JP7144765B2 - Variable magnification optical system and optical equipment - Google Patents

Description

The present invention relates to a variable power optical system and an optical instrument.

2. Description of the Related Art Conventionally, variable power optical systems suitable for photographic cameras, electronic still cameras, video cameras, etc. have been proposed (see, for example, Patent Document 1). However, Patent Document 1 has a problem that further improvement in optical performance is demanded.

JP 2006-113572 A

A variable magnification optical system according to a first aspect of the present invention has, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, and positive refractive power. Consisting of substantially five lens groups, the third lens group, the fourth lens group having negative refractive power, and the fifth lens group having positive refractive power, the During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the distance between the third lens group and the fourth lens group changes. However, the distance between the fourth lens group and the fifth lens group changes, the fourth lens group moves along the optical axis during focusing, and the first lens group consists of one single lens. , the fifth lens group is composed of a single lens, is fixed with respect to the image plane during zooming, and satisfies the following condition.
2.000 < f1/(d12t - d12w) < 8.000
however,
d12t: the distance between the first lens group and the second lens group in the telephoto end state d12w: the distance between the first lens group and the second lens group in the wide-angle end state f1: the focal length of the first lens group

2 is a cross-sectional view showing the lens configuration of the variable power optical system according to the first example; FIG. FIG. 4 is a diagram of various aberrations in the wide-angle end state of the variable-magnification optical system according to the first embodiment, in which (a) is a diagram of various aberrations when in focus at infinity, and (b) is in a state of focus at infinity; FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 4 is a diagram of various aberrations in an intermediate focal length state of the variable-magnification optical system according to the first embodiment, where (a) is a diagram of various aberrations when in focus at infinity, and (b) is in a state of infinity focus; FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . FIG. 4 is a diagram of various aberrations in the telephoto end state of the variable-magnification optical system according to the first embodiment, where (a) is a diagram of various aberrations when in focus at infinity, and (b) is in a state of focus at infinity; FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10 is a diagram of various aberrations in the zooming optical system according to the first embodiment in a close-range in-focus state, (a) being a diagram of various aberrations in the wide-angle end state, and (b) being in an intermediate focal length state; and (c) is a diagram of various aberrations in the telephoto end state. FIG. 10 is a cross-sectional view showing the lens configuration of the variable-magnification optical system according to the second example; FIG. 4 is a diagram of various aberrations in the wide-angle end state of the variable magnification optical system according to the second embodiment, (a) being a diagram of various aberrations when in focus at infinity, and (b) being in a state of infinity focus. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 4 is a diagram of various aberrations in an intermediate focal length state of the variable power optical system according to the second embodiment, where (a) is a diagram of various aberrations when in focus at infinity, and (b) is in a state of infinity focus; FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . FIG. 10 is a diagram of various aberrations in the telephoto end state of the variable power optical system according to the second embodiment, (a) being a diagram of various aberrations when in focus at infinity, and (b) in a state of focus at infinity. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10 is a diagram of various aberrations in the zooming optical system according to the second embodiment in a close-range in-focus state, (a) being a diagram of various aberrations in the wide-angle end state, and (b) being in an intermediate focal length state; and (c) is a diagram of various aberrations in the telephoto end state. FIG. 11 is a cross-sectional view showing the lens configuration of a variable-magnification optical system according to a third example; FIG. 10A is a diagram of various aberrations in the wide-angle end state of the variable power optical system according to the third embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10A is a diagram of various aberrations in an intermediate focal length state of the variable power optical system according to the third embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . FIG. 10A is a diagram of various aberrations in the telephoto end state of the variable power optical system according to the third embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10A is a diagram of various aberrations in the zooming optical system according to the third embodiment in the state of focusing at a close distance, FIG. and (c) is a diagram of various aberrations in the telephoto end state. FIG. 11 is a cross-sectional view showing the lens configuration of a variable-magnification optical system according to a fourth example; 4A is a diagram of various aberrations in the wide-angle end state of the variable-magnification optical system according to the fourth embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10A is a diagram of various aberrations in an intermediate focal length state of the variable magnification optical system according to the fourth embodiment, in which (a) is a diagram of various aberrations when in focus at infinity, and (b) is a diagram in focus at infinity; FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . 4A is a diagram of various aberrations in the telephoto end state of the variable-magnification optical system according to the fourth embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; 4A and 4B are various aberration diagrams in the close-distance focused state of the variable magnification optical system according to the fourth embodiment, where (a) is the various aberration diagrams in the wide-angle end state, and (b) is in the intermediate focal length state. and (c) is a diagram of various aberrations in the telephoto end state. FIG. 11 is a cross-sectional view showing the lens configuration of a variable-magnification optical system according to a fifth example; FIG. 10A is a diagram of various aberrations in the wide-angle end state of the variable power optical system according to the fifth embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; FIG. 10A is a diagram of various aberrations in an intermediate focal length state of the variable power optical system according to the fifth embodiment, in which FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . FIG. 10A is a diagram of various aberrations in the telephoto end state of the variable power optical system according to the fifth embodiment, FIG. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; 10A and 10B are various aberration diagrams in the close-distance focused state of the variable power optical system according to the fifth embodiment, where (a) is the various aberration diagrams in the wide-angle end state, and (b) is in the intermediate focal length state. and (c) is a diagram of various aberrations in the telephoto end state. FIG. 12 is a cross-sectional view showing the lens configuration of a variable-magnification optical system according to a sixth example; 10A and 10B are various aberration diagrams in the wide-angle end state of the variable power optical system according to the sixth embodiment, in which (a) is a diagram of various aberrations when in focus at infinity, and (b) is a diagram in infinity focus; FIG. 10 is a lateral aberration diagram when camera shake correction is performed; 10A and 10B are various aberration diagrams in an intermediate focal length state of the variable-magnification optical system according to the sixth embodiment, in which (a) is an aberration diagram when in focus at infinity, and (b) is in infinity focus state; FIG. 10 is a lateral aberration diagram when camera shake correction is performed at . 10A and 10B are aberration diagrams in the telephoto end state of the variable power optical system according to the sixth embodiment, in which (a) is an aberration diagram when in focus at infinity, and (b) is in infinity focus state. FIG. 10 is a lateral aberration diagram when camera shake correction is performed; 10A and 10B are various aberration diagrams in the close-range in-focus state of the variable power optical system according to the sixth embodiment, where (a) is the various aberration diagrams in the wide-angle end state, and (b) is in the intermediate focal length state. and (c) is a diagram of various aberrations in the telephoto end state. It is a cross-sectional view of a camera equipped with the variable magnification optical system. 4 is a flow chart for explaining a method of manufacturing the variable magnification optical system;

Preferred embodiments are described below with reference to the drawings. As shown in FIG. 1, the variable magnification optical system ZL according to the present embodiment includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, It has a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power, and has a wide-angle end state to a telephoto end state. , the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the distance between the third lens group G3 and the fourth lens group G3 changes. The distance from the lens group G4 changes, and the distance between the fourth lens group G4 and the fifth lens group G5 changes. In this way, the variable-power optical system ZL according to the present embodiment has a positive/negative/positive/negative/positive five-group structure, and by changing the distance between the lens groups during zooming, it is possible to obtain good optical performance in a small size. .

Further, the variable magnification optical system ZL according to this embodiment is configured such that the fourth lens group G4 moves along the optical axis during focusing. By performing focusing with the fourth lens group G4 in this way, it is possible to suppress changes in image magnification, spherical aberration, and astigmatism during focusing.

In addition, in the variable power optical system ZL according to this embodiment, it is desirable that the first lens group G1 is composed of one lens component. By configuring in this way, it is possible to obtain small size and good optical performance.

Further, in the variable power optical system ZL according to this embodiment, it is desirable that the fifth lens group G5 is fixed with respect to the image plane I during variable power. Since the fifth lens group G5 is fixed with respect to the image plane I during zooming, the mechanism for moving the lens group can be simplified, and the zooming optical system ZL can be made compact. Also, manufacturing error sensitivity (astigmatism variation) can be reduced.

Further, in the variable-magnification optical system ZL according to this embodiment, it is desirable that the first lens group G1 has a lens that satisfies the following conditional expression (1).

40.000 < νd1 (1)
however,
νd1: Abbe number for the d-line of the medium of the lens constituting the first lens group G1

Conditional expression (1) defines the Abbe number of the first lens group G1. By arranging a lens that satisfies conditional expression (1) in the first lens group G1, it is possible to suppress fluctuations in axial chromatic aberration and lateral chromatic aberration that occur during zooming. In order to ensure the effect of conditional expression (1), it is desirable to set the lower limit of conditional expression (1) to 50.000. In order to further ensure the effect of conditional expression (1), it is desirable to set the lower limit of conditional expression (1) to 60.000.

Moreover, it is desirable that the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (2).

