JP6098863B2 - Variable magnification optical system, optical apparatus having the variable magnification optical system, and method of manufacturing the variable magnification optical system - Google Patents

Description

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

JP-A-11-174329

  However, the conventional variable-power optical system has a problem that the aberration fluctuation at the time of zooming is large and that it cannot cope with the aberration fluctuation at the time of camera shake correction.

  The present invention has been made in view of such a problem, and a variable power optical system having an optical performance that is small in aberration fluctuation at the time of zooming and can cope with aberration fluctuation at the time of camera shake correction, and the variable power optical system It is an object of the present invention to provide an optical device having the above and a method for manufacturing a variable magnification optical system.

In order to solve the above problems, a variable magnification optical system according to the present invention includes, in order from the object side, a first lens group having negative refractive power, a second lens group having positive refractive power, and negative refraction. The first lens group is composed of substantially four lens groups, ie, a third lens group having power and a fourth lens group having positive refractive power, when zooming from the wide-angle end state to the telephoto end state. Between the second lens group and the second lens group, the distance between the second lens group and the third lens group is changed, and the distance between the third lens group and the fourth lens group is changed. The at least one single lens is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis. The first lens group has the first negative lens closest to the object side, and is the most image-capable lens. It has a positive lens on the side and satisfies the following condition.
2.32 ≦ f1gr / (− f1gf) < 2.44
0.65 ≦ f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f4: focal length of the fourth lens group

The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens having a negative refractive power. And a fourth lens group having a positive refractive power, and when zooming from the wide-angle end state to the telephoto end state, the first lens group and the second lens group , The distance between the second lens group and the third lens group is changed, the distance between the third lens group and the fourth lens group is changed, and at least one single lens in the second lens group is changed. The lens is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis. The first lens group has a first negative lens closest to the object side and a positive lens closest to the image side. And the condition of the following formula is satisfied.
2.10 <f1gr / (− f1gf) <3.00
0.82 ≦ f2 / (− f3) ≦ 0.84
However,
f1gf: focal length of the first negative lens
f1gr: Focal length of the positive lens
f2: Focal length of the second lens group
f3: focal length of the third lens unit

The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens having a negative refractive power. And a fourth lens group having a positive refractive power, and when zooming from the wide-angle end state to the telephoto end state, the first lens group and the second lens group , The distance between the second lens group and the third lens group is changed, the distance between the third lens group and the fourth lens group is changed, and at least one single lens in the second lens group is changed. The lens is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis. The first lens group has a first negative lens closest to the object side and a positive lens closest to the image side. And the condition of the following formula is satisfied.
2.10 <f1gr / (− f1gf) <2.44
0.81 <f2 / (− f3) ≦ 0.84
However,
f1gf: focal length of the first negative lens
f1gr: Focal length of the positive lens
f2: Focal length of the second lens group
f3: focal length of the third lens unit

The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens having a negative refractive power. And a fourth lens group having a positive refractive power, and when zooming from the wide-angle end state to the telephoto end state, the first lens group and the second lens group , The distance between the second lens group and the third lens group is changed, the distance between the third lens group and the fourth lens group is changed, and at least one single lens in the second lens group is changed. The lens is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis. The first lens group has a first negative lens closest to the object side and a positive lens closest to the image side. And the condition of the following formula is satisfied.
2.10 <f1gr / (− f1gf) <3.00
0.81 <f2 / (− f3) <1.00
0.60 <f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens
f1gr: Focal length of the positive lens
f2: Focal length of the second lens group
f3: focal length of the third lens unit
f4: focal length of the fourth lens unit

The variable magnification optical system manufacturing method according to the present invention has, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a negative refractive power. A variable magnification optical system manufacturing method comprising substantially four lens groups of a third lens group and a fourth lens group having a positive refractive power, the first lens group, the second lens group, When changing the magnification of the third lens group and the fourth lens group 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 second lens group and the third lens group The distance between the third lens group and the fourth lens group is changed so that at least one single lens of the second lens group has a component in a direction perpendicular to the optical axis. Arranged as an anti-vibration lens group that moves so as to include the first negative lens on the most object side of the first lens group, Also a positive lens disposed on the image side, characterized in that arranged so as to satisfy the condition of following equation.
2.32 ≦ f1gr / (− f1gf) < 2.44
0.65 ≦ f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f4: focal length of the fourth lens group

  When the present invention is configured as described above, a variable magnification optical system having an optical performance that is small in aberration variation at the time of zooming and can cope with aberration variation at the time of camera shake correction, an optical device having the variable magnification optical system, and A variable magnification optical system manufacturing method can be provided.

