JP2018036664A - Variable magnification optical system, optical instrument and manufacturing method of variable magnification optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable magnification optical system that is bright and has excellent optical performance, an optical instrument having the variable magnification optical system, and a manufacturing method of a variable magnification optical system.SOLUTION: A variable magnification optical system ZL for use in an optical instrument such as a camera 1 has, in order from an object,: a first lens group G1 that has positive refractive power; a second lens group G2 that has negative refractive power; and a rear group (a third lens group G3) that is arranged on an image plane side farther than the second lens group G2, and has the positive refractive power. Upon varying a magnification from a wide-angle end state to a telephoto end state, an interval between the first lens group G1 and the second lens group G2 varies, and an interval between the second lens group G2 and the rear group (the third lens group G3) varies. The rear group (the third lens group G3) has, arranged in order from the object side: an intermediate group G3b that has a positive lens, a negative lens, a negative lens and a positive lens; and a vibration proof lens group Gv that is arrange on the image plane side farther than the intermediate group G3b, has a positive refractive power, and moves so as to have a component in a direction orthogonal to an optical axis.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable magnification optical system, an optical apparatus, and a method for manufacturing the 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). However, the conventional variable magnification optical system has a problem in that it cannot sufficiently meet the demand for a large aperture for obtaining a bright lens having a large F number.

JP 2007-219094 A

  The variable magnification optical system according to the first aspect 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 an image from the second lens group. And a rear group having a positive refractive power disposed on the surface side, and when changing magnification from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, The distance between the two lens group and the rear group is changed, and the rear group is arranged in order from the object side, an intermediate group including a positive lens, a negative lens, a negative lens, and a positive lens, and closer to the image plane side than the intermediate group And an anti-vibration lens group that has a positive refractive power and moves so as to have a component in a direction orthogonal to the optical axis.

  In addition, the variable magnification optical system manufacturing method according to the first aspect 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 rear lens group having a positive refractive power disposed on the image surface side from the two lens groups, and a first lens for the zooming from the wide-angle end state to the telephoto end state. The distance between the second lens group and the second lens group is changed, and the distance between the second lens group and the rear group is changed. In the rear group, the positive lens, the negative lens, and the negative lens are sequentially arranged from the object side. An intermediate group having a lens and a positive lens, and an anti-vibration lens group having a positive refractive power arranged on the image plane side of the intermediate group and moving so as to have a component perpendicular to the optical axis It is characterized by doing.

It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 1 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in the wide-angle end state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to the first example in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in an intermediate focal length state, and FIG. It is a coma aberration diagram when image blur correction is performed. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 1 in an infinitely focused state, in which FIG. 9A illustrates various aberrations in the telephoto end state, and FIG. 9B illustrates image blurring in the telephoto end state. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 2 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations when the zoom lens is in the wide-angle end state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 2 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in an intermediate focal length state, and FIG. It is a coma aberration diagram when image blur correction is performed. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 2 in an infinitely focused state, in which FIG. 9A illustrates various aberrations in the telephoto end state, and FIG. 9B illustrates image blurring in the telephoto end state. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 3 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations when the zoom lens is in the wide-angle end state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 3 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in an intermediate focal length state, and FIG. It is a coma aberration diagram when image blur correction is performed. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 3 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in the telephoto end state, and FIG. 9B is an image blur in the telephoto end state. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 4th Example. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 4 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in the wide-angle end state, and FIG. It is a coma aberration figure when correct | amending. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 4 in an infinitely focused state, in which FIG. 9A is a diagram illustrating various aberrations in an intermediate focal length state, and FIG. It is a coma aberration diagram when image blur correction is performed. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 4 in an infinitely focused state, where FIG. 9A illustrates various aberrations in the telephoto end state, and FIG. 9B illustrates image blurring in the telephoto end state. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 5th Example. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 5 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in the wide-angle end state, and FIG. It is a coma aberration figure when correct | amending. FIG. 9A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 5 in the infinite focus state, where FIG. 9A is a diagram illustrating aberrations in the intermediate focal length state, and FIG. It is a coma aberration diagram when image blur correction is performed. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 5 in an infinitely focused state, where FIG. 9A is a diagram illustrating various aberrations in the telephoto end state, and FIG. 9B is an image blur in the telephoto end state. It is a coma aberration figure when correct | amending. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 6th Example. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 6, wherein FIG. 9A is a diagram illustrating various aberrations when in the wide-angle end state, and FIG. 9B is a diagram when performing image blur correction in the wide-angle end state. It is a coma aberration diagram. FIG. 7A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 6, wherein FIG. 9A is a diagram illustrating various aberrations in the intermediate focal length state, and FIG. 9B is an image blur correction performed in the intermediate focal length state. It is a coma aberration figure at the time. FIG. 6A is a diagram illustrating various aberrations of the variable magnification optical system according to Example 6, wherein FIG. 9A is a diagram illustrating various aberrations when in the telephoto end state, and FIG. 9B is a diagram illustrating when image blur correction is performed in the telephoto end state. It is a coma aberration diagram. It is sectional drawing of the camera carrying the said variable magnification optical system. It is a flowchart for demonstrating the manufacturing method of the said variable magnification optical system.

  Hereinafter, preferred embodiments will be described with reference to the drawings. As shown in FIG. 1, the variable magnification optical system ZL according to the present embodiment 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 rear group GR having a positive refractive power disposed on the image plane side of the second lens group G2. Further, in the zoom optical system ZL, when the zoom is changed 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 the rear group GR. It is comprised so that the space | interval may change. In the variable magnification optical system ZL, the rear group GR includes an intermediate group G3b having a positive lens, a negative lens, a negative lens, and a positive lens, which are arranged in order from the object side, and an image plane side from the intermediate group G3b. And an image side group having a positive refractive power disposed on the surface. Then, in a state where the position of the intermediate group G3b with respect to the image plane is fixed, the anti-vibration lens group that moves the image side group so as to have a component orthogonal to the optical axis (hereinafter referred to as “anti-vibration lens group Gv”) By doing so, camera shake correction (image blur correction) is performed. By configuring the variable magnification optical system ZL according to the present embodiment in such a configuration, a lens having a bright F number can have good optical performance. In other words, the intermediate group G3b of the rear group GR is configured by a positive, negative, and positive four-lens lens so as to have a symmetrical structure, so that spherical aberration, field curvature, and coma aberration can be reduced with respect to the brightness of the F number. It is possible to correct well. Further, by arranging the anti-vibration lens group Gv having positive refractive power on the image side of the intermediate group G3b, the anti-vibration function can be achieved without increasing the number of lenses of the anti-vibration lens group Gv even with a bright lens having a large F number. Can be installed. The lens component is a single lens or a cemented lens in which a plurality of lenses are cemented.

  In the variable magnification optical system ZL according to the present embodiment, the rear group GR includes at least a third lens group G3 that is disposed closest to the object side and has a positive refractive power, from the wide-angle end state to the telephoto end state. At the time of zooming, the distance between the lenses constituting the third lens group G3 can be made constant. The third lens group G3 has the above-described intermediate group G3b. The variable magnification optical system ZL having such a configuration desirably satisfies the following conditional expression (1).

1.0 <f3 / ΔT3 <2.2 (1)
However,
ΔT3: Amount of movement of the third lens group G3 when zooming from the wide-angle end state to the telephoto end state f3: Focal length of the third lens group G3

  Conditional expression (1) defines the focal length of the third lens group G3 and the amount of movement of the third lens group G3 during zooming. If the upper limit of this conditional expression (1) is exceeded, Since the power becomes too weak with respect to the amount of movement of the third lens group G3, the movement of the third lens group G3 cannot contribute to zooming, and the power of the first lens group G1 and the second lens group G2 becomes stronger. This is not preferable because the first lens group G1 and the second lens group G2 are increased in size or the field curvature aberration cannot be corrected well. In order to secure the effect of the present application, it is desirable to set the upper limit of conditional expression (1) to 2.0. In order to further secure the effect of the present application, it is desirable to set the upper limit of conditional expression (1) to 1.8. In order to further secure the effect of the present application, it is desirable to set the upper limit of conditional expression (1) to 1.75. On the other hand, if the lower limit of conditional expression (1) is not reached, the power becomes too strong with respect to the amount of movement of the third lens group G3, and correction of spherical aberration cannot be performed satisfactorily. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (1) to 1.2. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (1) to 1.3. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (1) to 1.4.

  In the zoom optical system ZL according to the present embodiment, it is desirable that the rear group GR has an object side group G3a having a positive refractive power on the object side of the intermediate group G3b. With such a configuration, even better optical performance can be maintained with a bright F-number lens. It is possible to satisfactorily correct higher-order spherical aberration that is likely to occur with a bright lens.

  In the variable magnification optical system ZL according to the present embodiment, it is desirable that the image stabilizing lens group Gv is composed of one positive lens. With such a configuration, it is possible to reduce the lens used for vibration isolation, and it is easy to reduce the weight of the vibration isolation mechanism and improve the vibration isolation performance. Further, it is desirable that the image stabilizing lens group Gv is composed of one biconvex lens. By adopting such a configuration, it is possible to suppress coma aberration fluctuations that occur during image stabilization.

