JP6108075B2 - Variable magnification optical system, optical apparatus, and variable magnification optical system manufacturing method - Google Patents

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, a variable magnification optical system suitable for a photographic camera, an electronic still camera, a video camera, and the like has been proposed (see, for example, Patent Document 1).

JP 2009-180844 A

  However, the conventional variable magnification optical system has a problem that the aberration variation at the time of zooming is large.

  The present invention has been made in view of such a problem, and an object thereof is to provide a variable magnification optical system, an optical device, and a method for manufacturing the variable magnification optical system, in which aberration fluctuation at the time of variable magnification is satisfactorily suppressed. .

In order to solve the above problems, a variable magnification optical system according to the present invention 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 positive refraction. A third lens group having a power, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. It is characterized by satisfying the following formula.
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) <3.0
1.9 <f1 / f5 ≦ 2.7
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group

  The zoom optical system according to the present invention 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 having a positive refractive power. And a fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power, and the second lens group is fixed with respect to the image plane upon zooming, It satisfies the following conditions.
2.0 <f1 / (− f2) ≦ 5.1
1.8 ≦ f1 / (− f4) ≦ 2.4
1.9 <f1 / f5 <3.2
  However,
  f1: Focal length of the first lens group
  f2: Focal length of the second lens group
  f4: focal length of the fourth lens unit
  f5: focal length of the fifth lens unit

The zoom optical system according to the present invention 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 having a positive refractive power. And a fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power, and the second lens group is fixed with respect to the image plane upon zooming, It satisfies the following conditions.
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) ≦ 2.4
1.9 <f1 / f5 <3.2
1.1 ≦ (−f4) /f5≦1.4
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group

  An optical apparatus according to the present invention includes any of the above-described variable magnification optical systems that forms an image of an object on a predetermined image plane.

The variable magnification optical system manufacturing method according to the present invention 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. A method for manufacturing a variable magnification optical system having a third lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. The group is arranged so as to be fixed with respect to the image plane, and is arranged so as to satisfy the condition of the following expression.
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) <3.0
1.9 <f1 / f5 ≦ 2.7
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group

  According to the present invention, it is possible to provide a variable magnification optical system, an optical device, and a method for manufacturing the variable magnification optical system that can satisfactorily suppress aberration fluctuations during variable magnification.

It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. FIG. 5A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to the first example. FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. FIG. 5A is a diagram illustrating various aberrations in the intermediate focal length state of the variable magnification optical system according to the first example. FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when blurring correction is performed. FIG. 5A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the first example. FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. FIG. 7A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to the second example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations in the intermediate focal length state of the variable magnification optical system according to the second example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when blurring correction is performed. FIG. 5A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to Example 2, wherein FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. FIG. 7A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to the third example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations in the intermediate focal length state of the variable magnification optical system according to the third example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when blurring correction is performed. FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the third example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 4th Example. FIG. 7A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to the fourth example, where FIG. 9A is a diagram illustrating all aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations in the intermediate focal length state of the variable magnification optical system according to the fourth example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when blurring correction is performed. FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the fourth example, where FIG. 9A is a diagram illustrating various aberrations in the infinite focus state, and FIG. It is a coma aberration figure when correct | amending. A sectional view of a camera carrying the above-mentioned variable magnification optical system is shown. It is a flowchart for demonstrating the manufacturing method of the said variable magnification optical system.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the variable magnification optical system ZL according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, A third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power are configured. In the zoom optical system ZL, it is desirable that the second lens group G2 is fixed with respect to the image plane during zooming. With this configuration, the amount of movement of each lens group during zooming can be reduced. Further, by fixing the second lens group G2, it is possible to reduce the influence of eccentricity due to manufacturing errors.

  Now, conditions for constructing such a variable magnification optical system ZL will be described. First, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (1).

2.0 <f1 / (− f2) <6.1 (1)
However,
f1: Focal length of the first lens group G1 f2: Focal length of the second lens group G2

  Conditional expression (1) defines an appropriate focal length of the first lens group G1 with respect to the focal length of the second lens group G2. By satisfying conditional expression (1), it is possible to satisfactorily correct spherical aberration and chromatic aberration in the telephoto end state. If the lower limit of conditional expression (1) is not reached, the refractive power of the first lens group G1 becomes large, and it becomes difficult to correct spherical aberration and chromatic aberration in the telephoto end state, which is not preferable. If the lower limit value of conditional expression (1) is 3.0, the effect of the present application can be ensured. On the contrary, when the value exceeds the upper limit value of the conditional expression (1), the refractive power of the first lens group G1 becomes small, which leads to an increase in the total length, which is not preferable. If the upper limit of conditional expression (1) is 6.0, the effect of the present application can be ensured.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (2).

1.3 <f1 / (− f4) <3.0 (2)
However,
f1: Focal length of the first lens group G1 f4: Focal length of the fourth lens group G4

  Conditional expression (2) defines an appropriate focal length of the first lens group G1 with respect to the focal length of the fourth lens group G4. By satisfying conditional expression (2), it is possible to satisfactorily correct spherical aberration and chromatic aberration in the telephoto end state. If the lower limit of conditional expression (2) is not reached, the refractive power of the first lens group G1 becomes large, and it becomes difficult to correct spherical aberration and chromatic aberration in the telephoto end state. If the lower limit value of conditional expression (2) is 1.4, the effect of the present application can be ensured. On the contrary, when the value exceeds the upper limit value of the conditional expression (2), the refractive power of the first lens group G1 becomes small, which leads to an increase in the total length, which is not preferable. If the upper limit of conditional expression (2) is 2.8, the effect of the present application can be ensured.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (3).

