JP6857305B2 - Variable magnification optics and optical equipment - Google Patents

Description

The present invention relates to variable magnification optical systems and optical instruments.

Conventionally, variable magnification optical systems suitable for photographic cameras, electronic still cameras, video cameras and the like have been proposed (see, for example, Patent Document 1). However, Patent Document 1 has a problem that further improvement in optical performance is required.

Japanese Unexamined Patent Publication No. 2006-113572

The variable magnification optical system according to the first aspect of the present invention has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power in order from the object side. It consists of substantially five lens groups, a third lens group, a fourth lens group having a negative refractive force, and a fifth lens group having a positive refractive force, from a wide-angle end state to a telescopic end state. At the time of magnification change, 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 4th lens group and the 5th lens group changes, and when in focus, the 4th lens group moves along the optical axis, and the 1st lens group is composed of one lens component. At the time of scaling, the fifth lens group is fixed to the image plane and satisfies the condition of the following equation.
1.000 <f5 / f1 <4.100
0.400 <(-f4) / f1 <3,000
However,
f5: Focal length of the 5th lens group f1: Focal length of the 1st lens group
f4: Focal length of the fourth lens group The lens component indicates a single lens or a junction lens.

It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. It is the aberration diagram of the wide-angle end state of the variable magnification optical system which concerns on 1st Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram of the intermediate focal length state of the variable magnification optical system which concerns on 1st Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. It is the aberration diagram of the telephoto end state of the variable magnification optical system which concerns on 1st Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable-magnification optical system according to the first embodiment, (a) is the aberration diagram in the wide-angle end state, and (b) is the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. It is the aberration diagram of the wide-angle end state of the variable magnification optical system which concerns on 2nd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram of the intermediate focal length state of the variable magnification optical system which concerns on 2nd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. It is the aberration diagram of the telephoto end state of the variable magnification optical system which concerns on 2nd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable magnification optical system according to the second embodiment, (a) is the aberration diagram in the wide-angle end state, and (b) is the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. It is the aberration diagram of the wide-angle end state of the variable magnification optical system which concerns on 3rd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram of the intermediate focal length state of the variable magnification optical system which concerns on 3rd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. It is the aberration diagram of the telephoto end state of the variable magnification optical system which concerns on 3rd Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable magnification optical system according to the third embodiment, (a) is the aberration diagram in the wide-angle end state, and (b) is the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 4th Example. It is the aberration diagram of the wide-angle end state of the variable magnification optical system which concerns on 4th Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram of the intermediate focal length state of the variable magnification optical system which concerns on 4th Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. It is the aberration diagram of the telephoto end state of the variable magnification optical system which concerns on 4th Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable magnification optical system which concerns on 4th Example, (a) is the aberration diagram in the wide-angle end state, and (b) is in the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 5th Example. FIG. 5 is an aberration diagram of the wide-angle end state of the variable magnification optical system according to the fifth embodiment, (a) is an aberration diagram in the infinity in-focus state, and (b) is an infinity-focused state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram of the intermediate focal length state of the variable magnification optical system which concerns on 5th Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. It is the aberration diagram of the telephoto end state of the variable magnification optical system which concerns on 5th Example, (a) is the aberration diagram in the infinity focusing state, and (b) is the various aberration diagram in the infinity focusing state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable magnification optical system according to the fifth embodiment, (a) is the aberration diagram in the wide-angle end state, and (b) is the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 6th Example. FIG. 6 is an aberration diagram of the wide-angle end state of the variable magnification optical system according to the sixth embodiment, (a) is an aberration diagram in the infinity in-focus state, and (b) is an infinity-focused state. It is a lateral aberration diagram when camera shake correction is performed. FIG. 6 is an aberration diagram of an intermediate focal length state of the variable magnification optical system according to the sixth embodiment, (a) is an aberration diagram in the infinity focusing state, and (b) is an infinity focusing state. It is a lateral aberration diagram when the camera shake correction is performed in. FIG. 6 is an aberration diagram of the variable magnification optical system according to the sixth embodiment in the telephoto end state, (a) is an aberration diagram in the infinity in-focus state, and (b) is an infinity in-focus state. It is a lateral aberration diagram when camera shake correction is performed. It is the aberration diagram in the close-range focusing state of the variable magnification optical system according to the sixth embodiment, (a) is the aberration diagram in the wide-angle end state, and (b) is the intermediate focal length state. (C) is a diagram of various aberrations in the telephoto end state. It is sectional drawing of the camera which carries the said variable magnification optical system. It is a flowchart for demonstrating the manufacturing method of the said variable magnification optical system.

Hereinafter, preferred embodiments will be described with reference to the drawings. As shown in FIG. 1, in the variable magnification optical system ZL according to the present embodiment, in order from the object side, a first lens group G1 having a positive refractive force, a second lens group G2 having a negative refractive force, and so on. It has a third lens group G3 having a positive refractive force, a fourth lens group G4 having a negative refractive force, and a fifth lens group G5 having a positive refractive force, and has a wide-angle end state to a telescopic end state. When the magnification is changed to, 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 third lens group G3 and the fourth lens group G3 and the fourth lens group G3 change. The distance between the lens group G4 and the fourth lens group G4 changes, and the distance between the fourth lens group G4 and the fifth lens group G5 changes. As described above, the variable magnification optical system ZL according to the present embodiment has a positive / negative positive / negative / positive five-group configuration, and the distance between the lens groups changes at the time of magnification change, so that a small size and good optical performance can be obtained. ..

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

Further, in the variable magnification optical system ZL according to the present embodiment, it is desirable that the first lens group G1 is composed of one lens component. With such a configuration, it is possible to obtain a small size and good optical performance.

Further, in the variable magnification optical system ZL according to the present embodiment, it is desirable that the fifth lens group G5 is fixed to the image plane I at the time of magnification change. Since the fifth lens group G5 is fixed to the image plane I at the time of scaling, the mechanism for moving the lens group can be simplified, and a compact variable magnification optical system ZL can be obtained. Further, the manufacturing error sensitivity (variation of astigmatism) can be reduced.

Further, in the variable magnification optical system ZL according to the present embodiment, it is desirable that the first lens group G1 has a lens satisfying the conditional expression (1) shown below.

40.000 <νd1 (1)
However,
νd1: Abbe number with respect to the d-line of the medium of the lens constituting the first lens group G1

The conditional expression (1) defines the Abbe number of the first lens group G1. By arranging a lens satisfying the 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 magnification change. In order to ensure the effect of the conditional expression (1), it is desirable that the lower limit value of the conditional expression (1) is 50.000. Further, in order to further ensure the effect of the conditional expression (1), it is desirable to set the lower limit value of the conditional expression (1) to 60.000.

Further, it is desirable that the variable magnification optical system ZL according to the present embodiment satisfies the conditional expression (2) shown below.