2.000<f1/(d12t−d12w)<8.000 (2)
however,
d12t: the distance between the first lens group G1 and the second lens group G2 in the telephoto end state d12w: the distance between the first lens group G1 and the second lens group G2 in the wide-angle end state f1: the focal length of the first lens group G1

Conditional expression (2) defines the focal length of the first lens group G1 with respect to the amount of change in the distance between the first lens group G1 and the second lens group G2 from the wide-angle end state to the telephoto end state. Exceeding the upper limit of conditional expression (2) is not preferable because fluctuations in spherical aberration during zooming cannot be suppressed when the amount of movement of the first lens group G1 becomes small. In order to ensure the effect of conditional expression (2), it is desirable to set the upper limit of conditional expression (2) to 7.600. In order to further ensure the effect of conditional expression (2), it is desirable to set the upper limit of conditional expression (2) to 7.300. Further, if the lower limit of conditional expression (2) is not reached, the focal length of the first lens group G1 becomes small, which makes it difficult to correct chromatic aberration, which is not preferable. In order to ensure the effect of conditional expression (2), it is desirable to set the lower limit of conditional expression (2) to 2.200. In order to further ensure the effect of conditional expression (2), it is desirable to set the lower limit of conditional expression (2) to 2.400.

Moreover, it is desirable that the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (3).

0.120<(d12t−d12w) ² /Σ(dit−diw) ² <0.900 (3)
however,
d12t: Distance between the first lens group G1 and the second lens group G2 in the telephoto end state d12w: Distance between the first lens group G1 and the second lens group G2 in the wide-angle end state Σ(dit-diw) ² : Wide-angle end The sum of the squares of the amount of change between each lens group when zooming from the state to the telephoto end state

Conditional expression (3) expresses the amount of change in the group spacing between the first lens group G1 and the second lens group G2 from the wide-angle end state to the telephoto end state with respect to the amount of change in each group spacing from the wide-angle end state to the telephoto end state. It defines the relationship between Exceeding the upper limit of conditional expression (3) is not preferable because correction of chromatic aberration becomes difficult when the amount of movement of the first lens group G1 becomes large. In order to ensure the effect of conditional expression (3), it is desirable to set the upper limit of conditional expression (3) to 0.800. In order to further ensure the effect of conditional expression (3), it is desirable to set the upper limit of conditional expression (3) to 0.700. If the lower limit of conditional expression (3) is not reached, it is not preferable because fluctuations in spherical aberration during zooming cannot be suppressed when the amount of movement of the first lens group G1 becomes small. In order to ensure the effect of conditional expression (3), it is desirable to set the lower limit of conditional expression (3) to 0.140. In order to further ensure the effect of conditional expression (3), it is desirable to set the lower limit of conditional expression (3) to 0.150.

Further, it is desirable that the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (4).

0.800 < f5/f1 < 4.100 (4)
however,
f5: focal length of the fifth lens group G5 f1: focal length of the first lens group G1

Conditional expression (4) defines the focal length of the first lens group G1 with respect to the focal length of the fifth lens group G5. Exceeding the upper limit of conditional expression (4) is not preferable because the focal length of the first lens group G1 becomes short, making it difficult to correct chromatic aberration. In order to ensure the effect of conditional expression (4), it is desirable to set the upper limit of conditional expression (4) to 3.750. In order to further ensure the effect of conditional expression (4), it is desirable to set the upper limit of conditional expression (4) to 3.400. If the lower limit of conditional expression (4) is not reached, the focal length of the first lens group G1 increases and the total length in the telephoto end state increases, making it impossible to realize a compact optical system. Moreover, it is not preferable because fluctuations in spherical aberration and astigmatism during zooming cannot be suppressed. In order to ensure the effect of conditional expression (4), it is desirable to set the lower limit of conditional expression (4) to 1.000. In order to further ensure the effect of conditional expression (4), it is desirable to set the lower limit of conditional expression (4) to 1.400.

Further, it is desirable that the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (5).

0.400<(-f4)/f1<3.000 (5)
however,
f4: focal length of the fourth lens group G4 f1: focal length of the first lens group G1

Conditional expression (5) defines the focal length of the first lens group G1 with respect to the focal length of the fourth lens group G4, which is a focusing lens group. Exceeding the upper limit of conditional expression (5) is not preferable because fluctuations in spherical aberration and astigmatism during focusing cannot be suppressed. In order to ensure the effect of conditional expression (5), it is desirable to set the upper limit of conditional expression (5) to 2.500. In order to further ensure the effect of conditional expression (5), it is desirable to set the upper limit of conditional expression (5) to 2.200. Further, if the lower limit of conditional expression (5) is not reached, the refractive power of the fourth lens group G4 becomes too weak, resulting in an increase in the amount of movement during focusing. This is not preferable because fluctuations in spherical aberration and astigmatism during focusing cannot be suppressed. In order to ensure the effect of conditional expression (5), it is desirable to set the lower limit of conditional expression (5) to 0.500. In order to further ensure the effect of conditional expression (5), it is desirable to set the lower limit of conditional expression (5) to 0.700.

Also, in the variable power optical system ZL according to the present embodiment, it is desirable that the fifth lens group G5 is composed of a single lens. Such a configuration simplifies the configuration of the variable-magnification optical system ZL and realizes a compact lens.

Further, in the variable magnification optical system ZL according to this embodiment, it is desirable that the fifth lens group G5 has a lens that satisfies the following conditional expression (6).

νd5≦35.000 (6)
however,
νd5: Abbe number for the d-line of the medium of the lens constituting the fifth lens group G5

Conditional expression (6) defines the Abbe number of the fifth lens group G5. Exceeding the upper limit of conditional expression (6) is not preferable because it is impossible to suppress fluctuations in chromatic aberration of magnification during zooming. In order to ensure the effect of conditional expression (6), it is desirable to set the upper limit of conditional expression (6) to 30.000. In order to further ensure the effect of conditional expression (6), it is desirable to set the upper limit of conditional expression (6) to 25.000.

Also, in the variable magnification optical system ZL according to this embodiment, it is desirable that one lens component of the first lens group G1 is composed of a single lens. Such a configuration simplifies the configuration of the variable-power optical system ZL, thereby achieving further miniaturization.

Moreover, it is desirable that the variable magnification optical system ZL according to the present embodiment satisfies the following conditional expression (7).

29.00° < ωw < 60.00° (7)
however,
ωw: Half angle of view in the wide-angle end state

Conditional expression (7) defines an appropriate range of the maximum half angle of view in the wide-angle end state. By satisfying conditional expression (7), it is possible to satisfactorily correct various aberrations such as coma, distortion, and curvature of field while maintaining a wide angle of view. Further, if the lower limit of conditional expression (7) is not reached, it is not preferable because fluctuations in spherical aberration and chromatic spherical aberration during zooming cannot be suppressed. In order to ensure the effect of conditional expression (7), it is desirable to set the lower limit of conditional expression (7) to 32.00°. In order to further ensure the effect of conditional expression (7), it is desirable to set the lower limit of conditional expression (7) to 35.00°. In order to ensure the effect of conditional expression (7), it is desirable to set the upper limit of conditional expression (7) to 55.00°. In order to further ensure the effect of conditional expression (7), it is desirable to set the upper limit of conditional expression (7) to 50.00°. In order to further ensure the effect of conditional expression (7), it is desirable to set the upper limit of conditional expression (7) to 45.00°.

Moreover, it is desirable that the variable power optical system ZL according to the present embodiment satisfies the following conditional expression (8).

2.50° < ωt < 22.00° (8)
however,
ωt: Half angle of view in telephoto end state

Conditional expression (8) defines an appropriate range of the maximum half angle of view in the telephoto end state. By satisfying the conditional expression (8), various aberrations such as coma, distortion, and field curvature can be satisfactorily corrected. If the lower limit of conditional expression (8) is exceeded, the lens component (anti-vibration lens group Gvr) in the third lens group G3 that is not closest to the image side or closest to the object side corrects image blurring (hereinafter referred to as "anti-vibration ), the eccentric coma aberration during vibration reduction becomes relatively large, which is not preferable. In order to ensure the effect of conditional expression (8), it is desirable to set the lower limit of conditional expression (8) to 4.50°. In order to further ensure the effect of conditional expression (8), it is desirable to set the lower limit of conditional expression (8) to 6.50°. In order to ensure the effect of conditional expression (8), it is desirable to set the upper limit of conditional expression (8) to 20.00°. In order to further ensure the effect of conditional expression (8), it is desirable to set the upper limit of conditional expression (8) to 18.00°. In order to further ensure the effect of conditional expression (8), it is desirable to set the upper limit of conditional expression (8) to 16.00°.

In addition, the conditions and configurations described above exhibit the effects described above, and are not limited to those that satisfy all the conditions and configurations. It is possible to obtain the above-described effects even if the conditions or combinations of the above conditions are satisfied.

