lens L51 having a concave surface directed toward the object side. The positive meniscus lens L51 is a glass mold aspheric lens having an aspheric lens surface on the image side.

With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move along the optical axis.
Specifically, the first lens group G1 to the fourth lens group G4 move to the object side during zooming. The position of the fifth lens group G5 in the optical axis direction is fixed during zooming. The aperture stop S moves to the object side integrally with the third lens group G3 during zooming.
Thereby, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4. And the fifth lens group G5 increase in air space. At the time of zooming, the air gap between the third lens group G3 and the fourth lens group G4 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. Note that the air gap between the 3A lens group G3A and the V lens group GV in the third lens group G3 is constant during zooming.

  In the variable magnification optical system according to the present embodiment, when camera shake or the like occurs, the V lens group GV in the third lens group G3 is moved as a vibration-proof lens group so as to include a component in a direction orthogonal to the optical axis. To prevent vibration.

  In the variable magnification optical system according to the present embodiment, the F lens group GF in the third lens group G3 is moved to the object side along the optical axis as a focusing lens group, so that an object at a short distance from an object at infinity Focus on.

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 + A12h ¹²
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, A12 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.
[Amount of movement of the focusing lens group at the time of focusing] indicates a movement amount of the F lens group GF from the time of focusing on an object at infinity to the time of focusing on an object at a short distance (imaging magnification: -0.0100 times). The sign of the movement amount is positive when the F lens group GF moves to the object side. The shooting distance indicates the distance from the object plane to the image plane I.
[Lens Group Data] indicates the start surface and focal length of each lens group.
[Anti-Vibration Coefficient] indicates an anti-vibration coefficient that is a ratio of the moving amount of the image on the image plane I to the moving amount from the optical axis of the anti-vibration lens group (V lens group GV).
[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.
It should be noted that the symbols in Table 1 described above are similarly used in the table of the second embodiment described later.

(Table 1) First Example
[Surface data]
Surface number r d nd νd
Object ∞

1 140.5647 1.6350 1.903660 31.27
2 45.6913 7.6885 1.497820 82.57
3 -284.3669 0.1000
4 44.8550 4.5326 1.804000 46.60
5 209.3179 Variable

* 6 500.0000 0.1000 1.553890 38.09
7 190.3219 1.0000 1.883000 40.66
8 8.9187 4.3652
9 -114.5251 4.6494 1.808090 22.74
10 -9.8911 1.0000 1.851350 40.10
* 11 -141.3941 Variable

12 (Aperture S) ∞ 1.0000
13 22.3603 1.7845 1.589130 61.22
14 187.8269 0.2763
15 15.7519 1.9659 1.487490 70.31
16 -148.6118 1.8000
17 -28.8021 2.7134 1.903660 31.27
18 -9.8324 1.0000 1.801390 45.46
* 19 41.1794 1.8000
20 37.0997 2.9939 1.593190 67.90
21 -10.2317 1.0000 2.000690 25.46
22 -15.2899 0.1000
23 -37.4207 1.6662 1.851350 40.10
* 24 -4390.3946 5.9000
25 15.4513 1.0000 2.001000 29.14
26 10.6501 3.5906 1.618000 63.34
27 -71.8553 Variable

28 -69.6397 1.0000 1.883000 40.66
29 20.2769 1.8596
30 -24.0135 1.0000 1.902650 35.73
31 -41.9476 0.2011
32 29.1388 2.4495 1.698950 30.13
33 -43.6887 Variable

34 -46.1581 0.9998 1.583130 59.44
* 35 -30.3822 BF

Image plane ∞

[Aspherical data]
6th surface κ -8.90440
A4 2.59493E-05
A6 -1.90094E-08
A8 -1.65609E-09
A10 1.17227E-11
A12 -3.31780E-14

11th surface κ 11.00000
A4 -5.42096E-05
A6 -3.10136E-07
A8 1.12406E-09
A10 -6.77479E-11
A12 0.00000

19th surface κ 1.00000
A4 -9.95519E-06
A6 -1.63819E-07
A8 7.91554E-09
A10 -7.12206E-11
A12 0.00000

