WO2020136746A1

WO2020136746A1 - Variable power optical system, optical device, and method for manufacturing variable power optical system

Info

Publication number: WO2020136746A1
Application number: PCT/JP2018/047778
Authority: WO
Inventors: 幸介町田
Original assignee: 株式会社ニコン
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2020-07-02
Also published as: JP7196937B2; JPWO2020136746A1

Abstract

A variable power optical system (ZL) includes, lined up 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, a third lens group (G3) having a positive refractive power, a fourth lens group (G4) having a positive refractive power, and a rear lens group (GR), wherein the interval between adjacent lens groups is changed in order to vary the power, the rear lens group (GR) includes a focusing lens group that has a positive refractive power and moves during focusing, and the following conditional expression is satisfied.　3.40<f1/(-f2)<7.00, where f1 is the focal length of the first lens group (G1), and f2 is the focal length of the second lens group (G2).

Description

Magnifying optical system, optical device, and method for manufacturing variable optical system

The present invention relates to a variable power optical system, an optical device using the same, and a method for manufacturing the variable power optical system.

Conventionally, variable power optical systems suitable for photographic cameras, electronic still cameras, video cameras, etc. have been proposed (for example, refer to Patent Document 1). In a variable power optical system, it is required to suppress variation in aberration during variable power or focusing.

JP, 2013-160944, A

The variable power optical system according to the first aspect includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a second lens group having a positive refractive power, which are arranged in order from the object side. The zoom lens includes three lens groups, a fourth lens group having a positive refractive power, and a subsequent lens group, and the distance between adjacent lens groups changes during zooming. The focusing lens group having a positive refracting power that moves at the time of is satisfied, and the following conditional expression is satisfied.
3.40<f1/(-f2)<7.00
Where f1: focal length of the first lens group f2: focal length of the second lens group

The optical device according to the second aspect is configured by mounting the above-mentioned variable power optical system.

A method of manufacturing a variable power optical system according to a third aspect is configured such that a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power, which are arranged in order from the object side. A method of manufacturing a variable power optical system having a third lens group having a:, a fourth lens group having a positive refractive power, and a subsequent lens group, wherein The subsequent lens group has a focusing lens group having a positive refracting power that moves at the time of focusing because the distance changes, and each lens is placed in the lens barrel so as to satisfy the following conditional expression. Deploy.
3.40<f1/(-f2)<7.00
Where f1: focal length of the first lens group f2: focal length of the second lens group

It is a figure which shows the lens structure of the variable power optical system which concerns on 1st Example. 2(A), 2(B), and 2(C) show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to Example 1, respectively. 9 is a diagram of various types of aberrations in FIG. 3(A), 3(B), and 3(C) are respectively for the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the first example, when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 2nd Example. FIG. 5A, FIG. 5B, and FIG. 5C are respectively for focusing at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the second example. 9 is a diagram of various types of aberrations in FIG. 6(A), 6(B), and 6(C) respectively show a wide-angle end state, an intermediate focal length state, and a telephoto end state of the variable power optical system according to Example 2 when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 3rd Example. 8(A), 8(B), and 8(C) respectively show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to the third example. 9 is a diagram of various types of aberrations in FIG. 9(A), 9(B), and 9(C) respectively show the zoom lens system according to Example 3 at the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 4th Example. 11(A), 11(B), and 11(C) respectively show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to the fourth example. 9 is a diagram of various types of aberrations in FIG. 12(A), 12(B), and 12(C) respectively show the variable power optical system according to Example 4 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short distance focusing. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 5th Example. 14(A), 14(B), and 14(C) show the zoom lens system according to the fifth embodiment at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 9 is a diagram of various types of aberrations in FIG. 15(A), 15(B), and 15(C) respectively show the variable power optical system according to Example 5 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short-distance focusing. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 6th Example. 17(A), 17(B), and 17(C) show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to the sixth example, respectively. 9 is a diagram of various types of aberrations in FIG. 18(A), 18(B), and 18(C) respectively show the variable power optical system according to the sixth example at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short distance focusing. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the lens structure of the variable power optical system which concerns on 7th Example. 20(A), 20(B), and 20(C) respectively show the zoom lens system according to Example 7 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity. 9 is a diagram of various types of aberrations in FIG. 21(A), 21(B), and 21(C) respectively show a wide-angle end state, an intermediate focal length state, and a telephoto end state of the variable power optical system according to Example 7 when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. It is a figure which shows the structure of the camera provided with the variable power optical system which concerns on this embodiment. 6 is a flowchart showing a method of manufacturing a variable power optical system according to the present embodiment.

Hereinafter, the variable power optical system and the optical device according to the present embodiment will be described with reference to the drawings. First, a camera (optical device) including the variable power optical system according to this embodiment will be described with reference to FIG. As shown in FIG. 22, the camera 1 is a digital camera provided with a variable power optical system according to this embodiment as a taking lens 2. In the camera 1, light from an object (subject) (not shown) is condensed by the taking lens 2 and reaches the image sensor 3. Thus, the light from the subject is captured by the image sensor 3 and recorded as a subject image in a memory (not shown). In this way, the photographer can photograph the subject with the camera 1. Note that this camera may be a mirrorless camera or a single-lens reflex type camera having a quick return mirror.

Next, the variable power optical system (photographing lens) according to the present embodiment will be described. As shown in FIG. 1, the variable power optical system ZL(1) as an example of the variable power optical system (zoom lens) ZL according to the present embodiment has a positive refracting power arranged in order from the object side, as shown in FIG. The lens group G1, the second lens group G2 having a negative refractive power, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a positive refractive power, and the subsequent lens group GR. It is configured such that the distance between adjacent lens groups changes during zooming. The subsequent lens group GR includes a focusing lens group having a positive refractive power that moves during focusing.

The variable power optical system ZL according to this embodiment has at least five lens groups, and the distance between the lens groups changes during zooming. As a result, according to the present embodiment, it is possible to suppress variation in aberration during zooming from the wide-angle end state to the telephoto end state. Further, by disposing the focusing lens group in the succeeding lens group GR, the focusing lens group can be reduced in size and weight, and high-speed and quiet autofocus can be realized without increasing the size of the lens barrel. It will be possible. By disposing a focusing lens group having a positive refractive power as the focusing lens group, it is possible to suppress variations in various aberrations such as spherical aberration when focusing from an object at infinity to a near object. It will be possible.

The variable power optical system ZL according to the present embodiment may be the variable power optical system ZL(2) shown in FIG. 4, the variable power optical system ZL(3) shown in FIG. 7, or the variable power optical system shown in FIG. ZL(4) or the variable power optical system ZL(7) shown in FIG. 19 may be used.

Under the above configuration, the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (1).

3.40<f1/(-f2)<7.00 (1)
However, f1: focal length of the first lens group G1 f2: focal length of the second lens group G2

Conditional expression (1) defines the ratio between the focal length of the first lens group G1 and the focal length of the second lens group G2. By satisfying the conditional expression (1), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (1) exceeds the upper limit value, the refracting power of the second lens group G2 becomes too strong, which makes it difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the upper limit of conditional expression (1) to 6.80, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the upper limit of conditional expression (1) is set to 6.60, 6.50, 6.40, 6.30, 6.20, 6.10, 6. It may be set to 0.00, and further to 5.90.

When the corresponding value of the conditional expression (1) is less than the lower limit value, the refractive power of the first lens group G1 becomes too strong, and thus it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the lower limit of conditional expression (1) to 3.70, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the lower limit values of conditional expression (1) are set to 4.00, 4.20, 4.40, 4.50, 4.60, 4.80, 4 It may be set to 0.90, 5.00, 5.10, or 5.20.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expressions (2) to (3).

0.80<f1/f4<5.10 (2)
1.20<f4/fw<6.80 (3)
However, f4: focal length of the fourth lens group G4 fw: focal length of the variable magnification optical system ZL in the wide-angle end state

Conditional expression (2) defines the ratio between the focal length of the first lens group G1 and the focal length of the fourth lens group G4. By satisfying the conditional expression (2), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

If the corresponding value of the conditional expression (2) exceeds the upper limit value, the refracting power of the fourth lens group G4 becomes too strong, so that it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the upper limit of conditional expression (2) to 4.50, the effect of the present embodiment can be made more reliable. In order to further secure the effect of this embodiment, the upper limit values of conditional expression (2) are set to 4.00, 3.50, 3.00, 2.50, 2.00, 1.80, 1, .65, 1.60, and even 1.55.

When the corresponding value of the conditional expression (2) is less than the lower limit value, the refractive power of the first lens group G1 becomes too strong, so that it becomes difficult to suppress fluctuations of various aberrations such as spherical aberration during zooming. Become. By setting the lower limit of conditional expression (2) to 0.82, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit values of conditional expression (2) are set to 0.84, 0.85, 0.88, 0.90, 0.92, 0.95, 0. It may be set to 0.96, 0.97, 0.98, or even 1.00.

