WO2016121926A1

WO2016121926A1 - Zoom lens, optical apparatus, and zoom lens production method

Info

Publication number: WO2016121926A1
Application number: PCT/JP2016/052655
Authority: WO
Inventors: 武梅田
Original assignee: 株式会社ニコン
Priority date: 2015-01-30
Filing date: 2016-01-29
Publication date: 2016-08-04
Also published as: JP6915667B2; JP2020034946A; JP6683279B2; JPWO2016121926A1; JP2020160446A; JP2019164375A

Abstract

A zoom lens that has, in order along the optical axis thereof from an object side, a first lens group that has negative refractive power, a second lens group that has positive refractive power, a third lens group that has negative refractive power, a fourth lens group that has positive refractive power, and a fifth lens group. During power variation, the interval between the first lens group and the second lens group varies, the interval between the second lens group and the third lens group varies, the interval between the third lens group and the fourth lens group varies, and the interval between the fourth lens group and the fifth lens group varies. The zoom lens satisfies a prescribed conditional expression.

Description

Zoom lens, optical device, and method of manufacturing zoom lens

The present invention relates to a zoom lens, an optical apparatus, and a zoom lens manufacturing method suitable for a photographic camera, an electronic still camera, a video camera, and the like.
This application claims priority based on the Japan patent application 2015-017209 for which it applied on January 30, 2015, and uses the content here.

Conventionally, a wide-angle variable magnification optical system has been proposed (see, for example, Patent Document 1).

JP 2007-279077 A

However, the conventional variable power optical system as described above has a problem that it cannot sufficiently meet the demand for an optical system with a bright F number and high optical performance.

One embodiment of the present invention includes a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens having negative refractive power in order from the object side along the optical axis. And a fourth lens group having a positive refractive power, and a fifth lens group. During zooming, the distance between the first lens group and the second lens group changes, and the second lens group changes. The distance between the 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. A zoom lens that satisfies the following conditional expression is provided.
1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group

Further, according to one embodiment of the present invention, in order from the object side along the optical axis, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a first lens group having a negative refractive power. A zoom lens manufacturing method having three lens groups, a fourth lens group having a positive refractive power, and a fifth lens group, and configured to satisfy the following conditional expression, 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. The zoom lens manufacturing method is configured such that the distance between the fourth lens group and the fifth lens group changes.
1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group

FIGS. 1A, 1B, and 1C are cross-sectional views of the zoom lens according to the first example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 2 (a), 2 (b), and 2 (c), respectively, are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the first example. FIG. 3 (a), 3 (b), and 3 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the first example. FIG. 4 (a), 4 (b), and 4 (c) respectively show meridional laterals during vibration isolation in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to the first example. It is an aberration diagram. FIGS. 5A, 5B, and 5C are cross-sectional views of the zoom lens according to Example 2 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 6 (a), 6 (b), and 6 (c) are respectively when the object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the second example. FIG. FIGS. 7 (a), 7 (b), and 7 (c) respectively show the zoom lens according to the second embodiment when focusing on a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state. FIG. 8 (a), 8 (b), and 8 (c) respectively show the meridional lateral at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the second example. It is an aberration diagram. FIGS. 9A, 9B, and 9C are cross-sectional views of the zoom lens according to the third example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 10 (a), 10 (b), and 10 (c), respectively, are shown when an object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the third example. FIG. 11 (a), 11 (b), and 11 (c), respectively, are those when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to the third example. FIG. 12 (a), 12 (b), and 12 (c) respectively show meridional laterals during image stabilization in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 3. It is an aberration diagram. FIGS. 13A, 13B, and 13C are cross-sectional views of the zoom lens according to the fourth example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 14 (a), 14 (b), and 14 (c) respectively show a zoom lens according to the fourth example when focusing on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state. FIG. 15 (a), 15 (b), and 15 (c), respectively, are those when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 4. FIG. 16 (a), 16 (b), and 16 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the fourth example. It is an aberration diagram. FIGS. 17A, 17B, and 17C are sectional views of the zoom lens according to Example 5 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 18 (a), 18 (b), and 18 (c), respectively, are shown when an object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. FIG. 19 (a), 19 (b), and 19 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. FIG. 20 (a), 20 (b), and 20 (c) respectively show the meridional lateral at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. It is an aberration diagram. FIGS. 21A, 21B, and 21C are cross-sectional views of the zoom lens according to Example 6 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 22 (a), 22 (b), and 22 (c) respectively show the infinite object focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. FIG. 23 (a), 23 (b), and 23 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. FIG. 24 (a), 24 (b), and 24 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. It is an aberration diagram. FIGS. 25A, 25B, and 25C are cross-sectional views of the zoom lens according to the seventh example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 26 (a), 26 (b), and 26 (c) are respectively when the object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the seventh example. FIG. FIGS. 27 (a), 27 (b), and 27 (c) are respectively for focusing a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the seventh example. FIG. 28 (a), 28 (b), and 28 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 7. It is an aberration diagram. FIGS. 29A, 29B, and 29C are cross-sectional views of the zoom lens according to Example 8 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 30 (a), 30 (b), and 30 (c) are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 8. FIG. FIGS. 31 (a), 31 (b), and 31 (c) are respectively when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 8. FIGS. FIG. 32 (a), 32 (b), and 32 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 8. It is an aberration diagram. 33A, 33B, and 33C are cross-sectional views of the zoom lens according to Example 9 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 34 (a), 34 (b), and 34 (c) are focused on an object at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 9, respectively. FIG. FIGS. 35 (a), 35 (b), and 35 (c) are respectively for focusing a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 9. FIG. 36 (a), 36 (b), and 36 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 9. It is an aberration diagram. FIGS. 37A, 37B, and 37C are cross-sectional views of the zoom lens according to Example 10 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 38 (a), 38 (b), and 38 (c) are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10, respectively. FIG. FIGS. 39 (a), 39 (b), and 39 (c) are focused on a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10, respectively. FIG. 40 (a), 40 (b), and 40 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10. It is an aberration diagram. 41A, 41B, and 41C are cross-sectional views of the zoom lens according to Example 11 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. 42 (a), 42 (b), and 42 (c) are in-focus at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11, respectively. FIG. FIGS. 43 (a), 43 (b), and 43 (c) are respectively for focusing a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11. FIG. 44 (a), 44 (b), and 44 (c) respectively show the meridional horizontal during vibration isolation in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11. It is an aberration diagram. FIG. 45 is a schematic diagram illustrating a configuration of a camera including a zoom lens. FIG. 46 is a diagram showing an outline of a method for manufacturing a zoom lens.

Hereinafter, the zoom lens, the optical apparatus, and the manufacturing method of the zoom lens will be described for the embodiment. First, a zoom lens according to an embodiment will be described.

A zoom lens according to an embodiment includes, in order from the object side along the optical axis, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a first lens group having a negative refractive power. Three lens groups, a fourth lens group having a positive refractive power, and a fifth lens group, and when zooming, the distance between the first lens group and the second lens group changes, The distance between the second lens group and the third lens group changes, 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. Change. In one example, the fifth lens group may have a positive refractive power.
With this configuration, zooming can be realized, and good aberration correction can be achieved during zooming.

The zoom lens satisfies the following conditional expression (1).
(1) 1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group

Conditional expression (1) is a conditional expression for defining an appropriate range of the ratio between the focal length of the fifth lens group and the focal length of the first lens group. By satisfying conditional expression (1), it is possible to achieve a brightness with an F-number of about F2.8 to F4.0 while maintaining a wide angle, and it is possible to satisfactorily correct various aberrations including spherical aberration.

When the corresponding value of the conditional expression (1) exceeds the upper limit value, the power of the first lens group with respect to the fifth lens group increases, and it becomes difficult to correct curvature of field and curvature aberration particularly in the wide-angle end state. There is sex. In order to secure the effect, it is preferable that the upper limit value of conditional expression (1) is 8.700. In order to further secure the effect, it is preferable that the upper limit value of conditional expression (1) is 7.400.

On the other hand, if the corresponding value of conditional expression (1) is below the lower limit value, the power of the fifth lens group with respect to the first lens group will increase, and it will be difficult to correct field curvature and curvature aberration particularly in the telephoto end state. There is a possibility. In order to secure the effect, it is preferable that the lower limit value of conditional expression (1) is 1.700. In order to further secure the effect, it is preferable to set the lower limit value of conditional expression (1) to 2.400.

In addition, it is preferable that the zoom lens satisfies the following conditional expression (2).
(2) 0.300 <| m12 | / fw <5.000
However,
| M12 |: the amount of change from the wide-angle end state to the telephoto end state of the distance on the optical axis from the most image side lens surface of the first lens group to the most object side lens surface of the second lens group fw : Focal length of the entire zoom lens system in the wide-angle end state

Conditional expression (2) relates to a variable magnification load between the first lens group and the second lens group, from the lens surface closest to the image side of the first lens group with respect to the focal length of the entire zoom lens system in the wide-angle end state. It is a conditional expression for prescribing an appropriate range of the ratio of the amount of change from the wide-angle end state to the telephoto end state of the distance on the optical axis to the lens surface closest to the object side of the second lens group.

If the corresponding value of conditional expression (2) exceeds the upper limit value, the distance between the first lens group and the image plane increases, and in particular, the spherical aberration and coma aberration correction burdens of the second lens group increase. It may be difficult to correct spherical aberration and coma. In order to secure the effect, it is preferable to set the upper limit value of conditional expression (2) to 4.0000. In order to further secure the effect, it is preferable that the upper limit value of conditional expression (2) is 3.000.

On the other hand, if the corresponding value of the conditional expression (2) is less than the lower limit value, the zooming burden of the lens units other than the first lens unit increases, and in particular, the power of the fourth lens unit increases, so that coma aberration is increased. Correction may be difficult. In order to secure the effect, it is preferable to set the lower limit of conditional expression (2) to 0.600. In order to further secure the effect, it is preferable to set the lower limit of conditional expression (2) to 0.900.

In addition, the zoom lens can preferably satisfy the following conditional expression (3).
(3) 0.200 <f5 / f4 <4.00
However,
f5: focal length of the fifth lens group f4: focal length of the fourth lens group

Conditional expression (3) is a conditional expression for defining an appropriate range of the ratio between the focal length of the fifth lens group and the focal length of the fourth lens group. If the corresponding value of conditional expression (3) exceeds the upper limit value, the power of the fourth lens group with respect to the fifth lens group will increase, and it may be difficult to correct coma. In order to secure the effect, it is preferable that the upper limit value of conditional expression (3) is 3.300. In order to further secure the effect, it is preferable to set the upper limit value of conditional expression (3) to 2.600.

On the other hand, if the corresponding value of conditional expression (3) is less than the lower limit value, the power of the fifth lens group with respect to the fourth lens group will increase, which may make it difficult to correct field curvature. In order to secure the effect, it is preferable to set the lower limit of conditional expression (3) to 0.350. In order to further secure the effect, it is preferable to set the lower limit of conditional expression (3) to 0.450.

In addition, the zoom lens can preferably be configured such that at least a part of the lenses in the third lens group can be moved so as to include a component in a direction orthogonal to the optical axis. For example, the zoom lens can preferably be configured such that at least two lenses in the third lens group can be moved so as to include a component in a direction orthogonal to the optical axis.
In this way, by configuring at least two lenses in the third lens group to be movable so as to include a component in a direction perpendicular to the optical axis as a vibration-proof lens group, the vibration-proof lens group can be reduced in size. In addition, it is possible to satisfactorily correct decentration coma, decentration field curvature, and decentration magnification chromatic aberration during image stabilization.