24th surface κ 1.00000
A4 6.12158E-05
A6 9.54377E-08
A8 7.65997E-09
A10 -1.66332E-10
A12 0.00000

35th surface κ 1.00000
A4 4.40945E-05
A6 4.55406E-08
A8 -1.64694E-10
A10 0.00000
A12 0.00000

[Various data]
Scaling ratio 14.13

W T
f 9.27 to 130.95
FNO 3.62 to 5.80
ω 42.35 to 3.34 °
Y 8.00-8.00
TL 107.68-161.55

W M T
f 9.27006 35.10507 130.95123
ω 42.35293 12.26813 3.33615
FNO 3.62 4.86 5.80
φ 9.50 9.50 9.50
d5 1.99992 27.74462 49.07741
d11 26.66183 8.84274 1.60231
d27 1.50002 3.35186 1.50007
d33 2.49955 19.42198 34.34914
BF 13.84950 13.85022 13.85075

[Movement amount of focusing lens group during focusing]
W M T
Shooting magnification -0.0100 -0.0100 -0.0100
Shooting distance 1012.7397 3564.3738 13007.0879
Travel 0.0448 0.0946 0.2525

[Lens group data]
Group start surface f
1 1 72.95815
2 6 -9.72184
3 13 19.81920
4 28 -39.80048
5 34 148.96616

[Anti-vibration coefficient]
W M T
Anti-vibration coefficient -1.25 -1.80 -2.16

[Conditional expression values]
(1) ff / f3 = 1.337
(2) f1 / fw = 7.870
(3) ff / (-fv) = 1.088
(4) (−fv) /f3=1.229
(5) (−fv) /f3A=1.365
(6) (−fv) /fm=0.476
(7) ff / fm = 0.518

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.
3 (a), 3 (b), and 3 (c) are short distances 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. FIG. 6 is a diagram showing various aberrations when the object is in focus (imaging magnification: -0.01 times).
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 first example of the present application. FIG. 6 is a meridional lateral aberration diagram when the image stabilization is performed at the time of focusing on the object, and more specifically, when the V lens group GV is moved by 0.1 mm in a direction perpendicular to the optical axis and an image height of ± 5.6 mm. .
For example, in the variable magnification optical system according to the present example, since the image stabilization coefficient is −1.25 and the focal length is 9.27 mm in the wide-angle end state, the V lens group GV is moved by 0.1 mm from the optical axis. Thus, it is possible to correct the rotational shake of the rotation surface including the optical axis of −0.77 °.

  In each aberration diagram, FNO is the F number, NA is the numerical aperture of the light beam incident on the first lens group G1, A is the light beam incident angle, that is, the half field angle (unit is “°”), and H0 is the object height (the unit is “ mm "). 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. In the aberration diagrams of the second embodiment described later, the same reference numerals as in this embodiment are used.

  From each aberration diagram, the variable magnification optical system according to the present example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state. It can be seen that it has image performance.

(Second embodiment)
FIGS. 5A, 5B, and 5C 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 negative refractive power and a fifth lens group G5 having a positive refractive power which is an R lens group.

  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 facing the object side that is the first lens, a positive meniscus lens L22 having a concave surface facing the object side that is the second lens, and a third lens. And a cemented lens with a negative meniscus lens L23 having a concave surface facing the object side. The negative meniscus lens L21 is a composite aspheric lens formed by forming a resin layer provided on the glass surface on the object side into an aspherical shape, and the negative meniscus lens L23 has an aspherical surface on the image side. This is a glass mold aspheric lens.

The third lens group G3 includes, in order from the object side, a 3A lens group G3A having a positive refractive power, a V lens group GV having a negative refractive power, an M lens group GM having a positive refractive power, and a positive It consists of an F lens group GF having refractive power.
The 3A lens group G3A includes, in order from the object side, a positive meniscus lens L31 having a convex surface directed toward the object side, and a biconvex positive lens L32.
The V lens group GV includes, in order from the object side, a cemented lens of a positive meniscus lens L33 having a concave surface facing the object side and a biconcave negative lens L34. The negative lens L34 is a glass mold aspheric lens having an aspheric lens surface on the image side.
The M lens group GM includes, in order from the object side, a cemented lens of a biconvex positive lens L35 and a negative meniscus lens L36 having a concave surface facing the object side, and a negative meniscus lens L37 having a convex surface facing the object side. . The negative meniscus lens L37 is a glass mold aspheric lens having an aspheric lens surface on the image side.
The F lens group GF includes, in order from the object side, a cemented lens of a negative meniscus lens L38 having a convex surface facing the object side and a biconvex positive lens L39.
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 biconcave negative lens L41, a negative meniscus lens L42 having a concave surface directed toward the object side, and a biconvex positive lens L43.