2.000 <f1 / (d12t-d12w) <8.00 ( 2 )
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 f1: 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. If the upper limit of the conditional expression (2) is exceeded, the fluctuation of the spherical aberration at the time of scaling cannot be suppressed when the movement amount of the first lens group G1 becomes small, which is not preferable. In order to ensure the effect of the conditional expression (2), it is desirable that the upper limit value of the conditional expression (2) is 7.600. Further, in order to further ensure the effect of the conditional expression (2), it is desirable to set the upper limit value of the conditional expression (2) to 7.300. Further, if it is less than the lower limit of the conditional expression (2), 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 the conditional expression (2), it is desirable that the lower limit value of the conditional expression (2) is 2.200. Further, in order to further ensure the effect of the conditional expression (2), it is desirable to set the lower limit value of the conditional expression (2) to 2.400.

Further, it is desirable that the variable magnification optical system ZL according to the present embodiment satisfies the conditional expression (3) shown below.

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 Sum of squares of the amount of change between each lens group when the magnification is changed from the state to the telephoto end state

In the conditional equation (3), the amount of change from the wide-angle end state of each group interval to the telephoto end state is the amount of change of the group interval between the first lens group G1 and the second lens group G2 from the wide-angle end state to the telephoto end state. It defines the relationship between. If the upper limit of the conditional expression (3) is exceeded, it becomes difficult to correct the chromatic aberration when the amount of movement of the first lens group G1 becomes large, which is not preferable. In order to ensure the effect of the conditional expression (3), it is desirable that the upper limit value of the conditional expression (3) is 0.800. Further, in order to further ensure the effect of the conditional expression (3), it is desirable to set the upper limit value of the conditional expression (3) to 0.700. Further, if it is less than the lower limit of the conditional expression (3), the fluctuation of the spherical aberration at the time of scaling cannot be suppressed when the movement amount of the first lens group G1 becomes small, which is not preferable. In order to ensure the effect of the conditional expression (3), it is desirable that the lower limit value of the conditional expression (3) is 0.140. Further, in order to further ensure the effect of the conditional expression (3), it is desirable to set the lower limit value of the conditional expression (3) to 0.150.

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

0.800 <f5 / f1 <4.10 (4)
However,
f5: Focal length of the 5th lens group G5 f1: Focal length of the 1st 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. If the upper limit of the conditional expression (4) is exceeded, the focal length of the first lens group G1 becomes small and it becomes difficult to correct chromatic aberration, which is not preferable. In order to ensure the effect of the conditional expression (4), it is desirable that the upper limit value of the conditional expression (4) is 3.750. Further, in order to further ensure the effect of the conditional expression (4), it is desirable to set the upper limit value of the conditional expression (4) to 3.400. Further, if it is less than the lower limit of the conditional expression (4), the focal length of the first lens group G1 becomes large and the total length in the telephoto end state becomes large, so that a small optical system cannot be realized. Further, it is not preferable because the fluctuation of spherical aberration and astigmatism at the time of scaling cannot be suppressed. In order to ensure the effect of the conditional expression (4), it is desirable that the lower limit value of the conditional expression (4) is 1.000. Further, in order to further ensure the effect of the conditional expression (4), it is desirable that the lower limit value of the conditional expression (4) is 1.400.

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

0.400 <(-f4) / f1 <3,000 (5)
However,
f4: Focal length of the 4th lens group G4 f1: Focal length of the 1st 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 the focusing lens group. If the upper limit of the conditional expression (5) is exceeded, fluctuations in spherical aberration and astigmatism during focusing cannot be suppressed, which is not preferable. In order to ensure the effect of the conditional expression (5), it is desirable that the upper limit value of the conditional expression (5) is 2.500. Further, in order to further ensure the effect of the conditional expression (5), it is desirable to set the upper limit value of the conditional expression (5) to 2.200. Further, when the value is lower than the lower limit of the conditional expression (5), the refractive power of the fourth lens group G4 becomes too weak, so that the amount of movement during focusing increases. Then, fluctuations in spherical aberration and astigmatism during focusing cannot be suppressed, which is not preferable. In order to ensure the effect of the conditional expression (5), it is desirable that the lower limit value of the conditional expression (5) is 0.500. Further, in order to further ensure the effect of the conditional expression (5), it is desirable to set the lower limit value of the conditional expression (5) to 0.700.

Further, in the variable magnification optical system ZL according to the present embodiment, it is desirable that the fifth lens group G5 is composed of a single lens. With such a configuration, the configuration of the variable magnification optical system ZL is simplified, and a compact lens can be realized.

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

νd5 ≤ 35.000 (6)
However,
νd5: Abbe number with respect to the d-line of the medium of the lens constituting the fifth lens group G5

The conditional expression (6) defines the Abbe number of the fifth lens group G5. If the upper limit of the conditional expression (6) is exceeded, the fluctuation of chromatic aberration of magnification at the time of scaling cannot be suppressed, which is not preferable. In order to ensure the effect of the conditional expression (6), it is desirable that the upper limit value of the conditional expression (6) is 30.000. Further, in order to further ensure the effect of the conditional expression (6), it is desirable to set the upper limit value of the conditional expression (6) to 25.000.

Further, in the variable magnification optical system ZL according to the present embodiment, it is desirable that one lens component of the first lens group G1 is composed of a single lens. With such a configuration, the configuration of the variable magnification optical system ZL can be simplified and further miniaturization can be realized.

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

29.00 ° <ωw <60.00 ° (7)
However,
ωw: Half angle of view at wide-angle end

Conditional expression (7) defines an appropriate range of the maximum half-angle of view in the wide-angle end state. By satisfying this conditional expression (7), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected while having a wide angle of view. Further, if it is less than the lower limit of the conditional expression (7), fluctuations in spherical aberration and color spherical aberration during scaling cannot be suppressed, which is not preferable. In order to ensure the effect of the conditional expression (7), it is desirable that the lower limit value of the conditional expression (7) is 32.00 °. Further, in order to further ensure the effect of the conditional expression (7), it is desirable to set the lower limit value of the conditional expression (7) to 35.00 °. Further, in order to ensure the effect of the conditional expression (7), it is desirable to set the upper limit value of the conditional expression (7) to 55.00 °. Further, in order to further ensure the effect of the conditional expression (7), it is desirable to set the upper limit value of the conditional expression (7) to 50.00 °. Further, in order to further ensure the effect of the conditional expression (7), it is desirable to set the upper limit value of the conditional expression (7) to 45.00 °.

Further, it is desirable that the variable magnification optical system ZL according to the present embodiment satisfies the conditional expression (8) shown below.