In addition, it is preferable that the zoom lens be configured such that at least a part of the lenses in the second lens group can be moved so as to include a component in a direction orthogonal to the optical axis. For example, the zoom lens can preferably be configured such that at least two lenses in the second lens group can be moved so as to include a component in a direction orthogonal to the optical axis.
As described above, the anti-vibration lens group can be downsized by configuring the anti-vibration lens group so that at least two lenses in the second lens group can move so as to include a component in a direction perpendicular to the optical axis. Further, it is possible to satisfactorily correct decentration coma aberration, decentration field curvature, and decentration magnification chromatic aberration during image stabilization.

In addition, it is preferable that the zoom lens can be configured so that at least a part of the lenses in the fourth lens group can move so as to include a component in a direction orthogonal to the optical axis. For example, it is preferable that the zoom lens be configured such that at least two lenses in the fourth lens group can be moved so as to include a component in a direction orthogonal to the optical axis.
As described above, the anti-vibration lens group can be downsized by configuring the anti-vibration lens group so that at least two lenses in the fourth lens group can move so as to include a component in a direction orthogonal to the optical axis. Further, it is possible to satisfactorily correct decentration coma aberration, decentration field curvature, and decentration magnification chromatic aberration during image stabilization.

The zoom lens can preferably focus from an object at infinity to a near object by moving at least some of the lenses in the second lens group along the optical axis. For example, the zoom lens is preferably capable of focusing from an object at infinity to a near object by moving at least two lenses in the second lens group along the optical axis.
With this configuration, it is possible to reduce the size of the focusing lens group, and it is possible to satisfactorily correct variations in chromatic aberration and field curvature due to focusing.

In the zoom lens, it is preferable that at least a part of the third lens group is moved along the optical axis to focus from an object at infinity to a near object. For example, the zoom lens is preferably capable of focusing from an object at infinity to a near object by moving at least two lenses in the third lens group along the optical axis.
With this configuration, it is possible to reduce the size of the focusing lens group, and it is possible to satisfactorily correct variations in chromatic aberration and field curvature due to focusing.

In the zoom lens, it is preferable that at least a part of the lenses in the fourth lens group be moved along the optical axis to focus from an object at infinity to a near object. For example, the zoom lens is preferably capable of focusing from an object at infinity to a near object by moving at least two lenses in the fourth lens group along the optical axis.
With this configuration, it is possible to reduce the size of the focusing lens group, and it is possible to satisfactorily correct variations in chromatic aberration and field curvature due to focusing.

In addition, it is preferable that the zoom lens can focus from an object at infinity to an object at a short distance by moving part or all of the fifth lens group along the optical axis.
With this configuration, it is possible to satisfactorily correct axial chromatic aberration variation, spherical aberration variation, and coma aberration variation due to focusing.

The zoom lens preferably has an aperture stop between the second lens group and the third lens group.
With this configuration, spherical aberration, coma aberration, and lateral chromatic aberration can be favorably corrected.

The optical apparatus according to the embodiment includes the zoom lens having the above-described configuration. Thereby, an optical apparatus having a bright F number and high optical performance can be realized.

The zoom lens manufacturing method according to the embodiment includes, in order from the object side along the optical axis, a first lens group having negative refractive power, a second lens group having positive refractive power, and negative refraction. A method of manufacturing a zoom lens having a third lens group having a power, a fourth lens group having a positive refractive power, and a fifth lens group, wherein the following conditional expression (1) is satisfied: During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the third lens group and the third lens group The distance between the fourth lens group is changed, and the distance between the fourth lens group and the fifth lens group is changed. In one example, the fifth lens group may have a positive refractive power.
(1) 1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group

By such a zoom lens manufacturing method, a zoom lens lens having a bright F number and high optical performance can be manufactured.

(Numerical example)
Hereinafter, zoom lenses according to numerical examples will be described with reference to the accompanying drawings.

(First embodiment)
FIGS. 1A, 1B, and 1C are cross-sectional views of the zoom lens according to the first example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 1A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 1B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 1 (a), the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

The first lens group G1 includes, in order from the object side along the optical axis, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, a biconcave lens L13, and a biconvex lens. L14. The negative meniscus lens L11 is an aspherical lens in which the object-side lens surface and the image-side lens surface are aspherical.

The second lens group G2 includes, in order from the object side along the optical axis, a second F lens group G2F having a positive refractive power and a second R lens group G2R having a positive refractive power.
The second F lens group G2F includes, in order from the object side along the optical axis, a cemented lens of a biconvex lens L21 and a negative meniscus lens L22 having a concave surface facing the object side, and a negative meniscus lens L23 having a convex surface facing the object side. It is composed of The biconvex lens L21 is an aspheric lens having an aspheric lens surface on the object side.
The second R lens group G2R includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L24 having a convex surface facing the object side, a biconvex lens L25, and a negative meniscus lens L26 having a concave surface facing the object side. Has been.

The third lens group G3 includes, in order from the object side along the optical axis, an aperture stop S, a cemented lens of a biconcave lens L31 and a positive meniscus lens L32 having a convex surface facing the object side, and a flare-cut stop FS. Has been. The positive meniscus lens L32 is an aspheric lens having an aspheric surface on the image side.

The fourth lens group G4 includes, in order from the object side along the optical axis, a cemented lens of a biconvex lens L41 and a negative meniscus lens L42 having a concave surface facing the object side, and a negative meniscus lens L43 having a convex surface facing the object side. It is composed of a cemented lens with a positive meniscus lens L44 having a convex surface facing the object side. The negative meniscus lens L42 is an aspheric lens having an aspherical lens surface on the image side.

The fifth lens group G5 includes a positive meniscus lens L51 having a concave surface directed toward the object side. The positive meniscus lens L51 is an aspheric lens having an aspheric lens surface on the object side and a lens surface on the image side.

On the image plane I, an image sensor (not shown) composed of a CCD, a CMOS, or the like is disposed.

With the above configuration, the zoom lens according to the present embodiment reduces the distance between the first lens group G1 and the second lens group G2 when zooming from the wide-angle end state to the telephoto end state. The distance between the lens group G2 and the third lens group G3 increases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Thus, the first lens group G1, the second lens group G2, the third lens group G4, and the fourth lens group G4 move along the optical axis with respect to the image plane I. Specifically, at the time of zooming, the first lens group G1 once moves to the image plane I side and then moves to the object side, the second lens group G2 moves to the object side, and the third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side, and the fifth lens group G5 is fixed with respect to the image plane I.

The aperture stop S is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

In the zoom lens according to the present embodiment, focusing from an infinitely distant object to a close object is performed by moving the second F lens group G2F to the image plane I side.

In addition, the zoom lens according to the present example uses a cemented lens of the biconcave lens L31 of the third lens group G3 and the positive meniscus lens L32 having a convex surface toward the object side as a vibration-proof lens group, and a component in a direction orthogonal to the optical axis. Image plane correction when image blur occurs, that is, image stabilization is performed.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blurring correction is K (hereinafter referred to as “K”) This ratio is referred to as an anti-vibration coefficient K.) In order to correct the rotational shake at the angle θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K. .
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 0.54 and the focal length is 16.48 (mm) (see Table 1 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.43 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 0.68, and the focal length is 25.21 (mm) (see Table 1 below). The amount of movement of the anti-vibration lens group is 0.42 (mm). In the telephoto end state, the image stabilization coefficient K is 0.85, and the focal length is 33.95 (mm) (see Table 1 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.39 (mm).

Table 1 below lists specifications of the zoom lens according to the first example.
In [Overall specifications] in Table 1, f is the focal length of the entire zoom lens system, FNO is the F number, ω is the half field angle (unit: degree), Y is the image height, TL is the total length of the optical system, and BF is Each shows the back focus. Here, the total length TL of the optical system is a distance on the optical axis from the most object side lens surface in the first lens group G1 to the image plane I. Further, the back focus BF is a distance on the optical axis from the most image side lens surface to the image surface I in the fifth lens group G5. W indicates the wide-angle end state, M indicates the intermediate focal length state, and T indicates the respective focal length states in the telephoto end state.

In [Surface Data], the surface number is the order of the lens surfaces counted from the object side, r is the radius of curvature of the lens surfaces, d is the distance between the lens surfaces, nd is the refractive index with respect to the d-line (wavelength λ = 587.6 nm), νd represents the Abbe number for the d-line (wavelength λ = 587.6 nm). Further, the object plane indicates the object plane, (stop) indicates the aperture stop S, (FS) indicates the flare cut stop FS, and the image plane indicates the image plane I. Note that the radius of curvature r = ∞ indicates a plane, and the description of the refractive index of air d = 1.00000 is omitted. When the lens surface is an aspheric surface, the surface number is marked with * and the paraxial radius of curvature is shown in the column of the radius of curvature r.

[Lens Group Data] indicates the starting surface number and focal length of each lens group.

[Aspherical data] shows an aspherical coefficient and a conic constant when the shape of the aspherical surface shown in [Surface data] is expressed by the following equation.
x = (h ² / r) / [1+ {1-κ (h / r) ² } ^1/2 ]
+ A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰
Here, h is the height in the direction perpendicular to the optical axis, x is the distance (sag amount) from the tangent plane of the apex of the aspheric surface to the aspheric surface at the height h, and κ is the conic constant. , A4, A6, A8, A10 are aspherical coefficients, and r is the radius of curvature (paraxial curvature radius) of the reference sphere. Further, “E−n” indicates “× 10 ⁻ⁿ ”, for example, “1.234E-05” indicates “1.234 × 10 ⁻⁵ ”. The secondary aspherical coefficient A2 is 0 and is not shown.

In [variable interval data], f indicates the focal length of the entire zoom lens system, β indicates the photographing magnification, and dn (n is an integer) indicates the variable surface interval between the nth surface and the (n + 1) surface. Show. D0 indicates the distance from the object to the lens surface closest to the object. Note that W is the wide-angle end state, M is the intermediate focal length state, T is the telephoto end state, infinity is when focusing on an object at infinity, and short distance indicates when focusing on a near object.
[Conditional Expression Corresponding Value] indicates the corresponding value of each conditional expression.
Here, “mm” is generally used as the unit of the focal length f, the radius of curvature r, and other lengths described in Table 1. However, the optical system is not limited to this because an equivalent optical performance can be obtained even when proportionally enlarged or proportionally reduced.

In addition, the code | symbol of Table 1 described above shall be used similarly also in the table | surface of each Example mentioned later.