Conditional expression (3) defines the ratio between the focal length of the fourth lens group G4 and the focal length of the variable power optical system ZL in the wide-angle end state. By satisfying conditional expression (3), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (3) exceeds the upper limit value, the refractive power of the fourth lens group G4 becomes too weak, and thus it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the upper limit of conditional expression (3) to 6.70, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the upper limit values of conditional expression (3) are set to 6.60, 6.50, 6.30, 6.00, 5.80, 5.50, and 5. It may be set to .30, 5.00, 4.90, or 4.80.

When the corresponding value of the conditional expression (3) is less than the lower limit value, the refracting power of the fourth lens group G4 becomes too strong, which makes it difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the lower limit of conditional expression (3) to 1.50, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit values of conditional expression (3) are set to 2.00, 2.50, 2.80, 2.90, 3.00, 3.10, and 3. .20, 3.30, 3.40, or 3.50.

The variable power optical system ZL according to the present embodiment preferably satisfies the following conditional expression (4).

0.20<f3/f4<2.50 (4)
However, f3: focal length of the third lens group G3 f4: focal length of the fourth lens group G4

Conditional expression (4) defines the ratio between the focal length of the third lens group G3 and the focal length of the fourth lens group G4. By satisfying the conditional expression (4), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (4) exceeds the upper limit value, the refracting power of the fourth lens group G4 becomes too strong, so that it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the upper limit of conditional expression (4) to 2.40, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the upper limit of conditional expression (4) is set to 2.30, 2.20, 2.10, 2.00, 1.90, 1.80, 1. .50, 1.30, 1.00, or 0.90.

When the corresponding value of the conditional expression (4) is less than the lower limit value, the refractive power of the third lens group G3 becomes too strong, so that it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. Become. By setting the lower limit of conditional expression (4) to 0.22, the effect of the present embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the lower limit of conditional expression (4) is set to 0.25, 0.28, 0.30, 0.31, 0.32, 0.33, and It may be set to 0.34.

In the variable power optical system ZL according to this embodiment, it is desirable that the focusing lens group be composed of three or less single lenses. This makes it possible to reduce the size and weight of the focusing lens unit.

In the variable power optical system ZL according to the present embodiment, at least one of the focusing lens groups preferably has a single lens having a negative refractive power. This makes it possible to suppress variations in various aberrations such as spherical aberration when focusing from an infinitely distant object to a short-distance object.

In the variable power optical system ZL according to the present embodiment, it is desirable that the focusing lens group be arranged on the image side of the aperture stop S. This makes it possible to reduce the size and weight of the focusing lens unit.

In the variable power optical system ZL according to this embodiment, it is desirable that at least four lens groups are arranged on the image side of the aperture stop S. This makes it possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expression (5).

0.20<|fF|/ft<4.00 (5)
However, fF: focal length of the focusing lens unit having the strongest refractive power in the focusing lens unit ft: focal length of the variable power optical system ZL in the telephoto end state

Conditional expression (5) defines the ratio between the focal length of the focusing lens unit having the strongest refractive power among the focusing lens units and the focal length of the variable magnification optical system ZL in the telephoto end state. By satisfying the conditional expression (5), it is possible to suppress variations in various aberrations such as spherical aberration at the time of focusing from an object at infinity to a near object without increasing the size of the lens barrel.

When the corresponding value of the conditional expression (5) exceeds the upper limit value, the refractive power of the focusing lens group becomes too weak, so that the amount of movement of the focusing lens group at the time of focusing becomes large and the lens barrel becomes large. .. By setting the upper limit of conditional expression (5) to 3.80, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the upper limit of conditional expression (5) is set to 3.60, 3.40, 3.20, 3.00, 2.80, 2.60, 2 .40, 2.20, or even 2.00.

When the corresponding value of the conditional expression (5) is less than the lower limit value, the refractive power of the focusing lens unit becomes too strong, so that it becomes difficult to suppress variations in various aberrations such as spherical aberration during focusing. .. By setting the lower limit of conditional expression (5) to 0.23, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit of conditional expression (5) may be set to 0.25, 0.28, 0.30, 0.33, and 0.35. Good.

In the variable power optical system ZL according to the present embodiment, it is desirable that the fourth lens group G4 has a cemented lens of a negative lens and a positive lens. This makes it possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

In the variable power optical system ZL according to the present embodiment, it is desirable that the fourth lens group G4 has a cemented lens of a negative lens and a positive lens, and satisfies the following conditional expression (6).

1.00<nN/nP<1.35 (6)
Where nN: refractive index of negative lens in cemented lens nP: refractive index of positive lens in cemented lens

Conditional expression (6) defines the ratio of the refractive index of the negative lens and the positive lens of the cemented lens in the fourth lens group G4. By satisfying the conditional expression (6), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (6) exceeds the upper limit value, the negative lens in the cemented lens has too strong refracting power, so that spherical aberration is excessively corrected in the telephoto end state, and the wide-angle end state changes to the telephoto end state. It becomes difficult to suppress variations in various aberrations such as spherical aberration at the time of zooming. By setting the upper limit of conditional expression (6) to 1.33, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the upper limit of conditional expression (6) is set to 1.30, 1.29, 1.28, 1.27, 1.26, and 1.25. You may set it.

When the corresponding value of the conditional expression (6) is less than the lower limit value, the refractive power of the negative lens in the cemented lens becomes too weak, so that the spherical aberration in the telephoto end state is insufficiently corrected, and the wide-angle end state changes to the telephoto end state. It becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. By setting the lower limit of conditional expression (6) to 1.02, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit values of conditional expression (6) are set to 1.05, 1.08, 1.10, 1.11, 1.12, 1.13, 1, .14, 1.15 may be set.

In the variable power optical system ZL according to this embodiment, it is desirable that the fourth lens group G4 has a cemented lens of a negative lens and a positive lens, and satisfies the following conditional expression (7).

0.20<νN/νP<0.85 (7)
Where νN: Abbe number of negative lens in cemented lens νP: Abbe number of positive lens in cemented lens

The conditional expression (7) defines the ratio between the Abbe number of the negative lens and the Abbe number of the positive lens in the cemented lens in the fourth lens group G4. By satisfying conditional expression (7), it is possible to excellently correct chromatic aberration.

When the corresponding value of the conditional expression (7) exceeds the upper limit value, the Abbe number of the positive lens in the cemented lens becomes small, so that chromatic aberration excessively occurs and it becomes difficult to correct chromatic aberration. By setting the upper limit of conditional expression (7) to 0.83, the effect of the present embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the upper limit of conditional expression (7) is set to 0.80, 0.78, 0.75, 0.73, 0.70, 0.68, 0. .65, 0.63, 0.60, 0.58, 0.55, 0.53, and even 0.50.

When the corresponding value of the conditional expression (7) is below the lower limit value, the Abbe number of the negative lens in the cemented lens becomes small, and thus the correction of chromatic aberration becomes excessive. By setting the lower limit of conditional expression (7) to 0.22, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit of conditional expression (7) is set to 0.24, 0.25, 0.26, 0.27, 0.28, and 0.29. You may set it.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expression (8).

f1/|fRw|<5.00 (8)
However, fRw: focal length of the subsequent lens group GR in the wide-angle end state

The conditional expression (8) defines the ratio between the focal length of the first lens group G1 and the focal length of the subsequent lens group GR in the wide-angle end state. By satisfying the conditional expression (8), it is possible to suppress variations in various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

If the corresponding value of the conditional expression (8) exceeds the upper limit value, the refractive power of the subsequent lens group GR becomes too strong, and it becomes difficult to suppress variations in various aberrations such as spherical aberration during zooming. .. By setting the upper limit of conditional expression (8) to 4.80, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the upper limit values of the conditional expression (8) are set to 4.60, 4.40, 4.20, 4.00, 3.80, 3.50, 3 and 3. It may be set to 0.00, 2.80, 2.50, 2.30, 2.00, 1.80, or 1.50.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expression (9).

2ωw>75° (9)
Where ωw is the half angle of view of the variable magnification optical system ZL in the wide-angle end state

Conditional expression (9) defines the half angle of view of the variable power optical system ZL in the wide-angle end state. By satisfying the conditional expression (9), it is possible to suppress the fluctuation of the aberration at the time of zooming from the wide-angle end state to the telephoto end state while having a wide angle of view. By setting the lower limit of conditional expression (9) to 76°, the effect of the present embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the lower limit value of conditional expression (9) may be set to 77°, 78°, 79°, 80°, 81°, and further 82°.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expression (10).

0.10<BFw/fw<1.00 (10)
However, BFw: Back focus of the zoom optical system ZL in the wide-angle end state fw: Focal length of the zoom optical system ZL in the wide-angle end state

Conditional expression (10) defines the ratio between the back focus of the variable power optical system ZL in the wide-angle end state and the focal length of the variable power optical system ZL in the wide-angle end state. By satisfying conditional expression (10), it is possible to satisfactorily correct various aberrations such as coma in the wide-angle end state.