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 in the wide-angle end state of the variable magnification optical system according to the first example, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. FIG. 7 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the first example. FIG. 3A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the first example, where FIG. 5A is an aberration diagram in an infinite focus state, and FIG. It is a coma aberration figure when performing. 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 in the wide-angle end state of the variable magnification optical system according to Example 2, wherein FIG. 5A is an aberration diagram in the infinite focus state, and FIG. 5B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. FIG. 10 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the second example. FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to Example 2, wherein FIG. 9A is an aberration diagram in the infinite focus state, and FIG. 9B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. FIG. 6A is an aberration diagram in the wide-angle end state of the variable magnification optical system according to Example 3; FIG. 5A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. FIG. 12 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the third example. FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the third example, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. 9B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. 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 in the wide-angle end state of the variable magnification optical system according to the fourth example, where FIG. 5A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. FIG. 11 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the fourth example. FIG. 9A is a diagram illustrating various aberrations of the zoom optical system according to Example 4 in the telephoto end state, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. A sectional view of a camera carrying the above-mentioned variable magnification optical system is shown. It is a flowchart for demonstrating the manufacturing method of the said variable magnification optical system.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the variable magnification optical system ZL according to this embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, A third lens group G3 having a negative refractive power and a fourth lens group G4 having a positive refractive power are configured. In addition, when the zooming optical system ZL zooms 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 third lens group G3 change. The distance between the lens group G3 changes and the distance between the third lens group G3 and the fourth lens group G4 changes. In the variable magnification optical system ZL, at least one single lens (for example, the positive meniscus lens L21 in FIG. 1) of the second lens group G2 moves so as to include a component in a direction orthogonal to the optical axis. This is an anti-vibration lens group VL. When the zoom optical system ZL according to the present embodiment is configured in this manner, the coma aberration at the telephoto end and the field curvature aberration at the wide angle end at the time of zooming are effectively corrected, and the direction substantially orthogonal to the optical axis. A predetermined image plane movement amount can be ensured.

  Now, conditions for constructing such a variable magnification optical system ZL will be described. First, in the variable magnification optical system ZL, the first lens group G1 has a first negative lens (for example, an aspherical negative lens L11 in FIG. 1) closest to the object side, and a positive lens (for example, closest to the image side). It is desirable to have the positive meniscus lens L13) in FIG. 1 and satisfy the following conditional expression (1).

2.10 <f1gr / (− f1gf) <3.00 (1)
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens

  Conditional expression (1) appropriately sets the focal length f1gf of the first negative lens arranged closest to the object side and the focal length f1gr of the positive lens arranged closest to the image side with respect to the focal length of the first lens group G1. Is stipulated. Exceeding the upper limit value of conditional expression (1) is preferable because the focal length f1gf of the first negative lens is shortened and the focal length f1gr of the positive lens is increased, making it difficult to correct coma in the wide-angle end state. Absent. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (1) to 2.44. On the other hand, if the lower limit of conditional expression (1) is not reached, the focal length f1gf of the first negative lens becomes longer and the focal length f1gr of the positive lens becomes shorter, making it difficult to correct spherical aberration in the telephoto end state. Therefore, it is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (1) to 2.14.

  Here, by providing at least one negative lens (for example, the biconcave lens L12 in FIG. 1) between the first negative lens and the positive lens, an image near the wide-angle end is obtained without increasing the diameter of the front lens. Surface curvature can be corrected satisfactorily. Furthermore, this effect can be exhibited more by configuring the first lens group G1 with three lenses including a first negative lens, a second negative lens, and a positive lens.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (2).

0.35 <D3w / (− f3) <0.45 (2)
However,
D3w: Air distance between the third lens group G3 and the fourth lens group G4 in the wide-angle end state f3: Focal length of the third lens group G3

  Conditional expression (2) is a conditional expression for defining the air gap between the third lens group G3 and the fourth lens group G4 with respect to the focal length of the third lens group G3. When the upper limit of conditional expression (2) is exceeded, the air gap D3w between the third lens group G3 and the fourth lens group G4 in the wide-angle end state becomes wide, and the focal length f3 of the third lens group G3 becomes short. This is not preferable because it is difficult to correct spherical aberration in the wide-angle end state. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (2) to 0.42. On the other hand, if the lower limit of conditional expression (2) is not reached, the air gap D3w between the third lens group G3 and the fourth lens group G4 in the wide-angle end state becomes narrower, and the focal length f3 of the third lens group G3 becomes smaller. This is not preferable because it becomes long and it becomes difficult to correct curvature of field aberration in the wide-angle end state. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (2) to 0.38.