(Table 1) First Example [Overall Specifications]
W M T
f 16.48 25.21 33.95
FNO 2.83 2.83 2.83
ω 54.1 39.9 31.7
Y 21.64 21.64 21.64
TL 162.368 156.100 161.776
BF 18.068 18.076 18.058

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 75.44949 2.000 1.85135 40.1
* 2) 20.28508 6.283
3) 51.06676 2.000 1.90043 37.4
4) 24.72875 14.151
5) -37.47670 2.000 1.49782 82.6
6) 256.37590 0.150
7) 92.17324 6.061 2.00100 29.1
8) -101.88567 (variable)

* 9) 49.32957 10.021 1.61492 58.4
10) -33.33841 1.500 1.61772 49.8
11) -82.04309 0.150
12) 101.37291 1.500 1.51823 58.8
13) 37.71250 (variable)

14) 27.89843 1.500 1.80518 25.4
15) 20.73501 12.485 1.48749 70.3
16) -35.76178 1.500 1.68893 31.2
17) -69.08870 (variable)

18) (Aperture) ∞ 4.000
19) -191.55206 1.500 1.74400 44.8
20) 29.63471 3.611 1.80244 25.6
* 21) 65.28008 1.000
22) (FS) ∞ (variable)

23) 26.78513 6.812 1.49782 82.6
24) -98.18107 1.500 1.88202 37.2
* 25) -107.04814 0.150
26) 135.48608 1.500 1.90043 37.4
27) 20.03626 9.030 1.49782 82.6
28) 2971.25110 (variable)

* 29) -129.34917 5.005 1.76116 50.5
* 30) -43.36071 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -26.25
G2 9 39.27
G3 18 -70.00
G4 23 93.83
G5 29 83.59

[Aspherical data]
Surface number: 1
κ = 5.92300E-01
A4 = -2.443736E-06
A6 = 2.64717E-09
A8 = -1.54187E-12
A10 = 5.99784E-16

Surface number: 2
κ = 4.21200E-01
A4 = -6.62142E-06
A6 = 3.27522E-12
A8 = -7.76064E-12
A10 = 9.08049E-15

Surface number: 9
κ = 1.00000E + 00
A4 = -2.887523E-06
A6 = 2.47805E-10
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 21
κ = 8.46000E-01
A4 = -5.01566E-07
A6 = -1.49741E-08
A8 = 1.12108E-10
A10 = -2.97302E-13

Surface number: 25
κ = 1.00000E + 00
A4 = 1.18848E-05
A6 = -5.83406E-10
A8 = 2.65926E-11
A10 = -1.81664E-13

Surface number: 29
κ = 1.00000E + 00
A4 = 1.04301E-05
A6 = -2.889394E-08
A8 = 6.51407E-11
A10 = -6.88449E-14

Surface number: 30
κ = 1.00000E + 00
A4 = 1.61530E-05
A6 = -3.59475E-08
A8 = 7.02618E-11
A10 = -6.91220E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 110.00 116.28 110.58
β----0.1212 -0.1798 -0.2542
f 16.48 25.21 33.95---
d 8 29.353 9.442 0.500 34.199 14.324 5.898
d13 6.626 6.626 6.626 1.780 1.743 1.228
d17 2.000 5.729 7.157 2.000 5.729 7.157
d22 7.842 3.616 1.500 7.842 3.616 1.500
d28 3.071 17.203 32.526 3.071 17.203 32.526
BF 18.068 18.076 18.058 18.152 18.261 18.427

[Values for each conditional expression]
(1) f5 / (− f1) = 3.184
(2) | m12 | /fw=1.715
(3) f5 / f4 = 0.899

2 (a), 2 (b), and 2 (c), respectively, are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the first example. FIG.
3 (a), 3 (b), and 3 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the first example. FIG.
4 (a), 4 (b), and 4 (c) respectively show meridional laterals during vibration isolation in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to the first example. It is an aberration diagram.

In each aberration diagram, FNO is an F number, A is a light incident angle, that is, a half angle of view (unit is “°”), NA is a numerical aperture, and H0 is an object height (unit: mm). In the figure, d indicates an aberration curve at the d-line (wavelength λ = 587.6 nm), g indicates an aberration curve at the g-line (wavelength λ = 435.8 nm), and those not described are those at the d-line. An aberration curve is shown. The spherical aberration diagram shows the F-number value corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum half field angle or object height, and the lateral aberration diagram shows each half field angle or each object height. The value of is shown. In the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. The lateral aberration diagram shows meridional lateral aberration with respect to the d-line and the g-line. In addition, in the various aberration diagrams of the following examples, the same reference numerals as those of the present example are used.

As is clear from each aberration diagram, the zoom lens according to the first example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Second embodiment)
FIGS. 5A, 5B, and 5C are cross-sectional views of the zoom lens according to Example 2 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 5A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. The arrow below each lens group in FIG. 5B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 5A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

With the above configuration, the zoom lens according to the present embodiment reduces the distance between the first lens group G1 and the second lens group G2 when zooming from the wide-angle end state to the telephoto end state. The distance between the lens group G2 and the third lens group G3 increases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Thus, the first lens group G1, the second lens group G2, the third lens group G4, and the fourth lens group G4 move along the optical axis with respect to the image plane I. Specifically, at the time of zooming, the first lens group G1 once moves to the image plane I side and then moves to the object side, and the second lens group G2 and the fourth lens group G4 move together to the object side. The third lens group G3 moves toward the object side, and the fifth lens group G5 is fixed with respect to the image plane I.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to this example, in the wide-angle end state, the image stabilization coefficient K is 0.56, and the focal length is 16.48 (mm) (see Table 2 below). The amount of movement of the anti-vibration lens group for correcting the rotational blur is 0.42 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 0.70 and the focal length is 25.21 (mm) (see Table 2 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.41 (mm). In the telephoto end state, the image stabilization coefficient K is 0.87, and the focal length is 33.95 (mm) (see Table 2 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.38 (mm).

Table 2 below lists specifications of the zoom lens according to the second example.

(Table 2) Second embodiment [Overall specifications]
W M T
f 16.48 25.21 33.95
FNO 2.83 2.83 2.83
ω 54.0 40.0 31.8
Y 21.64 21.64 21.64
TL 162.361 156.840 162.363
BF 18.070 18.065 18.063

[Surface data]
Surface number r d nd νd
Object ∞

* 1) 73.22991 2.000 1.85135 40.1
* 2) 19.62926 7.474
3) 61.15202 2.000 1.90043 37.4
4) 26.50584 12.785
5) -37.55896 2.000 1.49782 82.6
6) 312.93830 0.150
7) 97.61558 6.381 2.00100 29.1
8) -90.94529 (variable)

* 9) 45.42754 8.894 1.58313 59.4
10) -33.86178 1.500 1.65160 58.6
11) -73.70296 1.496
12) 108.06528 1.500 1.51742 52.2
13) 36.32590 (variable)

14) 27.56863 1.500 1.84416 24.0
15) 20.91099 12.393 1.48749 70.3
16) -40.66843 1.500 1.80328 25.5
17) -63.71042 (variable)

18) (Aperture) ∞ 3.500
19) -208.49060 1.500 1.74400 44.8
20) 26.99771 3.953 1.80244 25.6
* 21) 62.64116 1.000
22) (FS) ∞ (variable)

23) 26.91271 7.631 1.49782 82.6
24) -57.70103 1.500 1.88202 37.2
* 25) -93.99278 0.150
26) 62.42449 1.500 1.90043 37.4
27) 19.07512 7.749 1.49782 82.6
28) 83.05930 (variable)

* 29) -135.00000 5.076 1.77250 49.5
* 30) -44.25074 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -26.24
G2 9 40.29
G3 18 -70.00
G4 23 92.95
G5 29 83.19

[Aspherical data]
Surface number: 1
κ = 7.56000E-02
A4 = -2.78471E-06
A6 = 3.86364E-09
A8 = -2.669774E-12
A10 = 9.05111E-16

Surface number: 2
κ = 1.77500E-01
A4 = -2.58137E-06
A6 = 2.51888E-09
A8 = 2.34244E-12
A10 = 1.66721E-16

Surface number: 9
κ = 1.00000E + 00
A4 = -2.97350E-06
A6 = -1.01164E-09
A8 = 5.03482E-12
A10 = -6.96957E-15

Surface number: 21
κ = 1.27800E + 00
A4 = -2.19664E-07
A6 = -2.334247E-08
A8 = 1.80346E-10
A10 = -4.74051E-13

Surface number: 25
κ = 1.00000E + 00
A4 = 1.15418E-05
A6 = 5.82895E-09
A8 = -4.75474E-12
A10 = -1.24299E-13

Surface number: 29
κ = 1.00000E + 00
A4 = 1.07645E-05
A6 = -4.55699E-08
A8 = 1.31690E-10
A10 = 1.37085E-13

Surface number: 30
κ = 1.00000E + 00
A4 = 1.60203E-05
A6 = -5.49184E-08
A8 = 1.40358E-10
A10 = -1.35750E-13

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 110.01 115.53 110.00
β----0.1220 -0.1816 -0.2566
f 16.48 25.21 33.95---
d 8 28.899 9.423 0.500 33.772 14.498 6.164
d13 6.862 6.862 6.862 1.989 1.787 1.198
d17 2.000 5.572 7.582 2.000 5.572 7.582
d22 7.082 3.510 1.500 7.082 3.510 1.500
d28 4.315 18.275 32.723 4.315 18.275 32.723
BF 18.070 18.065 18.063 18.155 18.254 18.438

[Values for each conditional expression]
(1) f5 / (− f1) = 3.171
(2) | m12 | /fw=1.723
(3) f5 / f4 = 0.895

FIGS. 6 (a), 6 (b), and 6 (c) are respectively when the object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the second example. FIG.
FIGS. 7 (a), 7 (b), and 7 (c) respectively show the zoom lens according to the second embodiment when focusing on a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state. FIG.
8 (a), 8 (b), and 8 (c) respectively show the meridional lateral at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the second example. It is an aberration diagram.

As is apparent from each aberration diagram, the zoom lens according to the second example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Third embodiment)
FIGS. 9A, 9B, and 9C are cross-sectional views of the zoom lens according to the third example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 9A indicates the moving direction of each lens group during zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 9B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 9A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

With the above configuration, the zoom lens according to the present embodiment reduces the distance between the first lens group G1 and the second lens group G2 when zooming from the wide-angle end state to the telephoto end state. The distance between the lens group G2 and the third lens group G3 increases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Thus, the first lens group G1, the second lens group G2, the third lens group G4, the fourth lens group G4, and the fifth lens group G5 move along the optical axis with respect to the image plane I. Specifically, at the time of zooming, the first lens group G1 once moves to the image plane I side and then moves to the object side, and the second lens group G2 and the fourth lens group G4 move together to the object side. Then, the third lens group G3 moves to the object side, and the fifth lens group G5 once moves to the object side and then moves to the image plane I side.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to this example, in the wide-angle end state, the image stabilization coefficient K is 0.56 and the focal length is 16.48 (mm) (see Table 3 below). The amount of movement of the anti-vibration lens group for correcting the rotational blur is 0.42 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 0.70 and the focal length is 25.21 (mm) (see Table 3 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.41 (mm). In the telephoto end state, the image stabilization coefficient K is 0.87, and the focal length is 33.95 (mm) (see Table 3 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.39 (mm).

Table 3 below lists specifications of the zoom lens according to the third example.

