JP2011175185A - Zooming optical system, optical apparatus and method of manufacturing zooming optical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zooming optical system achieving favorable optical performance by sufficiently correcting chromatic aberration, to provide an optical apparatus, and to provide a method of manufacturing a zooming optical system. <P>SOLUTION: The zooming optical system includes at least a first lens group G1 to a sixth lens group G6, which are disposed in order from an object side, wherein the third lens group G3 has positive refractive power, and the first lens group G1 has at least two cemented lenses (in Fig.1, cemented lenses formed by the respective combinations: L11, L12; L14, L15 correspond thereto). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  As a method of correcting chromatic aberration, a method of combining two or more convex lenses and concave lenses is known. In addition, it is also known that when a convex lens and a concave lens are provided, by using a cemented lens, it is possible to suppress the influence of the performance deterioration with respect to decentration as compared with a case where a single lens is provided.

  By the way, the variable magnification optical system has two or more lens groups. Conventionally, an aberration correction for the entire optical system is performed by arranging a cemented lens composed of a convex lens and a concave lens as described above in each lens group constituting the variable magnification optical system, and correcting the aberration of each lens group. (For example, refer to Patent Document 1).

JP-A-10-133109

  However, the conventional variable magnification optical system has a problem that correction of chromatic aberration is not sufficient although a cemented lens is arranged in each lens group constituting the zoom lens.

  The present invention has been made in view of such a problem, and provides a variable magnification optical system, an optical apparatus, and a variable magnification optical system manufacturing method in which chromatic aberration is sufficiently corrected and good optical performance is provided. With the goal.

  In order to achieve such an object, the zoom optical system of the present invention has at least a first lens group to a sixth lens group arranged in order from the object side, and the third lens group has a positive refractive power. The first lens group has at least two cemented lenses.

  In the zoom optical system according to the present invention, it is preferable that the fourth lens group has a negative refractive power.

  In the variable magnification optical system of the present invention, it is preferable that the first lens group has a positive refractive power.

  In the zoom optical system according to the present invention, it is preferable that the second lens group has a negative refractive power.

  In the zoom optical system according to the present invention, it is preferable that the fifth lens group has a positive refractive power.

  In the zoom optical system according to the present invention, it is preferable that the sixth lens group has a negative refractive power.

  In the zoom optical system according to the present invention, when the Abbe number of the convex lens constituting the cemented lens of the first lens group is νp and the Abbe number of the concave lens is νn, at least two of the cemented lenses are: It is preferable to satisfy the condition of the formula 35.0 <νp−νn.

  In the zoom optical system of the present invention, when the refractive index of the convex lens constituting the cemented lens of the first lens group is np and the refractive index of the concave lens is nn, at least two of the cemented lenses are: It is preferable to satisfy the condition of formula 0.2 <nn-np.

  In the zoom optical system according to the present invention, it is preferable that each of the first to sixth lens groups has a cemented lens.

  In the zoom optical system of the present invention, it is preferable that any one of the cemented lenses is a focusing group.

  In the zoom optical system according to the present invention, it is preferable that the focusing group is the cemented lens positioned closest to the image side of the first lens group.

  In the zoom optical system according to the present invention, it is preferable that an aperture stop is provided and the aperture stop is fixed with respect to the image plane when zooming from the wide-angle end state to the telephoto end state.

  In the zoom optical system of the present invention, it is preferable that the aperture stop has an aperture stop, and the aperture diameter of the aperture stop is constant when zooming from the wide-angle end state to the telephoto end state.

  Further, an optical apparatus of the present invention has any one of the above variable magnification optical systems.

  Further, the present invention is a method for manufacturing a variable magnification optical system having at least a first lens group to a sixth lens group arranged in order from the object side, wherein the third lens group has a positive refractive power, Each lens is incorporated in the lens barrel so that the first lens group has at least two cemented lenses, and various operations are confirmed.

  According to the present invention, since the at least two cemented lenses are arranged in the first lens group in which the occurrence of chromatic aberration is large, the chromatic aberration can be sufficiently corrected, and the variable magnification optical system and the optical have good optical performance. An apparatus and a method for manufacturing a variable magnification optical system can be provided.

It is a figure which shows the structure and zoom locus | trajectory of this variable magnification optical system which concern on 1st Example. FIG. 6 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 1 when focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . FIG. 4 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the first example, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 6 is a diagram illustrating various aberrations when the zooming optical system according to Example 1 is in focus at short distances (total imaging distance R = 1.8 m), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this zoom optical system which concern on 2nd Example. FIG. 6 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 2 when focusing at infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . FIG. 6 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of a variable magnification optical system according to the second example, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 7A is a diagram illustrating various aberrations when the zooming optical system according to Example 2 is focused at a short distance (shooting distance R = 1.8 m of the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this zoom optical system which concern on 3rd Example. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 3 when focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . FIG. 7 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of a variable magnification optical system according to the third example, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 6A is a diagram illustrating various aberrations of the zoom optical system according to the third example when focusing at short distance (total imaging distance R = 1.8 m), where (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this zoom optical system which concern on 4th Example. FIG. 10 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 4 when focusing at infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . FIG. 6 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of a variable magnification optical system according to Example 4, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 11 is a diagram illustrating various aberrations of the zoom optical system according to Example 4 when focusing at close distance (shooting distance R = 1.8 m for the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this variable magnification optical system which concern on 5th Example. FIG. 10 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 5 when focusing at infinity, where (a) shows the wide-angle end state, (b) shows the intermediate focal length state, and (c) shows the telephoto end state. . FIG. 10 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of a variable magnification optical system according to Example 5, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 10 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 5 when focusing at short distance (the entire system photographing distance R = 1.8 m), where (a) is a wide-angle end state and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this variable magnification optical system which concern on 6th Example. FIG. 10 is various aberration diagrams of the zoom optical system according to Example 6 at the time of focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . It is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to Example 6, wherein (a) shows the wide-angle end state and (b) shows the telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 6 when focusing at short distance (shooting distance R = 1.8 m for the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this zoom optical system which concern on 7th Example. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 7 at the time of focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . FIG. 10 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of a variable magnification optical system according to Example 7, wherein (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 7 when focusing at short distance (shooting distance R = 1.8 m for the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this variable magnification optical system which concern on an 8th Example. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 8 at the time of focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . It is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to Example 8, wherein (a) shows the wide-angle end state and (b) shows the telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 8 when focusing at short distance (shooting distance R = 1.8 m for the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a figure which shows the structure and zoom locus | trajectory of this variable magnification optical system which concern on a 9th Example. FIG. 11A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 9 at the time of focusing on infinity, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows a telephoto end state. . It is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to Example 9, where (a) shows a wide-angle end state and (b) shows a telephoto end state. FIG. 11A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 9 when focusing at close distance (shooting distance R = 1.8 m for the entire system), (a) is a wide-angle end state, and (b) is an intermediate focal length. The state (c) shows the telephoto end state. It is a schematic sectional view of a digital single-lens reflex camera CAM provided with a variable magnification optical system having the above configuration as a photographic lens. It is a flowchart for demonstrating the manufacturing method of the variable magnification optical system of the said structure.

  Hereinafter, the present embodiment will be described with reference to the drawings.

  As shown in FIG. 1, the zoom optical system according to the present embodiment includes at least a first lens group G1 to a sixth lens group G6 arranged in order from the object side, and the third lens group G3 has a positive refractive power. The first lens group G1 has at least two cemented lenses (in FIG. 1, two cemented lenses, that is, cemented lenses composed of combinations of the lenses L11, L12, L14, and L15 are applicable).

  As described above, the variable magnification optical system according to the present embodiment has a total of six or more lens groups, so that an optical system with a high zoom ratio can be easily obtained. Further, since the third lens group G3 has a positive refractive power, it is easy to correct spherical aberration. Further, by arranging at least two cemented lenses in the first lens group G1 where the occurrence of chromatic aberration is greatest, the occurrence of chromatic aberration can be suppressed very effectively. In addition, by arranging the cemented lens in this way, a decrease in performance due to decentration is reduced, and good optical performance can be realized.

  In the present embodiment, it is preferable that the fourth lens group G4 has a negative refractive power. This configuration facilitates correction of spherical aberration.

  In the present embodiment, it is preferable that the first lens group G1 has a positive refractive power. With this configuration, the overall length of the optical system can be shortened and distortion can be easily corrected.

  In the present embodiment, it is preferable that the second lens group G2 has a negative refractive power. This configuration facilitates correction of field curvature.

  In the present embodiment, it is preferable that the fifth lens group G5 has a positive refractive power. This configuration facilitates correction of field curvature.

  In the present embodiment, it is preferable that the sixth lens group G6 has a negative refractive power. This configuration facilitates correction of distortion.

  In this embodiment, when the Abbe number of the convex lens constituting the cemented lens of the first lens group G1 is νp and the Abbe number of the concave lens is νn, at least two cemented lenses have the following conditional expression (1): Is preferably satisfied.

  35.0 <νp−νn (1)

  Conditional expression (1) defines the difference between the Abbe number νp of the convex lens and the Abbe number νn of the concave lens that form the cemented lens in the first lens group G1. The variable magnification optical system according to the present embodiment can achieve good optical performance by satisfying the conditional expression (1). If the lower limit of conditional expression (1) is not reached, the difference between the Abbe numbers of the convex lens and the concave lens becomes small, and correction of axial chromatic aberration becomes difficult.