Next, a camera, which is an optical device equipped with the variable-magnification optical system ZL according to this embodiment, will be described with reference to FIG. This camera 1 is a so-called mirrorless camera of an interchangeable lens type provided with a variable magnification optical system ZL according to the present embodiment as a photographing lens 2 . In this camera 1, light from an unillustrated object (subject) is condensed by a photographing lens 2 and passed through an unillustrated OLPF (Optical low pass filter) onto an imaging surface of an imaging unit 3. to form an image of the subject. Then, a subject image is photoelectrically converted by a photoelectric conversion element provided in the imaging unit 3 to generate an image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1 . This allows the photographer to observe the subject through the EVF4.

Also, when a release button (not shown) is pressed by the photographer, an image photoelectrically converted by the imaging section 3 is stored in a memory (not shown). In this manner, the photographer can photograph the subject with the camera 1. FIG. In the present embodiment, an example of a mirrorless camera has been described. , the same effects as those of the camera 1 can be obtained.

Note that the contents described below can be appropriately adopted within a range that does not impair the optical performance.

In this embodiment, the variable power optical system ZL having a 5-group configuration is shown, but the above configuration conditions and the like can also be applied to other group configurations such as 6-group and 7-group configuration. A configuration in which a lens or lens group is added closest to the object side, or a configuration in which a lens or lens group is added closest to the image plane side may be used. Specifically, a configuration in which a lens group whose position with respect to the image plane is fixed during zooming or focusing is added to the side closest to the image plane. Also, a lens group refers to a portion having at least one lens separated by an air gap that changes during zooming or focusing. A lens component refers to a single lens or a cemented lens in which a plurality of lenses are cemented together.

Also, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to form a focusing lens group that performs focusing from an object at infinity to an object at a short distance. In this case, the focusing lens group can also be applied to autofocus and is suitable for driving a motor (such as an ultrasonic motor) for autofocus. In particular, it is preferable that at least a portion of the fourth lens group G4 is used as a focusing lens group, and the positions of the other lenses with respect to the image plane are fixed during focusing. Considering the load on the motor, the focusing lens group preferably consists of a single lens.

In addition, the lens group or partial lens group is moved so as to have a displacement component in the direction perpendicular to the optical axis, or rotated (oscillated) in the in-plane direction including the optical axis to correct image blur caused by camera shake. An anti-vibration lens group may also be used. In particular, it is preferable to use at least part of the third lens group G3 as a vibration reduction lens group.

Also, the lens surface may be spherical, planar, or aspherical. If the lens surface is spherical or flat, it is preferable because it facilitates lens processing and assembly adjustment and prevents deterioration of optical performance due to errors in processing and assembly adjustment. Also, even if the image plane is deviated, there is little deterioration in rendering performance, which is preferable. If the lens surface is aspherical, the aspherical surface can be ground aspherical, glass-molded aspherical, which is formed into an aspherical shape from glass, or composite aspherical, which is formed into an aspherical shape from resin on the surface of glass. Any aspheric surface may be used. Further, the lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

The aperture stop S is preferably arranged in the vicinity of or inside the third lens group G3, but a lens frame may be used instead of providing a member as the aperture stop.

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

Further, the variable power optical system ZL of this embodiment has a variable power ratio of about 1.8 to 10 times.

The outline of the method for manufacturing the variable-magnification optical system ZL according to this embodiment will be described below with reference to FIG. First, each lens is arranged to prepare the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 (step S100). When zooming to the telephoto end state, the lens groups G1 to G5 are arranged so that the distance between them changes (step S200). Also, the fourth lens group G4 is arranged to move along the optical axis during focusing (step S300), and one lens component is arranged as the first lens group G1 (step S400).

Specifically, in this embodiment, for example, as shown in FIG. 1, in order from the object side, a cemented positive lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12 are cemented together; A positive meniscus lens L13 having a convex surface facing the object side is arranged as a first lens group G1, and a negative meniscus lens L21 having an aspherical surface formed by providing a resin layer on the lens surface on the object side, a biconcave negative lens L21. A second lens group G2 is formed by arranging a negative lens L22 and a biconvex positive lens L23, and a positive meniscus lens L31 having an aspheric lens surface on the object side, an aperture stop S, and an object side lens. A cemented positive lens in which a negative meniscus lens L32 having a convex surface facing toward the object side and a positive meniscus lens L33 having a convex surface facing the object side are cemented together, and a biconvex positive lens L34 and a lens surface on the image side are formed in an aspherical shape. , a cemented positive lens cemented with a negative meniscus lens L35 having a concave surface facing the object side is arranged as a third lens group G3, and a negative meniscus lens having an aspheric lens surface on the image side. A fourth lens group G4 is provided with a negative lens L41 having a shape, and a positive meniscus lens L51 having a concave surface facing the object side and having aspherical lens surfaces on the object side and the image side is disposed. are referred to as a fifth lens group G5. The lens groups prepared in this way are arranged according to the procedure described above to manufacture the variable power optical system ZL.

With the configuration described above, it is possible to provide a variable power optical system ZL that is compact and has excellent optical performance, an optical apparatus having this variable power optical system ZL, and a method for manufacturing the variable power optical system ZL.

Each embodiment of the present application will be described below with reference to the drawings. 1, 6, 11, 16, 21, and 26 are cross-sectional views showing the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL6) according to each example. . At the bottom of the cross-sectional views of these variable power optical systems ZL1 to ZL6, each lens group when changing power from the wide-angle end state (W) to the telephoto end state (T) via the intermediate focal length state (M) The directions of movement of G1-G5 along the optical axis are indicated by arrows.

In each embodiment, the aspherical surface has a height y in the direction perpendicular to the optical axis, and the distance along the optical axis from the tangent plane of the vertex of each aspherical surface at height y to each aspherical surface (amount of sag) is S(y), r is the radius of curvature of the reference sphere (paraxial radius of curvature), K is the conic constant, and An is the n-th order aspherical surface coefficient. . In the following examples, "En" indicates "×10 ^-n ".

S(y)=(y ² /r)/{1+(1−K×y ² /r ² ) ^1/2 }
+A4×y4+A6× ^y6 +A8× ^y8 +A10× ^y10 +A12× ^{y12 (} a)

In each embodiment, the second-order aspheric coefficient A2 is zero. In addition, in the tables of each example, an asterisk (*) is attached to the right side of the surface number of an aspherical surface.

[First embodiment (reference example) ]
FIG. 1 is a diagram showing the configuration of a variable magnification optical system ZL1 according to the first embodiment. This variable magnification optical system ZL1 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable-magnification optical system ZL1, the first lens group G1 is a cemented positive lens in which, from the object side, 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 are cemented together. consists of The second lens group G2 is composed of, in order from the object side, a biconcave negative lens L21, a biconcave negative lens L22, and a positive meniscus lens L23 having a convex surface facing the object side. The third lens group G3 includes, in order from the object side, a positive double-convex positive lens L31 having an aspherical lens surface on the object side, and a double-convex positive lens L32 with a concave surface facing the object side. It is composed of a cemented positive lens cemented with a negative meniscus lens L33, and a cemented positive lens cemented with a negative meniscus lens L34 having a convex surface facing the object side and a biconvex positive lens L35. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 is composed of a negative meniscus-shaped negative lens L41 having an aspherical image-side lens surface and a convex surface facing the object side. The fifth lens group G5 is composed of a positive meniscus lens L51 having a convex surface facing the object side. An aperture diaphragm S is arranged on the object side of the third lens group G3 (the object side of the positive lens L31). Also, the positive lens L31 and the negative lens L41 are glass-molded aspherical lenses. Also, the first lens group G1 is composed of one lens component (a cemented lens). The fifth lens group G5 is composed of one lens component (single lens).

When zooming from the wide-angle end state to the telephoto end state, the variable magnification optical system ZL1 increases the distance between the first lens group G1 and the second lens group G2, and the distance between the second lens group G2 and the third lens group G3 increases. , 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 increases. , the second lens group G2, the third lens group G3 and the fourth lens group G4 are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed with respect to the image plane during zooming.

Further, in this variable-magnification optical system ZL1, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side. The fourth lens group G4 is composed of a single lens.