(Table 3) Third Example [Overall Specifications]
W M T
f 16.48 25.21 33.95
FNO 2.83 2.83 2.83
ω 54.0 39.9 31.7
Y 21.64 21.64 21.64
TL 162.369 156.568 162.359
BF 18.069 18.479 18.059

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 73.35843 2.000 1.85135 40.1
* 2) 19.65231 7.423
3) 60.85659 2.000 1.90043 37.4
4) 26.46067 12.865
5) -37.68469 2.000 1.49782 82.6
6) 319.60622 0.150
7) 98.35638 6.315 2.00100 29.1
8) -91.84642 (variable)

* 9) 45.12179 9.169 1.58313 59.4
10) -32.35918 1.500 1.65160 58.6
11) -70.79534 1.426
12) 116.36340 1.500 1.51742 52.2
13) 36.40999 (variable)

14) 27.76490 1.500 1.84500 23.9
15) 21.11208 12.352 1.48749 70.3
16) -40.48676 1.500 1.79173 26.0
17) -63.27082 (variable)

18) (Aperture) ∞ 3.500
19) -209.12746 1.500 1.74400 44.8
20) 27.47317 3.887 1.80244 25.6
* 21) 62.77212 1.000
22) (FS) ∞ (variable)

23) 26.82011 7.501 1.49782 82.6
24) -55.69746 1.500 1.88202 37.2
* 25) -89.72149 0.150
26) 63.20031 1.500 1.90043 37.4
27) 19.07631 7.703 1.49782 82.6
28) 80.36061 (variable)

* 29) -135.00000 5.077 1.77250 49.5
* 30) -44.25947 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -26.11
G2 9 40.20
G3 18 -70.00
G4 23 93.63
G5 29 83.21

[Aspherical data]
Surface number: 1
κ = 8.75000E-02
A4 = -2.78056E-06
A6 = 3.66529E-09
A8 = -2.332659E-12
A10 = 7.29739E-16

Surface number: 2
κ = 1.25600E-01
A4 = -1.66529E-06
A6 = 1.18889E-09
A8 = 5.12891E-12
A10 = -1.72885E-16

Surface number: 9
κ = 1.00000E + 00
A4 = -3.12858E-06
A6 = -1.15459E-09
A8 = 5.52871E-12
A10 = -7.23502E-15

Surface number: 21
κ = 1.36390E + 00
A4 = -1.54769E-07
A6 = -2.666171E-08
A8 = 2.07963E-10
A10 = -5.54299E-13

Surface number: 25
κ = 1.00000E + 00
A4 = 1.15286E-05
A6 = 7.02471E-09
A8 = -1.60325E-11
A10 = -9.68792E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 1.12240E-05
A6 = -4.41692E-08
A8 = 1.19461E-10
A10 = -1.22999E-13

Surface number: 30
κ = 1.00000E + 00
A4 = 1.62814E-05
A6 = -5.22346E-08
A8 = 1.25318E-10
A10 = -1.19716E-13

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 110.00 115.79 110.00
β----0.1221 -0.1814 -0.2567
f 16.48 25.21 33.95---
d 8 28.797 9.141 0.500 33.624 14.169 6.113
d13 6.847 6.847 6.847 2.020 1.820 1.234
d17 2.000 5.812 7.792 2.000 5.812 7.792
d22 7.292 3.480 1.500 7.292 3.480 1.500
d28 4.346 17.791 32.643 4.346 17.791 32.643
BF 18.069 18.479 18.059 18.154 18.667 18.434

[Values for each conditional expression]
(1) f5 / (− f1) = 3.187
(2) | m12 | /fw=1.717
(3) f5 / f4 = 0.889

10 (a), 10 (b), and 10 (c), respectively, are shown when an object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the third example. FIG.
11 (a), 11 (b), and 11 (c), respectively, are those when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to the third example. FIG.
12 (a), 12 (b), and 12 (c) respectively show meridional laterals during image stabilization in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 3. It is an aberration diagram.

As is apparent from each aberration diagram, the zoom lens according to the third example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Fourth embodiment)
FIGS. 13A, 13B, and 13C are cross-sectional views of the zoom lens according to the fourth example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 13A indicates the moving direction of each lens group during zooming from the wide-angle end state to the intermediate focal length state. The arrow below each lens group in FIG. 13B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 13A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to this example, in the wide-angle end state, the image stabilization coefficient K is 0.81, and the focal length is 18.54 (mm) (see Table 4 below). The amount of movement of the anti-vibration lens group for correcting the rotational blur is 0.30 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 1.00 and the focal length is 25.21 (mm) (see Table 4 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.29 (mm). Further, in the telephoto end state, the image stabilization coefficient K is 1.26, and the focal length is 33.95 (mm) (see Table 4 below), so that a rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.27 (mm).

Table 4 below lists specifications of the zoom lens according to the fourth example.

(Table 4) Fourth Example [Overall Specifications]
W M T
f 18.54 25.21 33.95
FNO 2.83 2.83 2.83
ω 49.9 40.1 31.7
Y 21.64 21.64 21.64
TL 160.545 157.622 162.364
BF 18.069 18.074 18.064

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 64.13853 2.000 1.82080 42.7
* 2) 20.52237 7.450
3) 42.79628 2.000 1.84300 37.4
4) 23.01367 14.005
5) -42.12649 2.000 1.49782 82.6
6) 60.80104 0.150
7) 55.48158 6.486 2.00100 29.1
8) -197.93506 (variable)

* 9) 46.12318 12.702 1.58313 59.4
10) -26.66064 1.500 1.61772 49.8
11) -71.59323 0.150
12) 68.72530 1.500 1.51742 52.2
13) 35.19343 (variable)

14) 27.39712 1.500 1.84666 23.8
15) 20.26274 11.974 1.48749 70.3
16) -34.96195 1.500 1.80000 25.6
17) -55.58525 (variable)

18) (Aperture) ∞ 4.000
19) -144.55027 1.500 1.74400 44.8
20) 20.23731 4.012 1.80244 25.6
* 21) 40.54944 1.000
22) (FS) ∞ (variable)

23) 29.62933 6.997 1.49782 82.6
24) -75.50908 1.500 1.88202 37.2
* 25) -112.41227 0.150
26) 34.10106 1.500 1.90043 37.4
27) 19.08383 7.811 1.49782 82.6
28) 56.03390 (variable)

* 29) -135.00000 4.569 1.77250 49.5
* 30) -51.50452 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -26.00
G2 9 38.17
G3 18 -45.00
G4 23 54.97
G5 29 105.29

[Aspherical data]
Surface number: 1
κ = 1.97190E + 00
A4 = -3.80899E-06
A6 = 3.65826E-09
A8 = -2.38771E-12
A10 = 7.43869E-16

Surface number: 2
κ = 8.82000E-02
A4 = -1.21936E-06
A6 = 2.60285E-09
A8 = 9.42881E-13
A10 = 3.22230E-15

Surface number: 9
κ = 1.00000E + 00
A4 = -3.25645E-06
A6 = 5.35394E-10
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 21
κ = 4.59700E-01
A4 = -1.02727E-06
A6 = -1.01707E-08
A8 = 9.24484E-11
A10 = -2.40570E-13

Surface number: 25
κ = 1.00000E + 00
A4 = 9.28617E-06
A6 = 1.98222E-09
A8 = 3.47233E-11
A10 = -1.62414E-13

Surface number: 29
κ = 1.00000E + 00
A4 = 8.29178E-06
A6 = -3.50865E-08
A8 = 1.26307E-10
A10 = -1.60070E-13

Surface number: 30
κ = 1.00000E + 00
A4 = 1.30379E-05
A6 = -4.40208E-08
A8 = 1.33306E-10
A10 = -1.56261E-13

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 111.82 114.75 110.00
β----0.1327 -0.1788 -0.2514
f 18.54 25.21 33.95---
d 8 22.618 9.438 0.500 27.248 14.104 5.591
d13 8.395 8.395 8.395 3.766 3.729 3.304
d17 3.500 5.288 6.734 3.500 5.288 6.734
d22 4.734 2.946 1.500 4.734 2.946 1.500
d28 5.273 15.525 29.215 5.273 15.525 29.215
BF 18.069 18.074 18.064 18.169 18.256 18.424

[Values for each conditional expression]
(1) f5 / (− f1) = 4.050
(2) | m12 | /fw=1.193
(3) f5 / f4 = 1.915

FIGS. 14 (a), 14 (b), and 14 (c) respectively show a zoom lens according to the fourth example when focusing on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state. FIG.
15 (a), 15 (b), and 15 (c), respectively, are those when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 4. FIG.
16 (a), 16 (b), and 16 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the fourth example. It is an aberration diagram.

As is apparent from the respective aberration diagrams, the zoom lens according to the fourth example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(5th Example)
FIGS. 17A, 17B, and 17C are sectional views of the zoom lens according to Example 5 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 17A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 17B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 17A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 0.47 and the focal length is 15.45 (mm) (see Table 5 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.48 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 0.61, and the focal length is 25.21 (mm) (see Table 5 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.48 (mm). In the telephoto end state, the image stabilization coefficient K is 0.76, and the focal length is 33.95 (mm) (see Table 5 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.44 (mm).

Table 5 below lists specifications of the zoom lens according to the fifth example.

(Table 5) Fifth embodiment [Overall specifications]
W M T
f 15.45 25.21 33.95
FNO 2.83 2.83 2.83
ω 56.2 40.0 31.8
Y 21.64 21.64 21.64
TL 168.787 161.395 167.660
BF 18.067 18.070 18.058

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 84.32721 2.000 1.82080 42.7
* 2) 22.42250 6.533
3) 40.43903 2.000 1.90043 37.4
4) 22.79897 18.443
5) -36.72174 2.000 1.49782 82.6
6) 108.66132 0.150
7) 86.07473 6.091 2.00100 29.1
8) -113.52466 (variable)

* 9) 56.20536 8.334 1.58313 59.4
10) -34.82724 1.500 1.62896 51.8
11) -62.67282 0.150
12) 1521.91690 1.500 1.51742 52.2
13) 63.48881 (variable)

14) 32.18721 1.500 1.83207 24.9
15) 23.97842 11.952 1.48749 70.3
16) -42.36534 1.500 1.79889 25.4
17) -64.06791 (variable)

18) (Aperture) ∞ 4.000
19) -402.90754 1.500 1.74400 44.8
20) 29.51707 4.016 1.80244 25.6
* 21) 67.51202 1.000
22) (FS) ∞ (variable)

23) 30.01453 8.025 1.49782 82.6
24) -48.32228 1.500 1.88202 37.2
* 25) -80.74589 0.150
26) 73.99805 1.500 1.90043 37.4
27) 19.28578 8.991 1.49782 82.6
28) 131.61654 (variable)

* 29) -135.00000 5.020 1.77250 49.5
* 30) -45.90440 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -26.00
G2 9 40.61
G3 18 -85.00
G4 23 113.40
G5 29 87.88

[Aspherical data]
Surface number: 1
κ = 1.07450E + 00
A4 = -1.57852E-06
A6 = 2.55869E-09
A8 = -1.24755E-12
A10 = 2.99043E-16

Surface number: 2
κ = 2.82500E-01
A4 = -5.25879E-06
A6 = 2.99379E-09
A8 = -1.07006E-13
A10 = 2.38338E-15

Surface number: 9
κ = 1.00000E + 00
A4 = -3.444380E-06
A6 = 6.36234E-10
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 21
κ = 5.97700E-01
A4 = -1.14555E-08
A6 = -6.90561E-09
A8 = 2.24606E-11
A10 = -2.11799E-15

Surface number: 25
κ = 1.00000E + 00
A4 = 8.46457E-06
A6 = -1.83245E-09
A8 = 1.13124E-11
A10 = -6.67256E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 1.35371E-05
A6 = -4.85133E-08
A8 = 1.04081E-10
A10 = -9.31604E-14

Surface number: 30
κ = 1.00000E + 00
A4 = 2.00382E-05
A6 = -5.78531E-08
A8 = 1.07159E-10
A10 = -8.91147E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 103.58 110.97 104.70
β----0.1177 -0.1847 -0.2625
f 15.45 25.21 33.95---
d 8 32.660 9.394 0.500 37.602 14.284 5.903
d13 6.126 6.126 6.126 1.184 1.237 0.724
d17 1.500 5.658 7.190 1.500 5.658 7.190
d22 7.190 3.032 1.500 7.190 3.032 1.500
d28 3.889 19.760 34.930 3.889 19.760 34.930
BF 18.067 18.070 18.058 18.146 18.265 18.451

[Values for each conditional expression]
(1) f5 / (-f1) = 3.380
(2) | m12 | /fw=2.082
(3) f5 / f4 = 0.775

18 (a), 18 (b), and 18 (c), respectively, are shown when an object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. FIG.
19 (a), 19 (b), and 19 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. FIG.
20 (a), 20 (b), and 20 (c) respectively show the meridional lateral at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 5. It is an aberration diagram.