  In order to secure the effect of the present embodiment, it is desirable to set the lower limit value of conditional expression (1) to 36.0.

  In this embodiment, when the refractive index of the convex lens constituting the cemented lens of the first lens group G1 is np and the refractive index of the concave lens is nn, at least two cemented lenses have the following conditional expression (2). Is preferably satisfied.

  0.2 <nn-np (2)

  Conditional expression (2) defines the difference between the refractive index np of the convex lens and the refractive index nn of the concave lens constituting the cemented lens in the first lens group G1. The zoom optical system according to the present embodiment can achieve good optical performance by satisfying the conditional expression (2). If the lower limit of conditional expression (2) is not reached, the difference in refractive index between the convex lens and the concave lens becomes small, making it difficult to correct field curvature.

  In order to secure the effect of the present embodiment, it is desirable to set the lower limit value of conditional expression (2) to 0.25.

  In the present embodiment, it is preferable that each of the first lens group G1 to the sixth lens group G6 has a cemented lens. This configuration facilitates correction of chromatic aberration. In addition, a decrease in performance due to eccentricity is reduced, and good optical performance can be realized.

  In the present embodiment, any one of the cemented lenses is preferably set as a focusing group. With this configuration, it becomes easy to reduce the change in chromatic aberration due to focusing.

  In the present embodiment, the focusing group is a cemented lens positioned closest to the image side of the first lens group G1 (in FIG. 1, a cemented lens formed by a combination of the lenses L14 and L15 of the rear group G1R). Is preferred. With this configuration, the focusing mechanism can be simplified and the focusing speed can be increased.

  In the present embodiment, it is preferable that the aperture stop S is provided, and the aperture stop S is fixed with respect to the image plane I in the optical axis direction when zooming from the wide-angle end state to the telephoto end state. With this configuration, a mechanism for interlocking the position of the aperture stop S with zooming becomes unnecessary, and the configuration of the present optical system can be simplified.

  In the present embodiment, it is preferable that the aperture stop S is provided and the aperture diameter of the aperture stop S is constant when zooming from the wide-angle end state to the telephoto end state. With this configuration, a mechanism for interlocking the aperture diameter of the aperture stop S with zooming becomes unnecessary, and the configuration of the present optical system can be simplified.

  FIG. 37 is a schematic cross-sectional view of a digital single-lens reflex camera CAM (optical apparatus) provided with the variable magnification optical system having the above configuration as a photographic lens 1. In the digital single-lens reflex camera CAM shown in FIG. 37, light from an object (subject) (not shown) is collected by the photographing lens 1 and imaged on the focusing screen 4 via the quick return mirror 3. The light imaged on the focusing screen 4 is reflected a plurality of times in the pentaprism 5 and guided to the eyepiece lens 6. Thus, the photographer can observe the object (subject) image as an erect image through the eyepiece 6.

  Further, when a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and light of an object (subject) (not shown) condensed by the photographing lens 1 is captured on the image sensor 7. Form an image. Thereby, the light from the object (subject) is captured by the image sensor 7 and recorded as an object (subject) image in a memory (not shown). In this way, the photographer can photograph an object (subject) with the camera CAM. The camera CAM described in FIG. 37 may be one that holds the photographing lens 1 in a detachable manner or may be molded integrally with the photographing lens 1. The camera CAM may be a so-called single-lens reflex camera or a compact camera that does not have a quick return mirror or the like.

  Next, a manufacturing method of the variable magnification optical system having the above configuration will be described with reference to FIG. First, each lens (for example, the lenses L11 to L62 in FIG. 1) is assembled in a cylindrical barrel (step S1). When assembling the lenses into the lens barrel, the lenses may be incorporated into the lens barrel one by one in the order along the optical axis, or a part or all of the lenses may be integrally held by the holding member and then assembled with the lens barrel member. Good. Next, after each lens is incorporated in the lens barrel, it is confirmed whether an object image is formed in a state where each lens is incorporated in the lens barrel, that is, whether the centers of the lenses are aligned (step) S2). Subsequently, various operations of the variable magnification optical system are confirmed (step S3). As an example of various operations, a zooming operation that performs zooming from the wide-angle end state to the telephoto end state (for example, in FIG. 1, the second lens group G2, the third lens group G3, the fifth lens group G5, and the sixth lens). Group G6 moves along the optical axis direction), and a lens (for example, rear group G1R in FIG. 1) that focuses from a long distance object point to a short distance object point moves along the optical axis direction. Examples include a focus operation and a camera shake correction operation that moves at least a part of the lenses (for example, the fourth lens group G4 in FIG. 1) so as to have a component in a direction perpendicular to the optical axis. Note that the order of confirming the various operations is arbitrary.

  Hereinafter, each example according to the present embodiment will be described with reference to the drawings. Tables 1 to 9 are shown below, but these are tables of specifications in the first to ninth examples. In [Overall specifications], f represents the focal length of the entire system, FNO represents the F number, TL represents the total length of the entire system, 2ω represents the total angle of view, and Φ represents the aperture stop diameter. In [Lens data], the surface number is the order of the lens surfaces from the object side along the direction in which the light beam travels, r is the radius of curvature of each lens surface, and d is the next optical surface from each optical surface (or The distance between the surfaces on the optical axis to the image plane I), nd is the refractive index for the d-line (wavelength 587.6 nm), νd is the Abbe number for the d-line, and BF is the back focus. When the lens surface is aspherical, an asterisk is attached to the surface number, and the paraxial radius of curvature is indicated in the column of the radius of curvature r. The curvature radius “0.0000” indicates a plane or an opening. Further, the description of the refractive index “1.00000” of air is omitted. In [variable interval data], f indicates the focal length of the entire system, β indicates the lateral magnification of the entire system, and Di (where i is an integer) indicates the variable interval between the i-th surface and the (i + 1) -th surface. In [Each Group Focal Length Data], the initial surface and focal length of each group are shown. In [Conditional Expression], values corresponding to the conditional expressions (1) and (2) are shown.

In [Aspherical data], the shape of the aspherical surface shown in [Lens data] is shown by the following equation (a). That is, y is the height in the direction perpendicular to the optical axis, and S (y) is the distance (sag amount) along the optical axis from the tangent plane at the apex of the aspheric surface to the position on the aspheric surface at height y. When the radius of curvature of the reference spherical surface (paraxial radius of curvature) is r, the conic coefficient is κ, and the n-th aspherical coefficient is An, the following equation (a) is given. E-n represents ^x10 -n. For example, 1.234E-05 = 1.234 × 10 ⁻⁵ .

S (y) = (y ² / r) / {1+ (1−κ · y ² / r ² ) ^1/2 }
^{+ A4 × y 4 + A6 ×} y 6 + A8 × y 8 + A10 × y 10 ... (a)

  In the table, “mm” is generally used as the focal length f, radius of curvature r, surface interval d, and other length units. However, since the optical system can obtain the same optical performance even if it is proportionally enlarged or reduced, the unit is not limited to “mm”, and other appropriate units can be used.

  The description of the above table is the same in other examples, and the description thereof is omitted.

(First embodiment)
A first embodiment will be described with reference to FIGS. FIG. 1 shows a lens configuration diagram and zoom locus of the first embodiment. As shown in FIG. 1, the variable magnification optical system according to the first example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive lens having a convex surface facing the object side. A meniscus lens L13. The rear group G1R has a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a biconvex positive lens L15, which are arranged in order from the object side along the optical axis.

  The second lens group G2 includes a cemented lens of a biconvex positive lens L21 and a biconcave negative lens L22, a biconcave negative lens L23, and the object side, which are arranged in order from the object side along the optical axis. The lens has a cemented lens with a positive meniscus lens L24 having a convex surface and a negative biconcave lens L25.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32, and a biconcave negative lens L33, And a positive lens L34 having a convex shape.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L41 having a concave surface directed toward the object side and a biconcave negative lens L42, which are arranged in order from the object side along the optical axis.

  The fifth lens group G5 is composed of a biconvex positive lens L51 arranged in order from the object side along the optical axis, a negative meniscus lens L52 having a convex surface directed toward the object side, and a biconvex positive lens L53. And a lens.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the image plane correction at the time of blurring is performed by shifting the cemented lens of the lens L41 and the lens L42 in the fourth lens group G4 in the direction orthogonal to the optical axis. Done. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, the blur correction coefficient K is −2.100 and the focal length is 81.6 (mm). Therefore, the lens L41 and the lens for correcting the rotational blur of 0.350 ° The amount of movement of the cemented lens with L42 is -0.237 (mm). In the telephoto end state of the present embodiment, since the shake correction coefficient K is −2.131 and the focal length is 392 (mm), the lens L41 and the lens L42 for correcting the rotational shake of 0.160 ° The amount of movement of the cemented lens is -0.512 (mm).

  Table 1 below lists values of various specifications of the variable magnification optical system according to the first example. The surface numbers 1 to 35 shown in Table 1 correspond to the surfaces 1 to 35 shown in FIG.