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

0.81 <f2 / (− f3) <1.00 (3)
However,
f2: Focal length of the second lens group G2 f3: Focal length of the third lens group G3

  Conditional expression (3) defines an appropriate focal length of the third lens group G3 with respect to the focal length of the second lens group G2. If the upper limit of conditional expression (3) is exceeded, the focal length of the third lens group G3 becomes short and the focal length of the second lens group G2 becomes long, so that it is difficult to correct field curvature aberration in the telephoto end state. This is not preferable. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (3) to 0.84. On the other hand, if the lower limit value of conditional expression (3) is not reached, the focal length of the third lens group G3 becomes longer and the focal length of the second lens group G2 becomes shorter, making it difficult to correct spherical aberration in the wide-angle end state. This is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (3) to 0.82.

  The variable magnification optical system ZL preferably has an aperture stop S in the vicinity of the third lens group G3. According to such a configuration, the open aperture diameter from the wide-angle end to the telephoto end is made constant, and the mechanical configuration is simplified, thereby preventing the optical performance from being deteriorated due to an assembly error.

  In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (4).

0.60 <f2 / f4 <0.70 (4)
However,
f2: Focal length of the second lens group G2 f4: Focal length of the fourth lens group G4

  Conditional expression (4) defines an appropriate focal length of the fourth lens group G4 with respect to the focal length of the second lens group G2. If the upper limit value of the conditional expression (4) is exceeded, the focal length of the fourth lens group G4 becomes short, and the focal length of the second lens group G2 becomes long, so that it becomes difficult to correct spherical aberration in the wide-angle end state. Therefore, it is not preferable. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (4) to 0.68. On the other hand, if the lower limit value of conditional expression (4) is not reached, the focal length of the fourth lens group G4 becomes longer and the focal length of the second lens group G2 becomes shorter, so that the field curvature aberration in the telephoto end state is corrected. Is not preferable because it becomes difficult. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (4) to 0.65.

  In the variable magnification optical system ZL, the most object side lens in the first lens group G1 has an aspherical surface (for example, the image side surface (third surface) of the aspherical negative lens L11 in FIG. 1). It is desirable. Thereby, the field curvature aberration in the wide-angle end state and the spherical aberration in the telephoto end state can be effectively corrected.

  In the zoom optical system ZL, it is desirable that the third lens group G3 is composed of a cemented lens in which a positive lens and a negative lens are bonded together. Thereby, the chromatic coma aberration in the wide-angle end state can be effectively corrected.

  Further, in the zoom optical system ZL, when zooming from the wide-angle end state to the telephoto end state, the distance between the second lens group G2 and the third lens group G3 increases, and the third lens group G3 and the fourth lens group G4 It is desirable that the distance from the lens group G4 is reduced. As a result, it is possible to ensure a predetermined zoom ratio while effectively correcting variations in spherical aberration and field curvature.

  In the variable magnification optical system ZL, it is desirable that all of the second lens group G2, the third lens group G3, and the fourth lens group G4 are spherical lenses. Thereby, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in processing and assembly adjustment can be prevented.

  Next, a camera that is an optical device 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 the four-group configuration is shown, but the above-described configuration conditions and the like can be applied to other group configurations such as the fifth group and the sixth group. Further, a configuration in which a lens or a lens group is added to the most object side or a configuration in which a lens or a lens group is added to the most image side may be used. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming.

  Alternatively, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to be a focusing lens group that performs focusing from an object at infinity to a near object. In this case, the focusing lens group can be applied to autofocus, and is also suitable for driving a motor for autofocus (such as an ultrasonic motor). In particular, as described above, it is preferable that at least a part of the first lens group G1 is a focusing lens group.

  Also, by moving the lens group or partial lens group so that it has a component in the direction perpendicular to the optical axis, or rotating (swinging) in the in-plane direction including the optical axis, image blur caused by camera shake is corrected. An anti-vibration lens group may be used. In particular, as described above, it is preferable that at least a part of the second lens group G2 is a vibration-proof lens group.

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

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

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

  The variable magnification optical system ZL of the present embodiment has a variable magnification ratio of about 2.0 to 5.0.