Further, in this variable power optical system ZL1, image position correction (vibration reduction) when camera shake occurs is performed by a cemented positive lens in the third lens group G3, which is formed by cementing a biconvex positive lens L32 and a negative meniscus lens L33. This is done by moving the anti-vibration lens group Gvr so as to have a displacement component in the direction orthogonal to the optical axis. Note that the focal length of the entire system is f, and the image stabilization coefficient (the ratio of the amount of image movement on the imaging plane to the amount of movement of the image stabilization lens group Gvr in correcting the image position when camera shake occurs) is K. To correct the rotational shake of the angle .theta., the anti-vibration lens group Gvr should be moved by (f.tan .theta.)/K in the direction perpendicular to the optical axis (the same applies to the following embodiments). In the wide-angle end state of the first embodiment, the vibration reduction coefficient is 0.69 and the focal length is 10.17 [mm]. The amount of movement of the group Gvr is 0.13 [mm]. In the intermediate focal length state of the first embodiment, the vibration reduction coefficient is 0.86 and the focal length is 18.17 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.18 [mm]. In the telephoto end state of the first embodiment, the vibration reduction coefficient is 1.21 and the focal length is 48.50 [mm]. The amount of movement of the vibrating lens group Gvr is 0.35 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L34 and the biconvex positive lens L35 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 1 below lists the values of the specifications of the variable-magnification optical system ZL1. In this Table 1, f shown in the overall specifications is the focal length of the entire system, FNO is the F number, ω is the half angle of view, Y is the maximum image height, TL is the total length, and BF is the back focus value. It is shown for each end state, intermediate focal length state, and telephoto end state. Here, the total length TL indicates the distance on the optical axis from the lens surface (first surface) closest to the object side to the image plane I at infinity focus. Further, the back focus BF indicates the distance (air conversion length) on the optical axis from the lens surface closest to the image plane (32nd surface) to the image plane I when focusing on infinity. In addition, the first column m in the lens data indicates the order (surface number) of the lens surfaces from the object side along the direction in which light rays travel, the second column r indicates the radius of curvature of each lens surface, and the third column d is the distance (surface distance) on the optical axis from each optical surface to the next optical surface, and the fourth column nd and fifth column νd are the refractive index and Abbe number for the d-line (λ = 587.6 nm). is shown. A radius of curvature of 0.00000 indicates a plane, and the refractive index of air of 1.00000 is omitted. Incidentally, the lens group focal length indicates the starting surface number and the focal length of each of the first to fifth lens groups G1 to G5.

Here, the focal length f, radius of curvature r, surface spacing d, and other lengths listed in all the specifications below are generally expressed in units of "mm". The same optical performance can be obtained even if the size is reduced, so the size is not limited to this. Further, the explanation of these symbols and the explanation of the specification table are the same in the following embodiments.

(Table 1) First embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 10.17 to 18.17 to 48.50
F No = 3.54 - 4.23 - 5.73
ω [°] = 38.1 to 23.7 to 9.1
Y = 6.70 - 7.75 - 7.97
TL = 71.638 - 73.782 - 93.744
BF = 12.116 - 12.116 - 12.116
BF (air conversion length) = 12.116 to 12.116 to 12.116

[Lens data]
m r d nd νd
object ∞
1 32.34508 0.900 1.75520 27.6
2 21.15371 4.896 1.62299 58.1
3 2495.21530 D3
4 -310.92005 0.900 1.72916 54.6
5 8.14844 4.237
6 -27.47484 0.900 1.51680 63.9
7 24.23307 0.100
8 14.46734 2.374 1.84666 23.8
9 41.08040 D9
10 0.00000 0.500 Aperture diaphragm S
11* 22.59721 1.859 1.62262 58.2
12 -219.49343 1.815
13 138.78758 2.736 1.65844 50.8
14 -10.05398 0.900 1.90366 31.3
15 -19.82246 2.100
16 29.47122 0.900 1.74400 44.8
17 9.09502 3.450 1.49782 82.6
18 -16.19199 D18
19 17662.68900 1.000 1.58913 61.2
20* 19.84465 D20
21 86.05770 1.837 1.72825 28.4
22 2063.41170 12.116
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 59.03
2nd lens group 4 -10.53
Third lens group 10 14.28
4th lens group 19 -33.72
5th lens group 21 123.27

In this variable power optical system ZL1, the 11th surface and the 20th surface are aspherical. Table 2 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 2)
[Aspheric data]
11th surface K= 1.00000e+00
A4 A6 A8 A10 A12
-7.86220e-05 4.32849e-07 -1.12684e-08 0.00000e+00 0.00000e+00
20th surface K= 1.00000e+00
A4 A6 A8 A10 A12
3.63605e-06 1.58785e-06 -1.92237e-07 5.32409e-09 0.00000e+00

In this variable magnification optical system ZL1, an axial air gap D3 between the first lens group G1 and the second lens group G2, an axial air gap D9 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D18 between G3 and the fourth lens group G4 and the axial air gap D20 between the fourth lens group G4 and the fifth lens group G5 change during zooming, as described above. Table 3 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state. D0 indicates the distance from the most object-side surface (first surface) of the variable power optical system ZL1 to the object, and β indicates the magnification (the same applies to the following embodiments).

(Table 3)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 128.36 126.22 106.26
β － － － -0.0701 -0.1212 -0.3017
f 10.17 18.17 48.50 - - -
D3 1.325 6.599 20.512 1.325 6.599 20.512
D9 18.793 9.399 2.000 18.793 9.399 2.000
D18 1.500 2.765 3.044 2.048 4.084 8.517
D20 6.500 11.498 24.668 5.952 10.179 19.195

Table 4 below shows values corresponding to each conditional expression in this variable magnification optical system ZL1. In Table 4, f1 is the focal length of the first lens group G1, f4 is the focal length of the fourth lens group G4, f5 is the focal length of the fifth lens group G5, and νd1 constitutes the first lens group G1. νd5 is the Abbe number for the d-line of the lens medium constituting the fifth lens group G5, and d12t is the Abbe number for the d-line of the lens medium constituting the fifth lens group G5, and d12t is the first lens group G1 and the second lens group G2 in the telephoto end state. d12w is the distance between the first lens group G1 and the second lens group G2 in the wide-angle end state, and Σ (dit-diw) ² is the distance between each lens when zooming from the wide-angle end state to the telephoto end state. ωw represents the half angle of view in the wide-angle end state, and ωt represents the half angle of view in the telephoto end state. The description of these symbols is the same for the following embodiments.

(Table 4)
[Value corresponding to conditional expression]
(1) νd1 = 58.1
(2) f1/(d12t-d12w)=3.077
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.375
(4) f5/f1 = 2.088
(5) (-f4)/f1 = 0.571
(6) νd5 = 28.4
(7) ωw = 38.1°
(8) ωt = 9.1°

In this manner, this variable power optical system ZL1 satisfies all of the above conditional expressions (1) to (8).

FIG. 2 shows spherical aberration, astigmatism, distortion, chromatic aberration of magnification, and lateral aberration in the wide-angle end state, intermediate focal length state, and telephoto end state of this variable magnification optical system ZL1 when focused on infinity. (a), FIG. 3(a), and FIG. 4(a) show lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 2(b), FIG. 3(b), and FIG. 4(b), spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state during close-up focusing, Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. 5(a) to 5(c). In each aberration diagram, FNO indicates F number, A indicates half angle of view (unit is [°]), NA indicates numerical aperture, and H0 indicates object height. The spherical aberration diagram shows the F number or numerical aperture corresponding to the maximum aperture, the astigmatism diagram and distortion diagram show the maximum value of the half angle of view or the maximum object height, and the lateral aberration diagram shows each half area. It indicates the value of the angle or each object height. d indicates the d-line (λ=587.6 nm) and g indicates the g-line (λ=435.8 nm). In the astigmatism diagrams, a solid line indicates a sagittal image plane, and a broken line indicates a meridional image plane. Further, in the aberration diagrams of each example shown below, the same reference numerals as in this example are used. From these aberration diagrams, it can be seen that the variable power optical system ZL1 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

[Second embodiment]
FIG. 6 is a diagram showing the configuration of a variable power optical system ZL2 according to the second example. This variable magnification optical system ZL2 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable power optical system ZL2, the first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side. The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L21 with a convex surface facing the object side, a biconcave negative lens L22, and a positive meniscus lens L23 with a convex surface facing the object side. . The third lens group G3 includes, in order from the object side, a positive biconvex positive lens L31 having an aspherical lens surface on the object side and an aspherical lens surface on the image side. It is composed of a double-convex positive lens-shaped positive lens L32, and a cemented positive lens in which a negative meniscus lens L33 having a convex surface facing the object side and a double-convex positive lens L34 are cemented together. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 is composed of a negative meniscus-shaped negative lens L41 having an aspherical image-side lens surface and a convex surface facing the object side. The fifth lens group G5 is composed of a positive meniscus lens L51 having a concave surface facing the object side. An aperture stop S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. Also, the positive lens L31, the positive lens L32, and the negative lens L41 are glass-molded aspherical lenses. The first lens group G1 is composed of one lens component (single lens). The fifth lens group G5 is composed of one lens component (single lens).

When zooming from the wide-angle end state to the telephoto end state, the variable magnification optical system ZL2 increases the distance between the first lens group G1 and the second lens group G2, and the distance between the second lens group G2 and the third lens group G3 increases. , 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 increases. , the second lens group G2, the third lens group G3 and the fourth lens group G4 are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed with respect to the image plane during zooming.