2.50 ° <ωt <22.00 ° (8)
However,
ωt: Half angle of view at the telephoto end

Conditional expression (8) defines an appropriate range of the maximum half-angle of view in the telephoto end state. By satisfying this conditional equation (8), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected. Further, when the value falls below the lower limit of the conditional expression (8), image blur correction is performed by the lens components (vibration-proof lens group Gvr) other than the most image side and the most object side in the third lens group G3 (hereinafter, "vibration-proof"). ”) Is not preferable because the eccentric coma aberration at the time of vibration isolation becomes relatively large. In order to ensure the effect of the conditional expression (8), it is desirable that the lower limit value of the conditional expression (8) is 4.50 °. Further, in order to further ensure the effect of the conditional expression (8), it is desirable that the lower limit value of the conditional expression (8) is 6.50 °. Further, in order to ensure the effect of the conditional expression (8), it is desirable to set the upper limit value of the conditional expression (8) to 20.00 °. Further, in order to further ensure the effect of the conditional expression (8), it is desirable that the upper limit value of the conditional expression (8) is 18.00 °. Further, in order to further ensure the effect of the conditional expression (8), it is desirable that the upper limit value of the conditional expression (8) is 16.00 °.

It should be noted that the conditions and configurations described above each exert the above-mentioned effects, and are not limited to those satisfying all the conditions and configurations, and any of the conditions or configurations, or any of them. It is possible to obtain the above-mentioned effects even if the combination of the above conditions or configurations is satisfied.

Next, a camera, which is an optical device provided with the variable magnification optical system ZL according to the present embodiment, will be described with reference to FIG. 31. This camera 1 is a so-called mirrorless camera of an interchangeable lens type provided with the variable magnification optical system ZL according to the present embodiment as a photographing lens 2. In the camera 1, the light from an object (subject) (not shown) is collected by the photographing lens 2 and passed through an OLPF (Optical low pass filter) (not shown) on the imaging surface of the imaging unit 3. Form a subject image. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3, and the image of the subject is generated. This image is displayed on the EVF (Electronic viewfinder) 4 provided in the camera 1. This allows the photographer to observe the subject via the EVF4.

Further, when the photographer presses the release button (not shown), the image photoelectrically converted by the image pickup unit 3 is stored in the memory (not shown). In this way, the photographer can shoot the subject with the camera 1. In this embodiment, an example of a mirrorless camera has been described, but a single-lens reflex type camera having a quick return mirror in the camera body and observing a subject by a finder optical system is used as a variable magnification optical system ZL according to the present embodiment. Even when the camera 1 is mounted, the same effect as that of the camera 1 can be obtained.

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

In the present embodiment, the variable magnification optical system ZL having a 5-group configuration is shown, but the above configuration conditions and the like can be applied to other group configurations such as 6-group and 7-group. Further, a configuration in which a lens or a lens group is added on the most object side or a configuration in which a lens or a lens group is added on the most image plane side may be used. Specifically, it is conceivable to add a lens group whose position with respect to the image plane is fixed at the time of magnification change or focusing on the image plane side. Further, the lens group refers to a portion having at least one lens separated by an air interval that changes at the time of magnification change or focusing. Further, the lens component means a single lens or a bonded lens in which a plurality of lenses are bonded.

Further, 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 for focusing from an infinity object to a short-range object. In this case, the focusing lens group can also be applied to autofocus, and is also suitable for driving a motor (such as an ultrasonic motor) for autofocus. In particular, it is preferable that at least a part of the fourth lens group G4 is a focusing lens group, and the positions of the other lenses with respect to the image plane are fixed at the time of focusing. Considering the load applied to the motor, the focusing lens group is preferably composed 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 orthogonal to the optical axis, or is rotationally moved (swinged) in the in-plane direction including the optical axis to correct image blur caused by camera shake. It may be a group of anti-vibration lenses. In particular, it is preferable that at least a part of the third lens group G3 is an anti-vibration lens group.

Further, the lens surface may be formed on a spherical surface or a flat surface, or may be formed on an aspherical surface. When the lens surface is spherical or flat, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to processing and assembly adjustment errors can be prevented, which is preferable. Further, even if the image plane is deviated, the depiction performance is less deteriorated, which is preferable. When the lens surface is aspherical, the aspherical surface is an aspherical surface formed by grinding, a glass mold aspherical surface formed by forming glass into an aspherical shape, or a composite aspherical surface formed by forming resin on the glass surface into an aspherical shape. Any aspherical surface may be used. Further, the lens surface may be a diffraction surface, and the lens may be a refractive index distribution type lens (GRIN lens) or a plastic lens.

The aperture diaphragm S is preferably arranged near or in the vicinity of or in the third lens group G3, but the role may be substituted by the frame of the lens without providing the member as the aperture diaphragm.

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

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

Hereinafter, an outline of a method for manufacturing the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. 32. 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), respectively, from the wide-angle end state. When the magnification is changed to the telephoto end state, the distance between the lens groups G1 to G5 is changed (step S200). Further, at the time of focusing, the fourth lens group G4 is arranged so as to move along the optical axis (step S300), and one lens component is arranged as the first lens group G1 (step S400).

Specifically, in the present embodiment, for example, as shown in FIG. 1, a bonded positive lens in which a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12 are joined in order from the object side, and a bonded positive lens. A positive meniscus lens L13 with a convex surface facing the object side is arranged to form the first lens group G1, and a resin layer is provided on the lens surface on the object side to form a negative meniscus lens-shaped negative lens L21, both concaves. A negative lens L22 and a biconvex positive lens L23 are arranged to form a second lens group G2, and a positive meniscus lens-shaped positive lens L31 having an aspherical lens surface on the object side, an aperture aperture S, and an object side. A bonded positive lens in which a negative meniscus lens L32 with a convex surface facing toward the surface and a positive meniscus lens L33 with a convex surface facing the object side are joined, and a biconvex positive lens L34 and a lens surface on the image side are formed in an aspherical shape. A negative meniscus lens in which a bonded positive lens joined with a negative meniscus lens-shaped negative lens L35 with a concave surface facing the object side is arranged to form a third lens group G3, and the lens surface on the image side is formed into an aspherical shape. A negative lens L41 having a shape is arranged to form a fourth lens group G4, and a positive lens L51 having a positive meniscus lens shape with a concave surface facing the object side in which the lens surfaces on the object side and the image side are formed in an aspherical shape is arranged. The fifth lens group is G5. Each lens group prepared in this way is arranged according to the procedure described above to manufacture a variable magnification optical system ZL.

With the above configuration, it is possible to provide a variable magnification optical system ZL which is small and has good optical performance, an optical device having this variable magnification optical system ZL, and a method for manufacturing the variable magnification optical system ZL.