1.9 <f1 / f5 <3.2 (3)
However,
f1: Focal length of the first lens group G1 f5: Focal length of the fifth lens group G5

  Conditional expression (3) defines an appropriate focal length of the first lens group G1 with respect to the focal length of the fifth lens group G5. By satisfying conditional expression (3), it is possible to satisfactorily correct spherical aberration and chromatic aberration in the telephoto end state. If the lower limit of conditional expression (3) is not reached, the refractive power of the first lens group G1 becomes large, and it becomes difficult to correct spherical aberration and chromatic aberration in the telephoto end state. If the lower limit value of conditional expression (3) is 2.0, the effect of the present application can be ensured. On the other hand, if the value exceeds the upper limit of conditional expression (3), the refractive power of the fifth lens group G5 increases, and it becomes difficult to correct curvature of field and distortion at the wide angle end, which is not preferable. If the upper limit value of conditional expression (3) is 3.0, the effect of the present application can be ensured.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (4).

0.8 <(− f4) / f5 <1.8 (4)
However,
f4: focal length of the fourth lens group G4 f5: focal length of the fifth lens group G5

  Conditional expression (4) defines an appropriate focal length of the fourth lens group G4 with respect to the focal length of the fifth lens group G5. By satisfying conditional expression (4), it is possible to satisfactorily correct curvature of field and distortion in the wide-angle end state. If the lower limit of conditional expression (4) is not reached, the refractive power of the fourth lens group G4 becomes large, and it becomes difficult to correct chromatic aberration in the telephoto end state. If the lower limit value of conditional expression (4) is 0.9, the effect of the present application can be ensured. On the other hand, exceeding the upper limit value of conditional expression (4) is not preferable because the refractive power of the fifth lens group G5 becomes large and it becomes difficult to correct curvature of field and distortion in the wide-angle end state. If the upper limit value of conditional expression (4) is 1.6, the effect of the present application can be ensured.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (5).

0.3 <(− f2) / f5 <0.8 (5)
However,
f2: Focal length of the second lens group G2 f5: Focal length of the fifth lens group G5

  Conditional expression (5) defines an appropriate focal length of the second lens group G2 with respect to the focal length of the fifth lens group G5. By satisfying conditional expression (5), it is possible to satisfactorily correct curvature of field and distortion in the wide-angle end state. If the lower limit of conditional expression (5) is not reached, the refractive power of the second lens group G2 becomes large, and it is difficult to correct coma in the wide-angle end state, which is not preferable. If the lower limit value of conditional expression (5) is 0.4, the effect of the present application can be ensured. On the other hand, if the upper limit value of conditional expression (5) is exceeded, the refractive power of the fifth lens group G5 increases, and it becomes difficult to correct field curvature and distortion in the wide-angle end state. If the upper limit value of conditional expression (5) is 0.7, the effect of the present application can be ensured. If the upper limit of conditional expression (5) is 0.6, the effect of the present application can be further ensured.

  The variable magnification optical system ZL preferably has an aperture stop S on the image side with respect to the second lens group G2. At this time, it is desirable to have an aperture stop S between the third lens group G3 and the fifth lens group G5. Furthermore, it is desirable to have an aperture stop S between the third lens group G3 and the fourth lens group G4. With this configuration, coma and curvature of field can be favorably corrected.

  In the variable power optical system ZL, it is desirable to move at least a part of the third lens group G3 along the optical axis during focusing. With this configuration, it is possible to perform rapid focusing, and it is possible to reduce field angle fluctuation and spherical aberration fluctuation during focusing.

  The variable magnification optical system ZL may be at least a part of the second lens group G2 to the fifth lens group G5 (a plurality of lens groups or any one lens group, or any lens). It may be desirable to move the lens so as to include a component orthogonal to the optical axis. At this time, it is more desirable to move at least a part of the second lens group G2 so as to include a component orthogonal to the optical axis. With this configuration, camera shake correction can be performed with a lens having a small diameter, so that the size of the lens barrel can be reduced.

  In the variable magnification optical system ZL, it is preferable that all lens surfaces are spherical surfaces. This configuration is preferable because it facilitates lens processing and assembly adjustment, and prevents deterioration in optical performance due to errors in processing and assembly adjustment. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance.

  Next, a camera that is an optical device including the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. This camera 1 is a so-called mirrorless camera of interchangeable lens provided with a variable magnification optical system ZL according to the present embodiment as a 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.

  Further, when a release button (not shown) is pressed by the photographer, an image photoelectrically converted 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. In the present embodiment, an example of a mirrorless camera has been described. However, a variable power optical system ZL according to the present embodiment is applied to a single-lens reflex camera that has a quick return mirror in the camera body and observes a subject with a finder optical system. Even when the camera is mounted, the same effect as the camera 1 can be obtained.

  The contents described below can be appropriately adopted as long as the optical performance is not impaired.

  In the present embodiment, the variable magnification optical system ZL having the 5-group and 6-group configurations is shown, but the above-described configuration conditions and the like can be applied to other group configurations such as the 7-group. Further, a configuration in which a lens or a lens group is added to the most object side or a configuration in which a lens or a lens group is added to the most image side may be used. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming.

  Alternatively, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to be a focusing lens group that performs focusing from an object at infinity to a near object. In this case, the focusing lens group can be applied to autofocus, and is also suitable for driving a motor for autofocus (such as an ultrasonic motor). In particular, it is preferable that at least a part of the third lens group G3 is a focusing lens group as described above.

  Also, by moving the lens group or partial lens group so that it has a component in the direction perpendicular to the optical axis, or rotating (swinging) in the in-plane direction including the optical axis, image blur caused by camera shake is corrected. An anti-vibration lens group may be used. In particular, as described above, it is preferable that at least a part of the second lens group G2 is a vibration-proof lens group.

  Further, the lens surface may be formed as a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, as described above, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in processing and assembly adjustment is 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 an aspheric surface, the aspheric surface is an aspheric surface by grinding, a glass mold aspheric surface made of glass with an aspheric shape, or a composite aspheric surface made of resin with an aspheric shape on the glass surface. Any aspherical surface may be used. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

  As described above, the aperture stop S is preferably disposed between the third lens group G3 and the fifth lens group G5. However, the aperture stop S does not have a member as an aperture stop, and plays a role in the lens frame. You may substitute.