If the corresponding value of the conditional expression (10) exceeds the upper limit value, the back focus becomes too large with respect to the focal length of the variable power optical system ZL in the wide-angle end state, so that various aberrations including coma aberration in the wide-angle end state. Is difficult to correct. By setting the upper limit of conditional expression (10) to 0.95, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the upper limit of conditional expression (10) is set to 0.90, 0.85, 0.80, 0.78, 0.75, 0.73, 0. It may be set to 0.70, 0.68, or 0.65.

When the corresponding value of the conditional expression (10) is less than the lower limit value, the back focus becomes too small with respect to the focal length of the variable power optical system ZL in the wide-angle end state, so various aberrations including coma aberration in the wide-angle end state. Is difficult to correct. Further, it becomes difficult to arrange the mechanical member of the lens barrel. By setting the lower limit of conditional expression (10) to 0.15, the effect of this embodiment can be made more reliable. In order to further secure the effect of the present embodiment, the lower limit of conditional expression (10) is set to 0.20, 0.25, 0.30, 0.35, 0.37, 0.38, 0. .40, 0.42, 0.44, and even 0.45.

It is desirable that the variable power optical system ZL according to this embodiment satisfies the following conditional expression (11).

0.00<(rR2+rR1)/(rR2-rR1)<8.00 (11)
However, rR1: radius of curvature of the object-side lens surface of the lens arranged closest to the image side of the variable power optical system ZL rR2: of the image side lens surface of the lens arranged closest to the image side of the variable power optical system ZL curvature radius

Conditional expression (11) defines the shape factor of the lens arranged closest to the image side in the variable power optical system ZL. By satisfying conditional expression (11), it is possible to suppress fluctuations of various aberrations such as spherical aberration during zooming from the wide-angle end state to the telephoto end state.

When the corresponding value of the conditional expression (11) exceeds the upper limit value, the coma aberration correction power of the lens arranged closest to the image side in the variable power optical system ZL becomes insufficient, so that fluctuations of various aberrations during zooming may occur. It becomes difficult to hold down. By setting the upper limit of conditional expression (11) to 7.50, the effect of this embodiment can be made more reliable. In order to further secure the effect of this embodiment, the upper limit values of the conditional expression (11) are set to 7.00, 6.80, 6.50, 6.30, 6.00, 5.80, 5 It may be set to .50, 5.30, or 5.00.

If the corresponding value of the conditional expression (11) is less than the lower limit value, the coma aberration correction power of the lens arranged closest to the image side of the variable power optical system ZL becomes insufficient, so that fluctuations of various aberrations at the time of variable power are suppressed. It becomes difficult to hold down. By setting the lower limit of conditional expression (11) to 0.10, the effect of the present embodiment can be made more reliable. In order to further secure the effect of this embodiment, the lower limit values of conditional expression (11) are set to 0.50, 0.80, 1.00, 1.20, 1.50, 1.80, 2 It may be set to 0.00, 2.20, or 2.50.

Next, the manufacturing method of the variable power optical system ZL according to the present embodiment will be outlined with reference to FIG. First, in order from the object side, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power, the third lens group G3 having a positive refractive power, and the positive refractive power A fourth lens group G4 having the following and a subsequent lens group GR are arranged (step ST1). Then, the configuration is such that the distance between adjacent lens groups changes during zooming (step ST2). Further, a focusing lens group having a positive refractive power that moves during focusing is arranged in the subsequent lens group GR (step ST3). Further, each lens is arranged in the lens barrel so as to satisfy at least the conditional expression (1) (step ST4). According to such a manufacturing method, it is possible to realize a high-speed and quiet autofocus without increasing the size of the lens barrel, and a variation in aberration during zooming from the wide-angle end state to the telephoto end state, and It becomes possible to manufacture a variable power optical system that suppresses variation in aberration when focusing from an object at infinity to a near object.

The variable power optical system ZL according to each embodiment will be described below with reference to the drawings. 1, FIG. 4, FIG. 7, FIG. 10, FIG. 13, FIG. 16, and FIG. 19 show the configurations of variable power optical systems ZL {ZL(1) to ZL(7)} according to the first to seventh examples. It is sectional drawing which shows refractive power distribution. The first to fourth examples and the seventh example are examples corresponding to the present embodiment, and the fifth to sixth examples are reference examples. In each cross-sectional view, the moving direction along the optical axis of each lens group when zooming from the wide-angle end state (W) to the telephoto end state (T) is indicated by an arrow. Furthermore, the moving direction when the focusing lens group focuses on an object at a short distance from infinity is indicated by an arrow together with the character "focus".

In these figures (FIG. 1, FIG. 4, FIG. 7, FIG. 10, FIG. 13, FIG. 16, FIG. 19), each lens group is represented by a combination of reference numeral G and a numeral, and each lens is represented by a combination of reference numeral L and a numeral. Each represents. In this case, in order to prevent the types and numbers of the symbols and numbers from becoming large and complicated, the lens groups and the like are represented independently by using combinations of symbols and numbers for each embodiment. Therefore, even if the same combination of reference numerals and numbers is used between the embodiments, it does not mean that they have the same configuration.

Tables 1 to 7 are shown below. Of these, Table 1 is the first embodiment, Table 2 is the second embodiment, Table 3 is the third embodiment, Table 4 is the fourth embodiment, and Table 5 is the first embodiment. 5th Example, Table 6 is a table showing the respective specification data in the 6th Example, and Table 7 is the 7th Example. In each embodiment, the d-line (wavelength λ=587.6 nm) and the g-line (wavelength λ=435.8 nm) are selected as targets for calculating the aberration characteristics.

In the table of [Overall Specifications], f is the focal length of the entire lens system, FNO is the F number, 2ω is the angle of view (unit is ° (degrees), ω is the half angle of view), and Ymax is the maximum image height. Indicates. TL represents the distance from the lens front surface to the final lens surface on the optical axis when focused on infinity, plus BF. BF is the image from the final lens surface on the optical axis when focused on infinity. The air-converted distance (back focus) to the surface I is shown. Note that these values are shown for each of the wide-angle end (W), the intermediate focal length (M), and the telephoto end (T) in each variable power state. In the table of [Overall Specifications], fRw represents the focal length of the subsequent lens group in the wide-angle end state.

In the table of [lens specifications], the surface number indicates the order of the optical surface from the object side along the traveling direction of the light beam, and R represents the radius of curvature of each optical surface (the surface whose center of curvature is located on the image side). Is a positive value), D is a surface distance that is a distance on the optical axis from each optical surface to the next optical surface (or image surface), nd is a refractive index of the material of the optical member with respect to d-line, and νd is an optical value. The Abbe numbers of the material of the member with respect to the d-line are shown respectively. The radius of curvature “∞” indicates a plane or an aperture, and (stop S) indicates an aperture stop. The description of the refractive index of air nd=1.0000 is omitted. When the lens surface is an aspherical surface, the surface number is marked with *, and the paraxial radius of curvature is shown in the column of radius of curvature R.

In the table of [aspherical surface data], the shape of the aspherical surface shown in [lens specifications] is shown by the following expression (A). X(y) is the distance (zag amount) along the optical axis from the tangent plane at the apex of the aspherical surface to the position on the aspherical surface at the height y, and R is the radius of curvature of the reference spherical surface (paraxial radius of curvature). , Κ is a conic constant, and Ai is an i-th order aspherical coefficient. “E-n” indicates “×10 ⁻ⁿ ”. For example, 1.234E-05=1.234×10 ⁻⁵ . The quadratic aspherical coefficient A2 is 0, and the description thereof is omitted.

X(y)=(y ² /R)/{1+(1-κ×y ² /R ² ) ^1/2 }+A 4×y ⁴ +A 6×y ⁶ +A 8×y ⁸ +A 10×y ¹⁰ +A 12×y ¹² ..(A)

The [Lens group data] table shows the starting surface (the surface closest to the object) and the focal length of each lens group.

The table of [Variable spacing data] shows the surface spacing at the surface number where the surface spacing is “variable” in the table showing [lens specifications]. Here, the surface distances at the wide-angle end (W), the intermediate focal length (M), and the telephoto end (T) in the variable power states are shown for focusing at infinity and short distance, respectively.

The table of [Values corresponding to conditional expressions] shows the values corresponding to each conditional expression.

In all of the following specification values, the focal length f, radius of curvature R, surface distance D, and other lengths listed are generally “mm” unless otherwise specified, but the optical system is enlarged proportionally. Alternatively, the same optical performance can be obtained even if the proportion is reduced, and the present invention is not limited to this.