(Table 1)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6 to 5.7 to 5.8
TL 256.6 to 256.6 to 256.6
2ω 29.7-12.0-6.1
Φ 25.0 to 22.0 to 19.2
[Lens data]
Surface number r d nd νd
1 179.4338 2.5 1.80610 40.9
2 89.5051 10.0 1.49782 82.5
3 -446.6400 0.1
4 110.9379 5.5 1.49782 82.5
5 234.3333 D5
6 92.3090 3.3 1.78472 25.7
7 70.7791 8.4 1.48749 70.5
8 -25475.8490 D8
9 1009.0937 4.8 1.80518 25.4
10 -89.8865 1.8 1.77250 49.6
11 65.0749 4.0
12 -181.3777 1.7 1.77250 49.6
13 36.8152 6.0 1.78472 25.7
14 226.5434 4.2
15 -66.7353 2.0 1.62299 58.2
16 368.8553 D16
17 66.6763 5.0 1.56384 60.7
18 -110.2881 0.1
19 44.7900 6.2 1.48749 70.5
20 -80.0154 2.0 1.75520 27.5
21 132.4317 0.1
22 115.9136 5.0 1.48749 70.5
23 -100.6044 D23
24 -47.5857 4.0 1.80809 22.8
25 -36.6835 1.8 1.72916 54.7
26 173.4251 2.3
27 0.0000 D27 (Aperture stop S)
28 470.5912 4.0 1.48749 70.5
29 -41.7072 0.1
30 51.3411 1.2 1.80 100 35.0
31 34.1887 5.0 1.48749 70.5
32 -432.2669 D32
33 -31.9511 1.1 1.78800 47.4
34 32.8230 4.5 1.67270 32.1
35 -81.3002 BF
[Variable interval data]
Infinity Near distance Wide angle end Medium telephoto end Wide angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.06 -0.14 -0.26
D0 0 0 0 1543.41 1543.41 1543.41
D5 14.5310 14.5310 14.5310 2.0000 2.0000 2.0000
D8 2.0014 30.5817 38.9987 14.5323 43.1127 51.5297
D16 54.2333 25.8372 2.0033 54.2333 25.8372 2.0033
D23 2.8656 2.6813 18.0983 2.8656 2.6813 18.0983
D27 10.0853 3.9231 2.0001 10.0853 3.9231 2.0001
D32 20.4765 22.0533 6.6083 20.4765 22.0533 6.6083
BF 55.7244 60.3097 77.6778 55.7244 60.3097 77.6778
[Each group focal length data]
Group number Group first surface Group focal length G1 1 101.2181
G2 9 -31.5893
G3 17 42.3904
G4 24 -52.1478
G5 28 49.2644
G6 33 -52.0818
[Conditional expression]
Conditional expression (1)
νp−νn = 41.6 (L11, L12), 44.8 (L14, L15)
Conditional expression (2)
nn-np = 0.30828 (L11, L12), 0.29723 (L14, L15)

  From the table of specifications shown in Table 1, it can be seen that the above-described conditional expressions (1) and (2) are satisfied in the variable magnification optical system according to this example.

  2A and 2B are graphs showing various aberrations of the variable magnification optical system according to the first example when focusing on infinity, where FIG. 2A is a wide-angle end state, FIG. 2B is an intermediate focal length state, and FIG. 2C is a telephoto end. Each state is shown. FIG. 3 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the first example. (A) is a wide-angle end state, and (b) is a telephoto end state. Each is shown. 4A and 4B are graphs showing various aberrations when the zooming optical system according to Example 1 is focused at a short distance (the imaging distance R of the entire system is R = 1.8 m). FIG. 4A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  In each aberration diagram, FNO indicates an F number, and Y indicates an image height (unit: mm). 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 coma diagram shows the value of each image height. Further, d indicates various aberrations with respect to the d-line (wavelength 587.6 nm), g indicates various aberrations with respect to the g-line (wavelength 435.8 nm), and those not described indicate various aberrations with respect to the d-line. In the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. The explanation of the above aberration diagrams is the same in the other examples, and the explanation is omitted.

  As is apparent from the respective aberration diagrams, in the first example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Second embodiment)
A second embodiment will be described with reference to FIGS. FIG. 5 shows a lens configuration diagram and zoom locus of the second embodiment. As shown in FIG. 5, the variable magnification optical system according to the second example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive lens having a convex surface facing the object side. A meniscus lens L13. The rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L21 having a convex surface facing the object side and a biconcave negative lens L22, and a biconcave negative lens. It has a cemented lens of L23 and a positive meniscus lens L24 having a convex surface facing the object side, and a biconcave negative lens L25.

  The third lens group G3 is formed by joining a biconvex positive lens L31, a biconvex positive lens L32, and a negative meniscus lens L33 having a convex surface toward the object side, which are arranged in order from the object side along the optical axis. And a lens.

  The fourth lens group G4 includes a cemented lens L42, which is arranged in order from the object side along the optical axis, and includes a positive meniscus lens L41 having a concave surface directed toward the object side and a biconcave negative lens.

  The fifth lens group G5 is composed of a biconvex positive lens L51 arranged in order from the object side along the optical axis, a negative meniscus lens L52 having a convex surface directed toward the object side, and a biconvex positive lens L53. And a lens.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the third lens group G3 and the fourth lens group G4, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the image plane correction at the time of blurring is performed by shifting the cemented lens of the lens L41 and the lens L42 in the fourth lens group G4 in the direction orthogonal to the optical axis. Done. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, the blur correction coefficient K is −1.882 and the focal length is 81.6 (mm). Therefore, the lens L41 and the lens for correcting the rotational blur of 0.350 ° The amount of movement of the cemented lens with L42 is -0.265 (mm). In the telephoto end state of the present embodiment, the blur correction coefficient K is −1.978 and the focal length is 392 (mm). Therefore, the lens L41 and the lens L42 for correcting the rotational blur of 0.160 ° The amount of movement of the cemented lens is -0.552 (mm).

  Table 2 below shows values of various specifications of the variable magnification optical system according to the second example. The surface numbers 1 to 33 shown in Table 2 correspond to the surfaces 1 to 33 shown in FIG.

(Table 2)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6 to 5.6 to 5.8
TL 257.8-257.8-257.8
2ω 30.1-12.2-6.2
Φ 24.2 to 22.0 to 20.4
[Lens data]
Surface number r d nd νd
1 151.4355 2.5 1.80 400 46.6
2 80.9045 10.0 1.49782 82.5
3 -660.7905 0.1
4 103.7009 5.5 1.49782 82.5
5 177.6269 D5
6 97.7191 3.3 1.84666 23.8
7 70.3201 8.4 1.58913 61.2
8 2650.6755 D8
9 2332.5539 4.8 1.80809 22.8
10 -95.5599 1.8 1.80440 39.6
11 66.9490 4.0
12 -266.6149 1.7 1.77250 49.6
13 29.9961 7.0 1.78472 25.7
14 356.0090 4.2
15 -70.4727 2.0 1.74400 44.8
16 286.5097 D16
17 47.3805 7.9 1.51680 64.1
18 -59.1743 0.2
19 56.3209 7.7 1.48749 70.5
20 -40.0873 2.0 1.80518 25.4
21 -168.1697 D21
22 0.0000 3.0 (Aperture stop S)
23 -46.9340 4.0 1.84666 23.8
24 -29.2304 1.8 1.74100 52.7
25 200.3114 D25
26 490.9425 4.0 1.48749 70.5
27 -67.9550 0.1
28 60.1092 1.2 1.84666 23.8
29 36.2041 6.0 1.48749 70.5
30 -53.9995 D30
31 -31.7589 1.1 1.75500 52.3
32 46.0734 3.7 1.84666 23.8
33 -8940.2754 BF
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.06 -0.14 -0.27
D0 0 0 0 1542.24 1542.24 1542.24
D5 13.4120 13.4120 13.4120 2.0000 2.0000 2.0000
D8 2.0000 28.5031 35.0926 13.4120 39.9151 46.5046
D16 52.6489 25.0338 2.0038 52.6489 25.0338 2.0038
D21 2.0000 3.1120 19.5525 2.0000 3.1120 19.5525
D25 20.1010 9.8885 9.1172 20.1010 9.8885 9.1172
D30 14.5969 14.6003 2.8343 14.5969 14.6003 2.8343
BF 55.0000 65.2091 77.7465 55.0000 65.2092 77.7464
[Each group focal length data]
Group number Group first surface Group focal length G1 1 114.7469
G2 9 -30.9191
G3 17 40.5507
G4 23 -55.0000
G5 26 47.9530
G6 31 -46.1818
[Conditional expression]
Conditional expression (1)
νp−νn = 35.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.30618 (L11, L12), 0.25753 (L14, L15)

  From the table of specifications shown in Table 2, it can be seen that the variable magnification optical system according to the present example satisfies the above conditional expressions (1) and (2).

  6A and 6B are graphs showing various aberrations of the variable magnification optical system according to Example 2 during focusing at infinity, where FIG. 6A is a wide-angle end state, FIG. 6B is an intermediate focal length state, and FIG. 6C is a telephoto end. Each state is shown. FIGS. 7A and 7B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the second example. FIG. 7A illustrates a wide-angle end state, and FIG. 7B illustrates a telephoto end state. Each is shown. FIGS. 8A and 8B are graphs showing various aberrations of the variable magnification optical system according to Example 2 when focusing at a short distance (shooting distance R = 1.8 m for the entire system). FIG. 8A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the second example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Third embodiment)
A third embodiment will be described using FIGS. 9 to 12 and Table 3. FIG. FIG. 9 shows a lens configuration diagram and zoom locus of the third embodiment. As shown in FIG. 9, the variable magnification optical system according to the third example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive lens having a convex surface facing the object side. A meniscus lens L13. The rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 is formed by joining a biconvex positive lens L31, a biconvex positive lens L32, and a negative meniscus lens L33 having a concave surface facing the object side, which are arranged in order from the object side along the optical axis. A lens and a positive meniscus lens L34 having a convex surface facing the object side.

