JP5540514B2 - Variable magnification optical system and optical apparatus having the variable magnification optical system - Google Patents

Description

The present invention, the variable magnification optical system, and to an optical apparatus having a variable magnification optical system.

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

JP 2006-227526 A

  However, the conventional zoom lens has a large number of lenses constituting the optical system, the compactness is lost, and when zooming is performed, the optical performance is significantly deteriorated and there is no satisfactory performance. There was a problem.

The present invention has been made in view of such a problem, and is a compact and highly variable power zooming optical system capable of achieving good optical performance, and an optical system having this variable power optical system. The purpose is to provide equipment.

In order to solve the above-described problem, the variable magnification optical system of the present invention has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A third lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. At least a part of any one of these lens groups moves so as to have a component in a direction substantially perpendicular to the optical axis, and when zooming from the wide-angle end state to the telephoto end state, the first lens The distance between the second lens group and the second lens group is changed, the distance between the second lens group and the third lens group is changed, the distance between the third lens group and the fourth lens group is changed, and The first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group move on the optical axis so that the interval with the fifth lens group changes , and the second lens group Is moved to the image side, then moved to the object side, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, When the focal length of the lens group is f5, the following expression 0.65 <(− f2) / f3 <0.90
0.55 <f2 / f4 <0.90
1.40 <f5 / (− f4) <2.00
Satisfy the conditions.

The zoom optical system of the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. And a fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power. At least a part of any one of these lens groups moves so as to have a component in a direction substantially perpendicular to the optical axis, and when zooming from the wide-angle end state to the telephoto end state, the first lens The distance between the second lens group and the second lens group is changed, the distance between the second lens group and the third lens group is changed, the distance between the third lens group and the fourth lens group is changed, and The first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group move on the optical axis so that the interval with the fifth lens group changes , and the second lens group Is moved to the image side, then moved to the object side, the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the focal length of the fourth lens group is f4. The following formula 0.65 <(− f2) / f3 <0.90
0.58 ≦ f2 / f4 <0.90
Satisfy the conditions.

Further, in such a variable magnification optical system, when the focal length of the fifth lens group is f5, the following formula 1.20 <f5 / (− f4) <2.00
It is preferable to satisfy the following conditions.

Also, in such a variable magnification optical system, the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fifth lens group when the amount of movement from the image side to the object side is positive is x5. Then, the following formula 0.70 <x5 / (− f2) <2.10
It is preferable to satisfy the following conditions.

Alternatively, in such a variable magnification optical system, the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fourth lens group when the amount of movement from the image side to the object side is positive is x4. When the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the third lens group is x3, the following expression 0.65 <x4 / x3 <0.90
It is preferable to satisfy the following conditions.

  In such a variable magnification optical system, it is preferable that the first lens unit moves from the image side to the object side when changing magnification from the wide-angle end state to the telephoto end state.

  In such a variable power optical system, it is preferable that the fifth lens unit moves from the image side to the object side when zooming from the wide-angle end state to the telephoto end state.

  In such a variable magnification optical system, it is preferable to focus on a short-distance object point by moving at least a part of the second lens group along the optical axis.

  In such a variable magnification optical system, it is preferable that the second lens group has an aspherical lens surface.

In such a variable magnification optical system, the third lens group includes at least one positive lens component, and the refractive index at the d-line of the medium of the positive lens component having the highest refractive index among the positive lens components is denoted by nd3b. Then, the following formula 1.70 <nd3b <1.85
It is preferable to satisfy the following conditions.

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

Variable magnification optical system according to the present invention, and, when forming the optical device having the variable power optical system as described above with a high magnification compact, it is possible to achieve good optical performance.

It is sectional drawing which shows the structure of the variable magnification optical system by 1st Example. FIG. 4 is a diagram illustrating various aberrations in the infinitely focused state in the wide-angle end state according to the first embodiment, (a) is an aberration diagram in the infinitely focused state in the wide-angle end state, and (b) is the wide-angle end state. FIG. 6 is a coma aberration diagram when blur correction is performed for 0.64 ° rotational blur in the infinite distance shooting state. FIG. 6 is an aberration diagram in the infinite focus state in the intermediate shooting distance state in the first example. FIG. 3A illustrates various aberrations in the infinitely focused state in the telephoto end state according to the first embodiment, FIG. 3A illustrates aberrations in the infinitely photographing state in the telephoto end state, and FIG. 3B illustrates infinite in the telephoto end state. FIG. 10 is a coma aberration diagram when blur correction is performed with respect to 0.29 ° rotational blur in a distance shooting state. It is sectional drawing which shows the structure of the variable magnification optical system by 2nd Example. FIG. 6A is a diagram illustrating various aberrations in an infinitely focused state in a wide-angle end state according to a second embodiment, FIG. 5A is an aberration diagram in an infinitely focused state in a wide-angle end state, and FIG. FIG. 6 is a coma aberration diagram when blur correction is performed for 0.64 ° rotational blur in the infinite distance shooting state. It is an aberration diagram in the infinity in-focus state in the intermediate shooting distance state of the second embodiment. These are various aberrations in the infinite focus state in the telephoto end state of the second embodiment, (a) is an aberration diagram in the infinity photographing state in the telephoto end state, and (b) is infinite in the telephoto end state. FIG. 10 is a coma aberration diagram when blur correction is performed with respect to 0.29 ° rotational blur in a distance shooting state. It is sectional drawing which shows the structure of the variable magnification optical system by 3rd Example. FIG. 10 is a diagram illustrating various aberrations in the infinitely focused state in the wide-angle end state according to the third embodiment, (a) is an aberration diagram in the infinitely focused state in the wide-angle end state, and (b) is the wide-angle end state. FIG. 6 is a coma aberration diagram when blur correction is performed for 0.64 ° rotational blur in the infinite distance shooting state. It is an aberration diagram in the infinity in-focus state in the intermediate shooting distance state of the third embodiment. FIG. 6A illustrates various aberrations in the infinitely focused state in the telephoto end state according to the third embodiment, FIG. 5A is an aberration diagram in the infinitely photographing state in the telephoto end state, and FIG. 6B illustrates infinite in the telephoto end state. FIG. 10 is a coma aberration diagram when blur correction is performed with respect to 0.29 ° rotational blur in a distance shooting state. It is sectional drawing which shows the structure of the variable magnification optical system by 4th Example. FIG. 6A is a diagram illustrating various aberrations in the infinitely focused state in the wide-angle end state according to the fourth embodiment, FIG. 5A is an aberration diagram in the infinitely focused state in the wide-angle end state, and FIG. FIG. 6 is a coma aberration diagram when blur correction is performed for 0.64 ° rotational blur in the infinite distance shooting state. FIG. 10 is an aberration diagram for an infinite focus state at the intermediate shooting distance state in the fourth example. FIG. 4A shows various aberrations in the infinitely focused state in the telephoto end state according to the fourth embodiment, FIG. 5A is an aberration diagram in the infinitely photographing state in the telephoto end state, and FIG. 4B is infinite in the telephoto end state. FIG. 10 is a coma aberration diagram when blur correction is performed with respect to 0.29 ° rotational blur in a distance shooting state. 1 is a cross-sectional view of a digital single-lens reflex camera equipped with a variable magnification optical system according to the present embodiment. It is a flowchart for demonstrating the manufacturing method of the variable magnification optical system which concerns on this embodiment.