The description of the table up to this point is common to all the examples, and the duplicated description below is omitted.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 3 and Table 1. FIG. 1 is a diagram showing a lens configuration of a variable power optical system according to the first example. The variable power optical system ZL(1) according to the first example includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a fifth lens group G5 having a positive refractive power. It is composed of a sixth lens group G6 and a seventh lens group G7 having a negative refractive power. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move in the directions shown by the arrows in FIG. Change. The lens group including the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 corresponds to the succeeding lens group GR, and has a negative refracting power as a whole. The symbol (+) or (−) attached to each lens group symbol indicates the refractive power of each lens group, and this is the same in all the examples below.

The first lens group G1 includes, in order from the object side, a positive lens cemented with a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side, and a convex surface facing the object side. And a positive meniscus lens L13.

The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a concave surface facing the object side. And a negative meniscus lens L24 facing the lens. The negative meniscus lens L21 has an aspherical lens surface on the object side.

The third lens group G3 is composed of a positive meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 arranged in order from the object side. The aperture stop S is provided near the object side of the third lens group G3, and moves together with the third lens group G3 during zooming. The positive meniscus lens L31 has an aspherical lens surface on the object side.

The fourth lens group G4 is composed of a cemented positive lens including a negative meniscus lens L41 having a convex surface directed toward the object side and a biconvex positive lens L42.

The fifth lens group G5 is composed of a negative meniscus lens L51 having a concave surface facing the object side and a biconvex positive lens L52 arranged in order from the object side.

The sixth lens group G6 is composed of a positive meniscus lens L61 having a concave surface facing the object side. The image-side lens surface of the positive meniscus lens L61 is aspheric.

The seventh lens group G7 is composed of a positive meniscus lens L71 having a concave surface facing the object side, a biconcave negative lens L72, and a negative meniscus lens L73 having a concave surface facing the object side, which are arranged in order from the object side. To be done. The negative lens L72 has an aspherical lens surface on the object side. The image plane I is disposed on the image side of the seventh lens group G7.

In the present embodiment, the fifth lens group G5 and the sixth lens group G6 are independently moved to the object side, thereby focusing from a long-distance object to a short-distance object (infinite object to finite object). Done. That is, the fifth lens group G5 corresponds to the first focusing lens group, and the sixth lens group G6 corresponds to the second focusing lens group.

Table 1 below lists values of specifications of the variable power optical system according to the first example.

(Table 1)
[Overall specifications]
Magnification ratio 2.74
fRw=-4993.677
W M T
f 24.8 50.0 67.9
FNO 2.92 2.92 2.92
2 ω 85.10 45.26 33.84
Ymax 21.60 21.60 21.60
TL 139.35 158.45 169.16
BF 11.93 23.42 28.62
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 234.3873 2.500 1.84666 23.80
2 109.5180 5.200 1.75500 52.34
3 389.6852 0.200
4 59.0627 5.700 1.77250 49.62
5 135.3649 D5 (variable)
6* 218.4420 2.000 1.74389 49.53
7 18.6957 9.658
8 -59.6856 1.300 1.77250 49.62
9 59.6856 0.442
10 39.2099 6.400 1.72825 28.38
11 -48.6731 1.933
12 -26.4065 1.300 1.61800 63.34
13 -71.7612 D13 (variable)
14 ∞ 1.712 (Aperture S)
15* 71.8876 2.500 1.69370 53.32
16 127.6411 0.716
17 38.7492 5.900 1.59319 67.90
18 -105.4274 D18 (variable)
19 67.0276 1.300 1.73800 32.33
20 19.5126 9.700 1.49782 82.57
21 -50.5609 D21 (variable)
22 -23.9237 1.200 1.72047 34.71
23 -56.2081 0.200
24 103.1749 5.900 1.59349 67.00
25 -33.0197 D25 (variable)
26 -70.6288 3.500 1.79189 45.04
27* -38.2153 D27 (variable)
28 -43.9824 3.000 1.94595 17.98
29 -32.4253 0.200
30* -100.5837 1.500 1.85207 40.15
31 88.1634 7.847
32 -25.2838 1.400 1.58913 61.22
33 -45.3661 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=5.27866E-06,A6=-5.41835E-09
A8=1.33113E-11,A10=-2.04736E-14,A12=2.05090E-17
15th surface κ=1.0000,A4=-4.55747E-06,A6=-1.40092E-10
A8=-8.81384E-13,A10=-8.42653E-15,A12=0.00000E+00
27th surface κ=1.0000,A4=1.09543E-05,A6=-2.36281E-08
A8=1.42728E-10,A10=-5.02724E-13,A12=7.51800E-16
30th surface κ=1.0000,A4=-2.18913E-06,A6=-2.29301E-08
A8=3.94582E-11,A10=-9.84200E-14,A12=0.00000E+00
[Lens group data]
Focal length G1 1 119.124
G2 6 -22.126
G3 14 40.880
G4 19 115.687
G5 22 124.717
G6 26 100.365
G7 28 -47.354
[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance D5 1.780 21.220 30.246 1.780 21.220 30.246
D13 19.285 6.132 2.013 19.285 6.132 2.013
D18 9.167 3.866 1.493 9.167 3.866 1.493
D21 5.179 14.279 19.018 4.137 12.991 17.666
D25 2.679 3.515 2.616 3.249 4.079 3.027
D27 6.128 2.807 1.953 6.600 3.530 2.893
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.384
Conditional expression (2) f1/f4=1.030
Conditional expression (3) f4/fw=4.674
Conditional expression (4) f3/f4=0.353
Conditional expression (5) |fF|/ft=1.837
Conditional expression (6) nN/nP=1.160
Conditional expression (7) νN/νP=0.392
Conditional expression (8) f1/|fRw|=0.024
Conditional expression (9) 2ωw=85.10
Conditional expression (10) BFw/fw=0.482
Conditional expression (11) (rR2+rR1)/(rR2-rR1)=3.518

2(A), 2(B), and 2(C) show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to Example 1, respectively. 9 is a diagram of various types of aberrations in FIG. 3(A), 3(B), and 3(C) are respectively for the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the first example, when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG.

In each of the aberration diagrams in FIGS. 2(A) to 2(C), FNO indicates the F number and Y indicates the image height. The spherical aberration diagram shows the F number value corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum image height, and the lateral aberration diagram shows the image height value. In each of the aberration diagrams of FIGS. 3A to 3C, NA represents the numerical aperture and Y represents the image height. The spherical aberration diagram shows the numerical aperture value corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum image height, and the lateral aberration diagram shows the image height value. In each aberration diagram, d represents the d-line (wavelength λ=587.6 nm), and g represents the g-line (wavelength λ=435.8 nm). In the astigmatism diagram, the solid line shows the sagittal image plane, and the broken line shows the meridional image plane. In the aberration diagrams of the respective examples shown below, the same reference numerals as those in this example are used, and the duplicated description will be omitted.

From the various aberration diagrams, the variable power optical system according to the first example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Second embodiment)
The second embodiment will be described with reference to FIGS. 4 to 6 and Table 2. FIG. 4 is a diagram showing a lens configuration of a variable power optical system according to the second example. The variable power optical system ZL(2) according to the second example includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a fifth lens group G5 having a positive refractive power. It is composed of a sixth lens group G6 and a seventh lens group G7 having a negative refractive power. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 respectively move in the directions shown by the arrows in FIG. Change. The lens group including the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 corresponds to the succeeding lens group GR, and has a negative refracting power as a whole.

The third lens group G3 is composed of a biconvex positive lens L31 and a biconvex positive lens L32, which are arranged in order from the object side. The aperture stop S is provided near the object side of the third lens group G3, and moves together with the third lens group G3 during zooming. The lens surface of the positive lens L31 on the object side is an aspherical surface.

Table 2 below lists values of specifications of the variable power optical system according to the second example.