  In the variable magnification optical system ZL according to the present embodiment, the anti-vibration lens group Gv has at least one positive lens, and the positive lens preferably satisfies the following conditional expression (2). .

ndVR + 0.0052 × νdVR−1.965 <0 (2)
However,
ndVR: refractive index of medium of positive lens included in image stabilizing lens group Gv with respect to d-line νdVR: Abbe number of medium of positive lens included in image stabilizing lens group Gv

  Conditional expression (2) defines the refractive index for the d-line of the medium of the positive lens included in the image stabilizing lens group Gv. If the upper limit of conditional expression (2) is exceeded, a glass material having a relatively high refractive power and a large color dispersibility is used for the positive lens, and the lateral chromatic aberration is reduced in the range of camera shake correction. Since it cannot correct | amend favorably, it is unpreferable.

  Further, it is desirable that the positive lens included in the image stabilizing lens group Gv satisfies the following conditional expression (3).

νdVR> 60 (3)
However,
νdVR: Abbe number of the medium of the positive lens included in the image stabilizing lens group Gv

  Conditional expression (3) defines the Abbe number of the medium of the positive lens included in the image stabilizing lens group Gv. If the lower limit of conditional expression (3) is not reached, the dispersibility of the image stabilizing lens group Gv increases, and the lateral chromatic aberration that is conspicuous at the time of camera shake correction cannot be sufficiently corrected within the range of camera shake correction. In order to secure the effect of the present application, it is desirable to set the lower limit value of conditional expression (3) to 62.

  In the zoom optical system ZL according to the present embodiment, when the rear group GR has an object side group G3a having positive refractive power on the object side of the intermediate group G3b, the object side group G3a It is desirable to have a positive lens and satisfy the following conditional expression (4).

νdO> 60 (4)
However,
νdO: Abbe number of the medium of the positive lens included in the object side group G3a

  Conditional expression (4) defines the Abbe number of the medium of the positive lens included in the object side group G3a of the rear group GR. If the lower limit value of conditional expression (4) is not reached, the axial chromatic aberration that tends to occur with a bright lens becomes large and correction becomes difficult, which is not preferable. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (4) to 62. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (4) to 65.

  In the zoom optical system ZL according to the present embodiment, the rear group GR includes a plurality of lens groups (for example, the third lens group G3 and the fourth lens group G4 in FIG. 1), and telephoto from the wide-angle end state. At the time of zooming to the end state, the intervals of the plurality of lens groups included in the rear group GR are changed. When the lens group closest to the image plane (the fourth lens group G4 in FIG. 1) among the plurality of lens groups is the final lens group, the zoom optical system ZL according to the present embodiment has the following conditions: It is desirable to satisfy Formula (5).

4.0 <fr / fw <11.0 (5)
However,
fr: focal length of the last lens unit fw: focal length of the entire variable magnification optical system ZL in the wide-angle end state

  Conditional expression (5) defines the focal length of the final lens group. Exceeding the upper limit value of conditional expression (5) is not preferable because the refractive power of the final lens group becomes weak and it becomes difficult to correct field curvature during zooming. In order to secure the effect of the present application, it is desirable to set the upper limit of conditional expression (5) to 10.0. In order to further secure the effect of the present application, it is desirable to set the upper limit of conditional expression (5) to 9.0. On the other hand, if the lower limit of conditional expression (5) is not reached, the refractive power of the final lens group becomes strong, it becomes difficult to correct distortion, and the back focus cannot be secured, which is not preferable. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (5) to 5.0. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (5) to 6.0.

  In the variable magnification optical system ZL according to the present embodiment, the rear group GR includes, in order from the object side, a third lens group G3 having a positive refractive power and a fourth lens group G4. In the zooming from the state to the telephoto end state, the distance between the third lens group G3 and the fourth lens group G4 can be changed. The third lens group G3 includes at least the above-described intermediate lens group G3b. The variable magnification optical system ZL having such a configuration desirably satisfies the following conditional expression (6).

0.9 <f3 / (fw × ft) ^1/2 <2.0 (6)
However,
f3: focal length of the third lens group G3 fw: focal length of the entire zooming optical system ZL in the wide-angle end state ft: focal length of the entire zooming optical system ZL in the telephoto end state

  Conditional expression (6) defines the focal length of the third lens group G3. Exceeding the upper limit of conditional expression (6) is not preferable because the refractive power of the third lens group G3 becomes weak and the entire length of the optical system increases. In order to secure the effect of the present application, it is desirable to set the upper limit of conditional expression (6) to 1.8. In order to further secure the effect of the present application, it is desirable to set the upper limit of conditional expression (6) to 1.6. On the other hand, if the lower limit of conditional expression (6) is not reached, the refractive power of the third lens group G3 becomes strong and it becomes difficult to correct spherical aberration, which is not preferable. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (5) to 1.0. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (5) to 1.1.

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

1.5 <fv × FNOw / f3 <5.0 (7)
However,
f3: focal length of the third lens group G3 fv: focal length of the anti-vibration lens group Gv FNOw: F-number in the wide-angle end state

  Conditional expression (7) defines the focal length of the image stabilizing lens group Gv and the third lens group G3. If the upper limit value of the conditional expression (7) is exceeded, the refractive power of the anti-vibration lens group Gv becomes weak, and the amount of movement of the anti-vibration lens group during Gv anti-vibration (image blur correction) increases. The diameter of the vibration lens group Gv is increased and the weight is increased, and the decentration coma during the image stabilization cannot be corrected well, which is not preferable. In order to secure the effect of the present application, it is desirable to set the upper limit of conditional expression (7) to 4.5. In order to further secure the effect of the present application, it is desirable to set the upper limit of conditional expression (7) to 4.0. On the other hand, if the lower limit value of conditional expression (7) is not reached, the refractive power of the anti-vibration lens group Gv becomes strong, and the decentration astigmatism and decentration coma during the anti-vibration cannot be corrected well. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (7) to 1.6. In order to further secure the effect of the present application, it is desirable to set the lower limit of conditional expression (7) to 1.8. In order to secure the effect of the present application, it is desirable to set the lower limit of conditional expression (7) to 2.2.

  Further, in the zoom optical system ZL according to the present embodiment, when zooming from the wide-angle end state to the telephoto end state, the first lens group G1 moves once to the image plane side and then moves to the object side. desirable. By adopting such a configuration, the diameter of the first lens group G1 can be kept small while preventing off-axis beam breakage when the distance between the first lens group G1 and the second lens group G2 is widened. In addition, a sharp change in distortion can be suppressed.

  The variable magnification optical system ZL according to the present embodiment includes, in order from the object side, the rear lens group GR, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, The distance between the third lens group G3 and the fourth lens group G4 may change at the time of zooming, or the third lens group G3 having a positive refractive power in order from the object side, and a negative The fourth lens group G4 having a refractive power of 5 and a fifth lens group G5 having a positive refractive power, and the distance between the third lens group G3 and the fourth lens group G4 changes during zooming. The interval between the fourth lens group G4 and the fifth lens group G5 may be changed. Further, in the zoom optical system ZL according to the present embodiment, the third lens group G3 that moves integrally during zooming includes, in order from the object side, a front group G3a, an intermediate group G3b, and a vibration-proof lens group Gv. The intermediate group G3b is preferably composed of four lenses of positive, negative and positive. The anti-vibration lens group Gv may not be included in the third lens group G3 but may be the fourth lens group G4. The object side group G3a arranged on the object side of the intermediate group G3b of the rear group GR may be omitted. Further, the positive, negative, and positive four-lens elements included in the intermediate group G3b may be a combination of a positive lens and a negative lens, or may be arranged as a single lens.

  In the third lens group G3, the zoom optical system ZL according to the present embodiment preferably includes at least two lens components closer to the image plane side than the intermediate group G3b. By having at least two lens components closer to the image plane than the intermediate group G3b, the focusing lens group and the image stabilizing lens group Gv can be disposed in the third lens group G3. The third lens group G3 is preferably composed of a front group G3a, an intermediate lens group G3b, an anti-vibration lens group Gv, and a focusing lens group in order from the object side. Further, the anti-vibration lens group Gv is preferably configured with one positive lens, but may be configured with one cemented lens or a plurality of lens components.

  Furthermore, in the variable magnification optical system ZL according to the present embodiment, the front group G3a is configured by one aspheric lens, but may be configured by two spherical lenses.

  With the configuration described above, it is possible to provide a variable magnification optical system ZL that is bright and has good optical performance.

  Next, a camera that is an optical apparatus including the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. This camera 1 is a so-called mirrorless camera of interchangeable lens provided with a variable magnification optical system ZL according to the present embodiment as a photographing lens 2. In the camera 1, light from an object (subject) (not shown) is collected by the photographing lens 2 and is on the imaging surface of the imaging unit 3 via an OLPF (Optical low pass filter) (not shown). A subject image is formed on the screen. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate an image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thus, the photographer can observe the subject via the EVF 4.

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

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

  In the present embodiment, the variable magnification optical system ZL having a four-group or five-group configuration is shown, but the above-described configuration conditions and the like can be applied to other group configurations such as the sixth group and the seventh group. Further, a configuration in which a lens or a lens group is added closest to the object side, or a configuration in which a lens or a lens group is added closest to the image plane side may be used. Specifically, a configuration in which a lens group whose position relative to the image plane is fixed at the time of zooming is added to the most image plane side. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming. Further, in the variable magnification optical system ZL of the present embodiment, the first lens group G1 to the fourth lens group G4 (or the fifth lens group G5) are respectively light so that the air gap between the groups changes at the time of zooming. Move along the axis.