Further, in this variable-magnification optical system ZL2, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side. The fourth lens group G4 is composed of a single lens.

Further, in this variable-magnification optical system ZL2, image position correction (anti-vibration) when camera shake occurs is performed by using the positive lens L32 in the third lens group G3 as a vibration reduction lens group Gvr, and setting this vibration reduction lens group Gvr to the optical axis. It is performed by moving so as to have a displacement component in the direction orthogonal to . That is, the anti-vibration lens group Gvr in this variable magnification optical system ZL2 is composed of a single lens. In the wide-angle end state of the second embodiment, the vibration reduction coefficient is 0.83 and the focal length is 10.30 [mm]. The amount of movement of the group Gvr is 0.11 [mm]. In the intermediate focal length state of the second embodiment, the vibration reduction coefficient is 1.03 and the focal length is 18.00 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.15 [mm]. In the telephoto end state of the second embodiment, the vibration reduction coefficient is 1.30 and the focal length is 29.10 [mm]. The amount of movement of the vibrating lens group Gvr is 0.20 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L33 and the biconvex positive lens L34 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 5 below lists the values of the specifications of the variable-magnification optical system ZL2.

(Table 5) Second embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 10.30 to 18.00 to 29.10
F No = 3.62 - 4.41 - 5.50
ω [°] = 37.7 to 23.9 to 15.2
Y = 6.96 to 7.83 to 7.97
TL = 61.283 - 64.483 - 73.283
BF = 13.549 to 13.549 to 13.549
BF (air conversion length) = 13.549 to 13.549 to 13.549

[Lens data]
m r d nd νd
object ∞
1 35.62351 3.039 1.51680 63.9
2 324.34362 D2
3 200.00000 1.000 1.69680 55.5
4 7.70916 3.406
5 -24.82548 0.850 1.58913 61.2
6 27.31877 0.157
7 14.00000 2.054 1.84666 23.8
8 44.00332 D8
9* 33.75124 1.404 1.62263 58.2
10 -118.85028 1.500
11 0.00000 1.500 Aperture diaphragm S
12 51.48519 1.577 1.62263 58.2
13* -28.96931 1.500
14 19.70495 0.850 1.84666 23.8
15 9.59601 2.355 1.49782 82.6
16 -13.97847 D16
17 167.72851 0.850 1.58913 61.2
18* 11.10365 D18
19 -55.00000 1.992 1.84666 23.8
20 -22.59467 13.549
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 77.16
2nd lens group 3 -10.97
3rd lens group 9 11.91
4th lens group 17 -20.22
5th lens group 19 44.05

In this variable power optical system ZL2, the 9th, 13th and 18th surfaces are formed in an aspherical shape. Table 6 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 6)
[Aspheric data]
9th surface K= 1.00000e+00
A4 A6 A8 A10 A12
-1.17196e-04 -1.66927e-06 4.54983e-08 0.00000e+00 0.00000e+00
13th side K= 1.00000e+00
A4 A6 A8 A10 A12
3.95781e-05 -7.83445e-07 2.83596e-08 0.00000e+00 0.00000e+00
18th surface K= 1.00000e+00
A4 A6 A8 A10 A12
3.84742e-05 -3.95114e-06 2.48978e-07 -8.34383e-09 0.00000e+00

In this variable magnification optical system ZL2, an axial air space D2 between the first lens group G1 and the second lens group G2, an axial air space D8 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D16 between G3 and the fourth lens group G4 and the axial air gap D18 between the fourth lens group G4 and the fifth lens group G5 change during zooming, as described above. Table 7 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state.

(Table 7)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 138.72 135.52 126.72
β - - - -0.0678 -0.1165 -0.1927
f 10.30 18.00 29.10 － － －
D2 1.800 7.462 12.655 1.800 7.462 12.655
D8 14.391 6.090 1.800 14.391 6.090 1.800
D16 1.500 3.314 4.791 1.835 4.143 6.489
D18 6.010 10.034 16.454 5.675 9.205 14.757

Table 8 below shows values corresponding to each conditional expression in this variable magnification optical system ZL2.

(Table 16)
[Value corresponding to conditional expression]
(1) νd1 = 63.9
(2) f1/(d12t-d12w)=7.108
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.297
(4) f5/f1 = 0.571
(5) (-f4)/f1 = 0.262
(6) νd5 = 23.8
(7) ωw = 37.7°
(8) ωt = 15.2°

Thus, this variable power optical system ZL2 satisfies all of the conditional expressions (1) to (8).

FIG. 7 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, lateral chromatic aberration diagrams, and lateral aberration diagrams in the wide-angle end state, intermediate focal length state, and telephoto end state when focusing on infinity of this zoom optical system ZL2. (a), FIG. 8(a), and FIG. 9(a) show lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 7(b), FIG. 8(b), and FIG. 9(b) show spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of close focus. Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. From these aberration diagrams, it can be seen that the variable power optical system ZL2 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

[Third embodiment]
FIG. 11 is a diagram showing the configuration of a variable power optical system ZL3 according to the third example. This variable magnification optical system ZL3 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable magnification optical system ZL3, the first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side. The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, and a biconcave negative lens having aspherical lens surfaces on the object side and the image side. L22 and a positive meniscus lens L23 having a convex surface facing the object side. The third lens group G3 includes, in order from the object side, a positive biconvex positive lens L31 having an aspherical lens surface on the object side and an aspherical lens surface on the image side. It is composed of a double-convex positive lens-shaped positive lens L32, and a cemented positive lens in which a negative meniscus lens L33 having a convex surface facing the object side and a double-convex positive lens L34 are cemented together. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 is composed of a negative meniscus-shaped negative lens L41 having an aspherical image-side lens surface and a convex surface facing the object side. The fifth lens group G5 is composed of a positive meniscus lens L51 having a concave surface facing the object side. An aperture stop S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. The negative lens L22, the positive lens L31, the positive lens L32 and the negative lens L41 are glass molded aspherical lenses. The first lens group G1 is composed of one lens component (single lens). The fifth lens group G5 is composed of one lens component (single lens).

When zooming from the wide-angle end state to the telephoto end state, the variable-magnification optical system ZL3 increases the distance between the first lens group G1 and the second lens group G2. , 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 increases. , the second lens group G2, the third lens group G3 and the fourth lens group G4 are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed with respect to the image plane during zooming.

Further, in this variable-magnification optical system ZL3, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side. The fourth lens group G4 is composed of a single lens.

Further, in this variable-power optical system ZL3, image position correction (anti-vibration) when a camera shake occurs is performed by using the positive lens L32 in the third lens group G3 as a vibration reduction lens group Gvr, and setting this vibration reduction lens group Gvr to the optical axis. It is performed by moving so as to have a displacement component in the direction orthogonal to . That is, the anti-vibration lens group Gvr in this variable power optical system ZL3 is composed of a single lens. In the wide-angle end state of the third embodiment, the vibration reduction coefficient is 0.41 and the focal length is 10.30 [mm]. The amount of movement of the group Gvr is 0.22 [mm]. Further, in the intermediate focal length state of the third embodiment, the vibration reduction coefficient is 0.51 and the focal length is 18.00 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.31 [mm]. In the telephoto end state of the third embodiment, the vibration reduction coefficient is 0.64 and the focal length is 29.10 [mm]. The amount of movement of the vibrating lens group Gvr is 0.40 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L33 and the biconvex positive lens L34 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 9 below lists the values of the specifications of the variable-magnification optical system ZL3.

(Table 9) Third embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 10.30 to 18.00 to 29.10
F No = 3.61 - 4.40 - 5.52
ω [°] = 40.2 to 24.2 to 15.4
Y = 8.19 to 8.19 to 8.19
TL = 63.284 - 64.891 - 76.284
BF = 13.550 - 13.550 - 13.550
BF (air conversion length) = 13.550 to 13.550 to 13.550

[Lens data]
m r d nd νd
object ∞
1 33.61149 3.895 1.51680 63.9
2 323.38590 D2
3 200.00000 1.000 1.67003 47.1
4 7.75519 3.712
5* -199.11981 0.850 1.62263 58.2
6* 12.83535 1.215
7 13.51415 2.470 1.80518 25.4
8 57.19295 D8
9* 22.27845 1.553 1.58913 61.2
10 -54.73672 1.500
11 0.00000 1.500 Aperture diaphragm S
12 166.91413 1.403 1.58913 61.2
13* -42.48113 1.500
14 24.65589 0.850 1.75520 27.6
15 8.64799 2.346 1.49782 82.6
16 -12.66309 D16
17 141.08623 0.850 1.62263 58.2
18* 12.57056 D18
19 -76.77811 1.891 1.84666 23.8
20 -26.30007 13.550
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 72.25
2nd lens group 3 -11.94
Third lens group 9 12.82
4th lens group 17 -22.22
5th lens group 19 46.45