(Table 2)
[Overall specifications]
Magnification ratio 2.74
fRw=-346.533
W M T
f 24.8 50.0 67.9
FNO 2.92 2.92 2.92
2 ω 85.08 45.32 33.84
Ymax 21.60 21.60 21.60
TL 139.96 156.15 168.00
BF 11.76 26.07 29.33
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 282.3733 2.500 1.84666 23.80
2 123.2365 5.647 1.77250 49.62
3 1180.1775 0.200
4 59.2907 4.310 1.81600 46.59
5 98.9987 D5 (variable)
6* 205.3191 2.000 1.74389 49.53
7 19.2200 9.185
8 -74.7032 1.300 1.83481 42.73
9 64.3697 0.324
10 41.9771 5.683 1.78472 25.64
11 -72.0408 4.071
12 -26.6709 1.300 1.60300 65.44
13 -52.5345 D13 (variable)
14 ∞ 1.500 (Aperture S)
15* 84.6431 3.039 1.58913 61.15
16 -4073.6051 0.200
17 42.4140 5.438 1.59319 67.90
18 -143.7473 D18 (variable)
19 74.9775 1.300 1.73800 32.33
20 20.9860 9.090 1.49782 82.57
21 -48.9247 D21 (variable)
22 -23.9603 1.200 1.73800 32.33
23 -52.8529 0.955
24 113.2572 5.800 1.59349 66.99
25 -32.1120 D25 (variable)
26 -120.6162 3.500 1.74389 49.53
27* -50.8923 D27 (variable)
28 -61.4253 3.215 1.94595 17.98
29 -34.3446 0.200
30* -69.3409 1.500 1.85108 40.12
31 72.0715 6.683
32 -23.1150 1.400 1.69680 55.52
33 -36.7553 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=4.34838E-06,A6=-2.30274E-09
A8=1.34342E-12,A10=2.08876E-15,A12=0.00000E+00
15th surface κ=1.0000,A4=-4.08736E-06,A6=2.82731E-09
A8=-1.71368E-11,A10=2.81580E-14,A12=0.00000E+00
27th surface κ=1.0000, A4=9.77330E-06, A6=-1.31611E-08
A8=7.02329E-11,A10=-1.28887E-13,A12=0.00000E+00
30th surface κ=1.0000,A4=-3.68898E-06,A6=-1.92901E-08
A8=3.36794E-11,A10=-8.19805E-14,A12=0.00000E+00
[Lens group data]
Focal length in front of group G1 1 133.226
G2 6 -23.579
G3 14 40.561
G4 19 115.254
G5 22 113.536
G6 26 115.868
G7 28 -42.726
[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance D5 2.000 18.194 30.046 2.000 18.194 30.046
D13 21.479 6.645 2.000 21.479 6.645 2.000
D18 9.801 4.462 1.500 9.801 4.462 1.500
D21 5.195 13.414 18.760 4.220 12.328 17.590
D25 2.295 3.824 2.737 2.742 4.222 2.950
D27 5.890 2.000 2.087 6.417 2.689 3.043
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.650
Conditional expression (2) f1/f4=1.156
Conditional expression (3) f4/fw=4.657
Conditional expression (4) f3/f4=0.352
Conditional expression (5) |fF|/ft=1.706
Conditional expression (6) nN/nP=1.160
Conditional expression (7) νN/νP=0.392
Conditional expression (8) f1/|fRw|=0.384
Conditional expression (9) 2ωw=85.08
Conditional expression (10) BFw/fw=0.475
Conditional expression (11) (rR2+rR1)/(rR2-rR1)=4.389

FIG. 5A, FIG. 5B, and FIG. 5C are respectively for focusing at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the second example. 9 is a diagram of various types of aberrations in FIG. 6(A), 6(B), and 6(C) respectively show a wide-angle end state, an intermediate focal length state, and a telephoto end state of the variable power optical system according to Example 2 when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. From the various aberration diagrams, the variable power optical system according to the second example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Third embodiment)
The third embodiment will be described with reference to FIGS. 7 to 9 and Table 3. FIG. 7 is a diagram showing a lens configuration of a variable power optical system according to the third example. The variable power optical system ZL(3) according to the third 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 an aperture. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a fifth lens group G5 having a positive refractive power. It is composed of a sixth lens group G6 and a seventh lens group G7 having a negative refractive power. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move in the directions shown by the arrows in FIG. Change. The lens group including the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 corresponds to the succeeding lens group GR, and has a negative refracting power as a whole.

The first lens group G1 includes, in order from the object side, a cemented positive lens composed 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 having a convex surface facing the object side. And L13.

The seventh lens group G7 includes, in order from the object side, a negative meniscus lens L71 having a convex surface directed toward the object side, a positive meniscus lens L72 having a concave surface directed toward the object side, and a negative meniscus lens having a concave surface directed toward the object side. And L73. The negative meniscus lens L73 has an aspherical lens surface on the object side. The image plane I is disposed on the image side of the seventh lens group G7.

Table 3 below lists values of specifications of the variable power optical system according to the third example.

(Table 3)
[Overall specifications]
Magnification ratio 3.33
fRw=-219.096
W M T
f 24.8 50.0 82.5
FNO 2.92 2.92 2.92
2 ω 85.12 45.44 28.34
Ymax 21.60 21.60 21.60
TL 150.97 164.85 185.45
BF 11.75 21.93 30.78
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 454.1335 2.500 1.94594 17.98
2 158.8346 5.629 1.81600 46.59
3 -185 0.8518 0.200
4 62.5732 5.149 1.81600 46.59
5 111.4228 D5 (variable)
6* 143.7538 2.000 1.81600 46.59
7 20.1321 9.695
8 -48.3009 2.346 1.88300 40.66
9 156.4679 0.200
10 65.6396 6.565 1.80518 25.45
11 -42.2522 2.354
12 -26.3896 1.200 1.69680 55.52
13 -61.8795 D13 (variable)
14 ∞ 1.500 (Aperture S)
15* 46.9137 2.985 1.81600 46.59
16 79.9069 0.200
17 56.4482 6.543 1.49782 82.57
18 -69.0474 D18 (variable)
19 78.4165 1.300 1.90366 31.27
20 26.6178 9.263 1.59319 67.90
21 -58.5857 D21 (variable)
22 -29.0948 1.200 1.80100 34.92
23 -53.3089 2.957
24 64.8393 6.500 1.48749 70.32
25 -36.2810 D25 (variable)
26 -486.6338 2.667 1.58887 61.13
27* -77.9833 D27 (variable)
28 208.9420 1.200 1.90366 31.27
29 40.1016 3.903
30 -103.6980 6.199 1.84666 23.80
31 -35.7067 3.104
32* -19.6292 1.500 1.81600 46.59
33 -40.5502 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=4.25283E-06,A6=-2.28156E-09
A8=-7.12258E-14,A10=7.16065E-15,A12=0.00000E+00
15th surface κ=1.0000,A4=-3.75837E-06,A6=9.56813E-10
A8=-1.31531E-12,A10=1.97978E-16,A12=0.00000E+00
27th surface κ=1.0000,A4=1.09037E-05,A6=-5.09501E-11
A8=-1.76649E-12,A10=1.58609E-14,A12=0.00000E+00
32nd surface κ=1.0000, A4=1.01091E-05, A6=1.61408E-08
A8=3.76726E-12,A10=1.25182E-13,A12=0.00000E+00
[Lens group data]
Focal length G1 1 130.092
G2 6 -23.049
G3 14 44.414
G4 19 100.000
G5 22 98.812
G6 26 157.320
G7 28 -42.703
[Variable interval data]
W M T W M T
Infinity Infinity Infinity Infinity Near Distance Near Distance Near Distance D5 2.000 21.323 36.906 2.000 21.323 36.906
D13 25.662 7.746 2.000 25.662 7.746 2.000
D18 9.597 5.312 1.500 9.597 5.312 1.500
D21 6.192 11.864 21.415 5.303 10.833 20.070
D25 2.000 3.105 2.000 2.411 3.415 2.346
D27 4.901 4.716 2.000 5.379 5.438 2.999
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.644
Conditional expression (2) f1/f4=1.301
Conditional expression (3) f4/fw=4.040
Conditional expression (4) f3/f4=0.444
Conditional expression (5) |fF|/ft=1.907
Conditional expression (6) nN/nP=1.195
Conditional expression (7) νN/νP=0.461
Conditional expression (8) f1/|fRw|=0.594
Conditional expression (9) 2ωw=85.12
Conditional expression (10) BFw/fw=0.475
Conditional expression (11) (rR2+rR1)/(rR2-rR1)=2.877

8(A), 8(A), and 8(C) respectively show focusing at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the third example. 9 is a diagram of various types of aberrations in FIG. 9(A), 9(B), and 9(C) respectively show the zoom lens system according to Example 3 at the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on a short distance. 9 is a diagram of various types of aberrations in FIG. From each aberration diagram, the variable power optical system according to Example 3 has excellent imaging performance by excellently correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. 10 to 12 and Table 4. FIG. 10 is a diagram showing a lens configuration of a variable power optical system according to the fourth example. The variable power optical system ZL(4) according to the fourth example includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a fifth lens group G5 having a negative refractive power. 6 lens group G6. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to sixth lens groups G1 to G6 respectively move in the directions shown by the arrows in FIG. Change. The lens group including the fifth lens group G5 and the sixth lens group G6 corresponds to the succeeding lens group GR and has a negative refracting power as a whole.

The fifth lens group G5 includes, in order from the object side, a negative meniscus lens L51 having a concave surface facing the object side, a biconvex positive lens L52, and a positive meniscus lens L53 having a concave surface facing the object side. To be done. The positive meniscus lens L53 has an aspherical lens surface on the image side.

The sixth lens group G6 includes, in order from the object side, a positive meniscus lens L61 having a concave surface facing the object side, a biconcave negative lens L62, and a negative meniscus lens L63 having a concave surface facing the object side. To be done. The negative lens L62 has an aspherical lens surface on the object side. The image plane I is disposed on the image side of the sixth lens group G6.