  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, the lenses are arranged to prepare lens groups G1 to G4, respectively (step S100). Further, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 changes, and the distance between the second lens group G2 and the third lens group G3 changes. Then, it arrange | positions so that the space | interval of the 3rd lens group G3 and the 4th lens group G4 may change (step S200). In addition, at least one single lens in the second lens group G2 is arranged as a vibration-proof lens group VL that moves so as to include a component in a direction orthogonal to the optical axis (step S300). Furthermore, in the first lens group G1, the first negative lens is disposed closest to the object side and the positive lens is disposed closest to the image side so as to satisfy the conditional expression (1) (step S400).

  Specifically, in the present embodiment, for example, as shown in FIG. 1, in order from the object side, a negative meniscus lens-shaped aspherical negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side A positive meniscus lens L13 having a convex surface is disposed to form a first lens group G1, and in order from the object side, a positive meniscus lens L21 having a concave surface on the object side, a negative meniscus lens L22 having a convex surface on the object side, and A positive meniscus lens L23 having a convex surface facing the object side is arranged as a second lens group G2, and a cemented lens of a positive meniscus lens L31 having a concave surface facing the object side and a biconcave lens L32 is arranged in order from the object side. In the third lens group G3, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side, and a negative meniscus having a concave surface facing the biconvex lens L42 and the object side Place a cemented lens of a lens L43 and the fourth lens group G4 with. The lens groups thus prepared are arranged according to 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, FIG. 5, FIG. 9 and FIG. 13 show the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL4) according to each example, and from the infinitely focused state to the short-distance focused state. It is sectional drawing which shows the mode of the movement of each lens group in the change of a focusing state. Further, in the lower part of the sectional views of these zoom optical systems ZL1 to ZL4, along the optical axes of the lens groups G1 to G4 when zooming from the wide-angle end state (W) to the telephoto end state (T) The direction of movement is indicated by an arrow. As shown in FIGS. 1, 5, 9, and 13, the variable magnification optical systems ZL1 to ZL4 according to the first to fourth examples are first lenses having negative refractive power in order from the object side. The lens unit includes a group G1, a second lens group G2 having a positive refractive power, a third lens group G3 having a negative refractive power, and a fourth lens group G4 having a positive refractive power. Then, during zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2 changes, and the air gap between the second lens group G2 and the third lens group G3 changes. The distance between the lens groups changes so that the air distance between the third lens group G3 and the fourth lens group G4 decreases and increases.

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

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

In each embodiment, the secondary aspheric coefficient A2 is zero. In the table of each example, an aspherical surface is marked with * on the right side of the surface number. In the following examples, “E−n” indicates “× 10 ⁻ⁿ ”.

[First embodiment]
FIG. 1 is a diagram showing a configuration of a variable magnification optical system ZL1 according to the first example. In the variable magnification optical system ZL1 shown in FIG. 1, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2, in order from the object side, includes a positive meniscus lens L21 having a concave surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a positive meniscus lens L23 having a convex surface facing the object side. It is configured. The third lens group G3 includes, in order from the object side, a cemented lens of a positive meniscus lens L31 having a concave surface directed toward the object side and a biconcave lens L32. The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side, and a cemented lens of a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object side. .

  The aperture stop S is disposed between the second lens group G2 and the third lens group G3 (near the object side of the third lens group G3), and is used for zooming from the wide-angle end state to the telephoto end state. It moves together with the three lens group G3. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

  In image blur correction (anti-shake), the positive meniscus lens L21 of the second lens group G2 is set as the anti-shake lens group VL, and the anti-shake lens group VL is moved to include a component in a direction orthogonal to the optical axis. By doing.

  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 VL in image blur correction) is K. Can be corrected by moving the image stabilizing lens group VL for blur correction by (f · tan θ) / K in the direction orthogonal to the optical axis (the same applies to the following embodiments). In the first embodiment, in the wide-angle end state, the image stabilization coefficient is 0.77, and the focal length is 18.11 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.45 ° is used. The movement amount of the group VL is 0.18 (mm). Further, in the telephoto end state of the first embodiment, the image stabilization coefficient is 1.29 and the focal length is 50.92 (mm). Therefore, the anti-shake for correcting the rotational blur of 0.27 ° is required. The moving amount of the vibration lens group VL is 0.18 (mm).