In this variable power optical system ZL3, the fifth, sixth, ninth, thirteenth and eighteenth surfaces are aspherical. Table 10 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 10)
[Aspheric data]
5th surface K = 1.00000e+00
A4 A6 A8 A10 A12
2.63618e-04 -4.56871e-06 4.40438e-08 -1.68618e-10 0.00000e+00
6th surface K = 1.00000e+00
A4 A6 A8 A10 A12
1.82171e-04 -6.53508e-06 7.09825e-08 -9.77402e-10 3.44260e-12
9th surface K= 1.00000e+00
A4 A6 A8 A10 A12
-1.19764e-04 -1.25633e-06 1.89897e-08 0.00000e+00 0.00000e+00
13th side K= 1.00000e+00
A4 A6 A8 A10 A12
3.12457e-05 -9.85529e-07 2.86908e-08 0.00000e+00 0.00000e+00
18th surface K= 1.00000e+00
A4 A6 A8 A10 A12
3.02684e-05 4.14910e-06 -5.85881e-07 2.45691e-08 0.00000e+00

In this variable magnification optical system ZL3, an axial air gap D2 between the first lens group G1 and the second lens group G2, an axial air gap D8 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D16 between G3 and the fourth lens group G4 and the axial air gap D18 between the fourth lens group G4 and the fifth lens group G5 change during zooming, as described above. Table 11 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state.

(Table 11)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 136.72 135.11 123.72
β － － － -0.0680 -0.1161 -0.1915
f 10.30 18.00 29.10 － － －
D2 1.800 7.059 13.463 1.800 7.059 13.463
D8 15.078 5.656 1.800 15.078 5.656 1.800
D16 1.500 3.201 3.473 1.902 4.184 5.298
D18 4.821 8.890 17.464 4.419 7.907 15.638

Table 12 below shows values corresponding to each conditional expression in this variable magnification optical system ZL3.

(Table 12)
[Value corresponding to conditional expression]
(1) νd1 = 63.9
(2) f1/(d12t-d12w) = 6.195
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.286
(4) f5/f1 = 0.643
(5) (-f4)/f1 = 0.308
(6) νd5 = 23.8
(7) ωw = 40.2°
(8) ωt = 15.4°

As described above, this variable power optical system ZL3 satisfies all of the above conditional expressions (1) to (8).

FIG. 12 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, lateral chromatic aberration diagrams, and lateral aberration diagrams in the wide-angle end state, intermediate focal length state, and telephoto end state of this variable power optical system ZL3 when focused on infinity. (a), FIG. 13(a), and FIG. 14(a) are lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 12(b), FIG. 13(b), and FIG. 14(b), spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state during close-up focusing. Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. From these aberration diagrams, it can be seen that the variable power optical system ZL3 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

[Fourth embodiment]
FIG. 16 is a diagram showing the configuration of a variable power optical system ZL4 according to the fourth example. This variable magnification optical system ZL4 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable magnification optical system ZL4, the first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side. The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, and a biconcave negative lens having aspherical lens surfaces on the object side and the image side. L22 and a positive meniscus lens L23 having a convex surface facing the object side. The third lens group G3 includes, in order from the object side, a positive biconvex positive lens L31 having an aspherical lens surface on the object side and an aspherical lens surface on the image side. It is composed of a double-convex positive lens-shaped positive lens L32, and a cemented positive lens in which a negative meniscus lens L33 having a convex surface facing the object side and a double-convex positive lens L34 are cemented together. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 is composed of a negative lens L41 having a biconcave negative lens shape with an aspherical lens surface on the image side. The fifth lens group G5 is composed of a positive meniscus lens L51 having a concave surface facing the object side. An aperture stop S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. The negative lens L22, the positive lens L31, the positive lens L32 and the negative lens L41 are glass molded aspherical lenses. The first lens group G1 is composed of one lens component (single lens). The fifth lens group G5 is composed of one lens component (single lens).

When zooming from the wide-angle end state to the telephoto end state, the variable power optical system ZL4 increases the distance between the first lens group G1 and the second lens group G2, and the distance between the second lens group G2 and the third lens group G3 increases. , 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 increases. , the second lens group G2, the third lens group G3 and the fourth lens group G4 are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed with respect to the image plane during zooming.

Further, in this variable-magnification optical system ZL4, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side. The fourth lens group G4 is composed of a single lens.

Further, in this variable-power optical system ZL4, image position correction (anti-vibration) when a camera shake occurs is performed by using the positive lens L32 in the third lens group G3 as a vibration reduction lens group Gvr, and setting this vibration reduction lens group Gvr to the optical axis. It is performed by moving so as to have a displacement component in the direction orthogonal to . That is, the anti-vibration lens group Gvr in this variable magnification optical system ZL4 is composed of a single lens. In the wide-angle end state of the fourth embodiment, the vibration reduction coefficient is 0.96 and the focal length is 9.27 [mm]. The amount of movement of the group Gvr is 0.08 [mm]. In the intermediate focal length state of the fourth embodiment, the vibration reduction coefficient is 1.22 and the focal length is 18.00 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.13 [mm]. In the telephoto end state of the fourth embodiment, the vibration reduction coefficient is 1.54 and the focal length is 29.10 [mm]. The amount of movement of the vibrating lens group Gvr is 0.17 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L33 and the biconvex positive lens L34 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 13 below lists the values of the specifications of the variable magnification optical system ZL4.

(Table 13) Fourth embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 9.27 to 18.00 to 29.10
F No = 3.63 - 4.51 - 5.62
ω [°] = 40.7 to 23.9 to 15.2
Y = 6.80 to 7.86 to 7.97
TL = 64.283 - 67.004 - 76.283
BF = 13.549 to 13.549 to 13.549
BF (air conversion length) = 13.549 to 13.549 to 13.549

[Lens data]
m r d nd νd
object ∞
1 33.97551 3.713 1.51680 63.9
2 313.97719 D2
3 200.00000 1.000 1.69680 55.5
4 7.55046 4.060
5* -38.65804 0.850 1.58913 61.2
6* 21.29952 0.100
7 14.00000 2.227 1.84666 23.8
8 42.23084 D8
9* 44.75981 1.317 1.62262 58.2
10 -539.86502 1.500
11 0.00000 1.500 Aperture diaphragm S
12 34.24579 1.609 1.62262 58.2
13* -29.07077 1.500
14 19.00255 0.850 1.90200 25.3
15 9.43667 2.363 1.49782 82.6
16 -12.69277 D16
17 -445.11665 0.850 1.58913 61.2
18* 11.74230 D18
19 -104.44105 1.997 1.84666 23.8
20 -27.62902 13.549
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 73.39
2nd lens group 3 -10.86
Third lens group 9 11.78
4th lens group 17 -19.41
5th lens group 19 43.85

In this variable power optical system ZL4, the fifth, sixth, ninth, thirteenth and eighteenth surfaces are aspherical. Table 14 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 14)
[Aspheric data]
5th surface K = 1.00000e+00
A4 A6 A8 A10 A12
-5.78996e-05 1.17227e-06 -2.35038e-08 8.42883e-11 0.00000e+00
6th surface K = 1.00000e+00
A4 A6 A8 A10 A12
-9.12145e-05 8.05476e-07 -2.35584e-08 0.00000e+00 0.00000e+00
9th surface K= 1.00000e+00
A4 A6 A8 A10 A12
-1.31071e-04 -1.59209e-06 2.45019e-08 0.00000e+00 0.00000e+00
13th side K= 1.00000e+00
A4 A6 A8 A10 A12
5.13314e-05 -5.12176e-07 1.98470e-08 0.00000e+00 0.00000e+00
18th surface K= 1.00000e+00
A4 A6 A8 A10 A12
2.28330e-05 -7.34466e-07 -1.38689e-07 6.30019e-09 0.00000e+00

In this variable magnification optical system ZL4, an axial air space D2 between the first lens group G1 and the second lens group G2, an axial air space D8 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D16 between G3 and the fourth lens group G4 and the axial air gap D18 between the fourth lens group G4 and the fifth lens group G5 change during zooming, as described above. Table 15 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state.

(Table 15)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 135.72 133.00 123.72
β － － － -0.0616 -0.1160 -0.1915
f 9.27 18.00 29.10 - - -
D2 1.814 8.601 13.713 1.814 8.601 13.713
D8 16.516 5.968 1.800 16.516 5.968 1.800
D16 1.501 3.393 4.413 1.768 4.173 5.948
D18 5.466 10.056 17.372 5.200 9.276 15.837

Table 16 below shows values corresponding to each conditional expression in this variable power optical system ZL4.

(Table 16)
[Value corresponding to conditional expression]
(1) νd1 = 63.9
(2) f1/(d12t-d12w) = 6.168
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.279
(4) f5/f1 = 0.597
(5) (-f4)/f1=0.264
(6) νd5 = 23.8
(7) ωw = 40.7°
(8) ωt = 15.2°

Thus, this variable power optical system ZL4 satisfies all of the conditional expressions (1) to (8).