As is clear from the respective aberration diagrams, the zoom lens according to Example 5 has various aberrations corrected well from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Sixth embodiment)
FIGS. 21A, 21B, and 21C are cross-sectional views of the zoom lens according to Example 6 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 21A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 21B indicates the moving direction of each lens group upon zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 21A, the zoom lens according to the present example includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

The first lens group G1 includes, in order from the object side along the optical axis, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, a biconcave lens L13, and a biconvex lens. L14. The negative meniscus lens L11 is an aspherical lens in which the object-side lens surface and the image-side lens surface are aspherical. The negative meniscus lens L12 is an aspherical lens having an aspherical lens surface on the image side.

The second lens group G2 includes, in order from the object side along the optical axis, a second F lens group G2F having a positive refractive power and a second R lens group G2R having a positive refractive power.
The second F lens group G2F includes, in order from the object side along the optical axis, a cemented lens of a biconvex lens L21 and a negative meniscus lens L22 having a concave surface facing the object side, and a biconcave lens L23. The biconvex lens L21 is an aspheric lens having an aspheric lens surface on the object side.
The second R lens group G2R includes, in order from the object side along the optical axis, a cemented lens of a negative meniscus lens L24 having a convex surface facing the object side, a biconvex lens L25, and a negative meniscus lens L26 having a concave surface facing the object side. Has been. The negative meniscus lens L24 is an aspheric lens having an aspheric lens surface on the object side.

The third lens group G3 includes, in order from the object side along the optical axis, an aperture stop S, a cemented lens of a biconcave lens L31 and a positive meniscus lens L32 having a convex surface facing the object side, and a flare-cut stop FS. Has been.

In the zoom lens according to the present embodiment, the second R lens group G2R is moved as a vibration-proof lens group in a direction including a component in a direction orthogonal to the optical axis, thereby correcting image plane when an image blur occurs, that is, vibration-proof. It is carried out.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to this example, in the wide-angle end state, the image stabilization coefficient K is 1.07 and the focal length is 16.48 (mm) (see Table 6 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.22 (mm). In the intermediate focal length state, the image stabilization coefficient K is 1.37, and the focal length is 25.21 (mm) (see Table 6 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.21 (mm). In the telephoto end state, the image stabilization coefficient K is 1.67 and the focal length is 33.95 (mm) (see Table 6 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.20 (mm).

Table 6 below lists specifications of the zoom lens according to the sixth example.

(Table 6) Sixth Example [Overall specifications]
W M T
f 16.48 25.21 33.95
FNO 4.00 4.00 4.00
ω 54.1 39.8 31.7
Y 21.64 21.64 21.64
TL 162.369 156.678 160.978
BF 18.069 18.064 18.074

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 180.13769 2.000 1.82080 42.7
* 2) 19.96088 6.970
3) 94.52854 2.000 1.90043 37.4
* 4) 28.44278 9.857
5) -42.62350 2.000 1.49782 82.6
6) 244.08326 0.150
7) 61.25466 5.605 2.00100 29.1
8) -150.06559 (variable)

* 9) 36.24721 7.764 1.58313 59.4
10) -22.60689 1.500 1.65844 50.8
11) -43.72965 0.151
12) -207.94715 1.500 1.51742 52.2
13) 40.03120 (variable)

* 14) 43.25649 1.500 1.79504 28.7
15) 26.23995 11.085 1.48749 70.3
16) -21.42752 1.500 1.68893 31.2
17) -29.56586 (variable)

18) (Aperture) ∞ 4.000
19) -74.75529 1.500 1.74400 44.8
20) 22.57348 3.362 1.80244 25.6
21) 84.92681 1.000
22) (FS) ∞ (variable)

23) 34.18409 11.631 1.49782 82.6
24) -22.09869 1.500 1.88202 37.2
* 25) -35.01463 0.150
26) 64.77675 1.500 1.90043 37.4
27) 18.18435 8.523 1.49782 82.6
28) 70.17847 (variable)

* 29) -135.00000 5.121 1.77250 49.5
* 30) -46.54146 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -23.15
G2 9 37.14
G3 18 -58.82
G4 23 86.56
G5 29 89.68

[Aspherical data]
Surface number: 1
κ = 2.00000E + 00
A4 = 7.91245E-06
A6 = -3.69643E-09
A8 = 1.11415E-12
A10 = -2.04281E-16

Surface number: 2
κ = 1.05500E-01
A4 = -1.07575E-05
A6 = 4.04887E-08
A8 = -2.80099E-11
A10 = 8.02396E-14

Surface number: 4
κ = 1.00000E + 00
A4 = 2.14895E-05
A6 = 5.07570E-09
A8 = -8.70469E-11
A10 = 9.89182E-14

Surface number: 9
κ = 1.00000E + 00
A4 = -5.58940E-06
A6 = -6.24739E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 14
κ = 1.00000E + 00
A4 = -4.10738E-06
A6 = 2.26991E-09
A8 = -1.27958E-11
A10 = 2.28497E-14

Surface number: 25
κ = 1.00000E + 00
A4 = 6.63910E-06
A6 = -2.70332E-09
A8 = -1.14938E-11
A10 = -3.86980E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 2.96724E-06
A6 = -7.37447E-10
A8 = 4.28602E-11
A10 = -7.07831E-14

Surface number: 30
κ = 1.00000E + 00
A4 = 5.46618E-06
A6 = -9.05640E-09
A8 = 6.16567E-11
A10 = -8.57111E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 110.00 115.69 111.40
β----0.1243 -0.1848 -0.2589
f 16.48 25.21 33.95---
d 8 27.344 8.875 0.500 31.204 12.826 4.873
d13 7.541 7.541 7.541 3.681 3.590 3.168
d17 2.000 7.319 11.342 2.000 7.319 11.342
d22 10.842 5.524 1.500 10.842 5.524 1.500
d28 4.704 17.488 30.153 4.704 17.488 30.158
BF 18.069 18.064 18.074 18.157 18.259 18.456

[Values for each conditional expression]
(1) f5 / (− f1) = 3.873
(2) | m12 | /fw=1.629
(3) f5 / f4 = 1.36

22 (a), 22 (b), and 22 (c) respectively show the infinite object focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. FIG.
23 (a), 23 (b), and 23 (c) are respectively when a short-distance object is focused in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. FIG.
24 (a), 24 (b), and 24 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 6. It is an aberration diagram.

As is apparent from the respective aberration diagrams, the zoom lens according to Example 6 has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Seventh embodiment)
FIGS. 25A, 25B, and 25C are cross-sectional views of the zoom lens according to the seventh example in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 25A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 25B indicates the moving direction of each lens group at the time of zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 25A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

The first lens group G1 has, in order from the object side along the optical axis, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, and a concave surface facing the object side. It is composed of a negative meniscus lens L13 and a biconvex lens L14. The negative meniscus lens L11 is an aspherical lens in which the object-side lens surface and the image-side lens surface are aspherical.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 0.56 and the focal length is 16.48 (mm) (see Table 7 below). The amount of movement of the anti-vibration lens group for correcting the rotational blur is 0.42 (mm). In the intermediate focal length state, the image stabilization coefficient K is 0.70, and the focal length is 25.21 (mm) (see Table 7 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.41 (mm). In the telephoto end state, the image stabilization coefficient K is 0.87, and the focal length is 33.95 (mm) (see Table 7 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.39 (mm).

Table 7 below lists specifications of the zoom lens according to the seventh example.

(Table 7) Seventh Example [Overall specifications]
W M T
f 16.48 25.21 33.95
FNO 4.00 4.00 4.00
ω 54.0 39.8 31.8
Y 21.64 21.64 21.64
TL 152.197 148.076 154.253
BF 18.060 18.054 18.063

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 89.63662 2.000 1.82080 42.7
* 2) 19.03463 6.400
3) 59.00594 2.000 1.90043 37.4
4) 25.04291 12.879
5) -34.42001 2.000 1.49782 82.6
6) -220.10809 0.150
7) 110.12188 5.234 2.00100 29.1
8) -94.03704 (variable)

* 9) 34.70954 8.195 1.58313 59.4
10) -22.32702 1.500 1.64013 58.3
11) -56.97811 0.150
12) 143.57014 1.500 1.51742 52.2
13) 29.47978 (variable)

14) 25.69484 1.500 1.79504 28.7
15) 18.31640 7.768 1.48749 70.3
16) -37.27717 1.500 1.73708 28.4
17) -69.75583 (variable)

18) (Aperture) ∞ 4.000
19) -172.99604 1.500 1.74400 44.8
20) 25.25276 3.145 1.80244 25.6
* 21) 65.66381 1.000
22) (FS) ∞ (variable)

23) 28.13736 7.994 1.49782 82.6
24) -39.84408 1.500 1.88202 37.2
* 25) -55.75469 0.150
26) 79.86144 1.500 1.90043 37.4
27) 18.03173 8.303 1.49782 82.6
28) 109.39627 (variable)

* 29) -135.00000 5.201 1.77250 49.5
* 30) -43.87168 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -25.31
G2 9 38.11
G3 18 -70.00
G4 23 97.42
G5 29 82.09

[Aspherical data]
Surface number: 1
κ = 0.00000E + 00
A4 = -1.65798E-06
A6 = 2.891887E-09
A8 = -2.10545E-12
A10 = 1.01969E-15

Surface number: 2
κ = 1.52100E-01
A4 = -3.98735E-06
A6 = 1.20818E-08
A8 = -2.550960E-11
A10 = 4.32957E-14

Surface number: 9
κ = 1.00000E + 00
A4 = -5.15908E-06
A6 = 1.64281E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 21
κ = 1.89270E + 00
A4 = -3.35320E-07
A6 = -5.17749E-08
A8 = 8.91765E-10
A10 = -5.73216E-12

Surface number: 25
κ = 1.00000E + 00
A4 = 1.10647E-05
A6 = 2.12638E-08
A8 = -1.45298E-10
A10 = 1.80548E-13

Surface number: 29
κ = 1.00000E + 00
A4 = 9.54720E-06
A6 = -3.28939E-08
A8 = 9.31216E-11
A10 = -9.94866E-14

Surface number: 30
κ = 1.00000E + 00
A4 = 1.57892E-05
A6 = -4.68421E-08
A8 = 1.10504E-10
A10 = -1.06766E-13

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 120.16 124.28 118.11
β----0.1141 -0.1719 -0.2434
f 16.48 25.21 33.95---
d 8 26.758 8.756 0.500 31.009 13.089 5.283
d13 7.532 7.532 7.532 3.280 3.198 2.749
d17 2.000 5.495 7.430 2.000 5.495 7.430
d22 6.930 3.434 1.500 6.930 3.434 1.500
d28 3.850 17.737 32.161 3.850 17.737 32.161
BF 18.060 18.054 18.063 18.135 18.223 18.401

[Values for each conditional expression]
(1) f5 / (− f1) = 3.244
(2) | m12 | /fw=1.593
(3) f5 / f4 = 0.743

FIGS. 26 (a), 26 (b), and 26 (c) are respectively when the object at infinity is in focus in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the seventh example. FIG.
FIGS. 27 (a), 27 (b), and 27 (c) are respectively for focusing a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to the seventh example. FIG.
28 (a), 28 (b), and 28 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 7. It is an aberration diagram.