Hereinafter, each embodiment of the present application will be described with reference to the drawings. 1, FIG. 6, FIG. 11, FIG. 16, FIG. 21, and FIG. 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 embodiment. .. Further, in the lower part of the cross-sectional view of these variable magnification optical systems ZL1 to ZL6, each lens group when changing the magnification from the wide-angle end state (W) to the telephoto end state (T) via the intermediate focal length state (M). The moving directions along the optical axes of G1 to G5 are indicated by arrows.

In each embodiment, the height of the aspherical surface in the direction perpendicular to the optical axis is y, and the distance (sag amount) along the optical axis from the tangent plane of the aspherical surface of each aspherical surface to each aspherical surface at the height y. Is S (y), the radius of curvature of the reference sphere (near-axis radius of curvature) is r, the conical constant is K, and the nth-order aspherical coefficient is An. .. In the following examples, "En" indicates " ^{x10 -n".}

S (y) = (y ² / r) / {1+ (1-K × y ² / r ² ) ^1/2 }
+ A4 x y ⁴ + A6 x y ⁶ + A8 x y ⁸ + A10 x y ¹⁰ + A12 x y ¹² (a)

In each embodiment, the second-order aspherical coefficient A2 is 0. Further, in the table of each embodiment, the aspherical surface is marked with * on the right side of the surface number.

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

In this variable magnification optical system ZL1, the first lens group G1 is a bonded positive lens in which 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 joined in order from the object side. It is composed of. Further, the second lens group G2 is composed of a biconcave negative lens L21, a biconcave negative lens L22, and a positive meniscus lens L23 with a convex surface facing the object side in order from the object side. Further, in the third lens group G3, in order from the object side, the lens surface on the object side is formed into an aspherical shape, the positive lens L31 having a biconvex regular lens shape, the biconvex regular lens L32, and the concave surface facing the object side. It is composed of a bonded positive lens in which a negative meniscus lens L33 is bonded and a bonded positive lens in which a negative meniscus lens L34 having a convex surface facing the object side and a biconvex positive lens L35 are bonded. As described above, the third lens group G3 is composed of three lens components having a positive refractive power. Further, the fourth lens group G4 is composed of a negative lens L41 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the convex surface is directed toward the object side. Further, the fifth lens group G5 is composed of a positive meniscus lens L51 having a convex surface facing the object side. Further, the aperture diaphragm S is arranged on the object side of the third lens group G3 (the object side of the positive lens L31). The positive lens L31 and the negative lens L41 are glass-molded aspherical lenses. Further, the first lens group G1 is composed of one lens component (junction lens). Further, the fifth lens group G5 is composed of one lens component (single lens).

In this variable magnification optical system ZL1, the distance between the first lens group G1 and the second lens group G2 increases when the magnification is changed from the wide-angle end state to the telescopic end state, and the second lens group G2 and the third lens group G3 The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. , The second lens group G2, the third lens group G3, and the fourth lens group G4 are configured to move along the optical axis. The aperture diaphragm S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed to the image plane at the time of scaling.

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 to the image side. The fourth lens group G4 is composed of a single lens.

Further, in the variable magnification optical system ZL1, the correction (vibration isolation) of the image position when camera shake occurs is performed by vibration-proofing the bonded positive lens in which the biconvex positive lens L32 and the negative meniscus lens L33 in the third lens group G3 are joined. This is performed by using a lens group Gvr and moving the anti-vibration lens group Gvr so as to have a displacement component in a direction orthogonal to the optical axis. A lens in which the focal length of the entire system is f and the anti-vibration coefficient (ratio of the amount of image movement on the image plane to the amount of movement of the anti-vibration lens group Gvr in correcting the image position when camera shake occurs) is K. In order to correct the rotational blur of the angle θ, the anti-vibration lens group Gvr may be moved by (f · tan θ) / K in the direction orthogonal to the optical axis (the same applies to the following examples). In the wide-angle end state of this first embodiment, the vibration isolation coefficient is 0.69 and the focal length is 10.17 [mm], so that the vibration isolation lens for correcting the rotational blur of 0.50 ° The amount of movement of the group Gvr is 0.13 [mm]. Further, in the intermediate focal length state of the first embodiment, the vibration isolation coefficient is 0.86 and the focal length is 18.17 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.18 [mm]. Further, in the telephoto end state of the first embodiment, the anti-vibration coefficient is 1.21 and the focal length is 48.50 [mm], so that the anti-vibration for correcting the rotational blur of 0.50 ° is prevented. The moving amount of the oscillating lens group Gvr is 0.35 [mm]. Here, the bonded positive lens in which the negative meniscus lens L34 and the biconvex positive lens L35 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

Table 1 below lists the specifications of the variable magnification optical system ZL1. In Table 1, f 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 represented by the end state, the intermediate focal length state, and the telephoto end state. Here, the total length TL indicates the distance on the optical axis from the lens surface (first surface) on the most object side to the image surface I at the time of infinite focusing. Further, the back focus BF indicates the distance (air equivalent length) on the optical axis from the lens surface (32nd surface) closest to the image plane to the image plane I at the time of focusing at infinity. Further, in the lens data, the first column m is the order (plane number) of the lens surfaces from the object side along the traveling direction of the light beam, and the second column r is the radius of curvature of each lens surface in the third column. d is the distance (plane spacing) on the optical axis from each optical surface to the next optical surface, and the fourth column nd and the fifth column νd are the refractive index and Abbe number with respect to the d line (λ = 587.6 nm). Is shown. The radius of curvature of 0.00000 indicates a plane, and the refractive index of air of 1.00000 is omitted. The lens group focal length indicates the number and focal length of the starting surface of each of the first to fifth lens groups G1 to G5.

Here, "mm" is generally used as the unit of the focal length f, the radius of curvature r, the surface spacing d, and other lengths listed in all the following specification values, but the optical system is proportionally expanded or proportional. It is not limited to this because the same optical performance can be obtained even if the reduction is performed. Further, the description of these symbols and the description of the specification table are the same in the following examples.

(Table 1) First Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.17 ~ 18.17 ~ 48.50
FNo = 3.54 ~ 4.23 ~ 5.73
ω [°] = 38.1 ~ 23.7 ~ 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 equivalent length) = 12.116 ~ 12.116 ~ 12.116

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start 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 magnification optical system ZL1, the eleventh plane and the twentieth plane are formed in an aspherical shape. Table 2 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 2)
[Aspherical data]
Side 11 K = 1.00000e + 00
A4 A6 A8 A10 A12
-7.86220e-05 4.32849e-07 -1.12684e-08 0.00000e + 00 0.00000e + 00
Side 20 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, the axial air gap D3 between the first lens group G1 and the second lens group G2, the 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 the 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 upon scaling as described above. Table 3 below shows the variable intervals 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 focus state and the close focus state. Note that D0 indicates the distance from the surface (first surface) on the most object side of the variable magnification optical system ZL1 to the object, and β indicates the magnification (the same applies to the following examples).