FIG. 17 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, lateral chromatic aberration diagrams, and lateral aberration diagrams in the wide-angle end state, intermediate focal length state, and telephoto end state of this variable power optical system ZL4 when focused on infinity. (a), FIG. 18(a), and FIG. 19(a) are lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 17(b), FIG. 18(b), and FIG. 19(b), spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state during close-up focusing. Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. From these aberration diagrams, it can be seen that the variable power optical system ZL4 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

[Fifth embodiment]
FIG. 21 is a diagram showing the configuration of a variable power optical system ZL5 according to the fifth example. This variable magnification optical system ZL5 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable magnification optical system ZL5, the first lens group G1 is composed of a biconvex positive lens L11. The second lens group G2 is composed of, in order from the object side, a biconcave negative lens L21, a biconcave negative lens L22, and a positive meniscus lens L23 having a convex surface facing the object side. The third lens group G3 includes, in order from the object side, a biconvex positive lens L31 having an aspheric lens surface on the object side, a positive meniscus lens L32 having a concave surface facing the object side, and an object lens. A cemented positive lens cemented with a negative meniscus lens L33 having a concave surface facing the object side, and a cemented positive lens cemented with a negative meniscus lens L34 having a convex surface facing the object side cemented with a biconvex positive lens L35. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave negative lens shape with an aspherical lens surface on the image side. It consists of cemented cemented negative lenses. The fifth lens group G5 is composed of a cemented positive lens in which a biconvex positive lens L51 and a biconcave negative lens L52 are cemented in order from the object side. An aperture diaphragm S is arranged on the object side of the third lens group G3 (the object side of the positive lens L31). Also, the positive lens L31, the positive lens L32, and the negative lens L42 are glass-molded aspherical lenses. The first lens group G1 is composed of one lens component (single lens). The fifth lens group G5 is composed of one lens component (cemented lens).

When zooming from the wide-angle end state to the telephoto end state, the variable-magnification optical system ZL5 increases the distance between the first lens group G1 and the second lens group G2. , 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 increases. , the second lens group G2, the third lens group G3 and the fourth lens group G4 are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed with respect to the image plane during zooming.

Further, in this variable-magnification optical system ZL5, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side.

Further, in this variable magnification optical system ZL5, image position correction (anti-vibration) when a camera shake occurs is performed by using a cemented positive lens in which the positive meniscus lens L32 and the negative meniscus lens L33 are cemented together in the third lens group G3 as an anti-vibration lens. This is done by moving the anti-vibration lens group Gvr so as to have a displacement component in the direction orthogonal to the optical axis. In the wide-angle end state of the fifth embodiment, the vibration reduction coefficient is 0.43 and the focal length is 10.30 [mm]. The amount of movement of the group Gvr is 0.21 [mm]. In the intermediate focal length state of the fifth embodiment, the vibration reduction coefficient is 0.56 and the focal length is 18.00 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.28 [mm]. In the telephoto end state of the fifth embodiment, the vibration reduction coefficient is 0.73 and the focal length is 30.26 [mm]. The amount of movement of the vibrating lens group Gvr is 0.36 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L34 and the biconvex positive lens L35 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 17 below lists the values of the specifications of the variable magnification optical system ZL5.

(Table 17) Fifth embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 10.30 to 18.00 to 30.26
F No = 3.71 - 4.55 - 5.75
ω [°] = 37.7 to 23.9 to 14.5
Y = 6.77 to 7.77 to 7.97
TL = 64.245 - 66.885 - 79.284
BF = 12.117 - 12.117 - 12.117
BF (air conversion length) = 12.117 to 12.117 to 12.117

[Lens data]
m r d nd νd
object ∞
1 57.09618 2.833 1.49782 82.6
2-83.26625 D2
3 -64.01769 0.900 1.72916 54.6
4 8.73070 2.764
5 -49.39768 0.900 1.51680 63.9
6 20.00511 0.437
7 13.86318 2.129 1.84666 23.8
8 46.07446 D8
9 0.00000 0.500 Aperture diaphragm S
10* 21.28713 1.806 1.62262 58.2
11 -219.49343 1.800
12 -937.71858 2.288 1.65844 50.8
13 -12.03509 0.900 1.90366 31.3
14 -23.24399 2.100
15 29.47122 0.900 1.74965 34.0
16 9.78909 2.762 1.49782 82.6
17-16.20858 D17
18 -186.63581 1.000 2.00069 25.5
19 -30.00000 0.900 1.62940 35.4
20* 22.83165 D20
21 70.62458 2.209 1.84666 23.8
22 -100.00000 0.900 1.72825 28.4
23 2063.41170 12.117
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 68.50
2nd lens group 3 -11.80
Third lens group 9 14.83
4th lens group 18 -48.81
5th lens group 21 78.06

In this variable power optical system ZL5, the 10th and 20th surfaces are aspherical. Table 18 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 18)
[Aspheric data]
10th surface K = 1.00000e+00
A4 A6 A8 A10 A12
-7.99825e-05 1.73203e-07 -1.66026e-08 0.00000e+00 0.00000e+00
20th surface K= 1.00000e+00
A4 A6 A8 A10 A12
3.01138e-05 -4.83908e-07 5.39231e-10 1.40011e-11 0.00000e+00

In this variable magnification optical system ZL5, an axial air space D2 between the first lens group G1 and the second lens group G2, an axial air space D8 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D17 between G3 and the fourth lens group G4 and the axial air gap D20 between the fourth lens group G4 and the fifth lens group G5 change during zooming, as described above. Table 19 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state.

(Table 19)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 185.75 183.11 170.72
β － － － -0.0518 -0.0906 -0.1581
f 10.30 18.00 30.26 - - -
D2 1.800 5.650 11.395 1.800 5.650 11.395
D8 15.201 6.380 2.000 15.201 6.380 2.000
D17 1.500 3.058 2.955 2.214 4.720 6.232
D20 5.600 11.652 22.789 4.886 9.990 19.513

Table 20 below shows values corresponding to each conditional expression in this variable power optical system ZL5.

(Table 20)
[Value corresponding to conditional expression]
(1) νd1 = 82.6
(2) f1/(d12t-d12w)=7.139
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.163
(4) f5/f1 = 1.140
(5) (-f4)/f1=0.713
(6) νd5 = 28.4
(7) ωw = 37.7°
(8) ωt = 14.5°

Thus, this variable power optical system ZL5 satisfies all of the conditional expressions (1) to (8).

FIG. 22 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, lateral chromatic aberration diagrams, and lateral aberration diagrams in the wide-angle end state, intermediate focal length state, and telephoto end state of this zoom optical system ZL5 when focused on infinity. (a), FIG. 23(a), and FIG. 24(a) are lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 22(b), FIG. 23(b), and FIG. 24(b), spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state during close-up focusing. Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. From these aberration diagrams, it can be seen that the variable power optical system ZL5 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

[Sixth embodiment (reference example) ]
FIG. 26 is a diagram showing the configuration of a variable power optical system ZL6 according to the sixth example. This variable magnification optical system ZL6 includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. , a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power.

In this variable magnification optical system ZL6, the first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side. The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L21 with a convex surface facing the object side, a biconcave negative lens L22, and a positive meniscus lens L23 with a convex surface facing the object side. . The third lens group G3 includes, in order from the object side, a positive double-convex positive lens L31 having an aspherical lens surface on the object side, and a double-convex positive lens L32 with a concave surface facing the object side. It is composed of a cemented positive lens cemented with a negative meniscus lens L33, and a cemented positive lens cemented with a negative meniscus lens L34 having a convex surface facing the object side and a biconvex positive lens L35. Thus, the third lens group G3 is composed of three lens components having positive refractive power. The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave negative lens shape with an aspherical lens surface on the image side. It consists of cemented cemented negative lenses. The fifth lens group G5 is composed of a cemented positive lens in which a biconvex positive lens L51 and a biconcave negative lens L52 are cemented in order from the object side. An aperture diaphragm S is arranged on the object side of the third lens group G3 (the object side of the positive lens L31). Also, the positive lens L31, the positive lens L32, and the negative lens L42 are glass-molded aspherical lenses. The first lens group G1 is composed of one lens component (single lens). The fifth lens group G5 is composed of one lens component (a cemented lens).

When zooming from the wide-angle end state to the telephoto end state, the variable power optical system ZL6 increases the distance between the first lens group G1 and the second lens group G2, and the distance between the second lens group G2 and the third lens group G3 increases. , the distance between the third lens group G3 and the fourth lens group G4 changes, the distance between the fourth lens group G4 and the fifth lens group G5 changes, and the back focus BF changes. In addition, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4 and the fifth lens group are configured to move along the optical axis. Note that the aperture stop S moves integrally with the third lens group G3.