  The fifth lens group G5 includes a positive meniscus lens L51 having a concave surface directed toward the object side. The positive meniscus lens L51 is a glass mold aspheric lens having an aspheric lens surface on the image side.

With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move along the optical axis.
Specifically, the first lens group G1 to the fourth lens group G4 move to the object side during zooming. The position of the fifth lens group G5 in the optical axis direction is fixed during zooming. The aperture stop S moves to the object side integrally with the third lens group G3 during zooming.
Thereby, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4. And the fifth lens group G5 increase in air space. At the time of zooming, the air gap between the third lens group G3 and the fourth lens group G4 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. Note that the air gap between the 3A lens group G3A and the V lens group GV in the third lens group G3 is constant during zooming.

  In the variable magnification optical system according to the present embodiment, when camera shake or the like occurs, the V lens group GV in the third lens group G3 is moved as a vibration-proof lens group so as to include a component in a direction orthogonal to the optical axis. To prevent vibration.

In the variable magnification optical system according to the present embodiment, the F lens group GF in the third lens group G3 is moved to the object side along the optical axis as a focusing lens group, so that an object at a short distance from an object at infinity Focus on.
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 ∞

1 144.9227 1.6350 1.903660 31.27
2 46.4543 7.6180 1.497820 82.57
3 -280.8281 0.1000
4 45.6286 4.5089 1.804000 46.60
5 218.0774 Variable

* 6 500.0000 0.1000 1.553890 38.09
7 201.2901 1.0000 1.883000 40.66
8 8.9082 4.3024
9 -176.6896 4.5658 1.808090 22.74
10 -10.0014 1.0000 1.851350 40.10
* 11 -200.0095 Variable

12 (Aperture S) ∞ 0.9999
13 23.8529 1.8095 1.589130 61.22
14 486.6979 0.1519
15 15.8304 2.0358 1.487490 70.31
16 -215.8847 1.8715
17 -29.0336 2.6709 1.903660 31.27
18 -9.9974 1.0000 1.801390 45.46
* 19 41.4658 1.8000
20 60.1509 3.0715 1.593190 67.90
21 -10.4089 0.9998 2.000690 25.46
22 -16.9605 0.0998
23 489.2464 1.6386 1.851350 40.10
* 24 70.3131 5.8990
25 15.2850 1.0000 2.001000 29.14
26 10.6499 3.7035 1.618000 63.34
27 -78.8215 Variable

28 -77.1108 1.0000 1.883000 40.66
29 19.2328 1.7995
30 -28.7053 1.0000 1.902650 35.73
31 -58.4684 0.2013
32 27.7625 2.4973 1.698950 30.13
33 -42.9090 Variable

34 -45.3546 0.9996 1.583130 59.44
* 35 -30.7592 BF

Image plane ∞

[Aspherical data]
6th surface κ -8.74540
A4 2.25905E-05
A6 1.19617E-07
A8 -4.53045E-09
A10 3.58335E-11
A12 -1.06040E-13

11th surface κ 11.00000
A4 -5.72909E-05
A6 -2.83675E-07
A8 -4.14714E-10
A10 -6.09625E-11
A12 0.00000

19th surface κ 1.00000
A4 -9.91318E-06
A6 -1.59863E-07
A8 6.78573E-09
A10 -5.85391E-11
A12 0.00000

24th surface κ 1.00000
A4 4.62032E-05
A6 1.66004E-07
A8 1.04366E-09
A10 -3.63478E-11
A12 0.00000

35th surface κ 1.00000
A4 4.27991E-05
A6 5.83932E-08
A8 -3.84157E-10
A10 0.00000
A12 0.00000