  Table 1 below lists values of specifications of the first embodiment. In Table 1, f represents the focal length, FNO represents the F number, 2ω represents the angle of view, and TL represents the total length. Here, the total length TL represents the distance on the optical axis from the first surface of the lens surface to the image plane I when focusing on infinity. Further, the first column m of the lens data 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 Abbe numbers and refractive indices for the d-line (λ = 587.6 nm). Is shown. The radius of curvature of 0.0000 indicates a plane, and the refractive index of air of 1.0000 is omitted. The surface numbers 1 to 22 shown in Table 1 correspond to the numbers 1 to 22 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)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.11 to 43.19 to 50.92
FNO = 3.62 to 5.12 to 5.72
2ω = 79.5 to 36.33 to 31.1
TL = 127.96 to 121.45 to 125.27

[Lens data]
m r d νd nd
1 69.440 2.00 61.22 1.58913
2 15.900 0.17 38.09 1.55389
3 * 13.749 10.00
4 -284.727 1.50 50.84 1.65844
5 39.340 2.70
6 31.807 2.80 23.78 1.84666
7 65.687 d7
8 -169.197 2.00 58.54 1.61272
9 -33.549 1.00
10 18.465 0.90 25.26 1.90200
11 13.324 0.40
12 13.850 3.80 67.90 1.59319
13 205.700 d13
14 0.000 1.50 Aperture stop S
15 -66.540 2.60 25.45 1.80518
16 -13.193 0.80 37.18 1.83400
17 52.452 d15
18 -110.104 2.80 70.31 1.48749
19 -17.370 0.10
20 81.550 4.20 63.88 1.51680
21 -15.015 1.30 37.18 1.83400
22 -54.306 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -25.74
Second lens group 8 27.22
Third lens group 15 -32.68
Fourth lens group 18 40.31

  In the first embodiment, the third surface is formed in an aspheric shape. The following Table 2 shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 2)
κ A4 A6 A8 A10
3rd surface -1.0 2.55993E-05 4.63315E-08 -2.47460E-11 6.32636E-13

  In the first embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2, and the axial air distance d13 between the aperture stop S moving together with the second lens group G2 and the third lens group G3. The on-axis air distance d17 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 3 below shows the values of the variable interval and the back focus Bf at each focal length in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. Note that the back focus Bf represents the distance on the optical axis from the most image side lens surface (the 20th surface in FIG. 1) to the image surface I. This description is the same in the following embodiments.

(Table 3)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 18.11 43.19 50.92
d7 32.88 5.45 2.93
d13 2.87 10.64 12.40
d17 13.06 5.29 3.53
Bf 38.58 59.50 65.84

  Table 4 below shows values corresponding to the conditional expressions in the first embodiment. In Table 4, f2 is the focal length of the second lens group G2, f3 is the focal length of the third lens group G3, f4 is the focal length of the fourth lens group G4, and f1gf is the first lens group G1. The focal length of the first negative lens, f1gr represents the focal length of the positive lens of the first lens group G1, and D3w represents the air gap between the third lens group G3 and the fourth lens group G4 in the wide-angle end state. Yes. The description of the above symbols is the same in the following embodiments.

(Table 4)
(1) f1gr / (− f1gf) = 2.35
(2) D3w / (− f3) = 0.40
(3) f2 / (− f3) = 0.83
(4) f2 / f4 = 0.68

  Thus, the variable magnification optical system ZL1 according to the first example satisfies all the conditional expressions (1) to (4).

  FIG. 2A shows an aberration diagram in the infinite focus state in the wide-angle end state of the first embodiment, and FIG. 3 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 4A shows an aberration diagram in the infinitely focused state in the state. FIG. 2B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.18) is performed in the infinite focus state at the wide-angle end state in the first embodiment. FIG. 4B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.18) is performed in the infinitely focused state at the telephoto end state. In each aberration diagram, FNO is an F number, Y is an image height with respect to a half angle of view, d is a d-line (λ = 587.6 nm), and g is a g-line (λ = 435.6 nm). Yes. In the aberration diagrams showing astigmatism, the solid line shows the sagittal image plane, and the broken line shows the meridional image plane. The explanation of this aberration diagram is the same in the following examples. As is apparent from the respective aberration diagrams, in the first embodiment, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

[Second Embodiment]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second example. In the variable magnification optical system ZL2 shown in FIG. 5, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2 includes, in order from the object side, a positive meniscus lens L21 having a concave surface facing the object side, and a cemented lens of a negative meniscus lens L22 having a convex surface facing the object side and a biconvex lens L23. . The third lens group G3 includes, in order from the object side, a cemented lens of a positive meniscus lens L31 having a concave surface directed toward the object side and a biconcave lens L32. The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side, and a cemented lens of a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object side. .