  The fourth lens group G4 includes a negative meniscus lens L41 having a convex surface directed toward the object side, a negative meniscus lens L42 having a biconcave shape, and a positive meniscus lens having a convex surface directed toward the object side, which are arranged in order from the object side along the optical axis. And a cemented lens with L43.

  The fifth lens group G5 is arranged in order from the object side along the optical axis. The positive meniscus lens L51 has a convex surface facing the object side, the negative meniscus lens L52 has a convex surface facing the object side, and a biconvex positive lens. And a cemented lens with L53.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction orthogonal to the optical axis, so that a blur occurs. Image plane correction is performed. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, since the shake correction coefficient K is −1.658 and the focal length is 81.6 (mm), a lens L41 for correcting a rotational shake of 0.350 °, The amount of movement of the cemented lens between the lens L42 and the lens L43 is -0.301 (mm). In the telephoto end state of this embodiment, the blur correction coefficient K is −1.900 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The amount of movement of the cemented lens between the lens L43 and the lens L43 is -0.575 (mm).

  Table 3 below lists values of various specifications of the variable magnification optical system according to the third example. The surface numbers 1 to 36 shown in Table 3 correspond to the surfaces 1 to 36 shown in FIG.

(Table 3)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6 to 5.6 to 5.8
TL 270.0-270.0-270.0
2ω 29.0-11.9-6.1
Φ 23.6 to 21.6 to 21.2
[Lens data]
Surface number r d nd νd
1 176.1767 3.1 1.79952 42.3
2 83.7010 8.5 1.49782 82.6
3 -8152.7306 0.1
4 90.6185 7.8 1.49782 82.6
5 28397.5490 D5
6 92.6435 2.8 1.84666 23.8
7 69.3835 9.5 1.58913 61.2
8 274.2400 D8
9 185.3195 1.9 1.81600 46.6
10 40.1404 4.6
11 -102.8423 1.9 1.75 500 52.3
12 40.3224 6.1 1.80809 22.8
13 -266.3547 2.3
14 -61.0923 1.9 1.81600 46.6
15 554.0525 D15
16 585.3312 4.2 1.69680 55.5
17 -80.8093 0.2
18 55.2370 7.4 1.60 300 65.5
19 -84.0213 2.3 1.84666 23.8
20 -1893.0691 0.1
21 60.6406 2.9 1.58913 61.2
22 147.6093 D22
23 81.2576 2.5 1.75520 27.5
24 46.0346 3.3
25 -103.3563 2.3 1.74400 44.8
26 42.0032 2.9 1.84666 23.8
27 245.2611 4.1
28 0.0000 D28 (Aperture stop S)
29 37.4902 3.4 1.48749 70.5
30 128.4907 12.2
31 62.3471 1.6 1.75520 27.5
32 23.3504 5.8 1.48749 70.5
33 -62.7817 D33
34 -32.6512 1.4 1.79500 45.3
35 35.0907 5.0 1.75520 27.5
36 -70.7458 BF
[Variable interval data]
Infinity Near distance Wide angle end Medium telephoto end Wide angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.06 -0.14 -0.27
D0 0 0 0 1530.00 1530.00 1530.00
D5 15.0817 15.0817 15.0817 2.0000 2.0000 2.0000
D8 2.0000 21.1264 29.0195 15.0817 34.2081 42.1012
D15 50.1722 23.1721 2.0000 50.1722 23.1721 2.0000
D22 2.0000 9.8738 23.1528 2.0000 9.8738 23.1528
D28 22.6871 9.4683 2.0000 22.6871 9.4683 2.0000
D33 10.9546 9.0485 3.2613 10.9546 9.0485 3.2613
BF 55.0000 70.1250 83.3805 55.0000 70.1250 83.3805
[Each group focal length data]
Group number Group first surface Group focal length G1 1 105.2506
G2 9 -27.2581
G3 16 42.3041
G4 23 -65.5390
G5 29 61.4146
G6 34 -72.2532
[Conditional expression]
Conditional expression (1)
νp−νn = 40.3 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.30170 (L11, L12), 0.25753 (L14, L15)

  It can be seen from the table of specifications shown in Table 3 that the conditional expressions (1) and (2) are satisfied in the variable magnification optical system according to this example.

  FIGS. 10A and 10B are graphs showing various aberrations of the variable magnification optical system according to the third example when focusing on infinity. FIG. 10A is a wide-angle end state, FIG. 10B is an intermediate focal length state, and FIG. Each state is shown. FIGS. 11A and 11B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the third example. FIG. 11A shows a wide-angle end state, and FIG. 11B shows a telephoto end state. Each is shown. FIGS. 12A and 12B are graphs showing various aberrations of the variable magnification optical system according to the third example at the time of focusing at a short distance (the photographing distance R of the entire system is R = 1.8 m), where FIG. 12A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the third example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. 13 to 16 and Table 4. FIG. FIG. 13 shows a lens configuration diagram and zoom locus of the fourth example. As shown in FIG. 13, the variable magnification optical system according to the fourth example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive lens having a convex surface facing the object side. A meniscus lens L13. The rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32, and a biconcave negative lens L33, And a positive lens L34 having a convex shape.

  The fourth lens group G4 includes a cemented lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface directed toward the object side, which are arranged in order from the object side along the optical axis.

  The fifth lens group G5 is composed of a biconvex positive lens L51 arranged in order from the object side along the optical axis, a negative meniscus lens L52 having a convex surface directed toward the object side, and a biconvex positive lens L53. And a lens.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the image plane correction at the time of blurring is performed by shifting the cemented lens of the lens L41 and the lens L42 in the fourth lens group G4 in the direction orthogonal to the optical axis. Done. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, the blur correction coefficient K is −1.918 and the focal length is 81.6 (mm). Therefore, the lens L41 and the lens for correcting the rotational blur of 0.350 ° The amount of movement of the cemented lens with L42 is -0.280 (mm). In the telephoto end state of the present embodiment, the blur correction coefficient K is −2.100, and the focal length is 392 (mm). Therefore, the lens L41 and the lens L42 for correcting the rotational blur of 0.160 ° The amount of movement of the cemented lens is -0.520 (mm).

  Table 4 below lists values of various specifications of the variable magnification optical system according to the fourth example. The surface numbers 1 to 34 shown in Table 4 correspond to the surfaces 1 to 34 shown in FIG.

(Table 4)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6 to 5.6 to 5.8
TL 258.0 to 258.0 to 258.0
2ω 29.9-12.1-6.2
Φ 23.8-21.4-19.4
[Lens data]
Surface number r d nd νd
1 126.2852 3.3 1.79952 42.3
2 79.6260 10.6 1.49782 82.5
3 -541.0387 0.1
4 94.0460 3.7 1.49782 82.5
5 141.4849 D5
6 84.8758 3.0 1.84666 23.8
7 57.9320 10.0 1.58913 61.2
8 885.9292 D8
9 862.8124 2.0 1.79500 45.3
10 48.1688 4.0
11 -176.6867 2.0 1.74 100 52.7
12 34.0469 6.7 1.84666 23.8
13 -305.8080 4.2
14 -74.2246 2.0 1.81600 46.6
15 181.5933 D15
16 111.3175 3.9 1.62299 58.2
17 -203.7316 0.1
18 52.5848 7.0 1.48749 70.5
19 -64.1320 2.0 1.75520 27.5
20 289.7602 0.5
21 54.1239 4.8 1.48749 70.5
22 -195.6914 D22
23 -89.0244 1.8 1.60311 60.7
24 24.8548 3.0 1.70154 41.2
25 45.6872 7.6
26 0.0000 D26 (Aperture stop S)
27 64.6827 3.5 1.48749 70.5
28 -104.5194 0.1
29 51.5479 1.5 1.83400 37.2
30 32.0407 4.7 1.48749 70.5
31 -120.2933 D31
32 -35.1150 1.5 1.80 400 46.6
33 45.0203 4.0 1.72825 28.5
34 -135.5442 BF
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1542.00 1542.00 1542.00
D5 11.6537 11.6537 11.6537 2.0000 2.0000 2.0000
D8 2.0226 20.7147 28.1109 11.6763 30.3684 37.7646
D15 51.8351 24.3452 2.0011 51.8351 24.3452 2.0011
D22 2.4769 11.2746 26.2226 2.4769 11.2746 26.2226
D26 16.2448 8.2055 2.0003 16.2448 8.2055 2.0003
D31 21.1668 15.7916 3.0201 21.1668 15.7916 3.0201
BF 55.0000 68.4145 87.3912 55.0000 68.4145 87.3912
[Each group focal length data]
Group number Group first surface Group focal length G1 1 102.5630
G2 9 -31.0371
G3 16 46.2095
G4 23 -54.5500
G5 27 46.9800
G6 32 -53.1076
[Conditional expression]
Conditional expression (1)
νp−νn = 40.2 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.30170 (L11, L12), 0.25753 (L14, L15)

  From the table of specifications shown in Table 4, it can be seen that the variable magnification optical system according to the present example satisfies the conditional expressions (1) and (2).