  Hereinafter, preferred embodiments of the present application will be described with reference to the drawings. As shown in FIG. 1, the variable magnification optical system ZL includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power. A third lens group G3 having a negative refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Then, at least a part of any one of these lens groups is moved so as to have a component substantially perpendicular to the optical axis.

  Now, conditions for constructing such a variable magnification optical system ZL will be described. First, in the zoom optical system ZL, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 changes, and the second lens group G2 and third lens The distance between the lens group G3 changes, the distance between the third lens 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. When the focal length of the second lens group G2 is f2, the focal length of the third lens group G3 is f3, and the focal length of the fourth lens group G4 is f4, the following conditional expressions (1) and ( It is desirable to satisfy 2).

0.65 <(− f2) / f3 <0.90 (1)
0.42 <f2 / f4 <0.90 (2)

  Conditional expression (1) is a conditional expression for defining the focal length of the third lens group G3 with respect to the focal length of the second lens group G2. This zoom optical system ZL can satisfy the conditional expression (1) to realize good optical performance and to secure a predetermined zoom ratio. Exceeding the upper limit of conditional expression (1) is not preferable because the refractive power of the third lens group G3 becomes strong and it becomes difficult to correct spherical aberration in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (1) to 0.80, and better optical performance can be realized. On the other hand, if the lower limit value of conditional expression (1) is not reached, the refractive power of the second lens group G2 becomes strong and it is difficult to correct astigmatism in the wide-angle end state, which is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (1) to 0.67, the refractive power of the second lens group G2 can be set appropriately, and at the time of zooming The fluctuation of coma aberration can be reduced.

  Conditional expression (2) is a conditional expression for defining the focal length of the fourth lens group G4 with respect to the focal length of the second lens group G2. The zooming optical system ZL satisfies this conditional expression (2), thereby realizing good optical performance and ensuring a predetermined zooming ratio. If the upper limit of conditional expression (2) is exceeded, the refractive power of the second lens group G2 becomes weak, and the first lens group G1 must be extended greatly in order to obtain a predetermined zoom ratio. Since curvature and astigmatism deteriorate, it is not preferable. In order to secure the effect of the present application, it is preferable to set the upper limit value of conditional expression (2) to 0.75, and better optical performance can be realized. In order to further secure the effect of the present application, it is preferable to set the upper limit of conditional expression (2) to 0.65. On the other hand, if the lower limit of conditional expression (2) is not reached, the refractive power of the fourth lens group G4 becomes weak, and it becomes difficult to correct fluctuations in field curvature during zooming. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (2) to 0.50, the refractive power of the second lens group G2 can be set appropriately, and at the time of zooming The fluctuation of coma aberration can be reduced. In order to further secure the effect of the present application, it is preferable to set the lower limit of conditional expression (2) to 0.55.

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

1.20 <f5 / (− f4) <2.00 (3)

  Conditional expression (3) is a conditional expression for defining the focal length of the fourth lens group G4 with respect to the focal length of the fifth lens group G5. This zoom optical system ZL can satisfy the conditional expression (3) to realize good optical performance and to ensure a predetermined zoom ratio. Exceeding the upper limit of conditional expression (3) is not preferable because the refractive power of the fourth lens group G4 becomes strong and it becomes difficult to correct coma in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (3) to 1.80, the refractive power of the fourth lens group G4 can be set appropriately, and the telephoto end state Can reduce coma aberration. In order to further secure the effect of the present application, it is preferable to set the upper limit of conditional expression (3) to 1.60. On the other hand, if the lower limit of conditional expression (3) is not reached, the refractive power of the fifth lens group G5 becomes strong, and it is difficult to correct astigmatism in the wide-angle end state. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (3) to 1.20, and better optical performance can be realized. In order to further secure the effect of the present application, it is preferable to set the lower limit of conditional expression (3) to 1.40.

  Further, in the zoom optical system ZL, the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fifth lens group G5 when the amount of movement from the image side to the object side is positive is x5. In this case, it is desirable that the following conditional expression (4) is satisfied. In conditional expression (4), the amount of movement from the image side to the object side is positive, and the amount of movement from the object side to the image side is negative. These are the same in the following conditional expression (5).

0.70 <x5 / (− f2) <2.10 (4)

  Conditional expression (4) is a conditional expression for defining the focal length of the second lens group G2 with respect to the movement amount of the fifth lens group G5. This zoom optical system ZL can satisfy the conditional expression (4) to realize good optical performance and to secure a predetermined zoom ratio. Exceeding the upper limit of conditional expression (4) is not preferable because the refractive power of the second lens group G2 becomes strong and it becomes difficult to correct astigmatism in the wide-angle end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (4) to 1.90, and better optical performance can be realized. In order to further secure the effect of the present application, it is preferable to set the upper limit of conditional expression (4) to 1.70. On the other hand, if the lower limit of conditional expression (4) is not reached, the amount of movement of the fifth lens group G5 becomes small, and the refractive power of each lens group must be set strongly, resulting in high-order coma aberration. Since performance deteriorates, it is not preferable. In order to ensure the effect of the present application, it is preferable to set the lower limit value of conditional expression (4) to 0.90, the amount of movement of the fifth lens group G5 can be set appropriately, and a predetermined change can be made. Higher-order coma aberration can be corrected while securing the magnification ratio. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (4) to 1.10.

  In the variable magnification optical system ZL, the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fourth lens group G4 when the amount of movement from the image side to the object side is positive is x4. When the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the third lens group G3 is x3, it is desirable to satisfy the following conditional expression (5).

0.65 <x4 / x3 <0.90 (5)

  Conditional expression (5) is a conditional expression for defining the movement amount of the third lens group G3 with respect to the movement amount of the fourth lens group G4. This zoom optical system ZL can satisfy the conditional expression (5) to realize good optical performance and to secure a predetermined zoom ratio. Exceeding the upper limit of conditional expression (5) is not preferable because the amount of movement of the third lens group G3 becomes small and it becomes difficult to correct spherical aberration in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (5) to 0.82, and better optical performance can be realized. In order to further secure the effect of the present application, it is preferable to set the upper limit of conditional expression (5) to 0.78. On the other hand, if the lower limit of conditional expression (5) is not reached, the amount of movement of the fourth lens group G4 becomes small, and it becomes difficult to correct fluctuations in field curvature and coma during zooming. It is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (5) to 0.68, so that the variation in field curvature and coma during zooming can be reduced. In order to further secure the effect of the present application, it is preferable to set the lower limit of conditional expression (5) to 0.70.

  In the zooming optical system ZL, it is preferable that the first lens group G1 moves from the image side to the object side when zooming from the wide-angle end state to the telephoto end state. As a result, it is possible to ensure a predetermined zoom ratio while effectively correcting variations in spherical aberration and field curvature.