  Further, each lens surface may be provided with an antireflection film having a high transmittance in a wide wavelength region in order to reduce flare and ghost and achieve high optical performance with high contrast.

  The variable magnification optical system ZL of the present embodiment has a variable magnification ratio of about 3.0 to 7.0.

  Hereinafter, an outline of a method for manufacturing the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. First, the lenses are arranged to prepare the lens groups G1 to G5, respectively (step S100). In zooming, the second lens group G2 is arranged so as to be fixed with respect to the image plane I (step S200). Furthermore, the lens groups G1 to G5 are arranged so as to satisfy the conditional expressions (1) to (3) described above (step S300).

  Specifically, in the present embodiment, for example, as illustrated in FIG. 1, in order from the object side, a cemented lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12 are cemented, and on the object side. A positive meniscus lens L13 having a convex surface is disposed to form a first lens group G1, a cemented lens in which a biconvex lens L21 and a biconcave lens L22 are cemented, a biconcave lens L23, and a positive meniscus lens L24 having a convex surface facing the object side. A cemented lens and a biconcave lens L25 are arranged to form the second lens group G2, and a biconvex lens L31 and a cemented lens in which a negative meniscus lens L32 having a convex surface facing the object side and a biconvex lens L33 are arranged. The third lens group G3 is a cemented lens in which a biconcave lens L41 and a positive meniscus lens L42 having a convex surface facing the object side are cemented. A fourth lens group G4; a cemented lens in which a biconvex lens L51, a planoconvex lens L52 having a convex surface facing the object side, a planoconcave lens L53 having a concave surface facing the image side, and a planoconvex lens L54 having a convex surface facing the object side are cemented A cemented lens in which a biconvex lens L55 and a plano-concave lens L56 having a concave surface facing the object side are cemented, and a negative meniscus lens L57 having a concave surface facing the object side are disposed to form a fifth lens group G5. The lens groups thus prepared are arranged in the above-described procedure to manufacture the variable magnification optical system ZL.

  Hereinafter, each example of the present application will be described with reference to the drawings. 1, FIG. 5, FIG. 9 and FIG. 13 are sectional views showing the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL4) according to each example. Further, in the lower part of the sectional view of the zoom optical systems ZL1 to ZL4, the optical axis of each lens group G1 to G5 or G6 when zooming from the wide-angle end state (W) to the telephoto end state (T) is shown. The direction of movement along is indicated by arrows. In any of the embodiments, the second lens group G2 is fixed with respect to the image plane I during zooming.

[First embodiment]
FIG. 1 is a diagram showing a configuration of a variable magnification optical system ZL1 according to the first example. The zoom optical system ZL1 shown in FIG. 1 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 first lens group having a positive refractive power. The third lens group G3 includes a third lens group G3, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. The first lens group G1 includes, in order from the object side, a cemented lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12 are cemented, and a positive meniscus lens L13 having a convex surface facing the object side. It is configured. The second lens group G2 includes, in order from the object side, a cemented lens in which the biconvex lens L21 and the biconcave lens L22 are cemented, and a cemented lens in which the biconcave lens L23 and a positive meniscus lens L24 having a convex surface facing the object side are cemented. And it is comprised from the biconcave lens L25. The third lens group G3 includes, in order from the object side, a biconvex lens L31, and a cemented lens in which a negative meniscus lens L32 having a convex surface facing the object side and a biconvex lens L33 are cemented. The fourth lens group G4 is composed of a cemented lens in which, in order from the object side, a biconcave lens L41 and a positive meniscus lens L42 having a convex surface directed toward the object side are cemented. The fifth lens group G5 includes, in order from the object side, a biconvex lens L51, a planoconvex lens L52 with a convex surface facing the object side, a planoconcave lens L53 with a concave surface facing the image side, and a planoconvex lens L54 with a convex surface facing the object side. Are cemented, a biconvex lens L55 and a plano-concave lens L56 having a concave surface facing the object side, and a negative meniscus lens L57 having a concave surface facing the object side.

  In the zoom optical system ZL1 according to the first example, when zooming from the wide-angle end state to the telephoto end state, the first lens group G1, the third lens group G3, and the fifth lens group G5 are arranged on the optical axis. The second lens group G2 and the fourth lens group G4 are fixed in the optical axis direction with respect to the image plane I. The aperture stop S is disposed on the object side of the fifth lens group G5 and moves together with the fifth lens group G5 upon zooming.

  Further, focusing from infinity to a close object is performed by moving the third lens group G3 to the image side.

  For image blur correction (anti-shake), a cemented lens in which the biconcave lens L23 of the second lens group G2 and a positive meniscus lens L24 having a convex surface facing the object side are cemented is used as an anti-shake lens group. Is moved to include a component in a direction orthogonal to the optical axis. It is to be noted that the focal length of the entire system is f, and the image stabilization coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the image stabilization lens group VL in image blur correction) is K. Can be corrected by moving the image stabilizing lens group for shake correction by (f · tan θ) / K in the direction orthogonal to the optical axis (the same applies to the following embodiments). In the wide-angle end state of the first embodiment, the image stabilization coefficient is −0.767 and the focal length is 81.6 (mm). Therefore, the image stabilization for correcting the rotational shake of 0.2 ° is performed. The moving amount of the lens group is −0.371 (mm). In addition, in the intermediate focal length state of the first embodiment, the image stabilization coefficient is −1.348 and the focal length is 200.0 (mm). Therefore, in order to correct 0.2 ° rotational shake. The amount of movement of the anti-vibration lens group is -0.518 (mm). In the telephoto end state of the first embodiment, the image stabilization coefficient is -2.103 and the focal length is 392.0 (mm). The moving amount of the image stabilizing lens group is −0.651 (mm).