  FIGS. 14A and 14B are graphs showing various aberrations of the variable magnification optical system according to Example 4 when focusing at infinity, where FIG. 14A is a wide-angle end state, FIG. 14B is an intermediate focal length state, and FIG. 14C is a telephoto end. Each state is shown. FIGS. 15A and 15B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the fourth example. FIG. 15A shows a wide-angle end state, and FIG. 15B shows a telephoto end state. Each is shown. FIGS. 16A and 16B are graphs showing various aberrations of the zoom optical system according to Example 4 when focusing at a short distance (total imaging distance R = 1.8 m), in which FIG. 16A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from each aberration diagram, in the fourth example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(5th Example)
The fifth embodiment will be described with reference to FIGS. 17 to 20 and Table 5. FIG. FIG. 17 shows a lens configuration diagram and zoom locus of the fifth example. As shown in FIG. 17, the variable magnification optical system according to the fifth example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a positive lens L12 having a convex surface facing the object side, and a biconvex positive lens. And a lens L13. The rear group G1R includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 includes a biconvex positive lens L31, and a cemented lens of a biconvex positive lens L32 and a biconcave negative lens L33, which are arranged in order from the object side along the optical axis. .

  The fourth lens group G4 is arranged in order from the object side along the optical axis, and includes a negative meniscus lens L41 having a convex surface directed toward the object side, a positive lens L42 having a concave surface directed toward the object side, and a biconcave negative lens L43. And a cemented lens.

  The fifth lens group G5 is arranged in order from the object side along the optical axis. The positive meniscus lens L51 has a convex surface facing the object side, the negative meniscus lens L52 has a convex surface facing the object side, and a biconvex positive lens. And a cemented lens with L53.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction orthogonal to the optical axis, thereby generating an image at the time of occurrence of blurring. Surface correction is performed. A lens having a focal length f of the entire system and a blur correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens unit for blur correction in the optical axis direction) at an angle θ
In order to correct the rotational shake, the lens group for shake correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, the blur correction coefficient K is −1.432, and the focal length is 81.6 (mm). Therefore, a lens L41 for correcting a rotational blur of 0.350 °, The amount of movement of the cemented lens between the lens L42 and the lens L43 is -0.348 (mm). In the telephoto end state of this embodiment, the blur correction coefficient K is −1.900 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The amount of movement of the cemented lens between the lens L43 and the lens L43 is -0.575 (mm).

  Table 5 below shows values of various specifications of the variable magnification optical system according to the fifth example. The surface numbers 1 to 34 shown in Table 5 correspond to the surfaces 1 to 34 shown in FIG.

(Table 5)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6-5.3-5.8
TL 260.0 to 260.0 to 260.0
2ω 29.5-12.0-6.2
Φ 20.3 〜 20.7 〜 21.5
[Lens data]
Surface number r d nd νd
1 189.2251 3.6 1.83481 42.7
2 85.1335 8.2 1.49782 82.6
3 1015.6177 0.1
4 108.8270 8.1 1.49782 82.6
5 -537.5395 D5
6 88.9642 3.2 1.84666 23.8
7 66.2716 8.1 1.58913 61.2
8 588.7120 D8
* 9 1000.0000 2.0 1.79050 45.0
10 92.9093 4.1
11 -84.2744 2.0 1.75 500 52.3
12 41.0861 5.8 1.80809 22.8
13 -176.5623 1.4
14 -68.0933 1.7 1.80 400 46.6
15 87.0261 D15
16 91.3387 4.8 1.79500 45.3
17 -88.6741 0.1
18 56.2501 7.1 1.51680 64.1
19 -56.2501 1.8 1.84666 23.8
20 33.1404 D20
21 105.8589 1.3 1.84666 23.8
22 69.0399 1.8
23 -73.2131 2.8 1.80518 25.4
24 -26.8863 1.3 1.72000 43.7
25 211.2287 4.1
26 0.0000 D26 (Aperture stop S)
27 27.6410 3.5 1.51680 64.1
28 125.3545 7.5
29 40.6460 1.3 1.84666 23.8
30 19.0178 12.9 1.51742 52.3
31 -58.3678 D31
32 -25.9539 1.3 1.80 400 46.6
33 25.9539 5.8 1.78472 25.7
34 -113.2339 BF
[Aspherical data]
9th surface κ = 1.0000, A4 = 1.4266E-06, A6 = 4.5344E-10, A8 = 3.7386E-13, A10 = 4.6201E-16
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1540.00 1540.00 1540.00
D5 11.8592 11.8592 11.8592 2.0153 2.0153 2.0154
D8 2.2708 21.6597 28.5685 12.1146 31.5035 38.4123
D15 49.0856 22.5061 2.0000 49.0856 22.5061 2.0000
D20 12.3526 19.5431 33.1404 12.3526 19.5431 33.1404
D26 27.1659 13.9317 2.0000 27.1659 13.9317 2.0000
D31 5.6235 5.1024 3.1982 5.6235 5.1024 3.1982
BF 45.9240 59.6793 73.5152 45.9240 59.6793 73.5153
[Each group focal length data]
Group number Group first surface Group focal length G1 1 102.4814
G2 9 -29.2207
G3 16 46.7169
G4 21 -64.5468
G5 27 41.5607
G6 32 -41.7749
[Conditional expression]
Conditional expression (1)
νp−νn = 39.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.33699 (L11, L12), 0.25753 (L14, L15)

  From the table of specifications shown in Table 5, it is understood that the variable magnification optical system according to the present example satisfies the conditional expressions (1) and (2).

  18A and 18B are graphs showing various aberrations of the variable magnification optical system according to Example 5 when focusing on infinity, where FIG. 18A is a wide-angle end state, FIG. 18B is an intermediate focal length state, and FIG. 18C is a telephoto end. Each state is shown. FIGS. 19A and 19B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing at infinity of the variable magnification optical system according to the fifth example. FIG. 19A shows a wide-angle end state, and FIG. 19B shows a telephoto end state. Each is shown. 20A and 20B are graphs showing various aberrations of the zoom optical system according to Example 5 when focusing at close distance (imaging distance R = 1.8 m for the entire system), where FIG. 20A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from each aberration diagram, in the fifth example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Sixth embodiment)
A sixth embodiment will be described with reference to FIGS. 21 to 24 and Table 6. FIG. FIG. 21 shows a lens configuration diagram and zoom locus of the sixth example. As shown in FIG. 21, the variable magnification optical system according to the sixth example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of 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 rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32, and a biconcave negative lens L33, an object And a positive meniscus lens L34 having a convex surface on the side.

  The fourth lens group G4 includes a negative meniscus lens L41 having a convex surface directed toward the object side, a positive meniscus lens L42 having a concave surface directed toward the object side, and a biconcave negative lens arranged in order from the object side along the optical axis. And a cemented lens with L43.

  The fifth lens group G5 is composed of a biconvex positive lens L51, a biconvex positive lens L52, and a negative meniscus lens L53 having a concave surface facing the object, which are arranged in order from the object side along the optical axis. And a lens.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction orthogonal to the optical axis, so that a blur occurs. Image plane correction is performed. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, since the shake correction coefficient K is −1.538 and the focal length is 81.6 (mm), a lens L41 for correcting a rotational shake of 0.350 °, The amount of movement of the cemented lens between the lens L42 and the lens L43 is -0.324 (mm). In the telephoto end state of this embodiment, the blur correction coefficient K is −1.900 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The amount of movement of the cemented lens between the lens L43 and the lens L43 is -0.575 (mm).

  Table 6 below shows values of various specifications of the variable magnification optical system according to the sixth example. The surface numbers 1 to 36 shown in Table 6 correspond to the surfaces 1 to 36 shown in FIG.