  In such a zoom optical system ZL, it is preferable that the fifth lens group G5 moves from the image side to the object side when zooming from the wide-angle end state to the telephoto end state. As a result, it is possible to ensure a predetermined zoom ratio while effectively correcting variations in spherical aberration and field curvature.

  In addition, it is desirable that the variable magnification optical system ZL performs focusing on a short-distance object point by moving at least a part of the second lens group G2 along the optical axis. This makes it possible to effectively correct aberration fluctuations such as spherical aberration and field curvature during focusing.

  In the variable magnification optical system ZL, it is desirable that the second lens group G2 has an aspheric lens surface. Thereby, distortion and field curvature in the wide-angle end state can be corrected simultaneously.

  In the variable magnification optical system ZL, the third lens group G3 includes at least one positive lens component, and the refractive index at the d-line of the medium of the positive lens component having the highest refractive index among the positive lens components is expressed by nd3b. It is desirable that the following conditional expression (6) is satisfied.

1.70 <nd3b <1.85 (6)

  Conditional expression (6) is a conditional expression for defining the refractive index at the d-line of the medium of the positive lens component having the highest refractive index in the third lens group G3. The zooming optical system ZL satisfies this conditional expression (6), thereby realizing good optical performance and ensuring a predetermined zooming ratio. Exceeding the upper limit of conditional expression (6) is not preferable because the Petzval sum becomes small and it becomes difficult to correct curvature of field in the wide-angle end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (6) to 1.80, the refractive index of the medium can be set appropriately, and the field curvature in the wide-angle end state Can be corrected more favorably. On the other hand, if the lower limit value of conditional expression (6) is not reached, the curvature of the positive lens component becomes strong, and correction of higher-order spherical aberration becomes difficult in the telephoto end state, which is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (6) to 1.75, and better optical performance can be realized.

  FIG. 17 shows a schematic cross-sectional view of a digital single-lens reflex camera 1 (hereinafter simply referred to as a camera) as an optical apparatus including the above-described variable magnification optical system ZL. In this camera 1, light from an object (subject) (not shown) is collected by the taking lens 2 (variable magnification optical system ZL) and imaged on the focusing screen 4 via the quick return mirror 3. The light imaged on the focusing screen 4 is reflected a plurality of times in the pentaprism 5 and guided to the eyepiece lens 6. Thus, the photographer can observe the object (subject) image as an erect image through the eyepiece 6.

  Further, when a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and light of an object (subject) (not shown) condensed by the photographing lens 2 is captured on the image sensor 7. Form an image. Thereby, the light from the object (subject) is captured by the image sensor 7 and recorded as an object (subject) image in a memory (not shown). In this way, the photographer can shoot an object (subject) with the camera 1. In addition, the camera 1 shown in FIG. 17 may hold | maintain the variable magnification optical system ZL so that attachment or detachment is possible, and may be shape | molded integrally with the variable magnification optical system ZL. The camera 1 may be a so-called single-lens reflex camera or a compact camera without a quick return mirror or the like.

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

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

  Alternatively, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to be a focusing lens group that performs focusing from an object at infinity to a near object. In this case, the focusing lens group can be applied to autofocus, and is also suitable for driving a motor for autofocus (such as an ultrasonic motor). In particular, as described above, it is preferable that at least a part of the second lens group G2 is a focusing lens group.

  In addition, the lens group or the partial lens group is moved so as to have a component in a direction perpendicular to the optical axis, or is rotated (swayed) in the in-plane direction including the optical axis to reduce image blur caused by camera shake. A vibration-proof lens group to be corrected may be used. In particular, it is preferable that at least a part of the third lens group G3 or at least a part of the fourth lens group G4 is an anti-vibration lens group.

  Further, the lens surface may be formed as a spherical surface, a flat surface, or an aspheric surface. It is preferable that the lens surface is a spherical surface or a flat surface because lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in processing and assembly adjustment is prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is an aspheric surface, the aspheric surface is an aspheric surface by grinding, a glass mold aspheric surface made of glass with an aspheric shape, or a composite aspheric surface made of resin with an aspheric shape on the glass surface. Any aspherical surface may be used. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

  The aperture stop S is preferably arranged in the vicinity of the third lens group G3 or in the third lens group G3. However, the role of the aperture stop may be substituted by a lens frame without providing a member as an aperture stop. .

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

  The variable magnification optical system ZL of the present embodiment has a variable magnification ratio of about 3.5 to 10.

  In the variable magnification optical system ZL of the present embodiment, it is preferable that the first lens group G1 has two positive lens components. In the first lens group G1, it is preferable that lens components are arranged in order of positive and negative in order from the object side with an air gap interposed therebetween. Alternatively, the first lens group G1 preferably has two positive lens components and one negative lens component. In the first lens group G1, it is preferable to dispose the lens components in the order of negative positive / negative in order from the object side with an air gap interposed therebetween.

  In the variable magnification optical system ZL of the present embodiment, it is preferable that the second lens group G2 has one positive lens component and three negative lens components. In the second lens group G2, it is preferable to dispose the lens components in the order of negative, positive and negative in order from the object side with an air gap interposed therebetween.

  In the variable magnification optical system ZL of the present embodiment, it is preferable that the third lens group G3 has three positive lens components. In the third lens group G3, it is preferable that lens components are arranged in order of positive and positive in order from the object side with an air gap interposed therebetween. Alternatively, it is preferable that the third lens group G3 has three positive lens components and one negative lens component. In the third lens group G3, it is preferable to arrange the lens components in order of positive, negative, positive from the object side with an air gap interposed therebetween.

  In the variable magnification optical system ZL of the present embodiment, it is preferable that the fourth lens group G4 has two negative lens components. In the fourth lens group G4, it is preferable to dispose the lens components in the order of negative and negative in order from the object side with an air gap interposed therebetween. Alternatively, it is preferable that the fourth lens group G4 has one positive lens component and two negative lens components. In the fourth lens group G4, it is preferable to dispose lens components in order of positive and negative from the object side.

  In the variable magnification optical system ZL of the present embodiment, it is preferable that the fifth lens group G5 has one positive lens component and one negative lens component. In the fifth lens group G5, it is preferable that lens components are arranged in order of positive and negative in order from the object side with an air gap interposed therebetween.

  In addition, in order to explain this application in an easy-to-understand manner, the configuration requirements of the embodiment have been described, but it goes without saying that the present application is not limited to this.