(Table 3)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL1. In Table 4, f1 constitutes the focal distance of the first lens group G1, f4 constitutes the focal distance of the fourth lens group G4, f5 constitutes the focal distance of the fifth lens group G5, and νd1 constitutes the first lens group G1. The abbe number with respect to the d-line of the medium of the lens to be used, νd5 is the abbe number with respect to the d-line of the medium of the lens 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 (di-diw) ² is each lens when the magnification is changed from the wide-angle end state to the telephoto end state. The sum of squares of the amount of change between groups is represented by ωw, which represents the half-angle in the wide-angle end state, and ωt, which represents the half-angle in the telephoto end state. The description of this reference numeral is the same in the following examples.

(Table 4)
[Conditional expression correspondence value]
(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 °

As described above, the variable magnification optical system ZL1 satisfies all of the above conditional expressions (1) to (8).

FIG. 2 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL1 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of focusing at infinity. (A), FIG. 3 (a), and FIG. 4 (a) are shown, and the transverse aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 2 (b), FIG. 3 (b), FIG. 4 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 5 (a) to 5 (c). In each aberration diagram, FNO is the F number, A is the half angle of view (unit is [°]), NA is the numerical aperture, and H0 is the object height. The spherical aberration diagram shows the value of the F number or numerical aperture corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum value of the half angle of view or the object height, respectively, and the transverse aberration diagram shows each half stroke. Indicates the value of the angle or the height of each object. d represents the d line (λ = 587.6 nm), and g represents the g line (λ = 435.8 nm). In the astigmatism diagram, the solid line shows the sagittal image plane and the broken line shows the meridional image plane. Further, in the aberration diagram of each embodiment shown below, the same reference numerals as those of this embodiment are used. From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL1, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

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

In this variable magnification optical system ZL2, the first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side. Further, the second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a positive meniscus lens L23 having a convex surface facing the object side in order from the object side. .. Further, in the third lens group G3, in order from the object side, the lens surface on the object side is formed into an aspherical shape, the positive lens L31 having a biconvex regular lens shape, and the lens surface on the image side is formed into an aspherical shape. It is composed of a positive lens L32 having a biconvex positive lens shape, and a bonded positive lens in which a negative meniscus lens L33 with a convex surface facing the object side and a biconvex positive lens L34 are joined. As described above, the third lens group G3 is composed of three lens components having a positive refractive power. Further, the fourth lens group G4 is composed of a negative lens L41 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the convex surface is directed toward the object side. Further, the fifth lens group G5 is composed of a positive meniscus lens L51 with a concave surface facing the object side. Further, the aperture diaphragm S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. The positive lens L31, the positive lens L32, and the negative lens L41 are glass-molded aspherical lenses. Further, the first lens group G1 is composed of one lens component (single lens). Further, the fifth lens group G5 is composed of one lens component (single lens).

In this variable magnification optical system ZL2, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3 The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. , The second lens group G2, the third lens group G3, and the fourth lens group G4 are configured to move along the optical axis. The aperture diaphragm S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed to the image plane at the time of scaling.

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 to the image side. The fourth lens group G4 is composed of a single lens.

Further, in the variable magnification optical system ZL2, for the correction (vibration isolation) of the image position when camera shake occurs, the positive lens L32 in the third lens group G3 is set as the anti-vibration lens group Gvr, and this anti-vibration lens group Gvr is used as the optical axis. This is done by moving the lens so that it has 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 this second embodiment, the vibration isolation coefficient is 0.83 and the focal length is 10.30 [mm], so that the vibration isolation lens for correcting the rotational blur of 0.50 ° The amount of movement of the group Gvr is 0.11 [mm]. Further, in the intermediate focal length state of the second embodiment, the vibration isolation coefficient is 1.03 and the focal length is 18.00 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.15 [mm]. Further, in the telephoto end state of the second embodiment, the vibration isolation coefficient is 1.30 and the focal length is 29.10 [mm], so that the rotation blur for correcting the rotational blur of 0.50 ° is prevented. The moving amount of the oscillating lens group Gvr is 0.20 [mm]. Here, the bonded positive lens in which the negative meniscus lens L33 and the biconvex positive lens L34 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

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

(Table 5) Second Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.30 ~ 18.00 ~ 29.10
FNo = 3.62 ~ 4.41 ~ 5.50
ω [°] = 37.7 ~ 23.9 ~ 15.2
Y = 6.96 ~ 7.83 ~ 7.97
TL = 61.283 ~ 64.483 ~ 73.283
BF = 13.549 ~ 13.549 ~ 13.549
BF (air equivalent length) = 13.549 ~ 13.549 ~ 13.549

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start surface Focal length 1st lens group 1 77.16
2nd lens group 3 -10.97
Third lens group 9 11.91
4th lens group 17 -20.22
5th lens group 19 44.05

In this variable magnification optical system ZL2, the ninth surface, the thirteenth surface, and the eighteenth surface are formed in an aspherical shape. Table 6 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 6)
[Aspherical data]
Side 9 K = 1.00000e + 00
A4 A6 A8 A10 A12
-1.17196e-04 -1.66927e-06 4.54983e-08 0.00000e + 00 0.00000e + 00
Page 13 K = 1.00000e + 00
A4 A6 A8 A10 A12
3.95781e-05 -7.83445e-07 2.83596e-08 0.00000e + 00 0.00000e + 00
Side 18 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, the axial air gap D2 between the first lens group G1 and the second lens group G2, the 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 the 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 upon scaling as described above. Table 7 below shows the variable intervals 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 focus state and the close focus state.

(Table 7)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL2.

(Table 16)
[Conditional expression correspondence value]
(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 °

As described above, the variable magnification optical system ZL2 satisfies all of the above conditional expressions (1) to (8).

FIG. 7 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL2 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of focusing at infinity. (A), FIG. 8 (a), and FIG. 9 (a) are shown, and the lateral aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 7 (b), FIG. 8 (b), FIG. 9 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 10 (a) to 10 (c). From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL2, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

[Third Example (Reference Example) ]
FIG. 11 is a diagram showing a configuration of the variable magnification optical system ZL3 according to the third embodiment. In this variable magnification optical system ZL3, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. It is composed of a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a 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. Further, the second lens group G2 is a negative meniscus lens L21 having a convex surface facing the object side in order from the object side, and a negative lens having a biconcave negative lens shape in which the lens surfaces on the object side and the image side are formed in an aspherical shape. It is composed of L22 and a positive meniscus lens L23 with a convex surface facing the object side. Further, in the third lens group G3, in order from the object side, the lens surface on the object side is formed into an aspherical shape, the positive lens L31 having a biconvex regular lens shape, and the lens surface on the image side is formed into an aspherical shape. It is composed of a positive lens L32 having a biconvex positive lens shape, and a bonded positive lens in which a negative meniscus lens L33 with a convex surface facing the object side and a biconvex positive lens L34 are joined. As described above, the third lens group G3 is composed of three lens components having a positive refractive power. Further, the fourth lens group G4 is composed of a negative lens L41 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the convex surface is directed toward the object side. Further, the fifth lens group G5 is composed of a positive meniscus lens L51 with a concave surface facing the object side. Further, the aperture diaphragm S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. Further, the negative lens L22, the positive lens L31, the positive lens L32 and the negative lens L41 are glass-molded aspherical lenses. Further, the first lens group G1 is composed of one lens component (single lens). Further, the fifth lens group G5 is composed of one lens component (single lens).