  Table 1 below lists values of specifications of the first embodiment. In Table 1, β in the overall specifications is a zoom ratio, f is a focal length of the entire system, FNO is an F number, 2ω is an angle of view, Y is an image height, and TL is a total length. Here, the total length TL represents the distance on the optical axis from the first surface of the lens surface to the image plane I when focusing on infinity. In the lens data, the first column m indicates the order (surface number) of the lens surfaces from the object side along the traveling direction of the light beam, the second column r indicates the curvature radius of each lens surface, and the third column. d is the distance on the optical axis from each optical surface to the next optical surface (surface interval). The fourth column νd and the fifth column nd are Abbe numbers and refractive indices for the d-line (λ = 587.6 nm). Is shown. Further, the radius of curvature of 0.000 indicates a plane, and the refractive index of air of 1.0000 is omitted. The surface numbers 1 to 33 shown in Table 1 correspond to the numbers 1 to 33 shown in FIG. The lens group focal length indicates the start surface and the focal length of each of the first to fifth lens groups G1 to G5. Here, the focal length f, the radius of curvature r, the surface interval d, and other length units listed in all the following specification values are generally “mm”, but the optical system is proportionally enlarged or proportional. Since the same optical performance can be obtained even if the image is reduced, the present invention is not limited to this. The description of these symbols and the description of the specification table are the same in the following embodiments.

(Table 1)
[Overall specifications]
β = 4.8
Wide-angle end state Intermediate focal length state Telephoto end state f = 81.6 to 200.0 to 392.0
FNO = 4.56 to 5.38 to 5.85
2ω = 29.6 to 12.1 to 6.2
Y = 21.6-21.6-21.6
TL = 246.4 to 283.4 to 302.5

[Lens data]
m r d νd nd
1 182.816 2.500 35.7 1.90265
2 92.566 10.000 82.6 1.49782
3 -707.416 0.100
4 83.365 9.200 95.0 1.43700
5 1420.361 D1
6 117.082 6.400 34.9 1.80 100
7 -117.044 2.200 82.6 1.49782
8 61.183 5.810
9 -265.081 2.000 46.6 1.81600
10 30.785 4.600 25.5 1.80518
11 92.264 6.200
12 -56.342 2.000 42.7 1.83481
13 158.965 D2
14 112.252 4.600 67.9 1.59319
15 -78.685 0.100
16 67.612 1.800 31.3 1.90366
17 35.499 6.400 67.9 1.59319
18 -238.177 D3
19 -58.467 1.600 54.6 1.72916
20 38.999 3.600 35.7 1.90265
21 146.900 D4
22 0.000 2.000 Aperture stop S
23 124.142 3.400 44.8 1.74400
24 -124.142 0.100
25 26.615 6.800 70.3 1.48749
26 0.000 2.000 29.4 1.95000
27 26.437 4.800 52.2 1.51742
28 0.000 17.600
29 176.178 6.000 33.7 1.64769
30 -19.703 1.600 65.4 1.60300
31 0.000 11.270
32 -22.131 1.600 42.7 1.83481
33 -33.748 BF

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 161.714
Second lens group 6 -32.531
Third lens group 14 50.816
Fourth lens group 19 -70.030
5th lens group 23 59.673

  In the first embodiment, the axial air distance D1 between the first lens group G1 and the second lens group G2, the axial air distance D2 between the second lens group G2 and the third lens group G3, and the third lens group G3. The axial air gap D3 between the first lens group G4 and the fourth lens group G4, the axial air gap D4 between the fourth lens group G4 and the fifth lens group G5 and the aperture stop S moving together with the fourth lens group G4, and the back focus BF change during zooming. To do. Table 2 below shows values of the variable intervals D1 to D4 and the back focus BF at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. Note that the back focus BF represents the distance on the optical axis from the most image side lens surface (the 33rd surface in FIG. 1) to the image surface I. This description is the same in the following embodiments.

(Table 2)
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
D1 8.225 to 45.191 to 64.292
D2 27.059-15.341-3.056
D3 5.388 to 17.106 to 29.391
D4 26.684-11.153-2.382
BF 52.8-68.3-77.1

  Table 3 below shows values corresponding to the conditional expressions in the first embodiment. In Table 3, f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, f4 is the focal length of the fourth lens group G4, and f5 is the fifth lens group G5. Each focal length is shown. The description of the above symbols is the same in the following embodiments.

(Table 3)
(1) f1 / (− f2) = 5.0
(2) f1 / (− f4) = 2.3
(3) f1 / f5 = 2.7
(4) (−f4) /f5=1.2
(5) (- f2) / f5 = 0.5

  Thus, the variable magnification optical system ZL1 according to the first example satisfies all the conditional expressions (1) to (5).

  FIG. 2A shows an aberration diagram in the infinite focus state in the wide-angle end state of the first embodiment, and FIG. 3A shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 4A shows an aberration diagram in the infinitely focused state in the telephoto end state. FIG. 2B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.371) is performed in the infinite focus state at the wide angle end state in the first embodiment. FIG. 3B shows a coma aberration diagram when the image blur correction (shift amount of the image stabilizing lens group = −0.518) is performed in the infinite focus state at the intermediate focal length state, and is shown at the telephoto end. FIG. 4B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.651) is performed in the infinite focus state in the state. In each aberration diagram, FNO represents an F number, A represents a half field angle, d represents a d-line (λ = 587.6 nm), and g represents a g-line (λ = 435.6 nm). In the aberration diagrams showing astigmatism, the solid line shows the sagittal image plane, and the broken line shows the meridional image plane. The explanation of this aberration diagram is the same in the following examples. As is apparent from the respective aberration diagrams, in the first example, various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and it can be seen that the imaging performance is excellent.