As is apparent from the respective aberration diagrams, the zoom lens according to the seventh example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Eighth embodiment)
FIGS. 29A, 29B, and 29C are cross-sectional views of the zoom lens according to Example 8 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 29A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 29B indicates the moving direction of each lens group upon zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 29A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

In the zoom lens according to the present example, the cemented lens of the biconvex lens L41 in the fourth lens group G4 and the negative meniscus lens L42 having a concave surface facing the object side is used as an anti-vibration lens group in a direction orthogonal to the optical axis. Image plane correction when image blur occurs, that is, image stabilization, is performed by moving in the direction including the component.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 0.84, and the focal length is 16.48 (mm) (see Table 8 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.28 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 1.12 and the focal length is 25.21 (mm) (see Table 8 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.26 (mm). In the telephoto end state, the image stabilization coefficient K is 1.39, and the focal length is 33.94 (mm) (see Table 8 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.24 (mm).

Table 8 below lists specifications of the zoom lens according to the eighth example.

(Table 8) Eighth Example [Overall Specifications]
W M T
f 16.48 25.21 33.94
FNO 4.00 4.00 4.00
ω 54.1 40.0 31.8
Y 21.64 21.64 21.64
TL 156.155 150.831 154.903
BF 18.066 18.053 18.060

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 193.58721 2.000 1.82080 42.7
* 2) 20.02145 6.905
3) 90.01817 2.000 1.90043 37.4
* 4) 27.89307 9.933
5) -41.38646 2.000 1.49782 82.6
6) 388.04959 0.150
7) 63.78120 5.582 2.00100 29.1
8) -140.47475 (variable)

* 9) 34.11887 7.683 1.58313 59.4
10) -23.19093 1.500 1.65844 50.8
11) -43.34847 0.150
12) -133.64479 1.500 1.51742 52.2
13) 43.43678 (variable)

* 14) 43.27875 1.500 1.79504 28.7
15) 26.75575 9.166 1.48749 70.3
16) -21.47016 1.500 1.68893 31.2
17) -29.83058 (variable)

18) (Aperture) ∞ 4.000
19) -117.95737 1.500 1.74400 44.8
20) 20.54277 3.285 1.80244 25.6
21) 54.89929 1.000
22) (FS) ∞ (variable)

23) 32.72024 9.645 1.49782 82.6
24) -23.86366 1.500 1.88202 37.2
* 25) -34.86203 0.150
26) 69.62430 1.500 1.90043 37.4
27) 18.05008 9.020 1.49782 82.6
28) 104.94552 (variable)

* 29) -135.00000 4.710 1.77250 49.5
* 30) -48.92153 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -23.31
G2 9 35.87
G3 18 -54.84
G4 23 83.18
G5 29 97.01

[Aspherical data]
Surface number: 1
κ = 2.00000E + 00
A4 = 7.90218E-06
A6 = -3.67128E-09
A8 = 1.11425E-12
A10 = -3.22487E-16

Surface number: 2
κ = 9.06000E-02
A4 = -1.10492E-05
A6 = 4.18700E-08
A8 = -2.82799E-11
A10 = 8.48422E-14

Surface number: 4
κ = 1.00000E + 00
A4 = 2.06544E-05
A6 = 1.14896E-09
A8 = -9.32488E-11
A10 = 1.06908E-13

Surface number: 9
κ = 1.00000E + 00
A4 = -5.99537E-06
A6 = -8.64207E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 14
κ = 1.00000E + 00
A4 = -5.24252E-06
A6 = 3.78138E-09
A8 = -1.26184E-11
A10 = -1.01048E-14

Surface number: 25
κ = 1.00000E + 00
A4 = 5.70046E-06
A6 = -3.54520E-09
A8 = 1.13461E-11
A10 = -1.29870E-13

Surface number: 29
κ = 1.00000E + 00
A4 = 2.14047E-06
A6 = -2.58918E-09
A8 = 4.54444E-11
A10 = -7.04486E-14

Surface number: 30
κ = 1.00000E + 00
A4 = 5.01764E-06
A6 = -9.55833E-09
A8 = 5.69307E-11
A10 = -7.79067E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 116.21 121.52 117.46
β----0.1183 -0.1768 -0.2470
f 16.48 25.21 33.94---
d 8 27.092 8.876 0.500 30.852 12.622 4.589
d13 7.348 7.348 7.348 3.588 3.603 3.259
d17 2.000 6.293 9.740 2.000 6.293 9.740
d22 9.240 4.947 1.500 9.240 4.947 1.500
d28 4.528 17.433 29.874 4.528 17.433 29.874
BF 18.066 18.053 18.060 18.146 18.232 18.406

[Values for each conditional expression]
(1) f5 / (− f1) = 4.162
(2) | m12 | /fw=1.614
(3) f5 / f4 = 1.166

FIGS. 30 (a), 30 (b), and 30 (c) are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 8. FIG.
FIGS. 31 (a), 31 (b), and 31 (c) are respectively when focusing on a short-distance object in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 8. FIGS. FIG.
32 (a), 32 (b), and 32 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 8. It is an aberration diagram.

As is apparent from the respective aberration diagrams, the zoom lens according to Example 8 has various aberrations corrected well from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Ninth embodiment)
33A, 33B, and 33C are cross-sectional views of the zoom lens according to Example 9 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 33A indicates the moving direction of each lens group during zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 33B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 33A, the zoom lens according to the present example includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. Consists of a lens group G2, an aperture stop S, a third lens group G3 having negative refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. Has been.

The second lens group G2 has, in order from the object side along the optical axis, a cemented lens of a biconvex lens L21 and a negative meniscus lens L22 having a concave surface on the object side, a biconcave lens L23, and a convex surface on the object side. It is composed of a negative meniscus lens L24, a biconvex lens L25, and a cemented lens of a negative meniscus lens L26 having a concave surface facing the object side. The biconvex lens L21 is an aspheric lens having an aspheric lens surface on the object side. The negative meniscus lens L24 is an aspheric lens having an aspheric lens surface on the object side.

The third lens group G3 is composed of a cemented lens of a biconcave lens L31 and a positive meniscus lens L32 having a convex surface directed toward the object side.

With the above configuration, the zoom lens according to the present embodiment reduces the distance between the first lens group G1 and the second lens group G2 when zooming from the wide-angle end state to the telephoto end state. The distance between the lens group G2 and the third lens group G3 increases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. In this way, the first lens group G1, the second lens group G2, the third lens group G4, the fourth lens group G4, and the fifth lens group move along the optical axis with respect to the image plane I. Specifically, at the time of zooming, the first lens group G1 once moves to the image plane I side and then moves to the object side, and the second lens group G2 and the fourth lens group G4 move together to the object side. Then, the third lens group G3 moves toward the object side, and the fifth lens group G5 moves toward the image plane I side.

Further, in the zoom lens according to the present embodiment, focusing from an object at infinity to a near object is performed by moving the third lens group G3 to the image plane I side.

In the zoom lens according to the present example, a cemented lens of a negative meniscus lens L24 having a convex surface facing the object side in the second lens group G2, a biconvex lens L25, and a negative meniscus lens L26 having a concave surface facing the object side is used. Image plane correction when image blur occurs, that is, image stabilization, is performed by moving the image stabilization lens group in a direction including a component in a direction orthogonal to the optical axis.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 1.06 and the focal length is 16.48 (mm) (see Table 9 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.22 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 1.32 and the focal length is 25.21 (mm) (see Table 9 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.22 (mm). Further, in the telephoto end state, the image stabilization coefficient K is 1.64, and the focal length is 33.95 (mm) (see Table 9 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.20 (mm).

Table 9 below lists specifications of the zoom lens according to Example 9.

(Table 9) Ninth Example [Overall Specifications]
W M T
f 16.48 25.21 33.95
FNO 4.00 4.00 4.00
ω 54.0 39.4 31.8
Y 21.64 21.64 21.64
TL 162.365 154.491 161.772
BF 23.901 22.523 18.067

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 206.62948 2.000 1.82080 42.7
* 2) 22.78595 5.394
3) 79.60930 2.000 1.90043 37.4
* 4) 28.62293 12.227
5) -36.79633 2.000 1.49782 82.6
6) 138.93269 0.150
7) 59.13309 5.614 2.00100 29.1
8) -157.09491 (variable)

* 9) 78.52593 8 .740 1.58313 59.4
10) -18.33622 1.500 1.65844 50.8
11) -31.62205 0.320
12) -53.95141 1.500 1.51742 52.2
13) 1642.72200 5.830
* 14) 56.55132 1.500 1.79504 28.7
15) 30.04155 10.867 1.48749 70.3
16) -20.18962 1.500 1.68893 31.2
17) -26.35355 (variable)

18) (Aperture) ∞ (Variable)

19) -107.45547 1.500 1.74400 44.8
20) 19.22984 3.482 1.80244 25.6
21) 51.40293 (variable)

22) 43.71137 7.983 1.49782 82.6
23) -23.27350 1.500 1.88202 37.2
* 24) -31.21137 0.150
25) 71.81959 1.500 1.90043 37.4
26) 18.76437 8.473 1.49782 82.6
27) 145.88740 (variable)

* 28) -135.00000 4.550 1.77250 49.5
* 29) -52.15640 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -24.38
G2 9 34.96
G3 19 -50.79
G4 22 84.06
G5 28 107.45

[Aspherical data]
Surface number: 1
κ = 0.00000E + 00
A4 = 7.49847E-06
A6 = -4.72101E-09
A8 = 1.34426E-12
A10 = 7.77327E-16

Surface number: 2
κ = 1.11000E-02
A4 = -2.39129E-05
A6 = 4.34446E-08
A8 = -4.32137E-11
A10 = 3.44930E-14

Surface number: 4
κ = 1.00000E + 00
A4 = 3.53137E-05
A6 = 6.78430E-09
A8 = -4.22471E-11
A10 = 4.95919E-14

Surface number: 9
κ = 1.00000E + 00
A4 = -4.89433E-06
A6 = -9.35308E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 14
κ = 1.00000E + 00
A4 = -6.54457E-06
A6 = 5.07738E-09
A8 = -5.16352E-11
A10 = 2.09233E-13

Surface number: 24
κ = 1.00000E + 00
A4 = 2.08758E-06
A6 = 1.15759E-08
A8 = -7.29250E-11
A10 = 1.18188E-13

Surface number: 28
κ = 1.00000E + 00
A4 = 2.27203E-06
A6 = 1.20614E-09
A8 = 2.01555E-11
A10 = -4.02390E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 6.10900E-06
A6 = -4.88513E-09
A8 = 2.18415E-11
A10 = -3.91619E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 110.00 117.87 110.60
β----0.1310 -0.1947 -0.2863
f 16.48 25.21 33.95---
d 8 27.288 7.805 0.500 27.288 7.805 0.500
d17 2.000 7.042 8.304 2.000 7.042 8.304
d18 4.000 4.000 4.000 5.664 7.386 9.288
d21 12.429 7.386 6.125 10.765 4.000 0.837
d27 2.468 15.455 34.496 2.468 15.455 34.496
BF 23.901 22.523 18.067 23.999 22.740 18.534

[Values for each conditional expression]
(1) f5 / (− f1) = 4.408
(2) | m12 | /fw=1.626
(3) f5 / f4 = 1.278

FIGS. 34 (a), 34 (b), and 34 (c) are focused on an object at infinity in the wide-angle end state, intermediate focal length state, and telephoto end state of the zoom lens according to Example 9, respectively. FIG.
FIGS. 35 (a), 35 (b), and 35 (c) are respectively for focusing a short distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 9. FIG.
36 (a), 36 (b), and 36 (c) respectively show the meridional horizontal at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 9. It is an aberration diagram.