  Hereinafter, the outline of the manufacturing method of the variable magnification optical system ZL of this embodiment is demonstrated with reference to FIG. First, each lens is arranged and a lens group is prepared (step S100). Specifically, in this embodiment, for example, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12, and a positive meniscus lens L13 having a convex surface facing the object side are provided. The first lens group G1 is arranged, and in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the image side, a biconvex lens L23, and a concave surface facing the object side. A negative meniscus lens L24 directed toward the second lens group G2, in order from the object side, a biconvex positive lens L31, a cemented lens of a negative meniscus lens L32 and a biconvex lens L33 having a convex surface facing the object side, and A biconvex lens L34 is arranged to form a third lens group G3, and in order from the object side, a positive meniscus lens L41 having a convex surface facing the image side and an L42 cemented lens of the biconcave lens. A negative meniscus lens L43 having a concave surface facing the object side is arranged as a fourth lens group G4, and in order from the object side, the biconvex lens L51, the biconvex lens L52 and the negative meniscus having a concave surface facing the object side A cemented lens with the lens L53 is arranged to form a fifth lens group G5.

  At this time, at least a part of any one of these lens groups is movably arranged so as to have a component in a direction substantially perpendicular to the optical axis (step S200). Further, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 changes, and the distance between the second lens group G2 and the third lens group G3 changes. Then, the lens groups are arranged such that the distance between the third lens 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 (step S300).

  When the focal length of the second lens group G2 is f2, the focal length of the third lens group G3 is f3, and the focal length of the fourth lens group G4 is f4, the following conditional expressions (1) and ( Arrange so as to satisfy 2) (step S400).

0.65 <(− f2) / f3 <0.90 (1)
0.42 <f2 / f4 <0.90 (2)

  Hereinafter, each example of the present application will be described with reference to the drawings. 1, 5, 9, and 13 show the configuration and refractive power distribution of the photographic lens SL (SL1 to SL4) according to each embodiment, and focusing from the infinitely focused state to the short-distance focused state. It is sectional drawing which shows the mode of movement of each lens group in the change of a state. As shown in FIGS. 1, 5, and 9, the variable magnification optical systems ZL <b> 1 to ZL <b> 3 according to the first to third examples are, in order from the object side, the first lens group G <b> 1 having a positive refractive power, A second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power It is composed of When zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2 increases, and the air gap between the second lens group G2 and the third lens group G3 is increased. The distance between the lens groups changes so that the air distance between the third lens group G3 and the fourth lens group G4 increases and the air distance between the fourth lens group G4 and the fifth lens group G5 decreases. To do.

  As shown in FIG. 13, the variable magnification optical system ZL4 according to the fourth example includes, in order from the object side, a first lens group G1 having a positive refractive power and a second lens group having a negative refractive power. G2, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, and a sixth lens group having a negative refractive power It consists of a lens group G6. When zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2 increases, and the air gap between the second lens group G2 and the third lens group G3 is increased. Decreases, the air gap between the third lens group G3 and the fourth lens group G4 increases, the air gap between the fourth lens group G4 and the fifth lens group G5 decreases, and the fifth lens group G5 and the sixth lens. The distance between the lens groups changes so that the air distance from the group G6 increases.

In each embodiment, the height of the aspheric surface in the direction perpendicular to the optical axis is y, and the distance (sag amount) along the optical axis from the tangential plane of the apex of each aspheric surface to each aspheric surface at height y. Is S (y), r is the radius of curvature of the reference sphere (paraxial radius of curvature), κ is the conic constant, and An is the nth-order aspheric coefficient, and is expressed by the following equation (a). . In the following examples, “E−n” indicates “× 10 ⁻ⁿ ”.

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

  In each embodiment, the secondary aspheric coefficient A2 is zero. In the table of each example, an aspherical surface is marked with * on the left side of the surface number.

[First embodiment]
FIG. 1 is a diagram showing a configuration of a variable magnification optical system ZL1 according to the first example of the present application. In the variable magnification optical system ZL1 of FIG. 1, the first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12, and a convex surface facing the object side. It is composed of a positive meniscus lens L13 directed to it. In order from the object side, the second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a negative meniscus lens L22 having a convex surface directed toward the image side, a biconvex lens L23, and a negative surface having a concave surface directed toward the object side. The negative meniscus lens L21 including the meniscus lens L24 and positioned closest to the object side of the second lens group G2 is an aspheric lens having an aspheric surface formed on the glass lens surface on the object side, and is a negative lens positioned closest to the image side. The meniscus lens L24 is an aspherical lens in which an aspherical surface is formed on the image side glass lens surface. When focusing from infinity to 0.45 mm, the second lens group G2 moves from the image side to the object side by 1.8 mm at the wide-angle end and 6.2 mm at the telephoto end.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31, a cemented lens of a negative meniscus lens L32 having a convex surface facing the object side, and a biconvex lens L33, and a biconvex lens L34. The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 having a convex surface facing the image side and a biconcave lens L42, and a negative meniscus lens L43 having a concave surface facing the object side. . The fifth lens group G5 includes, in order from the object side, a biconvex lens L51, and a cemented lens of the biconvex lens L52 and a negative meniscus lens L53 having a concave surface directed toward the object side. The biconvex lens L51 located closest to the object side. Is an aspherical lens in which an aspherical surface is formed on the glass lens surface on the object side.

  The aperture stop S is located adjacent to the image side of the most object side positive lens (biconvex lens L31) of the third lens group G3, and the third lens group during zooming from the wide-angle end state to the telephoto end state. Move with G3. Focusing from infinity to a short-distance object point is performed by moving the second lens group G2 in the object direction. Image blur correction (anti-vibration) is performed by moving the cemented lens of the fourth lens group G4 so as to have a component substantially perpendicular to the optical axis.

  It should be noted that the focal length of the entire system is f, and the image blur correction coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction) corrects rotational shake at an angle θ with a K lens. For this, the moving lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the first embodiment, the image stabilization coefficient is 0.98, and the focal length is 24.6 (mm). Therefore, the fourth lens group for correcting the rotational blur of 0.64 °. The moving amount of G4 is 0.28 (mm). In the telephoto end state of the first embodiment, since the image stabilization coefficient is 1.47 and the focal length is 117.1 (mm), the fourth lens group for correcting a rotational shake of 0.29 °. The moving amount of G4 is 0.40 (mm).

  Table 1 below lists values of specifications of the first embodiment. In Table 1, f represents a focal length, FNO represents an F number, ω represents a half field angle, and Bf represents a back focus. Furthermore, the surface number is the order of the lens surfaces from the object side along the direction of travel of the light beam, the surface interval is the distance on the optical axis from each optical surface to the next optical surface, and the refractive index and Abbe number are each The value for the d-line (λ = 587.6 nm) is shown. The total length represents the distance on the optical axis from the first surface of the lens surface to the image plane I when focusing on infinity. Here, “mm” is generally used for the focal length, the radius of curvature, the surface interval, and other length units listed in all the following specifications, but the optical system is proportionally enlarged or reduced. However, the same optical performance can be obtained, and the present invention is not limited to this. The radius of curvature of 0.0000 indicates a plane, and the refractive index of air of 1.0000 is omitted. The description of these symbols and the description of the specification table are the same in the following embodiments.