[Second Embodiment]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second example. The zoom optical system ZL2 shown in FIG. 5 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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, and a sixth lens group G6 having a negative refractive power. . The first lens group G1 includes, in order from the object side, a cemented lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12 are cemented, and a biconvex lens L13. The second lens group G2 includes, in order from the object side, a cemented lens in which a positive meniscus lens L21 having a concave surface facing the object side and a biconcave lens L22 are cemented, and a positive meniscus lens having a convex surface facing the biconcave lens L23 and the object side. It is composed of a cemented lens joined to L24 and a biconcave lens L25. The third lens group G3 includes, in order from the object side, a biconvex lens L31, and a cemented lens in which a biconvex lens L32 and a negative meniscus lens L33 having a concave surface facing the object side are cemented. The fourth lens group G4 includes a cemented lens in which a biconcave lens L41 and a biconvex lens L42 are cemented in order from the object side. The fifth lens group G5 includes, in order from the object side, a biconvex lens L51 and a cemented lens in which a biconvex lens L52 and a negative meniscus lens L53 having a concave surface facing the object side are cemented. The sixth lens group G6 includes a cemented lens in which a biconvex lens L61 and a biconcave lens L62 are cemented in order from the object side.

  The zoom optical system ZL2 according to the second example has a first lens group G1, a third lens group G3, a fifth lens group G5, and a sixth lens group G6 during zooming from the wide-angle end state to the telephoto end state. Moves in the object direction on the optical axis, and the second lens group G2 and the fourth lens group G4 are fixed with respect to the image plane I in the optical axis direction. The aperture stop S is disposed on the object side of the fifth lens group G5 and moves together with the fifth lens group G5 upon zooming.

  Further, focusing from infinity to a close object is performed by moving the third lens group G3 to the image side.

  For image blur correction (anti-shake), a cemented lens in which the biconcave lens L23 of the second lens group G2 and a positive meniscus lens L24 having a convex surface facing the object side are cemented is used as an anti-shake lens group. Is moved to include a component in a direction orthogonal to the optical axis. In the wide-angle end state of the second embodiment, the image stabilization coefficient is −0.637 and the focal length is 72.0 (mm). Therefore, the image stabilization for correcting the rotational shake of 0.2 ° is performed. The moving amount of the lens group is −0.395 (mm). In addition, in the intermediate focal length state of the second embodiment, the image stabilization coefficient is −1.158 and the focal length is 200.0 (mm). Therefore, in order to correct 0.2 ° rotational shake. The amount of movement of the anti-vibration lens group is −0.603 (mm). In the telephoto end state of the second embodiment, the image stabilization coefficient is −1.763 and the focal length is 390.0 (mm). The moving amount of the image stabilizing lens group is −0.772 (mm).

  Table 4 below lists values of specifications of the second embodiment. The surface numbers 1 to 30 shown in Table 4 correspond to the numbers 1 to 30 shown in FIG. The lens group focal length indicates the start surface and focal length of each of the first to sixth lens groups G1 to G6.

(Table 4)
[Overall specifications]
β = 5.4
Wide-angle end state Intermediate focal length state Telephoto end state f = 72.0 to 200.0 to 390.0
FNO = 4.54 to 5.44 to 5.88
2ω = 33.7 to 12.0 to 6.2
Y = 21.6-21.6-21.6
TL = 244.3 to 290.3 to 309.3

[Lens data]
m r d νd nd
1 218.093 1.800 40.7 1.88300
2 94.341 10.098 82.6 1.49782
3 -579.376 0.100
4 90.320 9.392 82.6 1.49782
5 -1839.350 D1
6 -1407.394 4.344 25.5 1.80518
7 -80.390 2.000 67.9 1.59319
8 128.565 4.528
9 -287.557 1.900 42.7 1.83481
10 40.640 3.951 23.8 1.84666
11 116.253 5.759
12 -69.042 1.800 42.7 1.83481
13 177.936 D2
14 102.836 4.827 60.2 1.64000
15 -70.986 0.100
16 85.954 5.583 61.2 1.58913
17 -58.889 2.000 23.8 1.84666
18 -910.681 D3
19 -57.570 1.800 47.4 1.78800
20 50.018 3.583 23.8 1.84666
21 -2308.874 D4
22 0.000 2.000 Aperture stop S
23 1105.472 3.337 50.3 1.71999
24 -60.251 0.100
25 53.693 5.265 70.3 1.48749
26 -61.018 2.000 23.8 1.84666
27 -839.528 D5
28 43.363 5.139 28.4 1.72825
29 -106.243 1.500 40.7 1.88300
30 33.800 BF

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 151.809
Second lens group 6 -32.015
Third lens group 14 53.583
Fourth lens group 19 -82.521
Fifth lens group 23 58.368
6th lens group 28 -110.027

  In the second embodiment, the axial air distance D1 between the first lens group G1 and the second lens group G2, the axial air distance D2 between the second lens group G2 and the third lens group G3, and the third lens group G3. And the fourth lens group G4, the axial air distance D3 between the fourth lens group G4 and the fifth lens group G5, the axial air distance D4 between the aperture stop S moving together with the fourth lens group G4, the fifth lens group G5 and the sixth lens group G6. The on-axis air distance D5 and the back focus BF change during zooming. Table 5 below shows values of the variable intervals D1 to D5 and the back focus BF at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 5)
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state f 72.0 to 200.0 to 390.0
D1 2.000 to 47.946 to 67.000
D2 28.700-17.520-3.000
D3 15.940 to 29.759 to 42.880
D4 29.040-8.875-2.000
D5 30.005 to 22.265 to 23.642
BF 55.7 to 81.0 to 87.9

  Table 6 below shows values corresponding to the conditional expressions in the second embodiment.

(Table 6)
(1) f1 / (− f2) = 4.7
(2) f1 / (− f4) = 1.8
(3) f1 / f5 = 2.6
(4) (−f4) /f5=1.4
(5) (- f2) / f5 = 0.5

  Thus, the zoom optical system ZL2 according to the second example satisfies all the conditional expressions (1) to (5).