In this variable magnification optical system ZL3, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3 The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. , The second lens group G2, the third lens group G3, and the fourth lens group G4 are configured to move along the optical axis. The aperture diaphragm S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed to the image plane at the time of scaling.

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 to the image side. The fourth lens group G4 is composed of a single lens.

Further, in the variable magnification optical system ZL3, for the correction (vibration isolation) of the image position when camera shake occurs, the positive lens L32 in the third lens group G3 is set as the anti-vibration lens group Gvr, and this anti-vibration lens group Gvr is used as the optical axis. This is done by moving the lens so that it has a displacement component in the direction orthogonal to. That is, the anti-vibration lens group Gvr in this variable magnification optical system ZL3 is composed of a single lens. In the wide-angle end state of this third embodiment, the vibration isolation coefficient is 0.41 and the focal length is 10.30 [mm], so that the vibration isolation lens for correcting the rotational blur of 0.50 ° The movement amount of the group Gvr is 0.22 [mm]. Further, in the intermediate focal length state of the third embodiment, the vibration isolation coefficient is 0.51 and the focal length is 18.00 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.31 [mm]. Further, in the telephoto end state of the third embodiment, the anti-vibration coefficient is 0.64 and the focal length is 29.10 [mm], so that the anti-vibration for correcting the rotational blur of 0.50 ° is prevented. The moving amount of the oscillating lens group Gvr is 0.40 [mm]. Here, the bonded positive lens in which the negative meniscus lens L33 and the biconvex positive lens L34 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

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

(Table 9) Third Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.30 ~ 18.00 ~ 29.10
FNo = 3.61 ~ 4.40 ~ 5.52
ω [°] = 40.2 ~ 24.2 ~ 15.4
Y = 8.19 ~ 8.19 ~ 8.19
TL = 63.284 ~ 64.891 ~ 76.284
BF = 13.550 ~ 13.550 ~ 13.550
BF (air equivalent length) = 13.550 ~ 13.550 ~ 13.550

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start 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 magnification optical system ZL3, the fifth surface, the sixth surface, the ninth surface, the thirteenth surface, and the eighteenth surface are formed in an aspherical shape. Table 10 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 10)
[Aspherical data]
Side 5 K = 1.00000e + 00
A4 A6 A8 A10 A12
2.63618e-04 -4.56871e-06 4.40438e-08 -1.68618e-10 0.00000e + 00
Side 6 K = 1.00000e + 00
A4 A6 A8 A10 A12
1.82171e-04 -6.53508e-06 7.09825e-08 -9.77402e-10 3.44260e-12
Side 9 K = 1.00000e + 00
A4 A6 A8 A10 A12
-1.19764e-04 -1.25633e-06 1.89897e-08 0.00000e + 00 0.00000e + 00
Page 13 K = 1.00000e + 00
A4 A6 A8 A10 A12
3.12457e-05 -9.85529e-07 2.86908e-08 0.00000e + 00 0.00000e + 00
Side 18 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, the axial air gap D2 between the first lens group G1 and the second lens group G2, the 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 the 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 upon scaling as described above. Table 11 below shows the variable intervals 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 focus state and the close focus state.

(Table 11)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL3.

(Table 12)
[Conditional expression correspondence value]
(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, the variable magnification optical system ZL3 satisfies all of the above conditional expressions (1) to (8).

FIG. 12 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL3 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of focusing at infinity. (A), FIG. 13 (a), and FIG. 14 (a) are shown, and the transverse aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 12 (b), FIG. 13 (b), FIG. 14 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 15 (a) to 15 (c). From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL3, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

[Fourth Example (Reference Example) ]
FIG. 16 is a diagram showing the configuration of the variable magnification optical system ZL4 according to the fourth embodiment. In this variable magnification optical system ZL4, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. It is composed of a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a 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. Further, the second lens group G2 is a negative meniscus lens L21 having a convex surface facing the object side in order from the object side, and a negative lens having a biconcave negative lens shape in which the lens surfaces on the object side and the image side are formed in an aspherical shape. It is composed of L22 and a positive meniscus lens L23 with a convex surface facing the object side. Further, in the third lens group G3, in order from the object side, the lens surface on the object side is formed into an aspherical shape, the positive lens L31 having a biconvex regular lens shape, and the lens surface on the image side is formed into an aspherical shape. It is composed of a positive lens L32 having a biconvex positive lens shape, and a bonded positive lens in which a negative meniscus lens L33 with a convex surface facing the object side and a biconvex positive lens L34 are joined. As described above, the third lens group G3 is composed of three lens components having a positive refractive power. Further, the fourth lens group G4 is composed of a negative lens L41 having a biconcave negative lens shape in which the lens surface on the image side is formed in an aspherical shape. Further, the fifth lens group G5 is composed of a positive meniscus lens L51 with a concave surface facing the object side. Further, the aperture diaphragm S is arranged between the positive lens L31 and the positive lens L32 of the third lens group G3. Further, the negative lens L22, the positive lens L31, the positive lens L32 and the negative lens L41 are glass-molded aspherical lenses. Further, the first lens group G1 is composed of one lens component (single lens). Further, the fifth lens group G5 is composed of one lens component (single lens).

In this variable magnification optical system ZL4, the distance between the first lens group G1 and the second lens group G2 increases when the magnification is changed from the wide-angle end state to the telescopic end state, and the second lens group G2 and the third lens group G3 The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. , The second lens group G2, the third lens group G3, and the fourth lens group G4 are configured to move along the optical axis. The aperture diaphragm S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed to the image plane at the time of scaling.

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 to the image side. The fourth lens group G4 is composed of a single lens.