  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, a part of the rear group (third lens group G3) (for example, the negative lens component disposed on the image plane side of the image stabilizing lens group Gv, or the second lens group disposed on the image plane side of the third lens group G3). The four lens group G4) is preferably a focusing lens group, and the other lenses are preferably fixed in position relative to the image plane during focusing. Considering the load applied to the motor, it is preferable that the focusing lens group is composed of a single lens.

  In addition, the lens group or partial lens group is moved so as to have a component orthogonal to the optical axis, or rotated (swinged) in the in-plane direction including the optical axis to correct image blur caused by camera shake. An anti-vibration lens group may be used. In particular, as described above, it is preferable that at least a part of the rear group GR (for example, the anti-vibration lens group Gv of the third lens group G3) is the anti-vibration lens group.

  Further, the lens surface may be formed as a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, lens processing and assembly adjustment are facilitated, and optical performance deterioration due to errors in 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 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. 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 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 2.5 to 4 times. In the variable magnification optical system ZL of the present embodiment, the F number is smaller than 3.5 from the wide-angle end state to the telephoto end state.

  Hereinafter, an outline of a method for manufacturing the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. First, each lens is arranged to prepare a first lens group G1, a second lens group G2, and a rear group GR (step S100). Further, at the time of 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 rear group GR changes. Arrange (step S200). Further, the rear group GR is arranged in order from the object side, and an intermediate group G3b having a positive lens, a negative lens, a negative lens, and a positive lens, and has a positive refractive power on the image plane side than the intermediate group G3b. An anti-vibration lens group Gv that moves so as to have a component orthogonal to the optical axis is disposed (step S300).

  Specifically, in this embodiment, for example, as shown in FIG. 1, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented in order from the object side. A cemented lens is arranged to form the first lens group G1, a negative lens L21 having a spherical surface formed by providing a resin layer on the object-side lens surface of a negative meniscus lens having a convex surface facing the object side, and a biconcave lens L22. A cemented lens obtained by cementing the biconvex lens L23, a positive meniscus lens L24 having a concave surface facing the object side, and a negative lens L25 having a concave surface facing the object side and an image surface side lens surface formed in an aspheric shape. The cemented lens is disposed to form the second lens group G2, and the positive lens L31, the biconvex lens L32, and the biconcave lens L33, in which the object-side and image-side lens surfaces are formed in an aspheric shape, are joined. The cemented lens, the cemented lens in which the biconcave lens L34 and the biconvex lens L35 are cemented, the positive lens L36 in which the object-side and image-side lens surfaces are formed in an aspherical shape, and the negative meniscus with the convex surface facing the object side. The third lens group G3 in which the lens L37 is disposed, and the positive lens L41 in which the lens surface on the object side is formed in an aspheric shape are disposed, and the fourth lens group G4 is disposed to form the rear group GR. The lens groups thus prepared are arranged in the above-described procedure to manufacture the variable magnification optical system ZL.

  Hereinafter, each example of the present application will be described with reference to the drawings. 1, 5, 9, 13, 17, and 21 are cross-sectional views illustrating the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL6) according to each example. Further, below the sectional views of these variable magnification optical systems ZL1 to ZL6, the light of each lens group G1 to G4 (or G5) when changing magnification from the wide angle end state (W) to the telephoto end state (T) is shown. The direction of movement along the axis is indicated by an arrow.

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), K is the conic constant, and An is the nth-order aspherical coefficient, it is expressed by the following equation (a). . In the following examples, “E−n” indicates “× 10 ⁻ⁿ ”.

S (y) = (y ² / r) / {1+ (1−K × y ² / r ² ) ^1/2 }
+ A4 × y ⁴ + A6 × y ⁶ + A8 × y ⁸ + A10 × y ¹⁰ + A12 × y ¹² (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 right 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. The zoom optical system ZL1 shown in FIG. 1 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 rear group GR. Further, the rear group GR is composed of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power in order from the object side.

  In the zoom optical system ZL1, the first lens group G1 is a cemented lens in which, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. The second lens group G2 includes, in order from the object side, a negative lens L21 in which an aspherical shape is formed by providing a resin layer on a lens surface on the object side of a negative meniscus lens having a convex surface facing the object side, and a biconcave lens L22. And a negative lens L25 having a concave surface facing the object side and a concave surface facing the object side, and a lens surface on the image side formed in an aspherical shape. It is comprised with the cemented lens which joined. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, The lens is composed of a cemented lens obtained by cementing a concave lens L34 and a biconvex lens L35, a positive lens L36 in which object-side and image-side lens surfaces are formed in an aspherical shape, and a negative meniscus lens L37 having a convex surface facing the object side. ing. The fourth lens group G4 is composed of a positive lens L41 having an aspheric lens surface on the object side. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L25, the positive lens L31, the positive lens L36, and the positive lens L41 are glass molded aspheric lenses.

  In the variable magnification optical system ZL1, the distance between the first lens group G1 and the second lens group G2 increases during the magnification change from the wide-angle end state to the telephoto end state, and the second lens group G2 and the third lens group G3. After the first lens group G1 and the second lens group G2 are moved to the image plane side so that the distance between the first lens group G3 and the fourth lens group G4 increases, the object side The third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and is then moved to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In the variable magnification optical system ZL1, focusing from an infinite distance to a short distance object is performed by using a negative lens component (negative meniscus lens L37) arranged on the image plane side of the image stabilizing lens group Gv of the third lens group G3. It is configured to be performed by moving it to the image plane side.

  In the variable magnification optical system ZL1, image blur correction (anti-shake) is performed by using the positive lens L36 of the third lens group G3 as the anti-shake lens group Gv, and the anti-shake lens group Gv in the direction orthogonal to the optical axis. It is performed by moving so as to include the component. It is to be noted that the focal length of the entire system is f, and the image stabilization coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the image stabilization lens group Gv in image blur correction) is K, and the rotational shake at an angle θ. Can be corrected by moving the image stabilizing lens group Gv for shake correction by (f · tan θ) / K in the direction orthogonal to the optical axis (the same applies to the following embodiments). In the wide-angle end state of the first embodiment, the image stabilization coefficient is −0.627 and the focal length is 9.3 (mm). Therefore, the image stabilization for correcting the rotational shake of 1.03 ° is performed. The moving amount of the lens group Gv is −0.170 (mm). In addition, in the intermediate focal length state of the first embodiment, the image stabilization coefficient is −0.831 and the focal length is 19.1 (mm), so that the rotational shake of 0.605 ° is corrected. The amount of movement of the anti-vibration lens group Gv is −0.177 (mm). Further, in the telephoto end state of the first embodiment, the image stabilization coefficient is −0.963 and the focal length is 29.1 (mm), so that it is possible to correct the rotational shake of 0.500 °. The moving amount of the image stabilizing lens group Gv is −0.264 (mm).

  Table 1 below lists values of specifications of the variable magnification optical system ZL1. In Table 1, f shown in the overall specifications is the focal length of the entire system, FNO is the F number, 2ω is the field angle, Y is the maximum image height, TL is the total length, and BF is the back focus value. This is shown for each state, intermediate focal length state, and telephoto end state. Here, the total length TL indicates the distance (air conversion length) on the optical axis from the most object side lens surface (first surface in FIG. 1) to the image plane I at the time of infinite focusing. Further, the back focus BF indicates the distance (air conversion length) on the optical axis from the most image surface side lens surface (the 27th surface in FIG. 1) to the image surface I when focusing on infinity. In the lens data, the first column m indicates the order (surface number) of the lens surfaces from the object side along the traveling direction of the light beam, the second column r indicates the curvature radius of each lens surface, and the third column. d is the distance on the optical axis from each optical surface to the next optical surface (surface interval), the fourth column νd and the fifth column nd are the Abbe number and the refractive index with respect to the d-line (λ = 587.6 nm). Is shown. Further, the radius of curvature of 0.000 indicates a plane, and the refractive index of air of 1.0000 is omitted. The surface numbers 1 to 33 shown in Table 1 correspond to the numbers 1 to 33 shown in FIG. The lens group focal length indicates the start surface and focal length of each of the first to fourth lens groups G1 to G4.

  Here, the focal length f, the radius of curvature r, the surface interval d, and other length units listed in all the following specification values are generally “mm”, but the optical system is proportionally enlarged or proportional. Since the same optical performance can be obtained even if the image is reduced, the present invention is not limited to this. The description of these symbols and the description of the specification table are the same in the following embodiments.