(Table 6)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.3
FNO 4.6-5.2-5.8
TL 260.0 to 260.0 to 260.0
2ω 29.2-12.0-6.2
Φ 19.8 〜 19.8 〜 19.8
[Lens data]
Surface number r d nd νd
1 141.4367 3.6 1.83481 42.7
2 77.5835 9.1 1.49782 82.6
3 1217.2505 0.1
4 98.6776 7.2 1.49782 82.6
5 1816.6879 D5
6 86.8450 3.2 1.84666 23.8
7 61.4144 8.6 1.58913 61.2
8 586.4327 D8
* 9 1000.0000 2.0 1.79050 45.0
10 78.7985 3.8
11 -115.6092 2.0 1.75500 52.3
12 34.4861 6.2 1.80809 22.8
13 -217.3620 1.5
14 -71.6505 1.7 1.81600 46.6
15 63.5472 D15
16 135.7647 4.1 1.74400 44.8
17 -89.5215 0.2
18 60.1055 6.6 1.61800 63.4
19 -61.6315 1.8 1.84666 23.8
20 587.4989 0.1
21 54.0842 2.9 1.48749 70.5
22 108.0347 D22
23 78.4319 1.3 1.84666 23.8
24 51.4225 2.8
25 -89.2197 3.2 1.80518 25.4
26 -26.3728 1.3 1.74400 44.8
27 162.3606 4.1
28 0.0000 D28 (Aperture stop S)
29 57.0723 4.1 1.48749 70.5
30 -47.3394 0.8
31 135.0079 7.6 1.51742 52.3
32 -31.0619 1.7 1.80518 25.4
33 -114.3448 D33
34 -46.0933 1.3 1.81600 46.6
35 31.0312 4.4 1.75520 27.5
36 -181.0133 BF
[Aspherical data]
9th surface κ = 1.0000, A4 = 1.7255E-06, A6 = 2.4724E-10, A8 = 7.1737E-13, A10 = -1.7822E-16
[Variable interval data]
Infinity Near distance Wide angle end Medium telephoto end Wide angle end Medium telephoto end f 81.6 200.0 392.3 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1540.00 1540.00 1540.00
D5 11.6403 11.6403 11.6403 2.0038 2.0038 2.0038
D8 2.0000 19.7154 26.6341 11.6366 29.3520 36.2707
D15 49.5877 22.9984 3.0852 49.5877 22.9984 3.0852
D22 11.5139 20.3877 33.3823 11.5139 20.3877 33.3823
D28 27.3128 14.4763 2.2541 27.3128 14.4763 2.2541
D33 6.7527 6.0569 3.4268 6.7527 6.0569 3.4268
BF 53.8135 67.3459 82.1982 53.8135 67.3459 82.1982
[Each group focal length data]
Group number Group first surface Group focal length G1 1 99.1871
G2 9 -26.5930
G3 16 42.7402
G4 23 -58.7482
G5 29 49.2727
G6 34 -65.5437
[Conditional expression]
Conditional expression (1)
νp−νn = 39.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.33699 (L11, L12), 0.25753 (L14, L15)

  It can be seen from the table of specifications shown in Table 6 that the conditional expressions (1) and (2) are satisfied in the variable magnification optical system according to this example.

  22A and 22B are graphs showing various aberrations of the variable magnification optical system according to Example 6 when focusing on infinity. FIG. 22A is a wide-angle end state, FIG. 22B is an intermediate focal length state, and FIG. 22C is a telephoto end. Each state is shown. FIG. 23 is a meridional lateral aberration diagram when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the sixth example. (A) is a wide-angle end state, and (b) is a telephoto end state. Each is shown. 24A and 24B are graphs showing various aberrations of the zoom optical system according to Example 6 when focusing at a short distance (total imaging distance R = 1.8 m), where FIG. 24A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the sixth example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and the imaging performance is excellent.

(Seventh embodiment)
The seventh embodiment will be described using FIGS. 25 to 28 and Table 7. FIG. FIG. 25 shows a lens configuration diagram and zoom locus of the seventh example. As shown in FIG. 25, the variable magnification optical system according to the seventh example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes a cemented lens of a negative meniscus lens L11 having a convex surface directed toward the object side and a positive meniscus lens L12 having a convex surface directed toward the object side, which are arranged in order from the object side along the optical axis, and a biconvex positive lens. And a lens L13. The rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a biconvex positive lens L32, a biconvex positive lens L33, and a biconcave negative lens. And a cemented lens with the lens L34.

  The fourth lens group G4 includes, in order from the object side along the optical axis, a cemented lens of a biconvex positive lens L41 and a biconcave negative lens L42, and a biconcave negative lens L43. .

  The fifth lens group G5 is arranged in order from the object side along the optical axis. The positive meniscus lens L51 has a convex surface facing the object side, the negative meniscus lens L52 has a convex surface facing the object side, and a biconvex positive lens. And a cemented lens with L53.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction orthogonal to the optical axis, so that a blur occurs. Image plane correction is performed. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, since the shake correction coefficient K is −1.513 and the focal length is 81.6 (mm), a lens L41 for correcting a rotational shake of 0.350 °, The amount of movement of the cemented lens between the lens L42 and the lens L43 is -0.329 (mm). In the telephoto end state of this embodiment, the blur correction coefficient K is −1.900 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The amount of movement of the cemented lens between the lens L43 and the lens L43 is -0.575 (mm).

  Table 7 below shows values of various specifications of the variable magnification optical system according to the seventh example. The surface numbers 1 to 36 shown in Table 7 correspond to the surfaces 1 to 36 shown in FIG.

(Table 7)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6-5.3-5.9
TL 259.9-259.9-259.9
2ω 29.5-11.9-6.1
Φ 19.0-19.0-19.0
[Lens data]
Surface number r d nd νd
1 136.5927 3.6 1.83481 42.7
2 77.4288 8.4 1.49782 82.6
3 480.1154 0.1
4 112.0728 7.7 1.49782 82.6
5 -763.0919 D5
6 89.3642 3.2 1.84666 23.8
7 65.2719 8.6 1.58913 61.2
8 622.4204 D8
* 9 856.4923 2.0 1.79050 45.0
10 75.8742 4.1
11 -106.9796 2.0 1.75500 52.3
12 36.4011 6.0 1.80809 22.8
13 -328.5252 1.7
14 -66.6918 1.7 1.80 400 46.6
15 89.8287 D15
16 131.5292 4.0 1.72916 54.7
17 -122.0116 0.1
18 88.6769 3.4 1.48749 70.5
19 -385.5563 0.1
20 61.9020 6.5 1.61800 63.4
21 -86.1967 1.8 1.84666 23.8
22 242.3945 D22
23 4432.8239 2.8 1.80518 25.4
24 -48.7019 1.3 1.74400 44.8
25 68.5468 1.8
26 -154.2813 1.3 1.77250 49.6
27 278.4806 4.1
28 0.0000 D28 (Aperture stop S)
29 28.3699 3.9 1.48749 70.5
30 269.2184 6.5
31 56.8377 1.3 1.75520 27.5
32 18.8512 7.3 1.51823 58.9
33 -60.6257 D33
34 -27.6815 1.3 1.80 400 46.6
35 29.3829 5.8 1.78472 25.7
36 -80.4905 BF
[Aspherical data]
9th surface κ = 1.0000, A4 = 1.1177E-06, A6 = 2.2238E-10, A8 = 5.3529E-13, A10 = -8.5532E-17
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1540.12 1540.12 1540.12
D5 11.7134 11.7134 11.7134 2.0000 2.0000 2.0000
D8 2.0000 21.4337 27.3996 11.7134 31.1472 37.1130
D15 49.3041 23.0636 2.4250 49.3041 23.0636 2.4250
D22 26.5526 15.3736 4.1319 26.5526 15.3736 4.1319
D28 6.9815 6.4986 4.1109 6.9815 6.4986 4.1109
BF 46.9037 58.5656 72.1951 46.9037 58.5656 72.1951
[Each group focal length data]
Group number Group first surface Group focal length G1 1 100.1359
G2 9 -27.4127
G3 16 44.5281
G4 23 -57.6921
G5 29 43.8984
G6 34 -53.1354
[Conditional expression]
Conditional expression (1)
νp−νn = 39.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.33699 (L11, L12), 0.25753 (L14, L15)

  It can be seen from the table of specifications shown in Table 7 that the conditional expressions (1) and (2) are satisfied in the variable magnification optical system according to this example.

  FIGS. 26A and 26B are graphs showing various aberrations of the variable magnification optical system according to Example 7 when focusing at infinity, where FIG. 26A is a wide-angle end state, FIG. 26B is an intermediate focal length state, and FIG. 26C is a telephoto end. Each state is shown. FIGS. 27A and 27B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the seventh example. FIG. 27A shows a wide-angle end state, and FIG. 27B shows a telephoto end state. Each is shown. 28A and 28B are graphs showing various aberrations of the zoom optical system according to Example 7 when focusing at close distance (imaging distance R = 1.8 m for the entire system), where FIG. 28A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the seventh example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Eighth embodiment)
The eighth embodiment will be described using FIGS. 29 to 32 and Table 8. FIG. FIG. 29 shows a lens configuration diagram and zoom locus of the eighth example. As shown in FIG. 29, the variable magnification optical system according to the eighth example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of 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 rear group G1R includes a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, which are arranged in order from the object side along the optical axis.

  The second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave negative lens L22, and a positive meniscus lens having a convex surface directed toward the object side, which are arranged in order from the object side along the optical axis. It has a cemented lens with L23 and a biconcave negative lens L24.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32, and a biconcave negative lens L33, an object And a positive meniscus lens L34 having a convex surface on the side.

  The fourth lens group G4 includes a negative meniscus lens L41 having a convex surface directed toward the object side, a positive meniscus lens L42 having a concave surface directed toward the object side, and a biconcave negative lens arranged in order from the object side along the optical axis. And a cemented lens with L43.

  The fifth lens group G5 is arranged in order from the object side along the optical axis. The positive meniscus lens L51 has a convex surface facing the object side, the negative meniscus lens L52 has a convex surface facing the object side, and a biconvex positive lens. And a cemented lens with L53.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction orthogonal to the optical axis, so that a blur occurs. Image plane correction is performed. When the focal length of the entire system is f, a shake correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens group for blur correction in the optical axis direction) is K and a rotational shake at an angle θ. In order to correct, the lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, since the shake correction coefficient K is −1.351 and the focal length is 81.6 (mm), a lens L41 for correcting a rotational shake of 0.350 °, The amount of movement of the cemented lens between the lens L42 and the lens L43 is -0.369 (mm). In the telephoto end state of the present embodiment, the blur correction coefficient K is −1.700 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The moving amount of the cemented lens between the lens L43 and the lens L43 is -0.642 (mm).