As is apparent from each aberration diagram, the zoom lens according to Example 9 has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Tenth embodiment)
FIGS. 37A, 37B, and 37C are cross-sectional views of the zoom lens according to Example 10 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 37A indicates the moving direction of each lens group upon zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 37B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 37A, the zoom lens according to the present embodiment includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

The third lens group G3 includes, in order from the object side along the optical axis, an aperture stop S, and a cemented lens of a biconcave lens L31 and a positive meniscus lens L32 having a convex surface facing the object side.

The fourth lens group G4 includes, in order from the object side along the optical axis, a fourth F lens group G4F having a positive refractive power and a fourth R lens group G4R having a negative refractive power.
The fourth F lens group G4F includes a cemented lens of a biconvex lens L41 and a negative meniscus lens L42 having a concave surface directed toward the object side. The negative meniscus lens L42 is an aspheric lens having an aspherical lens surface on the image side.
The fourth R lens group G4R includes a cemented lens including a negative meniscus lens L43 having a convex surface directed toward the object side and a positive meniscus lens L44 having a convex surface directed toward the object side.

With the above configuration, the zoom lens according to the present embodiment reduces the distance between the first lens group G1 and the second lens group G2 when zooming from the wide-angle end state to the telephoto end state. The distance between the lens group G2 and the third lens group G3 increases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. In this way, the first lens group G1, the second lens group G2, the third lens group G4, the fourth lens group G4, and the fifth lens group move along the optical axis with respect to the image plane I. Specifically, at the time of zooming, the first lens group G1 once moves to the image plane I side and then moves to the object side, and the second lens group G2 and the fourth lens group G4 move together to the object side. Then, the third lens group G3 moves to the object side, and the fifth lens group G5 once moves to the object side and then moves to the image plane I side.

In the zoom lens according to the present embodiment, focusing from an object at infinity to a near object is performed by moving the fourth F lens group G4F to the object side.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 1.01, and the focal length is 16.48 (mm) (see Table 10 below). The amount of movement of the vibration-proof lens group for correcting the rotation blur is 0.23 (mm). Further, in the intermediate focal length state, the image stabilization coefficient K is 1.28 and the focal length is 25.22 (mm) (see Table 10 below), so that the rotational blur of 0.66 ° is corrected. The amount of movement of the anti-vibration lens group is 0.23 (mm). In the telephoto end state, the image stabilization coefficient K is 1.58, and the focal length is 33.95 (mm) (see Table 10 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.21 (mm).

Table 10 below lists specifications of the zoom lens according to the tenth example.

(Table 10) Tenth Example [Overall Specifications]
W M T
f 16.48 25.22 33.95
FNO 4.00 4.00 4.00
ω 54.0 39.5 31.8
Y 21.64 21.64 21.64
TL 157.040 150.577 158.386
BF 19.612 20.204 18.091

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 748.12416 2.000 1.82080 42.7
* 2) 24.27981 6.249
3) 82.72688 2.000 1.90043 37.4
* 4) 29.19843 11.941
5) -38.35396 2.000 1.49782 82.6
6) 123.88139 0.150
7) 58.33566 5.662 2.00100 29.1
8) -157.62198 (variable)

* 9) 53.58324 6.922 1.58313 59.4
10) -22.47903 1.500 1.65454 55.0
11) -43.36840 0.150
12) -111.21206 1.500 1.51742 52.2
13) 108.52980 7.626
* 14) 45.76109 1.500 1.82227 25.8
15) 27.94575 10.712 1.48749 70.3
16) -23.08227 1.500 1.68893 31.2
17) -31.09319 (variable)

18) (Aperture) ∞ 4.000
19) -95.69123 1.500 1.74400 44.8
20) 28.24642 3.135 1.80244 25.6
21) 114.16154 (variable)

22) 45.66871 6.767 1.49782 82.6
23) -24.10121 1.500 1.88202 37.2
* 24) -36.88706 (variable)

25) 51.43628 1.500 1.90043 37.4
26) 17.97428 6.908 1.49782 82.6
27) 53.78862 (variable)

* 28) -135.00000 4.998 1.77250 49.5
* 29) -46.24500 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -24.13
G2 9 36.72
G3 18 -77.89
G4 22 151.54
G5 28 88.87

[Aspherical data]
Surface number: 1
κ = 0.00000E + 00
A4 = 9.52593E-06
A6 = -6.95106E-09
A8 = 1.81770E-12
A10 = 4.34677E-16

Surface number: 2
κ = 1.04000E-01
A4 = -2.28424E-05
A6 = 3.85220E-08
A8 = -4.02855E-11
A10 = 2.50646E-14

Surface number: 4
κ = 1.00000E + 00
A4 = 3.45313E-05
A6 = 2.43926E-08
A8 = -5.26585E-11
A10 = -1.44105E-14

Surface number: 9
κ = 1.00000E + 00
A4 = -3.39462E-06
A6 = -4.52751E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 14
κ = 1.00000E + 00
A4 = -3.999540E-06
A6 = 6.90128E-09
A8 = -7.15162E-11
A10 = 2.30252E-13

Surface number: 24
κ = 1.00000E + 00
A4 = 2.95224E-06
A6 = 6.31531E-09
A8 = -6.95778E-11
A10 = 9.58472E-14

Surface number: 28
κ = 1.00000E + 00
A4 = 3.07452E-06
A6 = 6.73524E-10
A8 = 1.35472E-11
A10 = -3.33968E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 7.09095E-06
A6 = -3.53806E-09
A8 = 1.19967E-11
A10 = -2.88780E-14

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 115.33 121.81 114.01
β----0.1237 -0.1846 -0.2688
f 16.48 25.22 33.95---
d 8 26.754 7.684 0.500 26.754 7.684 0.500
d17 2.000 7.900 9.425 2.000 7.900 9.425
d21 11.786 5.887 4.361 10.002 2.909 0.209
d24 0.150 0.150 0.150 1.935 3.128 4.301
d27 5.019 17.035 34.140 5.019 17.035 34.140
BF 19.612 20.204 18.091 19.700 20.399 18.504

[Values for each conditional expression]
(1) f5 / (− f1) = 3.682
(2) | m12 | /fw=1.593
(3) f5 / f4 = 0.586

FIGS. 38 (a), 38 (b), and 38 (c) are focused on an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10, respectively. FIG.
FIGS. 39 (a), 39 (b), and 39 (c) are focused on a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10, respectively. FIG.
40 (a), 40 (b), and 40 (c) are respectively the meridional laterals at the time of image stabilization in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 10. It is an aberration diagram.

As is apparent from each aberration diagram, the zoom lens according to the tenth example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

(Eleventh embodiment)
41A, 41B, and 41C are cross-sectional views of the zoom lens according to Example 11 in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.
An arrow below each lens group in FIG. 41A indicates the moving direction of each lens group at the time of zooming from the wide-angle end state to the intermediate focal length state. An arrow below each lens group in FIG. 41B indicates the moving direction of each lens group during zooming from the intermediate focal length state to the telephoto end state.

As shown in FIG. 41A, the zoom lens according to the present example includes a first lens group G1 having a negative refractive power and a second lens having a positive refractive power in order from the object side along the optical axis. The lens group G2 includes a third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

The fourth lens group G4 includes, in order from the object side along the optical axis, a cemented lens of a biconvex lens L41 and a negative meniscus lens L42 having a concave surface facing the object side, and a negative meniscus lens L43 having a convex surface facing the object side. It consists of a cemented lens with a biconvex lens L44. The negative meniscus lens L42 is an aspheric lens having an aspherical lens surface on the image side.

In the zoom lens according to the present embodiment, the fifth lens group G5 is moved to the object side, thereby focusing from an object at infinity to a near object.

Here, when the focal length of the entire zoom lens system according to the present embodiment is f and the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction is K, the angle In order to correct the rotational blur of θ, the anti-vibration lens group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.
In the zoom lens according to the present example, in the wide-angle end state, the image stabilization coefficient K is 0.97, and the focal length is 16.48 (mm) (see Table 11 below). The amount of movement of the anti-vibration lens group for correcting the rotation blur is 0.24 (mm). In the intermediate focal length state, the image stabilization coefficient K is 1.19, and the focal length is 25.21 (mm) (see Table 11 below). The amount of movement of the anti-vibration lens group is 0.24 (mm). In the telephoto end state, the image stabilization coefficient K is 1.43, and the focal length is 33.94 (mm) (see Table 11 below), so that the rotational blur of 0.57 ° is corrected. The moving amount of the anti-vibration lens group is 0.23 (mm).

Table 11 below lists specifications of the zoom lens according to the eleventh example.

(Table 11) Eleventh Example [Overall specifications]
W M T
f 16.48 25.21 33.94
FNO 4.00 4.00 4.00
ω 54.1 40.4 32.8
Y 21.64 21.64 21.64
TL 162.327 153.706 157.417
BF 18.026 19.051 18.015

[Surface data]
Surface number r d nd νd
Object ∞
* 1) 132.59820 2.000 1.82080 42.7
* 2) 19.32271 7.442
3) 160.87743 2.000 1.90043 37.4
* 4) 32.91214 9.741
5) -38.07464 2.000 1.49782 82.6
6) 561.24096 0.150
7) 73.09225 5.033 2.00100 29.1
8) -129.44599 (variable)

* 9) 40.27118 7.618 1.58313 59.4
10) -22.79658 1.500 1.65160 58.6
11) -37.12857 2.061
12) -39.17300 1.500 1.51742 52.2
13) 1874.52540 1.776
* 14) 51.35062 1.500 1.79504 28.7
15) 28.77558 8.221 1.48749 70.3
16) -23.13956 1.500 1.68893 31.2
17) -31.27181 (variable)

18) (Aperture) ∞ 4.000
19) -105.52859 1.500 1.74400 44.8
20) 25.92479 2.859 1.80244 25.6
21) 69.72964 1.000
22) (FS) ∞ (variable)

23) 65.71858 10.859 1.49782 82.6
24) -19.28535 1.500 1.88202 37.2
* 25) -31.97958 0.150
26) 89.97758 1.500 1.90043 37.4
27) 24.75006 11.838 1.49782 82.6
28) -103.72759 (variable)

* 29) -135.00000 4.892 1.77250 49.5
* 30) -59.90604 (BF)
Image plane ∞

[Lens group data]
Start surface Focal length
G1 1 -21.74
G2 9 34.29
G3 18 -60.80
G4 23 73.88
G5 29 135.56

[Aspherical data]
Surface number: 1
κ = 0.00000E + 00
A4 = 1.16094E-05
A6 = -9.06420E-09
A8 = 2.81639E-12
A10 = 2.24774E-15