In the present embodiment, by moving the fifth lens group G5 toward the object side, focusing from a long-distance object to a short-distance object (from an infinite object to a finite object) is performed. That is, the fifth lens group G5 corresponds to the focusing lens group.

Table 4 below shows values of specifications of the variable power optical system according to the fourth example.

(Table 4)
[Overall specifications]
Magnification ratio 2.75
fRw=-356.649
W M T
f 24.7 50.0 67.9
FNO 2.92 2.92 2.92
2 ω 85.08 45.26 33.84
Ymax 21.60 21.60 21.60
TL 139.95 154.92 168.36
BF 11.75 26.42 30.21
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 500.0000 2.500 1.84666 23.80
2 128.5654 5.629 1.77250 49.62
3 1528.3565 0.200
4 51.0685 4.893 1.81600 46.59
5 84.5957 D5 (variable)
6* 150.2756 2.000 1.74389 49.53
7 19.5218 9.332
8 -70.5990 1.300 1.83481 42.73
9 68.8663 0.377
10 44.7171 5.665 1.78472 25.64
11 -66.3 119 4.463
12 -25.4625 1.300 1.60300 65.44
13 -54.4747 D13 (variable)
14 ∞ 1.500 (Aperture S)
15* 93.5557 2.758 1.58913 61.15
16 73 1.3943 0.200
17 45.8800 5.212 1.59319 67.90
18 -126.9127 D18 (variable)
19 57.2400 1.300 1.73800 32.33
20 21.3782 8.742 1.49782 82.57
21 -52.7685 D21 (variable)
22 -23.6692 1.200 1.73800 32.33
23 -59.4644 0.200
24 110.3346 5.800 1.59349 67.00
25 -32.1046 4.444
26 -114.5585 3.326 1.74389 49.53
27* -41.8456 D27 (variable)
28 -51.0521 2.929 1.94594 17.98
29 -33.3238 0.200
30* -98.8101 1.500 1.85108 40.12
31 58.4711 6.329
32 -25.4692 1.400 1.69680 55.52
33 -42.7921 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=4.65692E-06,A6=-1.64542E-09
A8=3.72186E-13,A10=4.82369E-15,A12=0.00000E+00
15th surface κ=1.0000,A4=-3.70657E-06,A6=3.18672E-09
A8=-1.82835E-11,A10=3.59863E-14,A12=0.00000E+00
27th surface κ=1.0000, A4=1.13375E-05, A6=-1.49475E-08
A8=6.38011E-11,A10=-1.10074E-13,A12=0.00000E+00
30th surface κ=1.0000,A4=-5.84233E-06,A6=-2.49185E-08
A8=2.26680E-11,A10=-7.54165E-14,A12=0.00000E+00
[Lens group data]
Focal length G1 1 136.259
G2 6 -23.493
G3 14 44.223
G4 19 90.807
G5 22 53.777
G6 28 -40.364
[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance D5 2.000 16.966 30.403 2.000 16.966 30.403
D13 20.342 6.266 2.000 20.342 6.266 2.000
D18 10.475 3.778 2.048 10.475 3.778 2.048
D21 4.711 14.758 17.000 4.046 13.957 16.055
D27 5.973 2.030 2.000 6.639 2.831 2.945
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.800
Conditional expression (2) f1/f4=1.501
Conditional expression (3) f4/fw=3.669
Conditional expression (4) f3/f4=0.487
Conditional expression (5) |fF|/ft=0.792
Conditional expression (6) nN/nP=1.160
Conditional expression (7) νN/νP=0.392
Conditional expression (8) f1/|fRw|=0.382
Conditional expression (9) 2ωw=85.08
Conditional expression (10) BFw/fw=0.475
Conditional expression (11) (rR2+rR1)/(rR2-rR1)=3.941

11(A), 11(B), and 11(C) respectively show focusing at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the variable power optical system according to the fourth example. 9 is a diagram of various types of aberrations in FIG. 12(A), 12(B), and 12(C) respectively show the variable power optical system according to Example 4 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short distance focusing. 9 is a diagram of various types of aberrations in FIG. From the various aberration diagrams, the variable power optical system according to the fourth example has excellent imaging performance by excellently correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Fifth embodiment)
The fifth embodiment will be described with reference to FIGS. 13 to 15 and Table 5. FIG. 13 is a diagram showing a lens configuration of a variable power optical system according to the fifth example. The variable power optical system ZL(5) according to the fifth example includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture, which are arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. 6 lens group G6. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to sixth lens groups G1 to G6 respectively move in the directions shown by the arrows in FIG. Change. The lens group including the fifth lens group G5 and the sixth lens group G6 corresponds to the succeeding lens group GR and has a negative refracting power as a whole.

The first lens group G1 includes, in order from the object side, a cemented negative lens composed of a negative meniscus lens L11 having a convex surface directed toward the object side and a biconvex positive lens L12, and a positive meniscus lens having a convex surface directed toward the object side. And L13.

The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a positive meniscus lens L23 having a convex surface facing the object side, and an object. And a negative meniscus lens L24 having a concave surface directed to the side. The negative meniscus lens L21 has an aspherical lens surface on the object side.

The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a negative lens cemented with a biconcave negative lens L42 and a biconvex positive lens L43, and a biconvex positive lens. It is composed of a lens L44. The lens surface of the positive lens L41 on the object side is an aspherical surface. The image-side lens surface of the positive lens L44 is an aspherical surface.

The fifth lens group G5 includes, in order from the object side, a positive meniscus lens L51 having a concave surface facing the object side, a biconcave negative lens L52, and a biconcave negative lens L53. The negative lens L53 has an aspherical lens surface on the object side.

The sixth lens group G6 is composed of a biconvex positive lens L61. The image plane I is disposed on the image side of the sixth lens group G6.

In the present embodiment, by moving the fifth lens group G5 to the image plane I side, focusing from a long-distance object to a short-distance object (from an infinite object to a finite object) is performed. That is, the fifth lens group G5 corresponds to the focusing lens group.

Table 5 below lists values of specifications of the variable power optical system according to the fifth example.

(Table 5)
[Overall specifications]
Magnification ratio 2.75
fRw=-45.339
W M T
f 24.7 50.0 67.9
FNO 2.92 2.92 2.92
2 ω 85.16 45.24 34.12
Ymax 21.60 21.60 21.60
TL 134.73 154.61 169.45
BF 13.56 26.94 34.84
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 10957.4900 2.500 1.84666 23.80
2 273.2507 3.923 1.59319 67.90
3 -4164.8091 0.200
4 97.8909 5.850 1.81600 46.59
5 1686.5488 D5 (variable)
6* 500.0000 2.000 1.67798 54.89
7 19.6217 7.571
8 -119.4257 1.200 1.59319 67.90
9 74.2767 0.211
10 36.8572 5.028 1.85000 27.03
11 146.1931 4.217
12 -25.9063 1.200 1.60300 65.44
13 -48.3220 D13 (variable)
14 ∞ 1.500 (Aperture S)
15* 31.8609 3.346 1.79504 28.69
16 60.3817 1.288
17 65.3208 3.503 1.49782 82.57
18 -22831.8850 D18 (variable)
19* 52.1943 4.361 1.82098 42.50
20 -99.8775 0.663
21 -484.1811 1.200 1.85478 24.80
22 19.0497 8.079 1.49782 82.57
23 -86.9834 3.675
24 61.0249 5.155 1.80604 40.74
25* -60.8291 D25 (variable)
26 -310.5249 2.912 1.94594 17.98
27 -59.5174 0.200
28 -155.6589 1.200 1.77250 49.62
29 30.4299 6.880
30* -54.7368 1.300 1.95150 29.83
31 317.1233 D31 (variable)
32 72.1520 4.819 1.83481 42.73
33 -315.4491 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4= 5.57412E-06,A6=-5.71627E-09
A8=9.08385E-12,A10=-4.74214E-15,A12=0.00000E+00
15th surface κ=1.0000,A4=-5.90450E-06,A6=3.98445E-09
A8=-4.29920E-11,A10=9.10161E-14,A12=0.00000E+00
19th surface κ=1.0000,A4=-5.71112E-06,A6=-6.16170E-10
A8=2.42198E-11,A10=-5.71940E-14,A12=0.00000E+00
25th surface κ=1.0000, A4=2.37352E-06, A6=-6.63258E-09
A8=-2.39696E-11,A10=1.99908E-14,A12=0.00000E+00
30th surface κ=1.0000,A4=-6.17314E-06,A6=-3.26346E-08
A8=1.32620E-10,A10=-6.33629E-13,A12=0.00000E+00
[Lens group data]
Focal length G1 1 139.410
G2 6 -23.353
G3 14 51.116
G4 19 31.271
G5 26 -24.892
G6 32 70.741
[Variable interval data]
W M T W M T
Infinity Infinity Infinity Infinity Near Distance Near Distance Near Distance D5 2.000 21.443 31.758 2.000 21.443 31.758
D13 19.908 6.376 2.000 19.908 6.376 2.000
D18 9.100 3.184 2.000 9.100 3.184 2.000
D25 3.162 2.189 2.000 3.569 2.602 2.454
D31 3.023 10.499 12.881 2.616 10.087 12.426
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.970
Conditional expression (2) f1/f4=4.458
Conditional expression (3) f4/fw=1.263
Conditional expression (4) f3/f4=1.635
Conditional expression (5) |fF|/ft=0.367
Conditional expression (6) nN/nP=1.238
Conditional expression (7) νN/νP=0.300
Conditional expression (8) f1/|fRw|=3.075
Conditional expression (9) 2ωw=85.16
Conditional expression (10) BFw/fw=0.548