(Table 1) First Example [Overall Specifications]
Zoom ratio = 3.14
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.3 to 19.1 to 29.1
FNO = 1.8 to 2.5 to 2.9
2ω = 85.1 to 44.7 to 29.8
Y == 8.0-8.0-8.0
TL (air equivalent length) = 95.9 to 101.1 to 114.1
BF (air equivalent length) = 13.8 to 18.9 to 18.4

[Lens data]
m r d νd nd
Object ∞
1 52.520 1.60 17.98 1.94595
2 38.097 6.31 46.60 1.80400
3 299.948 D3
4 * 4632.762 0.20 36.64 1.56093
5 105.387 1.51 40.66 1.88300
6 11.700 6.42
7 -78.778 4.04 54.61 1.72916
8 44.775 3.44 23.78 1.84666
9 -31.132 1.04
10 -18.713 2.38 30.13 1.69895
11 -13.113 0.90 40.10 1.85135
12 * -35.882 D12
13 0.000 0.80 Aperture stop S
14 21.574 3.26 71.67 1.55332
15 * -59.840 0.30
16 35.781 4.78 23.78 1.84666
17 -14.139 0.80 28.38 1.72825
18 24.505 2.16
19 -28.756 1.50 22.74 1.80809
20 24.289 4.30 82.57 1.49782
21 -14.921 0.50
22 * 24.289 2.68 81.49 1.49710
23 * -70.000 1.50
24 34.328 0.80 82.57 1.49782
25 16.185 D25
26 * 28.150 2.21 81.49 1.49710
27 254.991 D27
28 0.000 0.50 63.88 1.51680
29 0.000 1.11
30 0.000 1.59 63.88 1.51680
31 0.000 0.30
32 0.000 0.70 63.88 1.51680
33 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 84.50
Second lens group 4 -13.26
Third lens group 14 22.97
Fourth lens group 26 63.45

  In the zoom optical system ZL1, the fourth surface, the twelfth surface, the fourteenth surface, the fifteenth surface, the twenty-second surface, the twenty-third surface, and the twenty-sixth surface are formed in an aspheric shape. The following Table 2 shows aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 2)
[Aspherical data]
K A4 A6 A8 A10
4th surface 0 4.41073E-05 -1.57931E-07 4.69697E-10 -7.44801E-13
12th surface 0 -1.20350E-05 -8.15569E-08 3.91594E-10 -3.58987E-12
14th face 0 -3.13883E-06 -1.57686E-08 -1.08799E-09 0.00000E + 00
15th face 0 5.63460E-05 4.70520E-09 0.00000E + 00 0.00000E + 00
Side 22 0 -1.41390E-05 -4.37524E-07 0.00000E + 00 0.00000E + 00
23rd face 0 -5.50201E-07 -4.06545E-07 -1.23018E-09 1.33941E-11
26th face 0 4.04787E-06 -4.49391E-08 2.97650E-10 0.00000E + 00

  In this variable magnification optical system ZL1, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D12 between the second lens group G2 and the third lens group G3 (aperture stop S). As described above, the axial air gap D25 between the third lens group G3 and the fourth lens group G4 and the axial air gap D27 between the fourth lens group G4 and the filter group FL change during zooming. . Table 3 below shows variable intervals in the respective focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 3)
[Variable interval data]
Wide angle end Middle Telephoto end f 9.3 19.1 29.1
D3 1.2 13.4 23.6
D12 21.4 5.4 1.5
D25 5.20 8.94 16.23
D27 9.8 15.0 14.5

  Table 4 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL1. In Table 4, f3 is the focal length of the third lens group G3, fv is the focal length of the image stabilizing lens group Gv, FNOw is the F number at the wide-angle end state, fr is the focal length of the final lens group, fw Is the focal length of the entire system in the wide-angle end state, ft is the focal length of the entire system in the telephoto end state, and ΔT3 is the rear group (third lens group G3) when zooming from the wide-angle end state to the telephoto end state. NdVR is the refractive index with respect to the d-line of the medium of the positive lens included in the image stabilizing lens group Gv, νdVR is the Abbe number of the medium of the positive lens included in the image stabilizing lens group Gv, and νdO is the rear group ( The Abbe numbers of the positive lenses included in the object side group G3a of the third lens group G3) are respectively shown. The description of the reference numerals is the same in the following embodiments. In the first example, the positive lens included in the image stabilizing lens group Gv is the positive lens L36, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fourth lens group. G4.

(Table 4)
[Conditional expression values]
(1) f3 / ΔT3 = 1.46
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 81.5
(4) νdO = 71.7
(5) fr / fw = 6.85
(6) f3 / (fw × ft) ^1/2 = 1.40
(7) fv × FNOw / f3 = 2.92

  Thus, this variable magnification optical system ZL1 satisfies all the conditional expressions (1) to (7).

  FIG. 2 is a spherical aberration diagram, astigmatism diagram, distortion diagram, magnification chromatic aberration diagram, and coma aberration diagram of the variable magnification optical system ZL1 in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. FIGS. 3A and 4A are diagrams showing coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 2 (b), FIG. 3 (b), and FIG. 4 (b). In each aberration diagram, FNO represents an F number, and Y represents an image height. The spherical aberration diagram shows the F-number value corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum image height, and the coma diagram shows the value of each image height. d represents a d-line (λ = 587.6 nm), and g represents a g-line (λ = 435.8 nm). In the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. Also, in the aberration diagrams of the respective examples shown below, the same reference numerals as those of the present example are used. From these respective aberration diagrams, it can be seen that in the variable magnification optical system ZL1, various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state.

[Second Embodiment]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second example. The zoom optical system ZL2 shown in FIG. 5 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 rear group GR. Further, the rear group GR is composed of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power in order from the object side.

  In the variable magnification optical system ZL2, the first lens group G1 is a cemented lens in which, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. The second lens group G2 includes, in order from the object side, a negative lens L21 in which an aspherical shape is formed by providing a resin layer on a lens surface on the object side of a negative meniscus lens having a convex surface facing the object side, and a biconcave lens L22. A cemented lens in which a biconvex lens L23, a positive meniscus lens L24 having a concave surface facing the object side, and a negative lens L25 having a concave surface facing the object side and an image surface side lens surface formed in an aspherical shape are cemented. It is configured. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, The lens is composed of a cemented lens obtained by cementing a concave lens L34 and a biconvex lens L35, a positive lens L36 in which object-side and image-side lens surfaces are formed in an aspherical shape, and a negative meniscus lens L37 having a convex surface facing the object side. ing. The fourth lens group G4 is composed of a positive lens L41 having an aspheric lens surface on the object side. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L25, the positive lens L31, the positive lens L36, and the positive lens L41 are glass molded aspheric lenses.

  In the variable magnification optical system ZL2, the distance between the first lens group G1 and the second lens group G2 increases during the magnification change from the wide-angle end state to the telephoto end state, and the second lens group G2 and the third lens group G3. After the first lens group G1 and the second lens group G2 are moved to the image plane side so that the distance between the first lens group G3 and the fourth lens group G4 increases, the object side The third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and is then moved to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In this variable magnification optical system ZL2, focusing from an infinite distance to a short distance object is performed by using a negative lens component (negative meniscus lens L37) disposed on the image plane side of the image stabilizing lens group Gv of the third lens group G3. It is configured to be performed by moving it to the image plane side.

  In the variable magnification optical system ZL2, image blur correction (anti-vibration) is performed by using the positive lens L36 of the third lens group G3 as an anti-vibration lens group Gv, and the anti-vibration lens group Gv in a direction orthogonal to the optical axis. It is performed by moving so as to include the component. In the wide-angle end state of the second embodiment, the image stabilization coefficient is −0.625 and the focal length is 9.3 (mm), and therefore image stabilization for correcting a rotational shake of 1.03 °. The moving amount of the lens group Gv is −0.170 (mm). Further, in the intermediate focal length state, the image stabilization coefficient is −0.814 and the focal length is 19.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.615 °. The amount of movement is −0.205 (mm). In the telephoto end state, the image stabilization coefficient is −0.939 and the focal length is 29.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.534 ° is used. The amount of movement is -0.271 (mm).

  Table 5 below lists values of specifications of the variable magnification optical system ZL2. The surface numbers 1 to 34 shown in Table 5 correspond to the numbers 1 to 34 shown in FIG.

(Table 5) Second Example [Overall Specifications]
Zoom ratio = 3.13
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.3 to 19.1 to 29.1
FNO = 1.8 to 2.5 to 2.9
2ω = 85.2 to 44.9 to 30.1
Y = 8.0 to 8.0 to 8.0
TL (air equivalent length) = 95.4 to 100.7 to 112.1
BF (Air equivalent length) = 13.8 to 18.7 to 19.8

[Lens data]
m r d νd nd
Object ∞
1 49.101 1.60 17.98 1.94595
2 35.955 6.34 46.60 1.80400
3 238.109 D3
4 * 32230.587 0.20 36.64 1.56093
5 92.951 1.51 40.66 1.88300
6 11.709 6.33
7 -61.701 1.00 54.61 1.72916
8 40.995 0.94
9 38.612 4.05 23.78 1.84666
10 -35.701 1.00
11 -18.790 2.40 31.16 1.68893
12 -13.145 1.00 40.10 1.85135
13 * -31.982 D13
14 0.000 0.80 Aperture stop S
15 * 22.706 3.20 71.68 1.55332
16 * -58.429 0.30
17 46.573 5.34 23.78 1.84666
18 -12.743 0.90 28.38 1.72825
19 35.112 1.91
20 -28.666 1.21 22.74 1.80809
21 24.685 4.43 82.57 1.49782
22 -15.272 0.50
23 * 24.333 2.63 81.56 1.49710
24 * -70.000 1.50
25 43.446 0.80 63.88 1.51680
26 15.925 D26
27 * 24.203 2.37 81.56 1.49710
28 220.780 D28
29 0.000 0.50 63.88 1.51680
30 0.000 1.11
31 0.000 1.59 63.88 1.51680
32 0.000 0.30
33 0.000 0.70 63.88 1.51680
34 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 81.70
Second lens group 4 -13.37
Third lens group 15 23.47
Fourth lens group 27 54.46