[Various data]
Scaling ratio 14.13

W T
f 9.27 to 130.95
FNO 3.59 to 5.68
ω 42.56 〜 3.34 °
Y 8.00-8.00
TL 107.46-162.00

W M T
f 9.27014 35.18344 130.95207
ω 42.56336 12.24162 3.33601
FNO 3.59 4.79 5.68
φ 9.52 9.52 9.52
d5 2.00004 28.13283 49.85756
d11 26.52876 8.54977 1.50011
d27 1.49960 3.51536 1.49981
d33 2.49961 19.00799 34.21187
BF 13.85090 13.85172 13.85176

[Movement amount of focusing lens group during focusing]
W M T
Shooting magnification -0.0100 -0.0100 -0.0100
Shooting distance 1012.6284 3571.8850 13006.4468
Travel 0.0445 0.0953 0.2527

[Lens group data]
Group start surface f
1 1 73.95013
2 6 -9.75125
3 13 19.75049
4 28 -40.13288
5 34 159.88013

[Anti-vibration coefficient]
W M T
Anti-vibration coefficient -1.23 -1.77 -2.13

[Conditional expression values]
(1) ff / f3 = 1.342
(2) f1 / fw = 7.977
(3) ff / (-fv) = 1.082
(4) (−fv) /f3=1.240
(5) (−fv) /f3A=1.356
(6) (−fv) /fm=0.495
(7) ff / fm = 0.536

6 (a), 6 (b), and 6 (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 second example of the present application. It is an aberration diagram at the time of focusing on an object.
FIGS. 7A, 7B, and 7C are short distances 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. FIG. 6 is a diagram showing various aberrations when the object is in focus (imaging magnification: -0.01 times).
8 (a), 8 (b), and 8 (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 second example of the present application. FIG. 6 is a meridional lateral aberration diagram when the image stabilization is performed at the time of focusing on the object, and more specifically, when the V lens group GV is moved by 0.1 mm in a direction perpendicular to the optical axis and an image height of ± 5.6 mm. .
For example, in the variable magnification optical system according to the present example, since the image stabilization coefficient is −1.23 and the focal length is 9.27 mm in the wide-angle end state, the V lens group GV is moved by 0.1 mm from the optical axis. Thus, it is possible to correct the rotation blur of the rotation surface including the optical axis of −0.76 °.

  From each aberration diagram, the variable magnification optical system according to the present example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state. It can be seen that it has image performance.

  According to each of the above embodiments, it is possible to realize a variable power optical system having a high zoom ratio, a small size, high optical performance, and high optical performance even when focused. 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 five-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, six groups) can also be configured. . 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, at least part of the fourth lens group, or at least part of the fifth 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 It can also be set as the structure which carries out anti-vibration by rotationally moving (swinging) inward. 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 equipped with the variable magnification optical system of the present application will be described with reference to FIG.
FIG. 9 is a diagram illustrating a configuration of a camera including the variable magnification optical system of the present application.
As shown in FIG. 9, the camera 1 is a so-called mirrorless camera of an interchangeable lens type that includes 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 in the camera 1 has a high zoom ratio, is small, has high optical performance, and has high optical performance even when focused. This is a variable magnification optical system having performance. Therefore, the present camera 1 can realize a reduction in size and high optical performance while having a high zoom ratio, and can also realize high optical performance even during focusing. Even if a camera equipped with the variable magnification optical system according to the second embodiment as the taking 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 manufacturing method of the variable magnification optical system of the present application shown in FIG. 10 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, and a positive refractive power. This is a method for manufacturing a variable magnification optical system having a third lens group, and includes the following steps S1 and S2.

  Step S1: The third lens group has a positive refracting power and has an F lens group that moves along the optical axis when focusing from an object at infinity to an object at a short distance. The lens group is arranged in the lens barrel in order from the object side.