  FIG. 6A shows an aberration diagram in the infinite focus state in the wide-angle end state of the second embodiment, and FIG. 7A shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 8A shows an aberration diagram in the infinitely focused state in the telephoto end state. FIG. 6B is a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.395) is performed in the infinitely focused state at the wide-angle end state in the second embodiment. FIG. 7B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = 0.603) is performed in the infinite focus state at the intermediate focal length state, and is shown at the telephoto end. FIG. 8B shows a coma aberration diagram when image blur correction (shift amount of the anti-vibration lens group = −0.772) is performed in the infinity in-focus state. As is apparent from the respective aberration diagrams, in the second example, various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and it can be seen that the imaging performance is excellent.

[Third embodiment]
FIG. 9 is a diagram illustrating a configuration of the variable magnification optical system ZL3 according to the third example. The zoom optical system ZL3 shown in FIG. 9 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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, and a sixth lens group G6 having a negative refractive power. . The first lens group G1 includes, in order from the object side, a cemented lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12 are cemented, and a biconvex lens L13. The second lens group G2 includes, in order from the object side, a cemented lens in which a biconvex lens L21 and a biconcave lens L22 are cemented, and a cemented lens in which a positive meniscus lens L23 having a concave surface facing the object side and a biconcave lens L24 are cemented. And it is comprised from the biconcave lens L25. The third lens group G3 includes a biconvex lens L31 and a cemented lens in which the biconvex lens L32 and the biconcave lens L33 are cemented in order from the object side. The fourth lens group G4 is composed of a cemented lens in which, in order from the object side, a biconcave lens L41 and a positive meniscus lens L42 having a convex surface directed toward the object side are cemented. The fifth lens group G5 includes, in order from the object side, a cemented lens in which a negative meniscus lens L51 having a convex surface facing the object side and a biconvex lens L52 are cemented, and a negative lens having a concave surface facing the biconvex lens L53 and the object side. It is composed of a cemented lens in which a meniscus lens L54 is cemented. The sixth lens group G6 includes a cemented lens in which a biconvex lens L61 and a biconcave lens L62 are cemented in order from the object side.

  The zoom optical system ZL3 according to the third example has a first lens group G1, a third lens group G3, a fifth lens group G5, and a sixth lens group G6 when zooming from the wide-angle end state to the telephoto end state. Moves in the object direction on the optical axis, and the second lens group G2 and the fourth lens group G4 are fixed with respect to the image plane I in the optical axis direction. The aperture stop S is disposed on the object side of the fifth lens group G5 and moves together with the fifth lens group G5 upon zooming.

  Further, focusing from infinity to a close object is performed by moving the third lens group G3 to the image side.

  Image blur correction (anti-vibration) is performed by using the entire second lens group G2 as an anti-vibration lens group and moving the anti-vibration lens group so as to include a component in a direction perpendicular to the optical axis. In the third embodiment, in the wide-angle end state, the image stabilization coefficient is -1.972 and the focal length is 72.0 (mm). Therefore, the image stabilization for correcting the rotational shake of 0.2 ° is performed. The moving amount of the lens group is −0.127 (mm). Further, in the intermediate focal length state of the third embodiment, the image stabilization coefficient is −3.534, and the focal length is 200.0 (mm), so that the 0.2 ° rotational shake is corrected. The amount of movement of the anti-vibration lens group is -0.198 (mm). In the telephoto end state of the third embodiment, the image stabilization coefficient is −5.379 and the focal length is 390.0 (mm). The moving amount of the anti-vibration lens group is −0.253 (mm).

  Table 7 below lists values of specifications of the third example. In addition, the surface numbers 1-31 shown in Table 7 respond | correspond to the numbers 1-31 shown in FIG. The lens group focal length indicates the start surface and focal length of each of the first to sixth lens groups G1 to G6.

(Table 7)
[Overall specifications]
β = 5.4
Wide-angle end state Intermediate focal length state Telephoto end state f = 72.0 to 200.0 to 390.0
FNO = 4.52 to 5.34 to 5.78
2ω = 34.0 to 12.1 to 6.2
Y = 21.6-21.6-21.6
TL = 239.3 to 285.8 to 304.3

[Lens data]
m r d νd nd
1 235.129 2.000 40.7 1.88300
2 85.937 10.435 82.6 1.49782
3 -492.987 0.100
4 81.734 9.789 82.6 1.49782
5 -2477.191 D1
6 94.480 3.279 28.7 1.79504
7 -1045.056 2.000 67.9 1.59319
8 57.468 3.373
9 -137.861 3.251 28.7 1.79504
10 -48.070 2.000 67.9 1.59319
11 69.776 3.889
12 -56.313 1.800 49.6 1.77250
13 135.256 D2
14 220.803 5.100 67.9 1.59319
15 -51.295 0.100
16 48.045 5.380 67.9 1.59319
17 -156.768 2.000 31.3 1.90366
18 209.257 D3
19 -51.770 1.500 54.6 1.72916
20 41.489 3.613 34.9 1.80 100
21 331.492 D4
22 0.000 2.000 Aperture stop S
23 86.564 2.000 40.7 1.88300
24 47.702 5.771 52.2 1.51742
25 -52.610 0.100
26 60.874 4.753 82.6 1.49782
27 -65.980 2.000 23.8 1.84666
28 -423.943 D5
29 43.795 3.743 27.6 1.75520
30 -80.630 1.500 40.7 1.88300
31 36.787 BF

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 151.723
Second lens group 6 -31.512
Third lens group 14 48.052
Fourth lens group 19 -67.397
5th lens group 23 58.111
6th lens group 29 -140.788

  In the third embodiment, the axial air distance D1 between the first lens group G1 and the second lens group G2, the axial air distance D2 between the second lens group G2 and the third lens group G3, and the third lens group G3. And the fourth lens group G4, the axial air distance D3 between the fourth lens group G4 and the fifth lens group G5, the axial air distance D4 between the aperture stop S moving together with the fourth lens group G4, the fifth lens group G5 and the sixth lens group G6. The on-axis air distance D5 and the back focus BF change during zooming. Table 8 below shows the values of the variable intervals D1 to D5 and the back focus BF at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 8)
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state f 72.0 to 200.0 to 390.0
D1 2.000 to 48.459 to 67.000
D2 25.107-13.069-2.000
D3 6.466 to 18.504 to 29.573
D4 29.312 to 12.120 to 2.428
D5 32.947 to 32.202 to 30.353
BF 55.1-73.0-84.5

  Table 9 below shows values corresponding to the conditional expressions in the third embodiment.