(Table 1)
Wide angle end Intermediate focal length Telephoto end
f = 24.6 to 50.6 to 117.1
FNO = 4.1 to 4.1 to 4.1
2ω = 85.4 to 45.1 to 20.4
Total length = 145.9-162.0-190.8
Bf = 38.4 to 49.7 to 65.7

Surface number Curvature radius Surface spacing Abbe number Refractive index
1 214.7722 2.0000 23.77 1.846660
2 87.5000 7.4635 67.87 1.593189
3 -1279.2497 0.1000
4 58.9352 5.2795 52.29 1.755000
5 147.0393 (d1)
* 6 244.7505 1.3500 42.72 1.834810
7 15.8707 7.5000
8 -34.1921 1.0000 42.72 1.834810
9 -306.6108 0.1000
10 64.5088 4.7500 23.77 1.846660
11 -28.6256 0.5082
12 -24.9541 1.0000 40.94 1.80610
* 13 -142.4696 (d2)
14 53.3000 2.5581 52.29 1.755000
15 -319.1136 1.4000
16 0.0000 0.5000 Aperture stop
17 31.1069 2.0000 23.77 1.846660
18 17.5705 7.2500 70.45 1.487490
19 -90.7232 0.1000
20 40.8460 2.7000 67.87 1.593189
21 -3872.3835 (d3)
22 -56.1850 3.3307 32.35 1.850 260
23 -16.8047 1.0000 52.29 1.755000
24 69.3978 2.7459
25 -49.7769 1.0000 52.29 1.755000
26 -208.3941 (d4)
* 27 131.4027 5.5000 61.18 1.589130
28 -24.1216 0.1000
29 471.8066 6.6400 70.45 1.487490
30 -20.9950 1.2000 32.35 1.850 260
31 -99.6677 (Bf)

[Focal length of each lens group]
Lens group Start surface Focal length G1 1 107.1
G2 6 -18.1
G3 14 25.3
G4 22 -30.3
G5 27 45.4

  In the first embodiment, the lens surfaces of the sixth surface, the thirteenth surface, and the twenty-seventh surface are formed in an aspherical shape. The following Table 2 shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 2)
κ A4 A6 A8 A10
6th surface 1.0000 9.85080E-06 -2.64620E-08 4.20250E-11 -2.74520E-14
13th surface 10.0000 -9.97690E-07 -1.34120E-08 -3.09280E-11 1.00000E-14
Face 27 -30.0000 -1.12040E-05 1.08940E-08 -4.34270E-11 9.85800E-14

  In the first embodiment, the axial air distance d1 between the first lens group G1 and the second lens group G2, the axial air distance d2 between the second lens group G2 and the third lens group G3, and the third lens group G3. The on-axis air gap d3 between the fourth lens group G4 and the on-axis air gap d4 between the fourth lens group G4 and the fifth lens group G5 changes during zooming. Table 3 below shows variable intervals at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity and near-distance object points.

(Table 3)
Wide angle end Intermediate focal length Telephoto end
d1 2.9 22.0 44.2
d2 24.8 10.8 1.2
d3 2.5 6.2 9.1
d4 8.2 4.2 1.4

  Table 4 below shows values corresponding to the conditional expressions in the first embodiment. In Table 4, f2 is the focal length of the second lens group G2, f3 is the focal length of the third lens group G3, f4 is the focal length of the fourth lens group G4, and x5 is the fifth lens group G5. The amount of movement on the optical axis from the wide-angle end state to the telephoto end state, x4 is the amount of movement of the fourth lens group G4 on the optical axis from the wide-angle end state to the telephoto end state, and x3 is the amount of movement of the third lens group G3. Nd3b represents the amount of movement on the optical axis from the wide-angle end state to the telephoto end state, and nd3b represents the refractive index at the d-line of the medium of the positive lens component having the highest refractive index in the third lens group G3. The description of the above symbols is the same in the following embodiments.

(Table 4)
(1) (-f2) /f3=0.72
(2) f2 / f4 = 0.60
(3) f5 / (− f4) = 1.50
(4) x5 / (− f2) = 1.18
(5) x4 / x3 = 0.72
(6) nd3b = 1.76

  FIG. 2A shows an aberration diagram in the infinite focus state in the wide-angle end state of the first embodiment, and FIG. 3 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 4A shows an aberration diagram in the infinitely focused state in the state. Further, FIG. 2B shows a coma aberration diagram when performing blur correction for 0.64 ° rotational blur in the infinity photographing state at the wide-angle end state of the first embodiment, and shows infinite in the telephoto end state. FIG. 4B shows a coma aberration diagram when blur correction is performed for 0.29 ° rotational blur in the far-field state. In each aberration diagram, FNO is an F number, Y is an image height, A is a half angle of view with respect to each image height, d is a d-line (λ = 587.6 nm), and g is a g-line (λ = 435. 6 nm) respectively. In the aberration diagrams showing astigmatism, the solid line shows the sagittal image plane, and the broken line shows the meridional image plane. As is apparent from the respective aberration diagrams, in the first embodiment, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

[Second Embodiment]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second example of the present application. In the variable magnification optical system ZL2 of FIG. 5, the first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12, and a convex surface facing the object side. It is composed of a positive meniscus lens L13 directed to it. The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave lens L22, a biconvex lens L23, and a negative meniscus lens L24 having a concave surface directed toward the object side. The negative meniscus lens L21 located closest to the object side of the two lens group G2 is an aspheric lens having an aspheric surface formed on the glass lens surface on the object side. When focusing from infinity to 0.45 mm, the second lens group G2 moves from the image side to the object side by 1.6 mm at the wide-angle end and 5.6 mm at the telephoto end.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31, a cemented lens of a negative meniscus lens L32 having a convex surface facing the object side, and a biconvex lens L33, and a biconvex lens L34. The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 having a convex surface facing the image side and a biconcave lens L42, and a negative meniscus lens L43 having a concave surface facing the object side. . The fifth lens group G5 includes, in order from the object side, a biconvex lens L51, a biconvex lens L52, and a cemented lens of a negative meniscus lens L53 having a concave surface facing the object side. The biconvex lens L51 located closest to the object side is It is an aspherical lens in which an aspherical surface is formed on the glass lens surface on the object side.

  The aperture stop S is located adjacent to the image side of the most object side positive lens (biconvex lens L31) of the third lens group G3, and together with the third lens group G3 during zooming from the wide-angle end state to the telephoto end state. Moving. Focusing from infinity to a short-distance object point is performed by moving the second lens group G2 in the object direction. Image blur correction (anti-vibration) is performed by moving the cemented lens of the fourth lens group G4 so as to have a component substantially perpendicular to the optical axis.

  It should be noted that the focal length of the entire system is f, and the image blur correction coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction) corrects rotational shake at an angle θ with a K lens. For this, the moving lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the second embodiment, the image stabilization coefficient is 0.98, and the focal length is 24.6 (mm). Therefore, the fourth lens group for correcting rotational blur of 0.64 °. The moving amount of G4 is 0.28 (mm). In the telephoto end state of the second embodiment, since the image stabilization coefficient is 1.47 and the focal length is 117.0 (mm), the fourth lens group for correcting a rotational shake of 0.29 °. The moving amount of G4 is 0.40 (mm).

  Table 5 below shows values of specifications of the second embodiment.