Further, in the variable magnification optical system ZL4, for the correction (vibration isolation) of the image position when camera shake occurs, the positive lens L32 in the third lens group G3 is set as the anti-vibration lens group Gvr, and this anti-vibration lens group Gvr is used as the optical axis. This is done by moving the lens so that it has 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 this fourth embodiment, the vibration isolation coefficient is 0.96 and the focal length is 9.27 [mm], so that the vibration isolation lens for correcting the rotational blur of 0.50 ° The amount of movement of the group Gvr is 0.08 [mm]. Further, in the intermediate focal length state of the fourth embodiment, the vibration isolation coefficient is 1.22 and the focal length is 18.00 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.13 [mm]. Further, in the telephoto end state of the fourth embodiment, the vibration isolation coefficient is 1.54 and the focal length is 29.10 [mm], so that the prevention of rotation blur of 0.50 ° is corrected. The moving amount of the oscillating lens group Gvr is 0.17 [mm]. Here, the bonded positive lens in which the negative meniscus lens L33 and the biconvex positive lens L34 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

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

(Table 13) Fourth Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.27 ~ 18.00 ~ 29.10
FNo = 3.63 ~ 4.51 ~ 5.62
ω [°] = 40.7 ~ 23.9 ~ 15.2
Y = 6.80 ~ 7.86 ~ 7.97
TL = 64.283 ~ 67.004 ~ 76.283
BF = 13.549 ~ 13.549 ~ 13.549
BF (air equivalent length) = 13.549 ~ 13.549 ~ 13.549

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start 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 magnification optical system ZL4, the fifth surface, the sixth surface, the ninth surface, the thirteenth surface, and the eighteenth surface are formed in an aspherical shape. Table 14 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 14)
[Aspherical data]
Side 5 K = 1.00000e + 00
A4 A6 A8 A10 A12
-5.78996e-05 1.17227e-06 -2.35038e-08 8.42883e-11 0.00000e + 00
Side 6 K = 1.00000e + 00
A4 A6 A8 A10 A12
-9.12145e-05 8.05476e-07 -2.35584e-08 0.00000e + 00 0.00000e + 00
Side 9 K = 1.00000e + 00
A4 A6 A8 A10 A12
-1.31071e-04 -1.59209e-06 2.45019e-08 0.00000e + 00 0.00000e + 00
Page 13 K = 1.00000e + 00
A4 A6 A8 A10 A12
5.13314e-05 -5.12176e-07 1.98470e-08 0.00000e + 00 0.00000e + 00
Side 18 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, the axial air gap D2 between the first lens group G1 and the second lens group G2, the 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 the 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 upon scaling as described above. Table 15 below shows the variable intervals 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 focus state and the close focus state.

(Table 15)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL4.

(Table 16)
[Conditional expression correspondence value]
(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 °

As described above, the variable magnification optical system ZL4 satisfies all of the above conditional expressions (1) to (8).

FIG. 17 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL4 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of focusing at infinity. (A), FIG. 18 (a), and FIG. 19 (a) are shown, and the lateral aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 17 (b), FIG. 18 (b), FIG. 19 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 20 (a) to 20 (c). From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL4, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

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

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

In this variable magnification optical system ZL5, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3 The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. , The second lens group G2, the third lens group G3, and the fourth lens group G4 are configured to move along the optical axis. The aperture diaphragm S moves integrally with the third lens group G3. Further, the fifth lens group G5 is fixed to the image plane at the time of scaling.

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 to the image side.

Further, in the variable magnification optical system ZL5, the correction (vibration isolation) of the image position when camera shake occurs is performed by using a junction positive lens in which the positive meniscus lens L32 and the negative meniscus lens L33 in the third lens group G3 are joined as an anti-vibration lens. This is performed by setting the group Gvr and moving the anti-vibration lens group Gvr so as to have a displacement component in a direction orthogonal to the optical axis. In the wide-angle end state of the fifth embodiment, the vibration isolation coefficient is 0.43 and the focal length is 10.30 [mm], so that the vibration isolation lens for correcting the rotational blur of 0.50 ° The movement amount of the group Gvr is 0.21 [mm]. Further, in the intermediate focal length state of the fifth embodiment, the vibration isolation coefficient is 0.56 and the focal length is 18.00 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.28 [mm]. Further, in the telephoto end state of the fifth embodiment, the vibration isolation coefficient is 0.73 and the focal length is 30.26 [mm]. The moving amount of the oscillating lens group Gvr is 0.36 [mm]. Here, the bonded positive lens in which the negative meniscus lens L34 and the biconvex positive lens L35 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

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

(Table 17) Fifth Example [Overall Specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.30 ~ 18.00 ~ 30.26
FNo = 3.71 ~ 4.55 ~ 5.75
ω [°] = 37.7 ~ 23.9 ~ 14.5
Y = 6.77 ~ 7.77 ~ 7.97
TL = 64.245 ~ 66.885 ~ 79.284
BF = 12.117 ~ 12.117 ~ 12.117
BF (air equivalent length) = 12.117 ~ 12.117 ~ 12.117

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start 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 magnification optical system ZL5, the tenth plane and the twentieth plane are formed in an aspherical shape. Table 18 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 18)
[Aspherical data]
Side 10 K = 1.00000e + 00
A4 A6 A8 A10 A12
-7.99825e-05 1.73203e-07 -1.66026e-08 0.00000e + 00 0.00000e + 00
Side 20 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, the axial air gap D2 between the first lens group G1 and the second lens group G2, the 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 D17 between the 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 upon scaling as described above. Table 19 below shows the variable intervals 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 focus state and the close focus state.

(Table 19)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL5.

(Table 20)
[Conditional expression correspondence value]
(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 °

As described above, the variable magnification optical system ZL5 satisfies all of the above conditional expressions (1) to (8).

FIG. 22 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL5 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of focusing at infinity. (A), FIG. 23 (a), and FIG. 24 (a) are shown, and the lateral aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 22 (b), FIG. 23 (b), FIG. 24 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 25 (a) to 25 (c). From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL5, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

[Sixth Example (Reference Example) ]
FIG. 26 is a diagram showing the configuration of the variable magnification optical system ZL6 according to the sixth embodiment. In this variable magnification optical system ZL6, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. It is composed of a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a 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. Further, the second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a positive meniscus lens L23 having a convex surface facing the object side in order from the object side. .. Further, in the third lens group G3, in order from the object side, the lens surface on the object side is formed into an aspherical shape, the positive lens L31 having a biconvex regular lens shape, the biconvex regular lens L32, and the concave surface facing the object side. It is composed of a bonded positive lens in which a negative meniscus lens L33 is bonded and a bonded positive lens in which a negative meniscus lens L34 having a convex surface facing the object side and a biconvex positive lens L35 are bonded. As described above, the third lens group G3 is composed of three lens components having a positive refractive power. Further, the fourth lens group G4 includes a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave negative lens shape in which the lens surface on the image side is formed in an aspherical shape, in order from the object side. It consists of a bonded negative lens. Further, the fifth lens group G5 is composed of a bonded positive lens in which a biconvex positive lens L51 and a biconcave negative lens L52 are joined in order from the object side. Further, the aperture diaphragm S is arranged on the object side of the third lens group G3 (the object side of the positive lens L31). The positive lens L31, the positive lens L32, and the negative lens L42 are glass-molded aspherical lenses. Further, the first lens group G1 is composed of one lens component (single lens). Further, the fifth lens group G5 is composed of one lens component (junction lens).