(Table 9)
(1) f1 / (− f2) = 4.8
(2) f1 / (− f4) = 2.3
(3) f1 / f5 = 2.6
(4) (−f4) /f5=1.2
(5) (−f2) /f5=0.5

  Thus, the variable magnification optical system ZL3 according to the third example satisfies all the conditional expressions (1) to (5).

  FIG. 10A shows an aberration diagram in the infinite focus state in the wide-angle end state of the third embodiment, and FIG. 11A shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 12A shows an aberration diagram in the infinitely focused state in the telephoto end state. FIG. 10B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.127) is performed in the infinite focus state at the wide-angle end state in the third example. FIG. 11B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.198) is performed in the infinite focus state at the intermediate focal length state, and is shown at the telephoto end. FIG. 12B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.253) is performed in an infinitely focused state in the state. As is apparent from the respective aberration diagrams, in the third example, various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and it can be seen that the imaging performance is excellent.

[Fourth embodiment]
FIG. 13 is a diagram showing a configuration of the variable magnification optical system ZL4 according to the fourth example. The variable magnification optical system ZL4 shown in FIG. 13 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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, and a sixth lens group G6 having a negative refractive power. . The first lens group G1 includes, in order from the object side, a cemented lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12 are cemented, and a biconvex lens L13. The second lens group G2 includes, in order from the object side, a cemented lens in which the biconvex lens L21 and the biconcave lens L22 are cemented, and a cemented lens in which the biconcave lens L23 and a positive meniscus lens L24 having a convex surface facing the object side are cemented. And it is comprised from the biconcave lens L25. The third lens group G3 includes, in order from the object side, a biconvex lens L31, and a cemented lens in which a negative meniscus lens L32 having a convex surface facing the object side and a biconvex lens L33 are cemented. The fourth lens group G4 is composed of a cemented lens in which, in order from the object side, a biconcave lens L41 and a positive meniscus lens L42 having a convex surface directed toward the object side are cemented. The fifth lens group G5 includes, in order from the object side, a cemented lens in which a negative meniscus lens L51 having a convex surface facing the object side and a biconvex lens L52 are cemented, and a negative lens having a concave surface facing the biconvex lens L53 and the object side. It is composed of a cemented lens in which a meniscus lens L54 is cemented. The sixth lens group G6 includes a cemented lens in which a biconvex lens L61 and a biconcave lens L62 are cemented in order from the object side.

  The zoom optical system ZL4 according to the fourth example has a first lens group G1, a third lens group G3, a fifth lens group G5, and a sixth lens group G6 when zooming from the wide-angle end state to the telephoto end state. Moves in the object direction on the optical axis, and the second lens group G2 and the fourth lens group G4 are fixed with respect to the image plane I in the optical axis direction. The aperture stop S is disposed on the object side of the fifth lens group G5 and moves together with the fifth lens group G5 upon zooming.

  Further, focusing from infinity to a close object is performed by moving the third lens group G3 to the image side.

  For image blur correction (anti-shake), a cemented lens in which the biconcave lens L23 of the second lens group G2 and a positive meniscus lens L24 having a convex surface facing the object side are cemented is used as an anti-shake lens group. Is moved to include a component in a direction orthogonal to the optical axis. In the fourth embodiment, in the wide-angle end state, the image stabilization coefficient is −0.888 and the focal length is 82.0 (mm). Therefore, the image stabilization for correcting the rotation blur of 0.2 ° is performed. The moving amount of the lens group is −0.322 (mm). Further, in the intermediate focal length state of the fourth embodiment, the image stabilization coefficient is −1.454 and the focal length is 200.0 (mm). The amount of movement of the anti-vibration lens group is −0.480 (mm). In the telephoto end state of the fourth embodiment, the image stabilization coefficient is -2.176 and the focal length is 390.0 (mm). The moving amount of the anti-vibration lens group is −0.626 (mm).

  Table 10 below lists values of specifications of the fourth example. In addition, the surface numbers 1-31 shown in Table 10 respond | correspond to the numbers 1-31 shown in FIG. The lens group focal length indicates the start surface and focal length of each of the first to sixth lens groups G1 to G6.

(Table 10)
[Overall specifications]
β = 4.8
Wide-angle end state Intermediate focal length state Telephoto end state f = 82.0 to 200.0 to 390.0
FNO = 5.05 to 5.61 to 5.82
2ω = 29.7〜12.0〜6.2
Y = 21.6-21.6-21.6
TL = 241.3 to 283.3 to 303.3

[Lens data]
m r d νd nd
1 227.795 2.000 40.7 1.88300
2 84.747 10.413 82.6 1.49782
3 -538.594 0.100
4 82.998 9.958 82.6 1.49782
5 -1048.042 D1
6 170.969 6.158 34.9 1.80 100
7 -66.891 2.000 65.4 1.60300
8 82.527 5.163
9 -168.234 2.000 47.4 1.78800
10 41.763 3.001 23.8 1.84666
11 88.369 6.493
12 -43.051 1.800 46.6 1.81600
13 411.913 D2
14 137.043 4.617 63.3 1.61800
15 -72.111 0.100
16 62.009 2.000 31.3 1.90366
17 34.150 6.473 63.3 1.61800
18 -167.969 D3
19 -50.276 1.500 50.3 1.71999
20 34.293 4.000 28.7 1.79504
21 221.433 D4
22 0.000 2.000 Aperture stop S
23 178.755 2.000 23.8 1.84666
24 75.314 5.063 63.9 1.51680
25 -50.146 0.107
26 72.928 4.620 58.8 1.51823
27 -62.568 2.000 23.8 1.84666
28 -197.918 D5
29 42.990 4.937 29.6 1.71736
30 -55.338 1.500 42.7 1.83481
31 37.334 BF