  Table 8 below lists values of various specifications of the variable magnification optical system according to the eighth example. The surface numbers 1 to 36 shown in Table 8 correspond to the surfaces 1 to 36 shown in FIG.

(Table 8)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.6-5.3-5.8
TL 259.8-259.8-259.8
2ω 29.4-12.0-6.1
Φ 19.6 〜 19.6 〜 19.6
[Lens data]
Surface number r d nd νd
1 129.9076 3.6 1.83481 42.7
2 75.6303 8.5 1.49782 82.6
3 442.7333 0.1
4 110.9240 7.5 1.49782 82.6
5 -816.2615 D5
6 85.9708 3.2 1.84666 23.8
7 62.0564 9.0 1.58913 61.2
8 598.8161 D8
* 9 884.9284 2.0 1.79050 45.0
10 71.3911 4.2
11 -106.6390 2.0 1.75 500 52.3
12 36.8443 6.0 1.80809 22.8
13 -267.9233 1.8
14 -62.3635 1.7 1.80 400 46.6
15 94.6941 D15
16 144.0036 4.0 1.74400 44.8
17 -91.4279 0.1
18 64.8767 8.4 1.60 300 65.5
19 -64.8767 1.8 1.84666 23.8
20 1898.9739 0.1
21 68.6533 2.3 1.48749 70.5
22 136.9385 D22
23 129.0250 1.3 1.62004 36.3
24 57.4273 1.8
25 -92.5865 3.1 1.79504 28.7
26 -27.0013 1.3 1.74400 44.8
27 332.0147 4.1
28 0.0000 D28 (Aperture stop S)
29 27.5541 4.2 1.48749 70.5
30 167.5525 7.1
31 55.7759 1.3 1.75520 27.5
32 18.2265 8.6 1.51823 58.9
33 -60.8589 D33
34 -27.7779 1.3 1.80 400 46.6
35 27.7779 5.6 1.78472 25.7
36 -84.5200 BF
[Aspherical data]
9th surface κ = 1.0000, A4 = 1.1546E-06, A6 = 2.2711E-10, A8 = 6.5905E-13, A10 = -2.0618E-16
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1540.20 1540.20 1540.20
D5 11.0323 11.0323 11.0323 1.8400 1.8400 1.8400
D8 2.0000 19.3680 26.5375 11.1923 28.5603 35.7297
D15 48.6029 22.6018 2.0000 48.6029 22.6018 2.0000
D22 13.9941 22.6272 36.0595 13.9941 22.6272 36.0595
D28 26.2541 12.0119 1.8900 26.2541 12.0119 1.8900
D33 6.1601 5.3477 3.0592 6.1601 5.3477 3.0592
BF 45.7684 60.8230 73.2333 45.7684 60.8230 73.2333
[Each group focal length data]
Group number Group first surface Group focal length G1 1 97.5902
G2 9 -26.8801
G3 16 45.7125
G4 23 -66.7628
G5 29 45.6409
G6 34 -51.7889
[Conditional expression]
Conditional expression (1)
νp-νn = 39.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.33699 (L11, L12), 0.25753 (L14, L15)

  From the table of specifications shown in Table 8, it can be seen that the variable magnification optical system according to the present example satisfies the conditional expressions (1) and (2).

  FIG. 30 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 8 at the time of focusing on infinity, where (a) is a wide-angle end state, (b) is an intermediate focal length state, and (c) is a telephoto end. Each state is shown. FIGS. 31A and 31B are meridional lateral aberration diagrams when blur correction is performed at the time of focusing on infinity of the variable magnification optical system according to the eighth example. FIG. 31A shows a wide-angle end state, and FIG. 31B shows a telephoto end state. Each is shown. FIGS. 32A and 32B are graphs showing various aberrations of the variable magnification optical system according to Example 8 at the short distance focusing (total imaging distance R = 1.8 m), where FIG. 32A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the eighth embodiment, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Ninth embodiment)
The ninth embodiment will be described using FIGS. 33 to 36 and Table 9. FIG. FIG. 33 shows a lens configuration diagram and zoom locus of the ninth example. As shown in FIG. 33, the variable magnification optical system according to the ninth example has a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a negative refractive power. The second lens group G2, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power, the fifth lens group G5 having a positive refractive power, and the negative refractive power And a sixth lens group G6.

  The first lens group G1 includes a front group G1F and a rear group G1R (focusing group) arranged in order from the object side along the optical axis. The front group G1F includes, in order from the object side along the optical axis, a cemented lens of 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 biconvex shape. And a positive lens L13. The rear group G1R includes, in order from the object side, a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side.

  The second lens group G2 is formed by joining a negative meniscus lens L21 having a convex surface toward the object side, which is arranged in order from the object side along the optical axis, and a biconcave negative lens L22 and a biconvex positive lens L23. It has a lens and a biconcave negative lens L24.

  The third lens group G3 includes, in order from the object side along the optical axis, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32, and a biconcave negative lens L33, an object And a positive meniscus lens L34 having a convex surface on the side.

  The fourth lens group G4 includes a negative meniscus lens L41 having a convex surface directed toward the object side, a positive meniscus lens L42 having a concave surface directed toward the object side, and a biconcave negative lens arranged in order from the object side along the optical axis. And a cemented lens with L43.

  The fifth lens group G5 is arranged in order from the object side along the optical axis. The positive meniscus lens L51 has a convex surface facing the object side, the negative meniscus lens L52 has a convex surface facing the object side, and a biconvex positive lens. And a cemented lens with L53.

  The sixth lens group G6 includes a cemented lens of a biconcave negative lens L61 and a biconvex positive lens L62, which are arranged in order from the object side along the optical axis.

  In the zoom optical system according to the present embodiment having such a configuration, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, The distance between the lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. Then, each lens group moves so that the distance between the fifth lens group G5 and the sixth lens group G6 decreases. However, the first lens group G1 and the fourth lens group G4 are fixed with respect to the image plane I during zooming from the wide-angle end state to the telephoto end state.

  The aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5, and is fixed with respect to the image plane I upon zooming from the wide-angle end state to the telephoto end state.

In the variable magnification optical system according to the present example, the lens L41 and the cemented lens of the lens L42 and the lens L43 in the fourth lens group G4 are shifted in a direction perpendicular to the optical axis, thereby generating blurring. Image plane correction is performed. Here, the focal length of the entire system is f, and a blur correction coefficient (ratio of the amount of movement of the image on the image plane I to the amount of movement of the lens unit for blur correction in the optical axis direction) is K and is an angle θ. In order to correct the rotational shake, the lens group for shake correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the present embodiment, the blur correction coefficient K is −1.488 and the focal length is 81.6 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.350 °, The moving amount of the cemented lens between the lens L42 and the lens L43 is −0.335 (mm). In the telephoto end state of this embodiment, the blur correction coefficient K is −1.900 and the focal length is 392 (mm). Therefore, the lens L41 for correcting the rotational blur of 0.160 ° and the lens L42 The amount of movement of the cemented lens between the lens L43 and the lens L43 is -0.575 (mm).

  Table 9 below lists values of various specifications of the variable magnification optical system according to the ninth example. The surface numbers 1 to 36 shown in Table 9 correspond to the surfaces 1 to 36 shown in FIG.

(Table 9)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f 81.6 to 200.0 to 392.0
FNO 4.5 to 5.3 to 5.8
TL 259.9-259.9-259.9
2ω 29.4-12.0-6.1
Φ 20.0 〜 20.0 〜 20.0
[Lens data]
Surface number r d nd νd
1 131.5273 3.6 1.83481 42.7
2 75.2890 8.6 1.49782 82.6
3 468.3641 0.1
4 106.0385 7.7 1.49782 82.6
5 -928.7919 D5
6 87.6000 3.2 1.84666 23.8
7 63.0110 8.8 1.58913 61.2
8 553.3485 D8
* 9 949.9140 2.0 1.79050 45.0
10 72.9166 4.2
11 -105.9661 2.0 1.75 500 52.3
12 36.6390 6.1 1.80809 22.8
13 -262.3986 1.8
14 -62.0851 1.7 1.80 400 46.6
15 89.8014 D15
16 156.9157 4.1 1.74400 44.8
17 -87.6277 0.1
18 64.6661 6.2 1.60300 65.5
19 -64.6450 1.8 1.84666 23.8
20 -1644.6864 0.1
21 62.7701 2.4 1.48749 70.5
22 114.6467 D22
23 114.8569 1.3 1.62004 36.2
24 54.8911 1.8
25 -92.2541 3.1 1.79504 28.7
26 -27.0180 1.3 1.74400 44.8
27 193.5011 4.1
28 0.0000 D28 (Aperture stop S)
29 27.2612 4.4 1.48749 70.5
30 298.2465 6.2
31 61.8805 1.3 1.75520 27.5
32 17.9910 7.7 1.51823 58.9
33 -53.6762 D33
34 -27.3003 1.3 1.80 400 46.6
35 27.3060 5.7 1.78472 25.7
36 -81.4626 BF
[Aspherical data]
9th surface κ = 1.0000, A4 = 1.2623E-06, A6 = 2.9682E-10, A8 = 5.7870E-13, A10 = -1.2302E-16
[Variable interval data]
Infinity short distance
Wide-angle end Medium telephoto end Wide-angle end Medium telephoto end f 81.6 200.0 392.0 − − −
β 0 0 0 -0.05 -0.13 -0.26
D0 0 0 0 1540.12 1540.12 1540.12
D5 11.5037 11.5037 11.5037 1.8932 1.8932 1.8932
D8 2.0055 19.3952 26.6587 11.6160 29.0058 36.2693
D15 47.4566 22.0189 2.1846 47.4566 22.0189 2.1846
D22 14.0706 22.1186 34.6893 14.0706 22.1186 34.6893
D28 27.0683 12.3291 2.0706 27.0683 12.3291 2.0706
D33 5.8957 5.2880 3.2943 5.8957 5.2880 3.2943
BF 49.1754 64.5223 76.7746 49.1754 64.5223 76.7746
[Each group focal length data]
Group number Group first surface Group focal length G1 1 98.5763
G2 9 -26.6117
G3 16 44.0942
G4 23 -60.3396
G5 29 43.5178
G6 34 -51.5312
[Conditional expression]
Conditional expression (1)
νp−νn = 39.9 (L11, L12), 37.4 (L14, L15)
Conditional expression (2)
nn-np = 0.33699 (L11, L12), 0.25753 (L14, L15)

  It can be seen from the table of specifications shown in Table 9 that the conditional expressions (1) and (2) are satisfied in the variable magnification optical system according to this example.