In this variable magnification optical system ZL6, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3 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. 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. The aperture diaphragm 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 to the image side.

Further, in the variable magnification optical system ZL6, the correction (vibration isolation) of the image position when camera shake occurs is performed by using a junction positive lens in which the positive meniscus lens L32 and the negative meniscus lens L33 in the third lens group G3 are joined as an anti-vibration lens. This is performed by setting the group Gvr and moving the anti-vibration lens group Gvr so as to have a displacement component in a direction orthogonal to the optical axis. In the wide-angle end state of the sixth embodiment, the vibration isolation coefficient is 0.74 and the focal length is 10.30 [mm]. Therefore, the vibration isolation lens for correcting the rotational blur of 0.50 °. The amount of movement of the group Gvr is 0.12 [mm]. Further, in the intermediate focal length state of the sixth embodiment, the vibration isolation coefficient is 0.91 and the focal length is 18.00 [mm], so that the rotational blur of 0.50 ° can be corrected. The amount of movement of the anti-vibration lens group Gvr is 0.17 [mm]. Further, in the telephoto end state of the sixth embodiment, the vibration isolation coefficient is 1.08 and the focal length is 30.00 [mm], so that the prevention of rotation blur of 0.50 ° is corrected. The moving amount of the oscillating lens group Gvr is 0.24 [mm]. Here, the bonded positive lens in which the negative meniscus lens L34 and the biconvex positive lens L35 are joined corresponds to the lens component G3L on the most image side of the third lens group G3.

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

(Table 21) 6th Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.30 ~ 18.00 ~ 30.00
FNo = 4.10 ~ 4.82 ~ 5.62
ω [°] = 37.7 ~ 23.9 ~ 14.9
Y = 6.77 ~ 7.58 ~ 7.80
TL = 64.247 ~ 65.089 ~ 78.749
BF = 7.838 ~ 16.554 ~ 15.244
BF (air equivalent length) = 7.838 ~ 16.554 ~ 15.244

[Lens data]
m r d nd ν d
Paraboloid ∞
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 aperture 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 Start surface Focal length 1st lens group 1 49.40
2nd lens group 3 -10.00
3rd lens group 9 13.16
4th lens group 18 -20.36
5th lens group 21 30.57

In this variable magnification optical system ZL6, the tenth plane and the twentieth plane are formed in an aspherical shape. Table 22 below shows the aspherical data, that is, the conical constant K and the values of the aspherical constants A4 to A12.

(Table 22)
[Aspherical data]
Side 10 K = 1.00000e + 00
A4 A6 A8 A10 A12
-7.14717e-05 2.26370e-07 3.68476e-09 0.00000e + 00 0.00000e + 00
Side 20 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, the axial air gap D2 between the first lens group G1 and the second lens group G2, the 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 D17 between the 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 upon scaling as described above. To do. Table 23 below shows the variable intervals 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 focus state and the close focus state.

(Table 23)
[Variable interval data]
Infinity close
W M T W M T
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 the values corresponding to each conditional expression in the variable magnification optical system ZL6.

(Table 24)
[Conditional expression correspondence value]
(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 °

As described above, the variable magnification optical system ZL6 satisfies the above conditional expressions (1) to (5), (7), and (8).

FIG. 27 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration of magnification diagram, and a transverse aberration diagram of the variable magnification optical system ZL6 in the wide-angle end state, the intermediate focal length state, and the telescopic end state at the time of infinity focusing. (A), FIG. 28 (a), and FIG. 29 (a) are shown, and the lateral aberration diagram when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of infinity focusing is shown. 27 (b), FIG. 28 (b), FIG. 29 (b), spherical aberration diagram, astigmatism diagram, distortion diagram in wide-angle end state, intermediate focal length state, and telephoto end state at the time of close focusing, The chromatic aberration of magnification diagram and the transverse aberration diagram are shown in FIGS. 30 (a) to 30 (c). From each of these aberration diagrams, it can be seen that in this variable magnification optical system ZL6, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

ZL (ZL1 to ZL6) Variable magnification 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 equipment)

Claims (9)

From the object side,
The first lens group with positive refractive power and
A second lens group with negative refractive power,
A third lens group with positive refractive power,
A fourth lens group with negative refractive power,
It consists of substantially five lens groups with a fifth lens group having a positive refractive power.
When the magnification is changed from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes. The distance between the third lens group and the fourth lens group changes, and the distance between the fourth lens group and the fifth lens group changes.
When in focus, the fourth lens group moves along the optical axis and
The first lens group is composed of one lens component.
At the time of scaling, the fifth lens group is fixed with respect to the image plane.
A variable magnification optical system characterized by satisfying the following conditions.
1.000 <f5 / f1 <4.100
0.400 <(-f4) / f1 <3,000
However,
f5: Focal length of the fifth lens group f1: Focal length of the first lens group
f4: Focal length of the fourth lens group The lens component indicates a single lens or a junction lens. The variable magnification optical system according to claim 1 , wherein the first lens group has a lens that satisfies the conditions of the following equation.
40.000 <νd1
However,
νd1: Abbe number with respect to the d-line of the medium of the lenses constituting the first lens group. The variable magnification optical system according to claim 1 or 2 , wherein the conditions of the following equation are satisfied.
2,000 <f1 / (d12t-d12w) <8,000
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 f1: Focal length of the first lens group The variable magnification optical system according to any one of claims 1 to 3, wherein the variable magnification optical system satisfies the condition of the following equation.
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 (di-diw) 2: Wide-angle end Sum of squares of the amount of change between each lens group when the magnification is changed from the state to the telephoto end state The variable magnification optical system according to any one of claims 1 to 4, wherein the fifth lens group is composed of a single lens. The variable magnification optical system according to any one of claims 1 to 5, wherein the fifth lens group has a lens that satisfies the conditions of the following equation.
νd5 ≤ 35.000
However,
νd5: Abbe number with respect to the d-line of the medium of the lens constituting the fifth lens group. The variable magnification optical system according to any one of claims 1 to 6, wherein the variable magnification optical system satisfies the condition of the following equation.
29.00 ° <ωw <60.00 °
However,
ωw: Half angle of view at wide-angle end The variable magnification optical system according to any one of claims 1 to 7, wherein the variable magnification optical system satisfies the condition of the following equation.
2.50 ° <ωt <22.00 °
However,
ωt: Half angle of view at the telephoto end An optical device having the variable magnification optical system according to any one of claims 1 to 8.

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