Surface number: 2
κ = 1.30300E-01
A4 = -1.18813E-05
A6 = 5.68936E-08
A8 = -9.29931E-11
A10 = 2.59824E-14

Surface number: 4
κ = 1.00000E + 00
A4 = 2.67754E-05
A6 = -6.40784E-09
A8 = -5.02628E-11
A10 = 2.60885E-13

Surface number: 9
κ = 1.00000E + 00
A4 = -2.885903E-06
A6 = -6.88788E-09
A8 = 0.00000E + 00
A10 = 0.00000E + 00

Surface number: 14
κ = 1.00000E + 00
A4 = -4.52862E-06
A6 = 3.83779E-09
A8 = -2.25240E-11
A10 = 7.59629E-14

Surface number: 25
κ = 1.00000E + 00
A4 = 4.32494E-06
A6 = 5.82097E-09
A8 = -4.56687E-11
A10 = 3.78592E-14

Surface number: 29
κ = 1.00000E + 00
A4 = 9.68518E-06
A6 = -2.01079E-08
A8 = 1.31643E-11
A10 = -2.09414E-15

Surface number: 30
κ = 1.00000E + 00
A4 = 8.93441E-06
A6 = -2.666479E-08
A8 = 2.35900E-11
A10 = -9.65459E-15

[Variable interval data]
W M T W M T
Infinity infinity infinity infinity short distance short distance short distance
d 0 ∞ ∞ ∞ 230.00 238.63 234.90
β----0.0651 -0.0951 -0.1271
f 16.48 25.21 33.94---
d 8 29.064 8.952 0.500 29.064 8.952 0.500
d17 2.000 9.683 15.225 2.000 9.683 15.225
d22 14.725 7.042 1.500 14.725 7.042 1.500
d28 4.371 14.839 28.037 0.147 6.667 14.415
BF 18.026 19.051 18.015 22.275 22.275 31.731

[Values for each conditional expression]
(1) f5 / (− f1) = 6.234
(2) | m12 | /fw=1.734
(3) f5 / f4 = 1.835

42 (a), 42 (b), and 42 (c) are in-focus at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11, respectively. FIG.
FIGS. 43 (a), 43 (b), and 43 (c) are respectively for focusing a short-distance object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11. FIG.
44 (a), 44 (b), and 44 (c) respectively show the meridional horizontal during vibration isolation in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens according to Example 11. It is an aberration diagram.

As is apparent from the respective aberration diagrams, the zoom lens according to the eleventh example has various aberrations well corrected from the wide-angle end state to the telephoto end state, and has high optical performance even during image stabilization. I understand.

As described above, according to the above embodiments, a zoom lens having a bright F number and high optical performance can be realized. In particular, in a zoom lens having a zoom ratio of about 1.5 to 2.5, a zoom lens having an F number of about 2.8 to 4.0 and a wide angle of view is realized. Can do. Furthermore, it is possible to reduce the size of the anti-vibration lens group and to exhibit high optical performance even during the anti-vibration period. Further, according to each of the above embodiments, it is possible to realize a zoom lens in which the half angle of view (unit: degree) in the wide-angle end state is in the range of 39 <ωW <57 (more preferably, 42 <ωW <57). .

In the zoom lens, the half angle of view (unit: degree) in the wide-angle end state is preferably in the range of 39 <ωW <57 (more preferably 42 <ωW <57). In addition, it is preferable that the F lens has a substantially constant F number when zooming. In the zoom lens, the motor for moving the focusing lens group is preferably a stepping motor. In zooming, it is preferable that the first lens group G1 once moves to the image plane I side and then moves to the object side during zooming. In the zoom lens, it is preferable that the fifth lens group G5 is fixed with respect to the image plane I during zooming. In zooming, it is preferable that the second lens group G2 and the fourth lens group G4 move to the object side along the same movement locus and have the same movement amount during zooming. In addition, in the zoom lens, during zooming, 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. It is preferable that the distance between the group G3 and the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

In addition, each said Example shows a specific example, and this embodiment is not limited to these. The following contents can be appropriately adopted as long as the optical performance of the zoom lens is not impaired.

Although a numerical example of the zoom lens having a five-group configuration is shown, it can also be applied to other group configurations such as a six-group. Further, a configuration in which a lens or a lens group is added to the most object side or a configuration in which a lens or a lens group is added to the most image side may be used. The lens group refers to a portion having at least one lens separated by an air interval.

Further, in the zoom lens, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction so as to perform focusing from an object at infinity to a near object. The focusing lens group can be applied to autofocus, and is also suitable for driving by an autofocus motor, such as an ultrasonic motor. In particular, it is preferable that a part of the second lens group G2 is a focusing lens group, but the whole or a part of the third lens group G3 and the fifth lens group G5 is a focusing lens group. Alternatively, the entire second lens group G2 may be used as the focusing lens group.

In a zoom lens, the lens group or partial lens group is moved so as to have a component perpendicular to the optical axis, or rotated (swinged) in the direction including the optical axis to correct image blur caused by camera shake. An anti-vibration lens group may be used. In particular, the entire third lens group G3 is preferably an anti-vibration lens group, but the entire or part of the fourth lens group G4 may be an anti-vibration lens group, and a part of the third lens group. May be used as a vibration-proof lens group.

Further, the lens surface of the lens constituting the zoom lens may be a spherical surface, a flat surface, or an aspherical surface. When the lens surface is a spherical surface or a flat surface, it is preferable because lens processing and assembly adjustment are easy, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is aspherical, any of aspherical surface by grinding, glass mold aspherical surface in which glass is molded into an aspherical shape, or composite aspherical surface in which resin provided on the glass surface is formed in an aspherical shape Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

In the zoom lens, it is preferable that the aperture stop be disposed between the second lens group G2 and the third lens group G3. However, the role of the aperture stop is not provided as a member in the lens frame. It is good also as a structure which substitutes.

In addition, the lens surface of the lens constituting the zoom lens may be provided with an antireflection film having high transmittance in a wide wavelength region in order to reduce flare and ghost and achieve high optical performance with high contrast. .

Next, a camera equipped with a zoom lens will be described with reference to FIG.
FIG. 45 is a schematic diagram illustrating a configuration of a camera including a zoom lens.
As shown in FIG. 45, the camera 1 is a digital single-lens reflex camera provided with the zoom lens according to the first embodiment as the photographing lens 2.
In the digital single-lens reflex camera 1 shown in FIG. 45, light from an object (subject) (not shown) is collected by the photographing lens 2 and formed on the focusing plate 5 via the quick return mirror 3. The light imaged on the collecting plate 5 is reflected a plurality of times in the pentaprism 7 and guided to the eyepiece lens 9. Thus, the photographer can observe the object (subject) image as an erect image through the eyepiece 9.

When a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and the light of the object (subject) collected by the photographing lens 2 forms a subject image on the image sensor 11. Thereby, the light from the object is picked up by the image pickup device 11 and stored in a memory (not shown) as an object image. In this way, the photographer can photograph an object with the camera 1.

Here, the zoom lens according to the first embodiment mounted on the camera 1 as the photographing lens 2 is a zoom lens having a bright F number and high optical performance. Therefore, the camera 1 is a camera with high optical performance. It should be noted that the same effects as those of the camera 1 can be obtained even if a camera in which the zoom lens according to the second to eleventh embodiments is mounted as the photographing lens 2 is configured. Moreover, the camera 1 may hold | maintain the photographic lens 2 so that attachment or detachment is possible, and may be shape | molded integrally with the photographic lens 2. FIG. The camera 1 may be a camera that does not have a quick return mirror or the like.

Next, a method for manufacturing a zoom lens will be described. FIG. 46 is a diagram showing an outline of a method for manufacturing a zoom lens.

The zoom lens manufacturing method includes, in order from the object side along the optical axis, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens having negative refractive power. 46. A zoom lens manufacturing method including a group, a fourth lens group having a positive refractive power, and a fifth lens group, and includes the following steps S1 and S2 as shown in FIG.
Step S1: It is configured so as to satisfy the following conditional expression (1).
(1) 1.000 <f5 / (− f1) <10.000
However,
f5: Focal length of the fifth lens group f1: Focal length of the first lens group Step S2: During zooming, the distance between the first lens group and the second lens group changes, and the second lens The distance between the third 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. Configure.

According to such a zoom lens manufacturing method, a zoom lens having a bright F number and high optical performance can be manufactured. Particularly, in a zoom lens having a zoom ratio of about 1.5 to 2.5 times, a zoom lens having an F number of about 2.8 to 4.0 and a wide angle of view is manufactured. Can do.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group Gf Focusing lens group S Aperture stop FS Flare cut stop I Image surface 1 Optical device 2 Shooting lens 3 Quick return mirror 5 focusing plate 7 pentaprism 9 eyepiece 11 image sensor

Claims

A first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a positive refractive power in order from the object side along the optical axis. A fourth lens group having a fifth lens group,
During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the third lens group and the fourth lens group change. The distance between the lens group changes, the distance between the fourth lens group and the fifth lens group changes,
A zoom lens that satisfies the following conditional expression.
1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.300 <| m12 | / fw <5.000
However,
| M12 |: the amount of change from the wide-angle end state to the telephoto end state of the distance on the optical axis from the most image side lens surface of the first lens group to the most object side lens surface of the second lens group fw : Focal length of the entire zoom lens system in the wide-angle end state
The zoom lens according to claim 1, wherein the zoom lens satisfies the following conditional expression.
0.200 <f5 / f4 <4.0000
However,
f5: focal length of the fifth lens group f4: focal length of the fourth lens group
The zoom lens according to any one of claims 1 to 3, wherein the fifth lens group has a positive refractive power.
The zoom lens according to any one of claims 1 to 4, wherein at least a part of the lenses in the third lens group is configured to be movable so as to include a component in a direction perpendicular to the optical axis.
The zoom lens according to any one of claims 1 to 4, wherein at least a part of the lenses in the second lens group is configured to be movable so as to include a component in a direction orthogonal to the optical axis.
The zoom lens according to any one of claims 1 to 4, wherein at least a part of the lenses in the fourth lens group is configured to be movable so as to include a component in a direction orthogonal to the optical axis.
The zoom lens according to any one of claims 1 to 7, wherein focusing from an object at infinity to an object at a short distance is performed by moving at least a part of the lenses in the second lens group along an optical axis. .
The zoom lens according to any one of claims 1 to 7, wherein focusing from an object at infinity to a near object is performed by moving at least a part of the lenses in the third lens group along an optical axis. .
The zoom lens according to any one of claims 1 to 7, wherein focusing from an object at infinity to an object at a short distance is performed by moving at least a part of the lenses in the fourth lens group along an optical axis. .
The zoom lens according to any one of claims 1 to 7, wherein focusing is performed from an object at infinity to an object at a short distance by moving a part or all of the fifth lens group along an optical axis.
The zoom lens according to any one of claims 1 to 11, further comprising an aperture stop between the second lens group and the third lens group.
An optical apparatus comprising the zoom lens according to any one of claims 1 to 12.
A first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a positive refractive power in order from the object side along the optical axis. A zoom lens having a fourth lens group and a fifth lens group,
Configure to satisfy the following conditional expression,
During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the third lens group and the fourth lens group change. A method of manufacturing a zoom lens, wherein the distance between the lens group changes and the distance between the fourth lens group and the fifth lens group changes.
1.000 <f5 / (− f1) <10.000
However,
f5: focal length of the fifth lens group f1: focal length of the first lens group