  FIGS. 34A and 34B are graphs showing various aberrations of the variable magnification optical system according to Example 9 when focused at infinity, where FIG. 34A is a wide-angle end state, FIG. 34B is an intermediate focal length state, and FIG. 34C is a telephoto end. Each state is shown. FIGS. 35A and 35B are meridional lateral aberration diagrams when blurring correction is performed at the time of focusing on infinity of the variable magnification optical system according to the ninth example. FIG. 35A is a wide-angle end state, and FIG. Each is shown. FIGS. 36A and 36B are graphs showing various aberrations of the zoom optical system according to Example 9 when focusing at short distance (the imaging distance R of the entire system is R = 1.8 m), where FIG. 36A is a wide-angle end state, and FIG. Indicates an intermediate focal length state, and (c) indicates a telephoto end state.

  As is apparent from the respective aberration diagrams, in the ninth example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

  In the above-described embodiment, the following description can be appropriately adopted as long as the optical performance is not impaired.

  In the above embodiment, the variable magnification optical system has a six-group configuration, but the present invention can be applied to other group configurations such as a fifth group, a seventh group, and an eighth group. Specifically, a configuration in which a positive lens group is added on the most object side and a configuration in which a positive or negative lens group is added on the most image side can be given.

  In addition, 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. 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 the cemented lens of the lens L14 and the lens L15 constituting the first lens group G1 is a focusing lens group.

  Alternatively, the lens group or the partial lens group may be vibrated in a direction perpendicular to the optical axis, and may be an anti-vibration lens group that corrects image blur caused by camera shake. In particular, it is preferable that at least a part of the fourth lens group G4 is an anti-vibration lens group.

  Each lens surface may be formed as a spherical surface, a flat surface, or an aspheric surface. In particular, it is preferable that at least a part of the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 be aspherical. In addition, it is preferable that the lens surface is a spherical surface or a flat surface because lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to processing and assembly adjustment errors can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. On the other hand, when the lens surface is an aspheric surface, this aspheric surface is an aspheric surface by grinding, a glass mold aspheric surface made of glass with an aspheric shape, or a composite type in which resin is formed on the glass surface in an aspheric shape Any aspherical surface may be used. Each 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 S is preferably arranged in the vicinity of the fourth lens group G4 (preferably on the image side) or in the vicinity of the third lens group G3. That role may be substituted.

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

  The variable magnification optical system of the present embodiment has a variable magnification ratio of about 4.5-6.

  In the variable magnification optical system of the present embodiment, it is preferable that the front group G1F of the first lens group G1 has two or three positive lenses and one negative lens. In the front group G1F, it is preferable that a negative lens, a positive lens, and a positive lens, or a negative lens, a positive lens, a positive lens, and a positive lens are arranged in order from the object side. Each lens may be a single lens or may be bonded to form a cemented lens.

  In the variable magnification optical system of the present embodiment, it is preferable that the rear group G1R of the first lens group G1 has one positive lens and one negative lens. In the rear group G1R, it is preferable to dispose a negative lens and a positive lens in order from the object side. The rear group G1R is preferably composed of one cemented lens.

  In the variable magnification optical system of the present embodiment, it is preferable that the second lens group G2 has one or two positive lenses and three negative lenses. The second lens group G2 includes, in order from the object side, a negative lens, a negative lens, a positive lens, a negative lens, or a positive lens, a negative lens, a negative lens, a positive lens, and a negative lens. It is preferable to arrange a lens. Each lens may be a single lens or may be bonded to form a cemented lens.

  In the variable magnification optical system of the present embodiment, it is preferable that the third lens group G3 has two or three positive lenses and one negative lens. In the third lens group G3, it is preferable that a positive lens, a positive lens, and a negative lens, or a positive lens, a positive lens, a negative lens, and a positive lens are arranged in order from the object side. . Each lens may be a single lens or may be bonded to form a cemented lens.

  In the variable power optical system of the present embodiment, it is preferable that the fourth lens group G4 has one positive lens and one or two negative lenses. In the fourth lens group G4, it is preferable that a positive lens and a negative lens, or a negative lens, a positive lens, and a negative lens are arranged in order from the object side. In the fourth lens group G4, it is preferable that a positive lens, a negative lens, and a negative lens, or a negative lens, a negative lens, and a positive lens are arranged in order from the object side. Each lens may be a single lens or may be bonded to form a cemented lens.

  In the variable power optical system of the present embodiment, it is preferable that the fifth lens group G5 has two or three positive lenses and one or two negative lenses. In the fifth lens group G5, it is preferable that a positive lens, a positive lens, and a negative lens, or a positive lens, a negative lens, and a positive lens are arranged in order from the object side. The fifth lens group G5 includes, in order from the object side, a positive lens, a positive lens, a negative lens, a positive lens, or a positive lens, a negative lens, a positive lens, and a negative lens. It is preferable to arrange. Further, in the fifth lens group G5, it is preferable that a positive lens, a negative lens, a positive lens, a negative lens, and a positive lens are arranged in order from the object side. Each lens may be a single lens or may be bonded to form a cemented lens.

  In the variable power optical system of the present embodiment, it is preferable that the sixth lens group G6 has one positive lens and one or two negative lenses. In the sixth lens group G6, it is preferable to dispose a negative lens and a positive lens in order from the object side. Each lens may be a single lens or may be bonded to form a cemented lens.

  In addition, in order to make this invention intelligible, although demonstrated with the component requirement of embodiment, it cannot be overemphasized that this invention is not limited to this.

  As described above, a variable power optical system, an optical device, and a method for manufacturing the variable power optical system, which are corrected for chromatic aberration, have good optical performance, and are suitable for a photographic camera, an electronic still camera, a video camera, and the like. can do.

G1 first lens group G1F front group G1R rear group (focusing group)
G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group G6 6th lens group S Aperture stop I Image surface CAM Digital single lens reflex camera (optical equipment)

Claims (15)

Having at least a first lens group to a sixth lens group arranged in order from the object side,
The third lens group has a positive refractive power;
The zoom lens system according to claim 1, wherein the first lens group includes at least two cemented lenses.   The variable power optical system according to claim 1, wherein the fourth lens group has a negative refractive power.   The variable power optical system according to claim 1, wherein the first lens group has a positive refractive power.   The variable power optical system according to claim 1, wherein the second lens group has a negative refractive power.   The variable power optical system according to any one of claims 1 to 4, wherein the fifth lens group has a positive refractive power.   The variable power optical system according to any one of claims 1 to 5, wherein the sixth lens group has a negative refractive power. When the Abbe number of the convex lens constituting the cemented lens of the first lens group is νp and the Abbe number of the concave lens is νn, at least two of the cemented lenses have the following formula 35.0 <νp−νn
The zoom lens system according to claim 1, wherein the zoom lens system satisfies the following condition. When the refractive index of the convex lens constituting the cemented lens of the first lens group is np and the refractive index of the concave lens is nn, at least two of the cemented lenses have the following formula 0.2 <nn−np
The zoom lens system according to claim 1, wherein the zoom lens system satisfies the following condition.   The variable power optical system according to any one of claims 1 to 8, wherein each of the first to sixth lens groups includes a cemented lens.   The variable power optical system according to claim 1, wherein any one of the cemented lenses is used as a focusing group.   The variable power optical system according to claim 10, wherein the focusing group is the cemented lens positioned closest to the image side of the first lens group. Having an aperture stop,
12. The zoom optical system according to claim 1, wherein the aperture stop is fixed with respect to the image plane when zooming from the wide-angle end state to the telephoto end state. Having an aperture stop,
The zoom optical system according to any one of claims 1 to 12, wherein the aperture diameter of the aperture stop is constant when zooming from the wide-angle end state to the telephoto end state.   An optical apparatus having the variable magnification optical system according to any one of claims 1 to 13. A method of manufacturing a variable magnification optical system having at least a first lens group to a sixth lens group arranged in order from the object side,
The third lens group has a positive refractive power;
The first lens group has at least two cemented lenses,
A method of manufacturing a variable magnification optical system, wherein each lens is incorporated in a lens barrel and various operations are confirmed.

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