14(A), 14(B), and 14(C) show the zoom lens system according to the fifth embodiment at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 9 is a diagram of various types of aberrations in FIG. 15(A), 15(B), and 15(C) respectively show the variable power optical system according to Example 5 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short-distance focusing. 9 is a diagram of various types of aberrations in FIG. From the various aberration diagrams, the variable power optical system according to Example 5 has excellent imaging performance by excellently correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Sixth embodiment)
The sixth embodiment will be described with reference to FIGS. 16 to 18 and Table 6. FIG. 16 is a diagram showing a lens configuration of a variable power optical system according to the sixth example. The variable power optical system ZL(6) according to Example 6 has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture, which are arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. It is composed of a sixth lens group G6 and a seventh lens group G7 having a positive refractive power. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 respectively move in the directions shown by the arrows in FIG. 16, and the distance between adjacent lens groups increases. Change. The lens group including the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 corresponds to the succeeding lens group GR, and has a negative refracting power as a whole.

The first lens group G1 includes, in order from the object side, a negative lens cemented with a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side, and a convex surface facing the object side. And a positive meniscus lens L13.

The sixth lens group G6 is composed of a positive meniscus lens L61 having a convex surface directed toward the object side.

The seventh lens group G7 is composed of a biconvex positive lens L71. The image plane I is disposed on the image side of the seventh lens group G7.

Table 6 below lists values of specifications of the variable power optical system according to the sixth example.

(Table 6)
[Overall specifications]
Magnification ratio 2.74
fRw=-40.687
W M T
f 24.8 50.0 67.9
FNO 2.96 2.98 2.99
2 ω 85.16 45.20 34.12
Ymax 21.60 21.60 21.60
TL 138.57 158.72 174.45
BF 13.13 25.93 34.76
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 800.0000 2.500 1.84666 23.80
2 214.4014 3.846 1.59319 67.90
3 1317.1215 0.200
4 112.4262 5.452 1.81600 46.59
5 6769.9563 D5 (variable)
6* 500.0000 2.000 1.67798 54.89
7 20.1483 7.488
8 -122.7141 1.200 1.59319 67.90
9 65.7886 0.272
10 36.9186 6.199 1.85000 27.03
11 167.8314 4.151
12 -26.0907 1.200 1.60300 65.44
13 -47.5468 D13 (variable)
14 ∞ 1.500 (Aperture S)
15* 34.4078 3.172 1.79504 28.69
16 61.0992 1.040
17 57.2334 3.808 1.49782 82.57
18 -5887.8063 D18 (variable)
19* 56.4489 4.200 1.82098 42.50
20 -110.1792 0.505
21 -291.5983 1.200 1.85478 24.80
22 21.3003 9.632 1.49782 82.57
23 -65.8810 3.027
24 55.5374 5.156 1.80604 40.74
25*-64.8934 D25 (variable)
26 -368.5041 2.887 1.94594 17.98
27 -62.4504 0.200
28 -158.4306 1.200 1.77250 49.62
29 31.1763 6.060
30* -91.4544 1.300 1.95150 29.83
31 81.4249 D31 (variable)
32 57.0897 2.149 1.80518 25.45
33 69.0085 D33 (variable)
34 73.7084 4.702 1.64000 60.19
35 -314.5384 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=4.89442E-06,A6=-5.03173E-09
A8=9.04508E-12,A10=-5.83062E-15,A12=0.00000E+00
15th surface κ=1.0000,A4=-5.12384E-06,A6=3.61548E-09
A8=-3.66003E-11,A10=7.76731E-14,A12=0.00000E+00
19th surface κ=1.0000,A4=-5.21485E-06,A6=-8.93869E-10
A8=2.28848E-11,A10=-5.34780E-14,A12=0.00000E+00
25th surface κ=1.0000, A4=3.45860E-06, A6=-6.25344E-09
A8=-1.37950E-11,A10=2.51017E-14,A12=0.00000E+00
30th surface κ=1.0000,A4=-6.74203E-06,A6=-2.42770E-08
A8= 5.92492E-11,A10=-3.49332E-13,A12=0.00000E+00
[Lens group data]
Focal length G1 1 152.425
G2 6 -24.007
G3 14 52.775
G4 19 30.001
G5 26 -24.147
G6 32 379.967
G7 34 93.748
[Variable interval data]
W M T W M T
Infinity Infinity Infinity Infinity Near Distance Near Distance Near Distance D5 2.000 22.083 33.118 2.000 22.083 33.118
D13 20.464 6.484 2.000 20.464 6.484 2.000
D18 9.842 3.320 2.000 9.842 3.320 2.000
D25 2.978 2.225 2.053 3.339 2.586 2.447
D31 2.915 10.198 13.200 2.555 9.837 12.806
D33 1.000 2.234 1.084 1.000 2.234 1.084
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=6.349
Conditional expression (2) f1/f4=5.081
Conditional expression (3) f4/fw=1.212
Conditional expression (4) f3/f4=1.759
Conditional expression (5) |fF|/ft=0.356
Conditional expression (6) nN/nP=1.238
Conditional expression (7) νN/νP=0.300
Conditional expression (8) f1/|fRw|=3.746
Conditional expression (9) 2ωw=85.16
Conditional expression (10) BFw/fw=0.530

17(A), 17(B), and 17(C) show focusing at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the sixth example, respectively. FIG. 8 is a diagram showing various types of aberration. 18(A), 18(B), and 18(C) respectively show the variable power optical system according to the sixth example at the wide-angle end state, the intermediate focal length state, and the telephoto end state at the short distance focusing. 9 is a diagram of various types of aberrations in FIG. From the various aberration diagrams, the variable power optical system according to the sixth example has excellent imaging performance by excellently correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

(Seventh embodiment)
The seventh embodiment will be described with reference to FIGS. 19 to 21 and Table 7. FIG. 19 is a diagram showing a lens configuration of a variable power optical system according to the seventh example. The variable power optical system ZL(7) according to Example 7 has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture, which are arranged in order from the object side. A diaphragm S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a fifth lens group G5 having a positive refractive power. It is composed of a sixth lens group G6 and a seventh lens group G7 having a negative refractive power. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move in the directions indicated by the arrows in FIG. 19, and the distance between adjacent lens groups becomes Change. The lens group including the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 corresponds to the succeeding lens group GR, and has a positive refracting power as a whole.

The seventh lens group G7 is composed of, in order from the object side, a positive meniscus lens L71 having a concave surface facing the object side, a biconcave negative lens L72, and a negative meniscus lens L73 having a concave surface facing the object side. It The image plane I is disposed on the image side of the seventh lens group G7. The negative lens L72 has an aspherical lens surface on the object side.

Table 7 below lists values of specifications of the variable power optical system according to the seventh example.