  In the variable magnification optical system ZL2, the fourth surface, the thirteenth surface, the fifteenth surface, the sixteenth surface, the twenty-third surface, the twenty-fourth surface, and the twenty-seventh surface are formed in an aspherical shape. Table 6 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 6)
[Aspherical data]
K A4 A6 A8 A10
4th surface 0 4.81180E-05 -1.64047E-07 4.26213E-10 -5.47014E-13
13th surface 0 -8.45829E-06 2.53106E-08 -1.62200E-09 1.06953E-11
15th face 0 -8.35604E-06 3.00666E-08 -1.56105E-09 0.00000E + 00
16th face 0 4.98849E-05 4.71546E-08 0.00000E + 00 0.00000E + 00
Side 23 0 -1.46890E-05 -3.34594E-07 0.00000E + 00 0.00000E + 00
24th face 0 3.77210E-07 -3.15609E-07 -1.42238E-09 1.85664E-11
27th face 0 -9.43792E-07 -4.37993E-08 2.66683E-10 0.00000E + 00

  In the variable magnification optical system ZL2, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D13 between the second lens group G2 and the third lens group G3 (aperture stop S). As described above, the axial air gap D26 between the third lens group G3 and the fourth lens group G4 and the axial air gap D28 between the fourth lens group G4 and the filter group FL change during zooming. . Table 7 below shows variable intervals in the respective focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 7)
[Variable interval data]
Wide angle end Middle Telephoto end f 9.3 19.1 29.1
D3 1.2 13.9 23.2
D13 22.0 6.1 1.5
D26 5.20 8.78 14.40
D28 9.8 14.8 15.9

  Table 8 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL2. In the second embodiment, the positive lens included in the image stabilizing lens group Gv is the positive lens L36, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fourth lens group. G4.

(Table 8)
[Conditional expression values]
(1) f3 / ΔT3 = 1.54
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 81.5
(4) νdO = 71.7
(5) fr / fw = 5.88
(6) f3 / (fw × ft) ^1/2 = 1.43
(7) fv × FNOw / f3 = 2.86

  Thus, this zoom optical system ZL2 satisfies all the conditional expressions (1) to (7).

  FIG. 6 shows a spherical aberration diagram, an astigmatism diagram, a distortion diagram, a chromatic aberration diagram, and a coma diagram in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable magnification optical system ZL2 when focusing on infinity. FIGS. 7A and 7A are diagrams illustrating coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 6 (b), FIG. 7 (b), and FIG. 8 (b). From these aberration diagrams, it is understood that various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state in the variable magnification optical system ZL2.

[Third embodiment]
FIG. 9 is a diagram illustrating a configuration of the variable magnification optical system ZL3 according to the third example. The variable magnification optical system ZL3 shown in FIG. 9 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 rear group GR. Further, the rear group GR is composed of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power in order from the object side.

  In the variable magnification optical system ZL3, the first lens group G1 is a cemented lens in which, from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. Further, the second lens group G2, in order from the object side, has a negative lens L21 in which a convex surface is directed toward the object side, the lens surfaces on the object side and the image surface side are formed in an aspheric shape, and a negative surface in which a concave surface is directed toward the object side. The lens includes a meniscus lens L22, a cemented lens in which a biconcave lens L23 and a biconvex lens L24 are cemented, and a negative lens L25 in which a concave surface is directed to the object side and an image surface side lens surface is formed in an aspherical shape. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, A cemented lens in which a concave lens L34 and a biconvex lens L35 are cemented, a cemented positive lens in which a negative meniscus lens L36 having a convex surface facing the object side, and a positive lens L37 in which the lens surface on the image surface side is formed in an aspherical shape; In addition, the lens includes a negative lens L38 having a convex surface facing the object side and an aspheric lens surface on the image plane side. The fourth lens group G4 includes a positive meniscus lens L41 having a convex surface directed toward the object side. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L21, the negative lens L25, the positive lens L31, the negative lens L36, and the positive lens L37 are glass molded aspheric lenses.

  In the variable magnification optical system ZL3, the distance between the first lens group G1 and the second lens group G2 increases during the magnification change from the wide-angle end state to the telephoto end state, and the second lens group G2 and the third lens group G3. After the first lens group G1 and the second lens group G2 are moved to the image plane side so that the distance between the first lens group G3 and the fourth lens group G4 increases, the object side The third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and is then moved to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In this variable magnification optical system ZL3, focusing from an infinite distance to a short-distance object is performed by using a negative lens component (negative meniscus lens L38) disposed on the image plane side of the image stabilizing lens group Gv of the third lens group G3. It is configured to be performed by moving it to the image plane side.

  In the variable magnification optical system ZL3, image blur correction (anti-shake) is performed by using a cemented positive lens composed of the negative lens L36 and the positive lens L37 of the third lens group G3 as an anti-shake lens group Gv. Gv is moved by including a component in a direction orthogonal to the optical axis. In the wide-angle end state of the third embodiment, the image stabilization coefficient is −0.723 and the focal length is 9.3 (mm). Therefore, the image stabilization for correcting the rotation shake of 0.911 ° is performed. The moving amount of the lens group Gv is −0.147 (mm). Further, in the intermediate focal length state, the image stabilization coefficient is −0.934 and the focal length is 19.1 (mm), and therefore the image stabilization lens group Gv for correcting the rotation blur of 0.534 °. The amount of movement is -0.177 (mm). In the telephoto end state, the image stabilization coefficient is -1.06 and the focal length is 29.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.474 ° is used. The amount of movement is -0.236 (mm).

  Table 9 below provides values of specifications of the variable magnification optical system ZL3. The surface numbers 1 to 35 shown in Table 9 correspond to the numbers 1 to 35 shown in FIG.

(Table 9) Third Example [Overall Specifications]
Zoom ratio = 3.12
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.3 to 19.1 to 29.1
FNO = 1.8 to 2.3 to 2.6
2ω = 84.3 to 45.3 to 30.7
Y = 8.0 to 8.0 to 8.0
TL (air equivalent length) = 93.4 to 99.2 to 110.9
BF (air equivalent length) = 13.7 to 21.1 to 21.5

[Lens data]
m r d νd nd
Object ∞
1 43.371 1.60 17.98 1.94595
2 32.926 6.90 45.31 1.79500
3 140.257 D3
4 * 175.520 1.50 42.65 1.82080
5 * 10.809 7.48
6 -15.455 0.92 29.14 2.00100
7 -20.858 0.28
8 -101.287 0.80 46.60 1.80400
9 38.949 0.00
10 36.831 4.78 23.78 1.84666
11 -25.842 0.94
12 -14.557 0.92 45.46 1.80139
13 * -25.880 D13
14 0.000 1.20 Aperture stop S
15 * 18.690 3.57 81.56 1.497103
16 * -63.173 0.78
17 42.863 3.79 22.74 1.80809
18 -17.820 1.00 28.69 1.79504
19 28.455 2.21
20 -54.464 0.90 22.74 1.80809
21 34.705 4.33 82.57 1.49782
22 -16.135 0.50
23 21.394 0.80 29.14 2.00 100
24 17.003 3.74 71.67 1.55332
25 * -60.926 1.60
26 29.947 0.80 81.49 1.49710
27 * 14.925 D27
28 29.674 1.90 82.57 1.49782
29 96.000 D29
30 0.000 0.50 63.88 1.51680
31 0.000 1.11
32 0.000 1.59 63.88 1.51680
33 0.000 0.30
34 0.000 0.70 63.88 1.51680
35 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 82.51
Second lens group 4 -11.97
Third lens group 15 21.69
Fourth lens group 28 85.46

  In the variable magnification optical system ZL3, the fourth surface, the fifth surface, the thirteenth surface, the fifteenth surface, the sixteenth surface, the twenty-fifth surface, and the twenty-seventh surface are formed in an aspheric shape. Table 10 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A12.

(Table 10)
[Aspherical data]
K A4 A6 A8 A10 A12
4th surface 0 6.79E-05 -4.38E-07 3.57E-09 -1.72E-11 3.66E-14
5th surface 0 3.02E-05 -1.77E-07 2.51E-09 2.36E-11 0.00E + 00
13th surface 0 -1.03E-05 -1.42E-07 2.00E-09 -1.18E-11 0.00E + 00
15th surface 0 1.60E-05 1.53E-08 4.77E-09 0.00E + 00 0.00E + 00
16th surface 0 9.01E-05 4.44E-09 5.55E-09 0.00E + 00 0.00E + 00
25th surface 0 2.01E-05 -2.52E-07 4.90E-09 -3.50E-11 0.00E + 00
27th face 0 -1.52E-05 2.25E-07 -5.15E-09 4.70E-11 0.00E + 00

  In the zoom optical system ZL3, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D13 between the second lens group G2 and the third lens group G3 (aperture stop S). As described above, the axial air gap D27 between the third lens group G3 and the fourth lens group G4 and the axial air gap D29 between the fourth lens group G4 and the filter group FL change during zooming. . Table 11 below shows variable intervals in the respective focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 11)
[Variable interval data]
Wide-angle end Medium Telephoto end f 9.3 19.0 29.1
D3 1.0 13.9 23.9
D13 19.2 4.9 1.2
D27 5.20 5.20 10.08
D29 9.8 17.2 17.5

  Table 12 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL3. In the third example, the positive lens included in the image stabilizing lens group Gv is the positive lens L37, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fourth lens group. G4.

(Table 12)
[Conditional expression values]
(1) f3 / ΔT3 = 1.72
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 71.7
(4) νdO = 81.6
(5) fr / fw = 9.22
(6) f3 / (fw × ft) ^1/2 = 1.33
(7) fv × FNOw / f3 = 2.87

  Thus, this variable magnification optical system ZL3 satisfies all the conditional expressions (1) to (7).