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

  According to the manufacturing method of the zooming optical system of the present application, a zooming optical system having a high zooming ratio, a small size, high optical performance, and high optical performance at the time of focusing is manufactured. Can do.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group (R lens group)
GV V lens group GF F lens group S Aperture stop I Image surface

Claims (28)

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
During 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 third lens group change,
The zoom lens system according to claim 1, wherein the third lens group includes an F lens group that has a positive refractive power and moves along the optical axis when focusing from an object at infinity to an object at a short distance. The variable magnification optical system according to claim 1, wherein the following conditional expression is satisfied.
0.320 <ff / f3 <5.200
However,
f3: focal length of the third lens group ff: focal length of the F lens group   The variable power optical system according to claim 1, wherein the F lens group is a partial lens group in the third lens group.   4. The variable power optical system according to claim 1, wherein the F lens group is disposed closest to the image side in the third lens group. 5. A fourth lens group having negative refractive power on the image side of the third lens group;
5. The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end state to the telephoto end state. 6. Variable magnification optical system. A fifth lens group on the image side of the fourth lens group;
6. The variable magnification optical system according to claim 5, wherein the distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end state to the telephoto end state. It has an R lens group on the most image side,
6. The zoom optical system according to claim 1, wherein the position of the R lens group is fixed at the time of zooming from the wide-angle end state to the telephoto end state. The zoom lens system according to any one of claims 1 to 7, wherein the following conditional expression is satisfied.
5.500 <f1 / fw <9.0000
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 third lens group has a V lens group that has a negative refractive power and moves so as to include a component in a direction perpendicular to the optical axis. The zoom optical system according to one item.   The variable power optical system according to claim 9, wherein the V lens group is disposed closer to the object side than the F lens group. The zoom lens system according to claim 9 or 10, wherein the following conditional expression is satisfied.
0.240 <ff / (-fv) <4.0000
However,
ff: focal length of the F lens group fv: focal length of the V lens group The zoom lens system according to any one of claims 9 to 11, wherein the following conditional expression is satisfied.
0.280 <(-fv) / f3 <5.200
However,
f3: focal length of the third lens group fv: focal length of the V lens group   The variable power optical system according to any one of claims 9 to 12, wherein the third lens group includes a 3A lens group having a positive refractive power on the object side of the V lens group. system. The variable magnification optical system according to claim 13, wherein the following conditional expression is satisfied.
0.300 <(-fv) / f3A <3.800
However,
f3A: focal length of the 3A lens group fv: focal length of the V lens group   15. The zoom optical system according to claim 13, wherein the distance between the 3A lens group and the V lens group is not changed during zooming from the wide-angle end state to the telephoto end state.   The said 3rd lens group has an M lens group which has positive refractive power between the said V lens group and the said F lens group, The any one of Claims 9-15 characterized by the above-mentioned. The variable power optical system described. The zoom lens system according to claim 16, wherein the following conditional expression is satisfied.
0.110 <(− fv) / fm <2.600
However,
fm: focal length of the M lens group fv: focal length of the V lens group The variable magnification optical system according to claim 16 or 17, wherein the following conditional expression is satisfied.
0.080 <ff / fm <1.700
However,
ff: focal length of the F lens group fm: focal length of the M lens group   The distance between the first lens group and the second lens group increases during zooming from the wide-angle end state to the telephoto end state, according to any one of claims 1 to 18. Variable magnification optical system.   20. The distance between the second lens group and the third lens group decreases during zooming from the wide-angle end state to the telephoto end state. Variable magnification optical system.   21. 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.   The zoom optical system according to any one of claims 1 to 21, wherein the third lens unit moves toward the object side during zooming from the wide-angle end state to the telephoto end state.   The zoom optical system according to any one of claims 1 to 22, wherein the second lens group moves along the optical axis during zooming from the wide-angle end state to the telephoto end state. .   The second lens group includes, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, and a third lens having a negative refractive power. The variable power optical system according to any one of claims 1 to 23, wherein:   25. The zoom optical system according to claim 24, wherein the second lens and the third lens are cemented.   26. The zoom optical system according to claim 24, wherein an object-side lens surface of the first lens and an image-side lens surface of the third lens are aspherical surfaces.   An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 26. In order from the object side, a variable magnification optical system manufacturing method including a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. There,
The third lens group has a positive refractive power and has an F lens group that moves along the optical axis when focusing from an object at infinity to an object at a short distance;
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 third lens group are changed. A method of manufacturing a variable magnification optical system characterized by the above.

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