(Table 5)
Wide angle end Intermediate focal length Telephoto end
f = 24.6 to 50.0 to 117.0
FNO = 4.1 to 4.1 to 4.1
2ω = 85.4 to 45.1 to 20.4
Total length = 145.8 to 163.7 to 192.6
Bf = 40.4 to 50.5 to 67.8

Surface number Curvature radius Surface spacing Abbe number Refractive index
1 168.6057 1.5000 23.75 1.846660
2 74.0037 7.6844 67.87 1.593189
3 -1572.0876 0.1000
4 52.4243 5.1021 52.29 1.755000
5 109.4928 (d1)
* 6 120.3215 1.3500 45.34 1.796680
* 7 14.6301 7.4992
8 -43.6507 1.0000 49.61 1.772500
9 67.8619 0.1000
10 37.0188 4.8917 25.41 1.805180
11 -37.6071 0.7823
12 -28.2744 1.0000 49.61 1.772500
13 -190.4764 (d2)
14 63.8494 2.3065 52.29 1.755000
15 -291.0862 1.4000
16 0.0000 0.5000 Aperture stop S
17 30.3754 1.3958 23.75 1.846660
18 18.7015 7.6600 70.45 1.487490
19 -56.3191 0.1000
20 44.8038 2.6036 67.87 1.593189
21 -1480.7317 (d3)
22 -60.0697 3.3444 32.33 1.850 260
23 -19.3470 1.0000 52.29 1.755000
* 24 64.5794 3.5520
25 -26.7812 1.0000 46.63 1.816000
26 -54.8874 (d4)
* 27 60.5775 7.3885 61.18 1.589130
* 28 -21.7258 0.1000
29 -197.0389 5.3709 70.45 1.487490
30 -23.1778 1.5000 31.31 1.903660
31 -102.0182 (Bf)

[Focal length of each lens group]
Lens group Start surface Focal length G1 1 102.8
G2 6 -16.7
G3 14 24.3
G4 22 -26.3
G5 27 39.1

  In the second embodiment, the lens surfaces of the sixth surface, the seventh surface, the 24th surface, the 27th surface and the 28th surface are formed in an aspherical shape. Table 6 below shows the aspheric data, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 6)
κ A4 A6 A8 A10
6th surface 1.0000 3.76150E-06 -4.32870E-08 1.63110E-10 -1.91840E-13
7th surface 1.0000 -5.24680E-06 -9.55930E-08 -1.37810E-10 -4.65040E-13
24th surface 1.0000 -2.42520E-06 1.40090E-08 -4.50560E-11 0.00000E + 00
27th surface 1.0000 -1.17490E-05 1.46620E-08 -7.63690E-11 -8.46830E-15
28th surface 1.0000 1.03350E-05 1.08360E-08 -3.24650E-12 -1.56130E-13

  In the second embodiment, the axial air distance d1 between the first lens group G1 and the second lens group G2, the axial air distance d2 between the second lens group G2 and the third lens group G3, and the third lens group G3. The on-axis air gap d3 between the fourth lens group G4 and the on-axis air gap d4 between the fourth lens group G4 and the fifth lens group G5 changes during zooming. Table 7 below shows variable intervals at the focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity and near-distance object points.

(Table 7)
Wide angle end Intermediate focal length Telephoto end
d1 2.7 22.1 42.5
d2 21.6 10.0 1.2
d3 2.8 6.5 9.4
d4 8.1 4.4 1.5

  Table 8 below shows values corresponding to the conditional expressions in the second embodiment.

(Table 8)
(1) (−f2) /f3=0.69
(2) f2 / f4 = 0.63
(3) f5 / (− f4) = 1.48
(4) x5 / (− f2) = 1.64
(5) x4 / x3 = 0.76
(6) nd3b = 1.76

  FIG. 6A shows an aberration diagram in the infinite focus state in the wide-angle end state of this second embodiment, and FIG. 7 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 8A shows an aberration diagram in the infinitely focused state in the state. Further, FIG. 6B shows a coma aberration diagram when the shake correction for 0.64 ° rotational blur is performed in the infinity photographing state in the wide-angle end state of the second embodiment, and the infinite in the telephoto end state. FIG. 8B shows a coma aberration diagram when blur correction is performed for 0.29 ° rotational blur in the far-field shooting state. As is apparent from the respective aberration diagrams, in the second example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

[Third embodiment]
FIG. 9 is a diagram showing a configuration of the variable magnification optical system ZL3 according to the third example of the present application. In the variable magnification optical system ZL3 in FIG. 9, the first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12, and a convex surface facing the object side. It is composed of a positive meniscus lens L13 directed to it. In order from the object side, the second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a negative meniscus lens L22 having a convex surface directed toward the image side, a biconvex lens L23, and a negative surface having a concave surface directed toward the object side. The negative meniscus lens L21 including the meniscus lens L24 and positioned closest to the object side of the second lens group G2 is an aspheric lens having an aspheric surface formed on the glass lens surface on the object side, and is a negative lens positioned closest to the image side. The meniscus lens L24 is an aspherical lens in which an aspherical surface is formed on the image side glass lens surface. When focusing from infinity to 0.45 mm, the second lens group G2 moves from the image side to the object side by 1.7 mm at the wide-angle end and 5.6 mm at the telephoto end.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31, a cemented lens of a negative meniscus lens L32 having a convex surface facing the object side, and a biconvex lens L33, and a biconvex lens L34. The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 having a convex surface facing the image side and a biconcave lens L42, and a negative meniscus lens L43 having a concave surface facing the object side. . The fifth lens group G5 includes, in order from the object side, a biconvex lens L51, and a cemented lens of a biconvex lens and a negative meniscus lens L52 having a concave surface facing the object side. The biconvex lens L51 located closest to the object side An aspherical lens having an aspherical surface formed on the glass lens surface on the object side.

  The aperture stop S is located between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 upon zooming from the wide-angle end state to the telephoto end state. Focusing from infinity to a short-distance object point is performed by moving the second lens group G2 in the object direction. Image blur correction (anti-vibration) is performed by using a biconvex lens L31 closest to the object side of the third lens group G3 and a cemented lens disposed adjacent to the image side (a negative meniscus lens L32 having a convex surface facing the object side and a biconvex lens). And a lens having a component substantially perpendicular to the optical axis.

  It should be noted that the focal length of the entire system is f, and the image blur correction coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction) corrects rotational shake at an angle θ with a K lens. For this, the moving lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the third embodiment, in the wide-angle end state, the image stabilization coefficient is 1.69, and the focal length is 24.7 (mm). Therefore, the third lens group for correcting the rotation blur of 0.64 °. The moving amount of G3 is 0.16 (mm). In the telephoto end state of the third embodiment, the image stabilization coefficient is 2.60, and the focal length is 111.8 (mm). Therefore, the third lens group for correcting rotational shake of 0.29 °. The moving amount of G3 is 0.22 (mm).

  Table 9 below shows values of specifications of the third embodiment.