  FIG. 10 shows spherical aberration diagrams, astigmatism diagrams, distortion diagrams, magnification chromatic aberration diagrams, and coma aberration diagrams of the variable magnification optical system ZL3 in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. 11A, 12A, and 12A are diagrams showing coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 10 (b), FIG. 11 (b), and FIG. 12 (b). From these respective aberration diagrams, it can be seen that various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state in the variable magnification optical system ZL3.

[Fourth embodiment]
FIG. 13 is a diagram showing a configuration of the variable magnification optical system ZL4 according to the fourth example. The variable magnification optical system ZL4 shown in FIG. 13 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 rear group GR. Further, the rear group GR is composed of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power in order from the object side.

  In the variable magnification optical system ZL4, the first lens group G1 is a cemented lens in which, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. The second lens group G2 includes, in order from the object side, a negative lens L21 having a convex surface directed toward the object side and an object-side lens surface formed in an aspherical shape, a cemented lens of a biconcave lens L22 and a biconvex lens L23, In addition, it is composed of a cemented lens of a positive meniscus lens L24 having a concave surface facing the object side and a negative lens L25 having a concave surface facing the object side and a lens surface on the image side formed in an aspherical shape. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, The lens includes a cemented lens in which a concave lens L34 and a biconvex lens L35 are cemented, a positive lens L36 having an aspheric lens surface on the image side, and a negative meniscus lens L37 having a convex surface facing the object side. The fourth lens group G4 includes a positive lens L41 having a convex surface directed toward the object side and an object-side lens surface formed in an aspherical shape. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L21, the negative lens L25, the positive lens L31, the positive lens L36, and the positive lens L41 are glass mold aspheric lenses.

  In the zoom optical system ZL4, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3. After the first lens group G1 and the second lens group G2 are moved to the image plane side so that the distance between the first lens group G3 and the fourth lens group G4 increases, the object side The third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and is then moved to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In the variable magnification optical system ZL4, focusing from an infinite distance to a short distance object is performed by using a negative lens component (negative meniscus lens L37) disposed on the image plane side of the image stabilizing lens group Gv of the third lens group G3. It is configured to be performed by moving it to the image plane side.

  In the variable magnification optical system ZL4, image blur correction (anti-vibration) is performed by using the positive lens L36 of the third lens group G3 as the anti-vibration lens group Gv, and the anti-vibration lens group Gv in the direction orthogonal to the optical axis. It is performed by moving so as to include the component. In the fourth embodiment, in the wide-angle end state, the image stabilization coefficient is −0.701 and the focal length is 9.26 (mm). Therefore, the image stabilization for correcting the rotation blur of 0.940 ° is performed. The moving amount of the lens group Gv is −0.152 (mm). Further, in the intermediate focal length state, the image stabilization coefficient is −0.929 and the focal length is 19.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.537 °. The amount of movement is -0.179 (mm). In the telephoto end state, the image stabilization coefficient is −1.05 and the focal length is 29.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.475 ° is used. The amount of movement is -0.241 (mm).

  Table 13 below provides values of specifications of the variable magnification optical system ZL4. The surface numbers 1 to 32 shown in Table 13 correspond to the numbers 1 to 32 shown in FIG.

(Table 13) Fourth Example [Overall Specifications]
Zoom ratio = 3.13
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.26 to 19.1 to 29.1
FNO = 1.8 to 2.3 to 2.6
2ω = 85.1 to 45.0 to 29.9
Y = 8.0 to 8.0 to 8.0
TL (air equivalent length) = 93.2 to 98.8 to 110.7
BF (Air equivalent length) = 13.71 to 19.12 to 20.67

[Lens data]
m r d νd nd
Object ∞
1 47.558 1.60 17.98 1.94595
2 35.327 6.23 46.60 1.80400
3 222.036 D3
4 * 5814.989 1.61 40.10 1.85135
5 11.700 6.30
6 -90.767 1.94 49.62 1.77250
7 47.951 3.78 23.78 1.84666
8 -36.068 1.81
9 -14.307 2.06 22.74 1.80809
10 -12.194 0.90 45.46 1.80139
11 * -25.687 D11
12 0.000 0.80 Aperture stop S
13 * 16.293 3.67 67.05 1.59201
14 * -77.139 0.30
15 70.431 3.48 25.45 1.80518
16 -16.780 0.80 33.73 1.64769
17 24.325 2.59
18 -33.946 1.09 25.45 1.80518
19 18.705 4.24 82.57 1.49782
20 -16.422 0.50
21 21.829 2.84 81.49 1.49710
22 * -60.000 1.60
23 113.472 0.80 82.57 1.49782
24 22.646 D24
25 * 26.180 2.35 81.49 1.49710
26 607.278 D26
27 0.000 0.50 63.88 1.51680
28 0.000 1.11
29 0.000 1.59 63.88 1.51680
30 0.000 0.30
31 0.000 0.70 63.88 1.51680
32 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 79.52
Second lens group 4 -12.62
Third lens group 13 22.96
Fourth lens group 25 54.96

  In the variable magnification optical system ZL4, the fourth surface, the eleventh surface, the thirteenth surface, the fourteenth surface, the twenty-second surface, and the twenty-fifth surface are formed in an aspherical shape. Table 14 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 14)
[Aspherical data]
K A4 A6 A8 A10
4th surface 0 3.94307E-05 -1.29628E-07 3.43564E-10 -3.78498E-13
11th surface 0 -1.30254E-05 -1.98133E-08 -6.57557E-10 4.01106E-12
13th face 0 -3.22653E-06 1.73408E-07 -7.04126E-11 0.00000E + 00
14th surface 0 7.18116E-05 1.79256E-07 0.00000E + 00 0.00000E + 00
Side 22 0 1.05439E-05 2.55453E-08 8.37397E-10 -1.64088E-12
25th surface 0 -1.35591E-05 1.71835E-07 -3.32810E-09 2.04907E-11

  In the variable magnification optical system ZL4, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D11 between the second lens group G2 and the third lens group G3 (aperture stop S). As described above, the axial air gap D24 between the third lens group G3 and the fourth lens group G4 and the axial air gap D26 between the fourth lens group G4 and the filter group FL change during zooming. . Table 15 below shows variable intervals in each of the focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity and focusing on a short distance.

(Table 15)
[Variable interval data]
Wide angle end Middle Telephoto end f 9.3 19.1 29.1
D3 1.0 13.9 23.9
D11 19.2 4.9 1.2
D24 5.20 9.06 13.43
D26 9.8 17.2 17.5

  Table 16 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL4. In the fourth example, the positive lens included in the image stabilizing lens group Gv is the positive lens L36, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fourth lens group. G4.

(Table 16)
[Conditional expression values]
(1) f3 / ΔT3 = 1.51
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 81.49
(4) νdO = 67.1
(5) fr / fw = 5.94
(6) f3 / (fw × ft) ^1/2 = 1.40
(7) fv × FNOw / f3 = 2.60

  Thus, this variable magnification optical system ZL4 satisfies all the conditional expressions (1) to (7).

  FIG. 14 shows spherical aberration diagrams, astigmatism diagrams, distortion diagrams, magnification chromatic aberration diagrams, and coma aberration diagrams of the zoom optical system ZL4 in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. FIGS. 15A, 16A, and 16A are diagrams showing coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 14 (b), FIG. 15 (b), and FIG. 16 (b). From these aberration diagrams, it is understood that various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state in the variable magnification optical system ZL4.

[Fifth embodiment]
FIG. 17 is a diagram showing a configuration of a variable magnification optical system ZL5 according to the fifth example. The variable magnification optical system ZL5 shown in FIG. 17 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 rear group GR. Further, the rear group GR is composed of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power in order from the object side.

  In the zoom optical system ZL5, the first lens group G1 is a cemented lens in which, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. The second lens group G2 includes, in order from the object side, a negative lens L21 in which an aspherical shape is formed by providing a resin layer on a lens surface on the object side of a negative meniscus lens having a convex surface facing the object side, and a biconcave lens L22. A cemented lens in which a biconvex lens L23, a positive meniscus lens L24 having a concave surface facing the object side, and a negative lens L25 having a concave surface facing the object side and an image surface side lens surface formed in an aspherical shape are cemented. It is configured. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, The lens is composed of a cemented lens obtained by cementing a concave lens L34 and a biconvex lens L35, a positive lens L36 in which object-side and image-side lens surfaces are formed in an aspherical shape, and a negative meniscus lens L37 having a convex surface facing the object side. ing. The fourth lens group G4 is composed of a positive lens L41 having an aspheric lens surface on the object side. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L25, the positive lens L31, the positive lens L36, and the positive lens L41 are glass molded aspheric lenses.

  In the variable magnification optical system ZL5, when the magnification is changed from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3. After the first lens group G1 and the second lens group G2 are moved to the image plane side so that the distance between the first lens group G3 and the fourth lens group G4 increases, the object side The third lens group G3 is moved to the object side, the fourth lens group G4 is once moved to the object side, and is then moved to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In the variable magnification optical system ZL5, focusing from an infinite distance to a short distance object is performed by using a negative lens component (negative meniscus lens L37) disposed on the image plane side of the image stabilizing lens group Gv of the third lens group G3. It is configured to be performed by moving it to the image plane side.