Further, in this variable-magnification optical system ZL6, focusing from infinity to a short-distance object point is performed by moving the fourth lens group G4 toward the image side.

Further, in this variable-power optical system ZL6, image position correction (anti-vibration) when camera shake occurs is performed by cementing the positive meniscus lens L32 and the negative meniscus lens L33 in the third lens group G3 as an anti-vibration lens. This is done by moving the anti-vibration lens group Gvr so as to have a displacement component in the direction orthogonal to the optical axis. In the wide-angle end state of the sixth embodiment, the vibration reduction coefficient is 0.74 and the focal length is 10.30 [mm]. The amount of movement of the group Gvr is 0.12 [mm]. In the intermediate focal length state of the sixth embodiment, the vibration reduction coefficient is 0.91 and the focal length is 18.00 [mm]. The amount of movement of the anti-vibration lens group Gvr is 0.17 [mm]. In the telephoto end state of the sixth embodiment, the vibration reduction coefficient is 1.08 and the focal length is 30.00 [mm]. The amount of movement of the vibrating lens group Gvr is 0.24 [mm]. Here, the cemented positive lens obtained by cementing the negative meniscus lens L34 and the biconvex positive lens L35 corresponds to the lens component G3L closest to the image side in the third lens group G3.

Table 21 below lists the values of the specifications of the variable magnification optical system ZL6.

(Table 21) Sixth embodiment [overall specifications]
Wide-angle state Intermediate focal length state Telephoto state f = 10.30 to 18.00 to 30.00
F No = 4.10 - 4.82 - 5.62
ω [°] = 37.7 to 23.9 to 14.9
Y = 6.77 to 7.58 to 7.80
TL = 64.247 to 65.089 to 78.749
BF = 7.838 - 16.554 - 15.244
BF (air conversion length) = 7.838 ~ 16.554 ~ 15.244

[Lens data]
m r d nd νd
object ∞
1 22.52929 4.999 1.49782 82.6
2 248.61062 D2
3 4865.94900 0.900 1.72916 54.6
4 8.63494 3.142
5 -64.21918 0.900 1.51680 63.9
6 13.26867 1.920
7 13.33792 1.985 1.84666 23.8
8 25.02924 D8
9 0.00000 0.500 Aperture diaphragm S
10* 18.92196 1.753 1.62262 58.2
11 -219.49343 1.800
12 75.77393 2.459 1.65844 50.8
13 -8.96476 0.900 1.90366 31.3
14 -17.67634 2.375
15 29.47122 0.900 1.65290 47.9
16 6.98841 2.867 1.49782 82.6
17-20.84873 D17
18 -63.57202 1.000 2.00069 25.5
19 -30.00000 0.900 1.65816 33.0
20* 14.81127 D20
21 22.62294 3.433 1.74682 36.0
22 -100.00000 0.900 1.74397 44.9
23 2063.41170 BF
Image plane ∞

[Lens group focal length]
Lens group Starting surface Focal length 1st lens group 1 49.40
2nd lens group 3 -10.00
Third lens group 9 13.16
4th lens group 18 -20.36
5th lens group 21 30.57

In this variable power optical system ZL6, the 10th and 20th surfaces are aspherical. Table 22 below shows the data of the aspheric surface, namely the values of the conic constant K and each of the aspheric constants A4-A12.

(Table 22)
[Aspheric data]
10th surface K = 1.00000e+00
A4 A6 A8 A10 A12
-7.14717e-05 2.26370e-07 3.68476e-09 0.00000e+00 0.00000e+00
20th surface K= 1.00000e+00
A4 A6 A8 A10 A12
-5.68760e-06 -6.85618e-07 -3.31915e-08 5.71453e-10 0.00000e+00

In this variable magnification optical system ZL6, an axial air space D2 between the first lens group G1 and the second lens group G2, an axial air space D8 between the second lens group G2 and the third lens group G3, and the third lens group The axial air gap D17 between G3 and the fourth lens group G4, the axial air gap D20 between the fourth lens group G4 and the fifth lens group G5, and the back focus BF change during zooming as described above. do. Table 23 below shows the variable distance in each focal length state of the wide-angle end state (W), the intermediate focal length state (M) and the telephoto end state (T) in the infinity in-focus state and the close-up in-focus state.

(Table 23)
[Variable interval data]
infinity close
WMT WMT
D0 ∞ ∞ ∞ 185.91 184.85 170.99
β － － － -0.0514 -0.0907 -0.1507
f 10.30 18.00 30.00 - - -
D2 2.001 5.151 12.675 2.001 5.151 12.675
D8 13.676 4.791 2.054 13.376 4.491 1.754
D17 2.617 1.500 2.548 3.029 2.448 4.656
D20 4.483 3.461 12.597 4.071 2.513 10.489
BF 7.838 16.554 15.244 7.982 16.917 15.808

Table 24 below shows values corresponding to each conditional expression in this variable magnification optical system ZL6.

(Table 24)
[Value corresponding to conditional expression]
(1) νd1 = 82.6
(2) f1/(d12t-d12w) = 4.628
(3) (d12t-d12w) ² /Σ(dit-diw) ² = 0.362
(4) f5/f1 = 0.619
(5) (-f4)/f1 = 0.412
(7) ωw = 37.7°
(8) ωt = 14.9°

Thus, this variable power optical system ZL6 satisfies the above conditional expressions (1) to (5), (7) and (8).

FIG. 27 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, lateral chromatic aberration diagrams, and lateral aberration diagrams in the wide-angle end state, intermediate focal length state, and telephoto end state of this variable power optical system ZL6 when focused on infinity. (a), FIG. 28(a), and FIG. 29(a) are lateral aberration diagrams when image blur is corrected in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 27(b), FIG. 28(b), and FIG. 29(b), spherical aberration diagrams, astigmatism diagrams, and distortion diagrams in the wide-angle end state, the intermediate focal length state, and the telephoto end state during close-up focusing, Magnification chromatic aberration diagrams and lateral aberration diagrams are shown in FIGS. From these aberration diagrams, it can be seen that the variable magnification optical system ZL6 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

ZL (ZL1 to ZL6) variable power optical system G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group Gvr Anti-vibration lens group 1 Camera (optical device)

Claims (9)

From the object side,
a first lens group having positive refractive power;
a second lens group having negative refractive power;
a third lens group having positive refractive power;
a fourth lens group having negative refractive power;
Consists of substantially five lens groups with a fifth lens group having positive refractive power,
During zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the distance between the third lens group and the fourth lens group changes, the distance between the fourth lens group and the fifth lens group changes,
During focusing, the fourth lens group moves along the optical axis;
The first lens group is composed of one single lens,
The fifth lens group is composed of a single lens,
During zooming, the fifth lens group is fixed with respect to the image plane,
A variable-magnification optical system that satisfies the following condition:
2.000 < f1/(d12t - d12w) < 8.000
however,
d12t: the distance between the first lens group and the second lens group in the telephoto end state d12w: the distance between the first lens group and the second lens group in the wide-angle end state f1: the focal length of the first lens group 2. The variable magnification optical system according to claim 1, wherein the first lens group has a lens satisfying the following condition.
40.000 < νd1
however,
νd1: Abbe number for the d-line of the medium of the lens constituting the first lens group 3. A variable power optical system according to claim 1, wherein the following condition is satisfied.
0.120<(d12t−d12w) ² /Σ(dit−diw) ² <0.900
however,
d12t: distance between the first lens group and the second lens group in the telephoto end state d12w: distance between the first lens group and the second lens group in the wide-angle end state Σ(dit-diw)2: wide-angle end The sum of the squares of the amount of change between each lens group when zooming from the state to the telephoto end state 4. The variable-magnification optical system according to claim 1, wherein the condition of the following equation is satisfied.
0.800 < f5/f1 < 4.100
however,
f5: focal length of the fifth lens group f1: focal length of the first lens group 5. The variable magnification optical system according to claim 1, wherein the condition of the following formula is satisfied.
0.400 < (-f4)/f1 < 3.000
however,
f4: focal length of the fourth lens group f1: focal length of the first lens group 6. The variable power optical system according to any one of claims 1 to 5, wherein the fifth lens group has a lens that satisfies the following formula.
vd5 ≤ 35.000
however,
νd5: Abbe number for the d-line of the medium of the lens constituting the fifth lens group 7. The variable-magnification optical system according to claim 1 , wherein the condition of the following equation is satisfied.
29.00° < ωw < 60.00°
however,
ωw: Half angle of view in the wide-angle end state 8. The variable magnification optical system according to claim 1 , wherein the condition of the following formula is satisfied.
2.50° < ωt < 22.00°
however,
ωt: Half angle of view in telephoto end state An optical instrument comprising the variable magnification optical system according to any one of claims 1 to 8 .

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