(Table 9)
Wide angle end Intermediate focal length Telephoto end
f = 24.7 to 49.0 to 111.8
FNO = 4.1 to 4.1 to 4.1
2ω = 85.4 to 45.1 to 20.4
Total length = 147.6 to 162.2 to 190.9
Bf = 34.7 to 46.1 to 59.2

Surface number Curvature radius Surface spacing Abbe number Refractive index
1 246.0491 2.0000 23.77 1.846660
2 84.7836 7.7000 67.87 1.593189
3 -885.6521 0.1000
4 59.1074 5.4790 46.63 1.816000
5 140.2546 (d1)
* 6 824.4655 0.1000 38.09 1.553890
7 195.0000 1.5000 46.63 1.816000
8 15.9678 8.0000
9 -34.9410 1.0000 42.72 1.834810
10 -201.2418 0.1000
11 54.8341 4.5000 23.77 1.846660
12 -33.9457 0.5374
13 -29.1034 1.2000 40.94 1.806100
* 14 -537.4230 (d2)
15 0.0000 1.5000 Aperture stop S
16 55.6400 3.0000 52.29 1.755000
17 -194.6988 0.1000
18 29.1963 2.2576 23.77 1.846660
19 16.8888 6.8000 70.45 1.487490
20 -196.1439 0.5000
21 49.6966 3.0000 67.87 1.593189
22 -205.9500 (d3)
23 -62.4232 3.3000 32.35 1.850 260
24 -17.7266 1.0000 52.29 1.755000
25 85.0141 2.4116
26 -40.4411 1.0000 55.52 1.696800
27 -241.7912 (d4)
* 28 115.7889 6.4000 61.18 1.589130
29 -22.7957 0.1000
30 -433.8211 6.5000 70.45 1.487490
31 -19.6120 1.3500 32.35 1.850 260
32 -85.0846 (Bf)

[Focal length of each lens group]
Lens group Start surface Focal length G1 1 107.2
G2 6 -17.8
G3 15 25.3
G4 23 -30.7
G5 28 45.5

  In the third embodiment, the lens surfaces of the sixth surface, the fourteenth surface, and the twenty-eighth surface are formed in an aspherical shape. Table 10 below shows the data of the aspheric surface, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 10)
κ A4 A6 A8 A10
6th surface 1.0000 1.59500E-05 -3.85270E-08 5.99450E-11 -5.06110E-14
14th surface 1.0000 6.16800E-07 -1.55190E-08 -1.73480E-11 0.00000E + 00
28th surface -30.0000 -1.26410E-05 -2.71420E-10 6.17710E-11 -2.07970E-13

  In the third example, the axial air gap d1 between the first lens group G1 and the second lens group G2, the axial air gap d2 between the second lens group G2 and the third lens group G3, and the third lens group G3. The on-axis air gap d3 between the fourth lens group G4 and the on-axis air gap d4 between the fourth lens group G4 and the fifth lens group G5 changes during zooming. Table 11 below shows variable intervals at the focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity and near-distance object points.

(Table 11)
Wide angle end Intermediate focal length Telephoto end
d1 3.1 20.1 44.7
d2 24.0 10.2 1.2
d3 4.0 8.2 11.1
d4 10.3 6.1 3.3

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

(Table 12)
(1) (-f2) /f3=0.70
(2) f2 / f4 = 0.58
(3) f5 / (− f4) = 1.48
(4) x5 / (− f2) = 1.38
(5) x4 / x3 = 0.71
(6) nd3b = 1.76

  FIG. 10A shows an aberration diagram in the infinite focus state in the wide-angle end state of the third embodiment, and FIG. 11 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 12A shows an aberration diagram in the infinitely focused state in the state. Further, FIG. 10B shows a coma aberration diagram when performing blur correction for 0.64 ° rotational blur in the infinity photographing state at the wide-angle end state of the third embodiment, and shows infinite in the telephoto end state. FIG. 12B shows a coma aberration diagram when blur correction is performed for 0.29 ° rotational blur in the far-field state. As is apparent from the respective aberration diagrams, in the third example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

[Fourth embodiment]
FIG. 13 is a diagram showing a configuration of a variable magnification optical system ZL4 (6-group configuration) according to a fourth example of the present application. In the variable magnification optical system ZL4 in FIG. 13, the first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex lens L12, and a convex surface facing the object side. And a positive meniscus lens L13. The second lens group G2, in order from the object side, has a negative meniscus lens L21 having a convex surface directed toward the object side, a negative meniscus lens L22 having a convex surface directed toward the image side, a biconvex lens L23, and a concave surface directed toward the object side. The negative meniscus lens L21 that includes the negative meniscus lens L24 and is located closest to the object side of the second lens group G2 is an aspheric lens having an aspheric surface formed on the glass lens surface on the object side, and is located closest to the image side. The negative meniscus lens L24 is an aspheric lens in which an aspheric surface is formed on the image side glass lens surface. When focusing from infinity to 0.45 mm, the second lens group G2 moves from the image side to the object side by 1.6 mm at the wide-angle end and 5.6 mm at the telephoto end.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31, a cemented lens of a negative meniscus lens L32 having a convex surface facing the object side, and a biconvex lens L33, and a biconvex lens L34. The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 having a convex surface facing the image side and a biconcave lens L42, and a negative meniscus lens L43 having a concave surface facing the object side. . The fifth lens group G5 includes, in order from the object side, a biconvex lens L51, and a cemented lens of the biconvex lens L52 and a negative meniscus lens L53 having a concave surface directed toward the object side. The biconvex lens L51 located closest to the object side. Is an aspherical lens in which an aspherical surface is formed on the glass lens surface on the object side. The sixth lens group G6 includes, in order from the object side, a positive meniscus lens L61 having a concave surface directed toward the object side.

  The aperture stop S is located adjacent to the image side of the most object side positive lens (biconvex lens L31) of the third lens group G3, and together with the third lens group G3 during zooming from the wide-angle end state to the telephoto end state. Moving. Focusing from infinity to a short-distance object point is performed by moving the second lens group G2 in the object direction. Image blur correction (anti-vibration) is performed by moving the cemented lens of the fourth lens group G4 so as to have a component substantially perpendicular to the optical axis.

  It should be noted that the focal length of the entire system is f, and the image blur correction coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction) corrects rotational shake at an angle θ with a K lens. For this, the moving lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K. In the wide-angle end state of the fourth embodiment, the image stabilization coefficient is 0.98 and the focal length is 24.8 (mm). Therefore, the fourth lens group for correcting a rotation blur of 0.64 °. The amount of movement of the cemented lens in G4 is 0.28 (mm). In the telephoto end state of the fourth embodiment, since the image stabilization coefficient is 1.47 and the focal length is 111.9 (mm), the fourth lens group for correcting a rotational shake of 0.29 °. The amount of movement of the cemented lens in G4 is 0.40 (mm).

  Table 13 below lists values of specifications of the fourth embodiment.