  In the variable magnification optical system ZL5, image blur correction (anti-shake) is performed by using the positive lens L36 of the third lens group G3 as the anti-shake lens group Gv, and the anti-shake lens group Gv in the direction orthogonal to the optical axis. It is performed by moving so as to include the component. In the wide-angle end state of the fifth embodiment, the image stabilization coefficient is −0.636 and the focal length is 9.3 (mm). Therefore, the image stabilization for correcting the rotation blur of 1.03 ° is performed. The moving amount of the lens group Gv is −0.167 (mm). Further, in the intermediate focal length state, the image stabilization coefficient is −0.859 and the focal length is 19.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.574 ° is used. The amount of movement is -0.194 (mm). In the telephoto end state, the image stabilization coefficient is −0.963 and the focal length is 29.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.519 ° is used. The amount of movement is -0.271 (mm).

  Table 17 below provides values of specifications of the variable magnification optical system ZL5. The surface numbers 1 to 34 shown in Table 17 correspond to the numbers 1 to 33 shown in FIG.

(Table 13) Fifth Example [Overall Specifications]
Zoom ratio = 3.14
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.3 to 19.1 to 29.1
FNO = 1.8 to 2.6 to 2.9
2ω = 85.0 to 45.2 to 30.1
Y = 8.0 to 8.0 to 8.0
TL (air equivalent length) = 95.9 to 98.8 to 112.6
BF (Air equivalent length) = 13.79 to 20.56 to 21.34

[Lens data]
m r d νd nd
Object ∞
1 48.703 1.60 17.98 1.94595
2 34.692 6.38 42.73 1.83481
3 197.349 D3
4 * 5896.385 0.20 36.64 1.56093
5 93.609 1.51 40.66 1.88300
6 11.700 6.47
7 -54.231 1.00 54.61 1.72916
8 54.855 1.56
9 49.676 3.34 23.78 1.84666
10 -32.621 1.12
11 -18.908 2.35 33.73 1.64769
12 -13.263 0.90 44.98 1.79050
13 * -37.964 D13
14 0.000 0.80 Aperture stop S
15 * 20.379 3.57 71.67 1.55332
16 * -42.773 0.30
17 46.219 4.49 23.78 1.84666
18 -14.503 0.90 27.57 1.75520
19 27.482 2.80
20 -29.885 1.34 25.45 1.80518
21 23.770 4.30 82.57 1.49782
22 -15.009 0.50
23 * 23.770 2.70 81.49 1.49710
24 * -70.000 1.50
25 54.480 0.80 67.90 1.59319
26 19.345 D26
27 * 26.011 2.37 81.49 1.49710
28 500.000 D28
29 0.000 0.50 63.88 1.51680
30 0.000 1.11
31 0.000 1.59 63.88 1.51680
32 0.000 0.30
33 0.000 0.70 63.88 1.51680
34 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 80.99
Second lens group 4 -12.86
Third lens group 15 22.96
Fourth lens group 27 55.11

  In the variable magnification optical system ZL5, the fourth surface, the thirteenth surface, the fifteenth surface, the sixteenth surface, the twenty-third surface, the twenty-fourth surface, and the twenty-seventh surface are formed in an aspheric shape. Table 14 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 14)
[Aspherical data]
K A4 A6 A8 A10
4th surface 0 4.87287E-05 -1.73017E-07 4.92743E-10 -6.73284E-13
13th face 0 -8.09198E-06 -3.28390E-08 -3.69807E-10 1.91943E-12
15th face 0 -1.61042E-05 3.65268E-08 -5.12033E-10 0.00000E + 00
16th face 0 4.30711E-05 5.71263E-08 0.00000E + 00 0.00000E + 00
Surface 23 0 -1.46815E-05 -3.11565E-07 0.00000E + 00 0.00000E + 00
24th face 0 -7.08073E-07 -3.08275E-07 -7.09313E-10 1.17051E-11
27th face 0 -2.64761E-06 -4.55080E-08 2.47961E-10 0.00000E + 00

  In the variable magnification optical system ZL5, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D13 between the second lens group G2 and the third lens group G3 (aperture stop S). As described above, the axial air gap D26 between the third lens group G3 and the fourth lens group G4 and the axial air gap D28 between the fourth lens group G4 and the filter group FL change during zooming. . Table 19 below shows variable intervals in the respective focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 19)
[Variable interval data]
Wide angle end Middle Telephoto end f 9.3 19.1 29.1
D3 1.2 11.3 22.9
D13 22.0 5.0 1.5
D26 5.20 8.12 13.07
D28 9.8 16.6 16.9

  Table 20 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL5. In the fifth example, the positive lens included in the image stabilizing lens group Gv is the positive lens L36, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fourth lens group. G4.

(Table 20)
[Conditional expression values]
(1) f3 / ΔT3 = 1.53
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 81.49
(4) νdO = 71.7
(5) fr / fw = 5.94
(6) f3 / (fw × ft) ^1/2 = 1.44
(7) fv × FNOw / f3 = 2.81

  Thus, this zoom optical system ZL5 satisfies all the conditional expressions (1) to (7).

  FIG. 18 shows spherical aberration diagrams, astigmatism diagrams, distortion diagrams, magnification chromatic aberration diagrams, and coma aberration diagrams of the zoom optical system ZL5 in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. FIGS. 19A, 19A, and 20A are diagrams showing coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 18 (b), FIG. 19 (b), and FIG. 20 (b). From these respective aberration diagrams, it is understood that various aberrations are satisfactorily corrected from the wide-angle end state to the telephoto end state in the variable magnification optical system ZL5.

[Sixth embodiment]
FIG. 21 is a diagram illustrating a configuration of the variable magnification optical system ZL6 according to the sixth example. The zoom optical system ZL6 shown in FIG. 21 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 rear group GR. Further, the rear group GR includes, in order from the object side, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group having a positive refractive power. G5.

  In the variable magnification optical system ZL6, the first lens group G1 is a cemented lens in which, from the object side, a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side are cemented. It is configured. The second lens group G2 includes, in order from the object side, a negative lens L21 in which an aspherical shape is formed by providing a resin layer on a lens surface on the object side of a negative meniscus lens having a convex surface facing the object side, and a biconcave lens L22. , A biconvex lens L23, and a negative lens L24 having an aspheric lens surface on the image side. The third lens group G3 includes, in order from the object side, a positive lens L31 in which the object-side and image-side lens surfaces are formed in an aspheric shape, a cemented lens in which a biconvex lens L32 and a biconcave lens L33 are cemented, The lens includes a cemented lens obtained by cementing the concave lens L34 and the biconvex lens L35, and a positive lens L36 in which the object-side and image-side lens surfaces are formed in an aspherical shape. The fourth lens group G4 includes a negative meniscus lens L41 having a convex surface directed toward the object side. The fifth lens group G5 is composed of a positive lens L51 having a lens surface on the object side formed in an aspherical shape. An aperture stop S is disposed between the second lens group G2 and the third lens group G3. A filter group FL having a low-pass filter, an infrared filter, and the like is disposed between the fourth lens group G4 and the image plane I. The negative lens L25, the positive lens L31, the positive lens L41, and the positive lens L51 are glass molded aspheric lenses.

  In the variable magnification optical system ZL6, when the magnification is changed from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 increases, and the second lens group G2 and the third lens group G3. And the distance between the third lens group G3 and the fourth lens group G4 once increases and then decreases, and after the first lens group G1 and the second lens group G2 once move to the image plane side, Moves to the object side, the third lens group G3 moves to the object side, the fourth lens group G4 once moves to the image side, then moves to the object side, and the fifth lens group G5 once moves to the object side Then, it is configured to move to the image plane side. The aperture stop S moves integrally with the third lens group G3.

  In the variable magnification optical system ZL6, focusing from an infinite distance to a short-distance object is performed by moving the fourth lens group G4 to the image plane side.

  In the variable magnification optical system ZL6, image blur correction (anti-vibration) is performed by using the positive lens L36 of the third lens group G3 as the anti-vibration lens group Gv, and the anti-vibration lens group Gv in a direction orthogonal to the optical axis. It is performed by moving so as to include the component. In the sixth embodiment, in the wide-angle end state, the image stabilization coefficient is −0.647 and the focal length is 9.3 (mm). Therefore, the image stabilization for correcting the rotation blur of 1.02 ° is performed. The moving amount of the lens group Gv is −0.165 (mm). Further, in the intermediate focal length state, the image stabilization coefficient is −0.897 and the focal length is 19.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.559 °. The amount of movement is -0.187 (mm). In the telephoto end state, the image stabilization coefficient is −1.02 and the focal length is 29.1 (mm). Therefore, the image stabilization lens group Gv for correcting the rotation blur of 0.493 ° is used. The amount of movement is -0.250 (mm).

  Table 21 below provides values of specifications of the variable magnification optical system ZL6. Note that the surface numbers 1 to 34 shown in Table 21 correspond to the numbers 1 to 34 shown in FIG.