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 148.584
Second lens group 6 -29.113
Third lens group 14 44.313
Fourth lens group 19 -63.143
5th lens group 23 59.877
6th lens group 29 -157.384

  In the fourth embodiment, the axial air distance D1 between the first lens group G1 and the second lens group G2, the axial air distance D2 between the second lens group G2 and the third lens group G3, and the third lens group G3. And the fourth lens group G4, the axial air distance D3 between the fourth lens group G4 and the fifth lens group G5, the axial air distance D4 between the aperture stop S moving together with the fourth lens group G4, the fifth lens group G5 and the sixth lens group G6. The on-axis air distance D5 and the back focus BF change during zooming. Table 11 below shows the values of the variable intervals D1 to D5 and the back focus BF at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 11)
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state f 82.0 to 200.0 to 390.0
D1 2.299 to 44.305 to 64.299
D2 24.152-13.739-2.000
D3 7.126 to 17.538 to 29.278
D4 17.672 to 6.713 to 2.399
D5 32.546 to 31.055 to 23.798
BF 58.1 to 70.5 to 82.1

  Table 12 below shows values corresponding to the conditional expressions in the fourth embodiment.

(Table 12)
(1) f1 / (− f2) = 5.1
(2) f1 / (− f4) = 2.4
(3) f1 / f5 = 2.5
(4) (−f4) /f5=1.1
(5) (−f2) /f5=0.5

  Thus, the zoom optical system ZL4 according to the fourth example satisfies all the conditional expressions (1) to (5).

  FIG. 14A shows an aberration diagram in the infinitely focused state in the wide-angle end state of this fourth embodiment, and FIG. 15A shows an aberration diagram in the infinitely focused state in the intermediate focal length state. FIG. 16A shows an aberration diagram in the infinitely focused state in the telephoto end state. FIG. 14B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group = −0.322) is performed in the infinite focus state at the wide-angle end state in the third embodiment. FIG. 15B shows a coma aberration diagram when image blur correction (shift amount of the anti-vibration lens group = −0.480) is performed in the infinite focus state at the intermediate focal length state, and is shown at the telephoto end. FIG. 16B shows a coma aberration diagram when image blur correction (shift amount of the anti-vibration lens group = −0.626) is performed in the infinite focus state in the state. As is apparent from the respective aberration diagrams, in the fourth example, various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and it can be seen that the imaging performance is excellent.

ZL (ZL1 to ZL4) Variable magnification optical system G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group G5 Fifth lens group S Aperture stop 1 Camera (optical device)

Claims (13)

From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
A fifth lens group having a positive refractive power,
During zooming, the second lens group is fixed with respect to the image plane,
A variable magnification optical system characterized by satisfying the following condition:
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) <3.0
1.9 <f1 / f5 ≦ 2.7
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
A fifth lens group having a positive refractive power,
During zooming, the second lens group is fixed with respect to the image plane,
A variable magnification optical system characterized by satisfying the following condition:
2.0 <f1 / (− f2) ≦ 5.1
1.8 ≦ f1 / (− f4) ≦ 2.4
1.9 <f1 / f5 <3.2
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
A fifth lens group having a positive refractive power,
During zooming, the second lens group is fixed with respect to the image plane,
A variable magnification optical system characterized by satisfying the following condition:
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) ≦ 2.4
1.9 <f1 / f5 <3.2
1.1 ≦ (−f4) /f5≦1.4
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group 3. The variable magnification optical system according to claim 1, wherein a condition of the following formula is satisfied.
0.8 <(− f4) / f5 <1.8
However,
f4: focal length of the fourth lens group f5: focal length of the fifth lens group The zoom lens system according to any one of claims 1 to 3, wherein a condition of the following formula is satisfied.
0.3 <(− f2) / f5 <0.8
However,
f2: Focal length of the second lens group f5: Focal length of the fifth lens group   6. The variable magnification optical system according to claim 1, further comprising an aperture stop closer to the image side than the second lens group. 7. The variable magnification optical system according to claim 6 , wherein the aperture stop is disposed between the third lens group and the fifth lens group.   The variable power optical system according to claim 1, wherein at the time of focusing, at least a part of the third lens group is moved along the optical axis.   The variable power optical system according to any one of claims 1 to 8, wherein at least a part of the fifth lens group is moved from the second lens group so as to include a component in a direction orthogonal to the optical axis. system.   The variable power optical system according to any one of claims 1 to 9, wherein at least a part of the second lens group is moved so as to include a component in a direction orthogonal to an optical axis.   The variable power optical system according to claim 1, wherein all lens surfaces are spherical surfaces.   An optical apparatus comprising the variable magnification optical system according to claim 1, wherein an object image is formed on a predetermined image plane. In order from the object side, 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 fourth lens having a negative refractive power A variable magnification optical system having a group and a fifth lens group having a positive refractive power,
During zooming, the second lens group is disposed so as to be fixed with respect to the image plane,
A method of manufacturing a variable magnification optical system, wherein the zoom lens is disposed so as to satisfy the condition of the following formula.
2.0 <f1 / (− f2) ≦ 5.1
1.3 <f1 / (− f4) <3.0
1.9 <f1 / f5 ≦ 2.7
However,
f1: focal length of the first lens group f2: focal length of the second lens group f4: focal length of the fourth lens group f5: focal length of the fifth lens group

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