(Table 13)
Wide angle end Intermediate focal length Telephoto end
f = 24.8 to 44.4 to 111.9
FNO = 4.1 to 4.0 to 4.0
2ω = 85.4 to 50.2 to 21.0
Total length = 148.2 to 159.3 to 190.0
Bf = 26.4-37.7-57.1

Surface number Curvature radius Surface spacing Abbe number Refractive index
1 198.1451 2.0000 23.77 1.846660
2 83.1076 7.5952 67.87 1.593189
3 -2407.2718 0.1000
4 58.1135 5.4790 52.29 1.755000
5 143.3465 (d1)
* 6 426.6084 1.2000 46.63 1.816000
7 15.6978 8.0182
8 -34.0153 1.0000 45.30 1.795000
9 -123.5592 0.1000
10 63.2721 4.2000 23.77 1.846660
11 -32.4461 0.5374
12 -27.9469 1.0000 40.94 1.806100
* 13 -528.6953 (d2)
14 50.2914 2.4342 52.29 1.755000
15 -1099.3184 1.4000
16 0.0000 0.5000 Aperture stop S
17 31.0475 3.0000 23.77 1.846660
18 17.1303 6.6000 70.45 1.487490
19 -82.4820 0.1000
20 41.5438 3.5000 67.87 1.593189
21 -589.6794 (d3)
22 -54.3208 3.5000 32.35 1.850 260
23 -17.0699 1.0000 52.29 1.755000
24 84.5694 3.0000
25 -52.8099 1.0000 53.89 1.713000
26 -590.9085 (d4)
* 27 94.2512 5.7349 61.18 1.589130
28 -24.4009 0.1000
29 -311.9655 6.5095 70.45 1.487490
30 -20.8486 1.0000 32.35 1.850 260
31 -100.0000 (d5)
32 -200.0000 2.0000 46.63 1.816000
33 -120.0032 (Bf)

[Focal length of each lens group]
Lens group Start surface Focal length G1 1 106.8
G2 6 -17.8
G3 14 25.3
G4 22 -30.7
G5 27 48.3
G6 32 363.6

  In the fourth embodiment, the lens surfaces of the sixth surface, the thirteenth surface, and the twenty-seventh surface are aspherical. Table 14 below shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 14)
κ A4 A6 A8 A10
6th surface 1.0000 1.16370E-05 -2.95490E-08 4.79300E-11 -4.07190E-14
13th surface 1.0000 -1.33470E-06 -2.08660E-08 3.94960E-12 -9.57420E-14
27th surface -30.0000 -8.76090E-06 -1.75720E-09 3.64680E-11 -1.18100E-13

  In the fourth embodiment, the axial air distance d1 between the first lens group G1 and the second lens group G2, the axial air distance d2 between the second lens group G2 and the third lens group G3, and the third lens group G3. Between the fourth lens group G4 and the fourth lens group G4, between the fourth lens group G4 and the fifth lens group G5, and between the fifth lens group G5 and the sixth lens group G6. d5 changes upon zooming. Table 15 below shows variable intervals at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state at infinity and near-distance object points.

(Table 15)
Wide angle end Intermediate focal length Telephoto end
d1 2.9 17.2 44.5
d2 24.0 11.7 1.2
d3 1.6 5.6 8.8
d4 8.1 4.7 1.1
d5 12.4 9.7 4.7

  Table 16 below shows values corresponding to the conditional expressions in the fourth embodiment.

(Table 16)
(1) (-f2) /f3=0.70
(2) f2 / f4 = 0.58
(3) f5 / (− f4) = 1.57
(4) x5 / (− f2) = 1.72
(5) x4 / x3 = 0.69
(6) nd3b = 1.82

  FIG. 14A shows an aberration diagram in the infinite focus state in the wide-angle end state of the fourth embodiment, and FIG. 15 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 16A shows an aberration diagram in the infinitely focused state in the state. Further, FIG. 14B shows a coma aberration diagram when the blur correction is performed with respect to the rotational blur of 0.64 ° in the infinity photographing state at the wide-angle end state in the fourth embodiment, and infinite in the telephoto end state. FIG. 16B shows a coma aberration diagram when blur correction is performed for 0.29 ° rotational blur in the far-field shooting state. As is apparent from the respective aberration diagrams, in the fourth example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

ZL (ZL1 to ZL4) Variable magnification optical system G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group G5 Fifth lens group S Aperture stop 1 Digital single-lens reflex camera (optical apparatus)

Claims (11)

From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
A fifth lens group having a positive refractive power,
At least a part of any one of the lens groups moves so as to have a component substantially perpendicular to the optical axis,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The first lens group, the second lens group, so that 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 . The third lens group, the fourth lens group, and the fifth lens group move on the optical axis, and the second lens group once moves to the image side, then moves to the object side ,
When the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5, The following formula 0.65 <(− f2) / f3 <0.90
0.55 <f2 / f4 <0.90
1.40 <f5 / (− f4) <2.00
Variable magnification optical system that satisfies the above conditions. From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
A fifth lens group having a positive refractive power,
At least a part of any one of the lens groups moves so as to have a component substantially perpendicular to the optical axis,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The first lens group, the second lens group, so that 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 . The third lens group, the fourth lens group, and the fifth lens group move on the optical axis, and the second lens group once moves to the image side, then moves to the object side ,
When the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the focal length of the fourth lens group is f4, the following expression 0.65 <(− f2) / f3 <0.90
0.58 ≦ f2 / f4 <0.90
Variable magnification optical system that satisfies the above conditions. When the focal length of the fifth lens group is f5, the following formula 1.20 <f5 / (− f4) <2.00
The variable magnification optical system according to claim 2, which satisfies the following condition. When the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fifth lens group when the amount of movement from the image side to the object side is positive is x5, the following expression 0.70 <x5 /(−f2)<2.10
The variable magnification optical system as described in any one of Claims 1-3 which satisfy | fills these conditions. When the amount of movement from the image side to the object side is positive, the amount of movement on the optical axis from the wide-angle end state to the telephoto end state of the fourth lens group is x4, and the wide-angle end state of the third lens group When the amount of movement on the optical axis from the telephoto end state to x3 is x3, the following expression 0.65 <x4 / x3 <0.90
The zoom lens system according to any one of claims 1 to 4, which satisfies the following condition.   The zoom optical system according to claim 1, wherein the first lens unit moves from the image side to the object side when zooming from the wide-angle end state to the telephoto end state.   The zoom optical system according to any one of claims 1 to 6, wherein the fifth lens group moves from the image side to the object side when zooming from the wide-angle end state to the telephoto end state.   The zoom optical system according to claim 1, wherein focusing on a short-distance object point is performed by moving at least a part of the second lens group along the optical axis.   The variable power optical system according to claim 1, wherein the second lens group has an aspherical lens surface. The third lens group includes at least one positive lens component, and when the refractive index at the d-line of the medium of the positive lens component having the highest refractive index among the positive lens components is nd3b, the following expression 1.70 < nd3b <1.85
The variable magnification optical system as described in any one of Claims 1-9 which satisfies these conditions.   An optical apparatus having the zoom optical system according to any one of claims 1 to 10.

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