(Table 21) Sixth Example [Overall specifications]
Zoom ratio = 3.14
Wide-angle end state Intermediate focal length state Telephoto end state f = 9.3 to 19.1 to 29.1
FNO = 1.8 to 2.5 to 2.9
2ω = 81.8 to 45.4 to 30.3
Y = 7.3 to 8.0 to 8.0
TL (air equivalent length) = 97.6 to 97.9 to 111.2
BF (Air equivalent length) = 13.77 to 20.21 to 22.17

[Lens data]
m r d νd nd
Object ∞
1 50.656 1.60 17.98 1.94595
2 37.840 4.41 46.60 1.80400
3 233.428 D3
4 * 4632.762 0.20 36.64 1.56093
5 109.440 1.50 42.73 1.83481
6 11.704 6.92
7 -23.983 1.00 55.52 1.69680
8 45.374 0.84
9 52.381 4.25 28.69 1.79504
10 -21.378 1.30
11 -13.669 0.00
12 -13.669 0.90 49.26 1.74330
13 * -20.257 D13
14 0.000 0.80 Aperture stop S
15 * 20.620 3.77 71.67 1.55332
16 * -59.068 0.15
17 73.847 7.46 22.74 1.80809
18 -17.447 0.90 27.57 1.75520
19 32.860 2.95
20 -133.340 0.90 23.78 1.84666
21 22.909 4.14 82.57 1.49782
22 -18.768 0.50
23 * 23.489 2.71 81.49 1.49710
24 * -70.000 D24
25 75.360 0.80 67.90 1.59319
26 20.437 D26
27 * 29.723 2.36 81.49 1.49710
28 2125.803 D28
29 0.000 0.50 63.88 1.51680
30 0.000 1.11
31 0.000 1.59 63.88 1.51680
32 0.000 0.30
33 0.000 0.70 63.88 1.51680
34 0.000 0.70

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 85.36
Second lens group 4 -14.13
Third lens group 15 20.88
Fourth lens group 25 -47.53
5th lens group 27 60.62

  In the variable magnification optical system ZL6, the fourth surface, the thirteenth surface, the fifteenth surface, the sixteenth surface, the twenty-third surface, the twenty-fourth surface, and the twenty-seventh surface are formed in an aspheric shape. Table 22 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 22)
[Aspherical data]
K A4 A6 A8 A10
4th surface 0 4.14925E-05 -1.40193E-07 3.89689E-10 -2.54524E-13
13th surface 0 -1.53196E-05 -7.94859E-08 -1.88545E-11 -1.26565E-12
15th face 0 -9.91269E-06 7.57161E-08 3.07024E-11 0.00000E + 00
16th surface 0 3.48959E-05 8.65483E-08 0.00000E + 00 0.00000E + 00
Side 23 0 -1.31286E-05 -1.33696E-07 0.00000E + 00 0.00000E + 00
24th face 0 -2.92174E-06 -1.15116E-07 6.91626E-11 8.78230E-13
Side 27 0 -1.97816E-06 -1.62889E-08 1.79202E-10 0.00000E + 00

  In this variable magnification optical system ZL6, the axial air distance D3 between the first lens group G1 and the second lens group G2, and the axial air distance D13 between the second lens group G2 and the third lens group G3 (aperture stop S). The on-axis air gap D24 between the third lens group G3 and the fourth lens group G4, the on-axis air gap D26 between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the filter group FL. As described above, the on-axis air gap D28 changes during zooming. Table 23 below shows variable intervals in the respective focal length states of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 23)
[Variable interval data]
Wide angle end Middle Telephoto end f 9.3 19.1 29.1
D3 1.20 10.52 22.40
D13 25.66 6.03 1.50
D24 1.50 1.61 1.50
D26 5.10 9.21 13.32
D28 9.82 16.26 18.22

  Table 24 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL6. In the sixth example, the positive lens included in the image stabilizing lens group Gv is the positive lens L36, the positive lens included in the object side group G3a is the positive lens L31, and the final lens group is the fifth lens group. G5.

(Table 24)
[Conditional expression values]
(1) f3 / ΔT3 = 1.49
(2) ndVR−0.0052 × νdVR−1.965 = −0.044
(3) νdVR = 81.49
(4) νdO = 71.7
(5) fr / fw = 6.54
(6) f3 / (fw × ft) ^1/2 = 1.27
(1) fv × FNOw / f3 = 3.15

  Thus, this variable magnification optical system ZL6 satisfies all the conditional expressions (1) to (7).

  FIG. 22 shows spherical aberration diagrams, astigmatism diagrams, distortion diagrams, magnification chromatic aberration diagrams, and coma aberration diagrams of the zoom optical system ZL6 at the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. FIGS. 23A and 24A are diagrams showing coma aberration when image blur correction is performed in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity. 22 (b), FIG. 23 (b), and FIG. 24 (b). From these aberration diagrams, it can be seen that the variable magnification optical system ZL6 is well corrected for various aberrations from the wide-angle end state to the telephoto end state.

  According to the present embodiment, it is possible to provide a variable magnification optical system that is bright and has good optical performance, an optical apparatus that includes the variable magnification optical system, and a method for manufacturing the variable magnification optical system.

DESCRIPTION OF SYMBOLS 1 Camera (optical apparatus) ZL (ZL1-ZL6) Variable magnification optical system G1 1st lens group G2 2nd lens group G3 Back group (3rd lens group)
G3a Object side group G3b Intermediate group Gv Anti-vibration lens group G4 Fourth lens group (final lens group) G5 Fifth lens group (final lens group)

The variable magnification optical system according to the first aspect 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, and when zooming from the wide-angle end state to the telephoto end state, the distance between the lens groups changes, and the first lens group includes at least a negative lens and a positive lens. Satisfy the conditions of the formula.
1.0 <f3 / ΔT3 <2.2
However,
ΔT3: Amount of movement of the third lens unit when zooming from the wide-angle end state to the telephoto end state f3: Focal length of the third lens unit

The variable magnification optical system manufacturing method according to the first aspect 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 positive lens group. And a third lens group having a refractive power of: a variable magnification optical system having a refracting power, wherein the distance between the lens groups is changed upon zooming from the wide-angle end state to the telephoto end state. As the first lens group, at least a negative lens and a positive lens are arranged and arranged so as to satisfy the condition of the following expression.
1.0 <f3 / ΔT3 <2.2
However,
ΔT3: Amount of movement of the third lens unit when zooming from the wide-angle end state to the telephoto end state f3: Focal length of the third lens unit

Claims (12)

From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A rear group having a positive refractive power disposed on the image plane side with respect to the second lens group,
Upon 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 rear group changes,
The rear group is
An intermediate group consisting of a positive lens, a negative lens, a negative lens, and a positive lens, arranged in order from the object side,
A zoom lens system having a positive refractive power disposed on the image plane side of the intermediate group and moving so as to have a component orthogonal to the optical axis. . The rear group has at least a third lens group that is disposed closest to the object side and has a positive refractive power;
During zooming from the wide-angle end state to the telephoto end state, the distance between the lenses constituting the third lens group is constant,
The third lens group includes the intermediate group,
2. The variable magnification optical system according to claim 1, wherein a condition of the following formula is satisfied.
1.0 <f3 / ΔT3 <2.2
However,
ΔT3: Amount of movement of the third lens group when zooming from the wide-angle end state to the telephoto end state f3: Focal length of the third lens group   3. The zoom optical system according to claim 1, wherein the rear group includes an object side group having a positive refractive power on the object side of the intermediate group.   The variable power optical system according to any one of claims 1 to 3, wherein the anti-vibration lens group includes a single positive lens.   The zoom lens system according to any one of claims 1 to 4, wherein the anti-vibration lens group includes one biconvex lens. The zoom lens system according to any one of claims 1 to 5, wherein the vibration-proof lens group includes at least one positive lens and satisfies a condition of the following expression.
ndVR + 0.0052 × νdVR−1.965 <0
νdVR> 60
However,
ndVR: refractive index of medium of the positive lens included in the anti-vibration lens group with respect to d-line νdVR: Abbe number of medium of the positive lens included in the anti-vibration lens group The rear group has an object side group having positive refractive power on the object side of the intermediate group,
The object side group has one positive lens,
The zoom lens system according to any one of claims 1 to 6, wherein a condition of the following formula is satisfied.
νdO> 60
However,
νdO: Abbe number of the medium of the positive lens included in the object side group The rear group has a plurality of lens groups,
Upon zooming from the wide-angle end state to the telephoto end state, the intervals between the plurality of lens groups included in the rear group change,
The zooming ratio according to any one of claims 1 to 7, wherein when the lens group closest to the image plane among the plurality of lens groups is a final lens group, the following expression is satisfied. Optical system.
4.0 <fr / fw <11.0
However,
fr: focal length of the final lens group fw: focal length of the entire system in the wide-angle end state The rear group includes, in order from the object side, a third lens group having a positive refractive power, and a fourth lens group.
During zooming from the wide-angle end state to the telephoto end state, the distance between the third lens group and the fourth lens group changes,
The third lens group includes at least the intermediate lens group,
The zoom lens system according to any one of claims 1 to 8, wherein a condition of the following formula is satisfied.
0.9 <f3 / (fw × ft) ^1/2 <2.0
However,
f3: focal length of the third lens group fw: focal length of the entire system in the wide-angle end state ft: focal length of the entire system in the telephoto end state   10. The zoom lens according to claim 1, wherein, when zooming from the wide-angle end state to the telephoto end state, the first lens group temporarily moves to the image plane side and then moves to the object side. The variable power optical system described.   An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 10. 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 rear group having a positive refractive power arranged on the image plane side from the second lens group. A variable magnification optical system having
At the time of zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group is changed, and the distance between the second lens group and the rear group is changed. ,
In the rear group, disposed in order from the object side, an intermediate group having a positive lens, a negative lens, a negative lens, and a positive lens, and a positive refractive power disposed on the image plane side than the intermediate group, An anti-vibration lens group that moves so as to have a component orthogonal to the optical axis is disposed.

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