(Table 7)
[Overall specifications]
Magnification ratio 2.74
fRw=4055.914
W M T
f 24.8 50.0 67.9
FNO 2.92 2.92 2.92
2 ω 85.10 45.24 33.84
Ymax 21.60 21.60 21.60
TL 139.31 158.27 168.76
BF 11.75 23.48 28.76
[Specifications of lens]
Surface number RD nd νd
Object plane ∞
1 189.0188 2.500 1.84666 23.80
2 98.2637 5.200 1.75500 52.33
3 281.1360 0.200
4 58.7593 5.700 1.77250 49.62
5 135.0000 D5 (variable)
6* 221.1138 2.000 1.74389 49.53
7 18.6091 9.662
8 -58.7660 1.300 1.77250 49.62
9 58.7660 0.506
10 39.8268 6.400 1.72825 28.38
11 -48.5880 1.773
12 -26.6513 1.300 1.61800 63.34
13 -70.7180 D13 (variable)
14 ∞ 1.702 (Aperture S)
15* 71.3000 2.500 1.69370 53.32
16 121.5261 0.202
17 38.6117 5.900 1.59319 67.90
18 -111.3842 D18 (variable)
19 66.4297 1.300 1.73800 32.33
20 19.7070 9.700 1.49782 82.57
21 -49.1811 D21 (variable)
22 -23.7160 1.200 1.72047 34.71
23 -55.5303 0.200
24 103.5406 5.980 1.59349 67.00
25 -32.7186 D25 (variable)
26 -75.1626 3.736 1.79189 45.04
27* -39.1303 D27 (variable)
28 -44.6016 3.000 1.94594 17.98
29 -32.9994 0.201
30* -101.4301 1.500 1.85207 40.15
31 85.4850 7.927
32 -25.8904 1.400 1.58913 61.22
33 -45.0397 BF
Image plane ∞
[Aspherical data]
6th surface κ=1.0000,A4=5.47971E-06,A6=-6.22095E-09
A8=1.44104E-11,A10=-2.08855E-14,A12=2.01910E-17
15th surface κ=1.0000,A4=-4.50985E-06,A6=2.81159E-10
A8=-2.63745E-12,A10=-4.80538E-15,A12=0.00000E+00
27th surface κ=1.0000, A4=1.09182E-05, A6=-2.25976E-08
A8=1.43325E-10,A10=-4.96895E-13,A12=6.77820E-16
30th surface κ=1.0000,A4=-2.19229E-06,A6=-2.44256E-08
A8=6.38954E-11,A10=-1.65927E-13,A12=0.00000E+00
[Lens group data]
Focal length G1 1 118.121
G2 6 -21.898
G3 14 41.497
G4 19 109.585
G5 22 123.527
G6 26 98.560
G7 28 -47.807
[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance D5 1.800 21.061 29.930 1.800 21.061 29.930
D13 19.119 6.127 2.000 19.119 6.127 2.000
D18 9.354 3.967 1.500 9.354 3.967 1.500
D21 5.286 14.229 18.845 4.337 12.953 17.517
D25 2.861 3.580 2.713 3.291 4.145 3.115
D27 6.143 2.841 2.028 6.662 3.552 2.955
[Value corresponding to conditional expression]
Conditional expression (1) f1/(-f2)=5.394
Conditional expression (2) f1/f4=1.078
Conditional expression (3) f4/fw=4.428
Conditional expression (4) f3/f4=0.379
Conditional expression (5) |fF|/ft=1.819
Conditional expression (6) nN/nP=1.160
Conditional expression (7) νN/νP=0.392
Conditional expression (8) f1/|fRw|=0.029
Conditional expression (9) 2ωw=85.10
Conditional expression (10) BFw/fw=0.475
Conditional expression (11) (rR2+rR1)/(rR2-rR1)=3.704

20(A), 20(B), and 20(C) respectively show the zoom lens system according to Example 7 at the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity. FIG. 8 is a diagram showing various types of aberration. 21(A), 21(C), and 21(C) are respectively for the short-distance focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the seventh example. FIG. 8 is a diagram showing various types of aberration. From the various aberration diagrams, the variable power optical system according to Example 7 has excellent imaging performance by excellently correcting various aberrations from the wide-angle end state to the telephoto end state, and further when focusing on a short distance. It can be seen that also has excellent imaging performance.

According to each of the embodiments, it is possible to realize high-speed and quiet autofocus without increasing the size of the lens barrel, fluctuation of aberration during zooming from the wide-angle end state to the telephoto end state, and infinity. It is possible to realize a variable power optical system that suppresses variation in aberration when focusing from an object to a short distance object.

Here, the above-mentioned first to fourth examples and the seventh example show specific examples of the present embodiment, and the present embodiment is not limited to these.

The following contents can be appropriately adopted within a range that does not impair the optical performance of the variable power optical system according to the present embodiment.

As the numerical examples of the variable power optical system, the six-group configuration and the seven-group configuration are shown, but the present application is not limited to this, and a variable-power optical system of other group configurations (for example, eight groups) is configured. You can also do it. Specifically, a configuration may be adopted in which a lens or a lens group is added on the most object side or the most image plane side of the variable power optical system. The lens group refers to a portion having at least one lens, which is separated by an air gap that changes during zooming.

The lens surface may be a spherical surface, a flat surface, or an aspherical surface. When the lens surface is a spherical surface or a flat surface, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to an error in processing and assembly adjustment can be prevented, which is preferable. Further, even if the image plane is deviated, the drawing performance is less deteriorated, which is preferable.

When the lens surface is an aspherical surface, the aspherical surface is an aspherical surface formed by grinding, a glass mold aspherical surface formed by molding glass into an aspherical shape, or a composite type aspherical surface formed by resin forming an aspherical surface on the glass surface. Either is fine. Further, the lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

The aperture stop is preferably arranged between the second lens group and the third lens group, but the role of the lens frame may be substituted instead of providing a member as the aperture stop.

-Each lens surface may be coated with an antireflection film having high transmittance in a wide wavelength range in order to reduce flare and ghosts and achieve high-contrast optical performance. Thereby, flare and ghost can be reduced and high optical performance with high contrast can be achieved.

G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group G5 Fifth lens group G6 Sixth lens group G7 Seventh lens group I Image plane S Aperture stop

Claims

A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a positive refractive power, which are arranged in order from the object side. Having four lens groups and a subsequent lens group,
The distance between adjacent lens groups changes during zooming,
The subsequent lens group includes a focusing lens group having a positive refractive power that moves during focusing.
A variable power optical system that satisfies the following conditional expression.
3.40<f1/(-f2)<7.00
Where f1: focal length of the first lens group f2: focal length of the second lens group
The variable power optical system according to claim 1, which satisfies the following conditional expression.
0.80<f1/f4<5.10
1.20<f4/fw<6.80
Here, f4: focal length of the fourth lens group fw: focal length of the variable power optical system in the wide-angle end state
The variable power optical system according to claim 1, which satisfies the following conditional expression.
0.20<f3/f4<2.50
However, f3: focal length of the third lens group f4: focal length of the fourth lens group
The variable power optical system according to any one of claims 1 to 3, wherein the focusing lens group includes three or less single lenses.
The variable power optical system according to any one of claims 1 to 4, wherein at least one of the focusing lens groups has a single lens having a negative refractive power.
The variable power optical system according to any one of claims 1 to 5, wherein the focusing lens group is arranged closer to the image side than the aperture stop.
The variable power optical system according to any one of claims 1 to 6, wherein at least four lens groups are arranged on the image side of the aperture stop.
8. The variable power optical system according to claim 1, which satisfies the following conditional expression.
0.20<|fF|/ft<4.00
Here, fF: focal length of the focusing lens group having the strongest refractive power among the focusing lens groups ft: focal length of the variable power optical system in the telephoto end state
The variable power optical system according to any one of claims 1 to 8, wherein the fourth lens group has a cemented lens of a negative lens and a positive lens.
The fourth lens group has a cemented lens of a negative lens and a positive lens,
10. The variable power optical system according to claim 1, which satisfies the following conditional expression.
1.00<nN/nP<1.35
Here, nN: Refractive index of the negative lens in the cemented lens nP: Refractive index of the positive lens in the cemented lens
The fourth lens group has a cemented lens of a negative lens and a positive lens,
The variable power optical system according to any one of claims 1 to 10, which satisfies the following conditional expression.
0.20<νN/νP<0.85
Where νN: Abbe number of the negative lens in the cemented lens νP: Abbe number of the positive lens in the cemented lens
The variable power optical system according to any one of claims 1 to 11, which satisfies the following conditional expression.
f1/|fRw|<5.00
However, fRw: focal length of the subsequent lens group in the wide-angle end state
The variable power optical system according to any one of claims 1 to 12, which satisfies the following conditional expression.
2ωw>75°
Where ωw is the half angle of view of the variable power optical system in the wide-angle end state
14. The variable power optical system according to claim 1, which satisfies the following conditional expression.
0.10<BFw/fw<1.00
However, BFw: back focus of the variable power optical system in the wide-angle end state fw: focal length of the variable power optical system in the wide-angle end state
The variable power optical system according to any one of claims 1 to 14, which satisfies the following conditional expression.
0.00<(rR2+rR1)/(rR2-rR1)<8.00
However, rR1: radius of curvature of the object-side lens surface of the lens arranged closest to the image side of the variable power optical system rR2: of the image side lens surface of the lens arranged closest to the image side of the variable power optical system curvature radius
Optical equipment configured with the variable power optical system according to any one of claims 1 to 15.
A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a positive refractive power, which are arranged in order from the object side. A method of manufacturing a variable power optical system having four lens groups and a subsequent lens group, comprising:
The distance between adjacent lens groups changes during zooming,
The subsequent lens group includes a focusing lens group having a positive refractive power that moves during focusing.
To satisfy the following conditional expression,
A method for manufacturing a variable power optical system in which each lens is arranged in a lens barrel.
3.40<f1/(-f2)<7.00
Where f1: focal length of the first lens group f2: focal length of the second lens group