  The aperture stop S is disposed between the second lens group G2 and the third lens group G3 (near the object side of the third lens group G3), and is used for zooming from the wide-angle end state to the telephoto end state. It moves together with the three lens group G3. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

  In image blur correction (anti-shake), the positive meniscus lens L21 of the second lens group G2 is set as the anti-shake lens group VL, and the anti-shake lens group VL is moved to include a component in a direction orthogonal to the optical axis. By doing. In the second embodiment, in the wide-angle end state, the image stabilization coefficient is 0.65 and the focal length is 10.30 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.61 °. The movement amount of the group VL is 0.17 (mm). Further, in the telephoto end state of the second embodiment, the image stabilization coefficient is 1.10 and the focal length is 29.60 (mm), so that the anti-shake for correcting the rotation blur of 0.36 ° is performed. The moving amount of the vibration lens group VL is 0.17 (mm).

  Table 5 below shows values of specifications of the second embodiment. The surface numbers 1 to 21 shown in Table 5 correspond to the numbers 1 to 21 shown in FIG.

(Table 5)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 10.30 to 19.40 to 29.60
FNO = 3.64 to 4.53 to 5.67
2ω = 80.2 to 45.84 to 30.7
TL = 68.73 to 64.04 to 67.33

[Lens data]
m r d νd nd
1 31.564 1.11 61.22 1.58913
2 8.825 0.09 38.09 1.55389
3 * 7.604 5.72
4 -70.851 0.83 63.88 1.51680
5 17.760 1.33
6 16.239 1.67 25.64 1.78472
7 34.618 d7
8 -230.613 1.08 61.22 1.58913
9 -22.997 0.56
10 10.388 0.50 23.78 1.84666
11 6.916 2.16 60.71 1.56384
12 -116.864 d12
13 0.000 0.83 Aperture stop S
14 -40.668 1.44 25.45 1.80518
15 -6.308 0.44 37.18 1.83400
16 25.885 d16
17 -102.429 1.55 70.31 1.48749
18 -10.217 0.06
19 33.821 2.33 70.31 1.48749
20 -9.235 0.72 37.18 1.83400
21 -33.599 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -14.60
Second lens group 8 14.57
Third lens group 14 -17.43
Fourth lens group 17 21.82

  In the second embodiment, the third surface is formed in an aspheric shape. Table 6 below shows the aspheric data, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 6)
κ A4 A6 A8 A10
3rd surface -1.0 1.69521E-04 8.82411E-07 -4.21030E-11 1.60414E-10

  In this second embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2 and the axial air distance d12 between the aperture stop S moving together with the second lens group G2 and the third lens group G3. The axial air distance d16 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 7 below shows the values of the variable interval and the back focus Bf at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity.

(Table 7)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 10.30 19.40 29.60
d7 17.11 4.64 0.59
d12 1.83 4.40 7.11
d16 7.36 4.79 2.08
Bf 20.00 27.79 35.11

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

(Table 8)
(1) f1gr / (− f1gf) = 2.14
(2) D3w / (− f3) = 0.42
(3) f2 / (− f3) = 0.84
(4) f2 / f4 = 0.67

  Thus, the zoom optical system ZL2 according to the second example satisfies all the conditional expressions (1) to (4).

  FIG. 6A shows an aberration diagram in the infinite focus state in the wide-angle end state of this second embodiment, and FIG. 7 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 8A shows an aberration diagram in the infinitely focused state in the state. FIG. 6B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.17) is performed in the infinite focus state at the wide-angle end state in the second embodiment. FIG. 8B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.17) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the second embodiment, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

[Third embodiment]
FIG. 9 is a diagram illustrating a configuration of the variable magnification optical system ZL3 according to the third example. In the zoom optical system ZL3 shown in FIG. 9, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2, in order from the object side, includes a positive meniscus lens L21 having a concave surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a positive meniscus lens L23 having a convex surface facing the object side. This is composed of a cemented lens. The third lens group G3 includes, in order from the object side, a cemented lens of a positive meniscus lens L31 having a concave surface directed toward the object side and a biconcave lens L32. The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface facing the object side, and a cemented lens of a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object side. .

  The aperture stop S is disposed between the second lens group G2 and the third lens group G3 (near the object side of the third lens group G3), and is used for zooming from the wide-angle end state to the telephoto end state. It moves together with the three lens group G3. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

  In image blur correction (anti-shake), the positive meniscus lens L21 of the second lens group G2 is set as the anti-shake lens group VL, and the anti-shake lens group VL is moved to include a component in a direction orthogonal to the optical axis. By doing. In the third embodiment, in the wide-angle end state, the image stabilization coefficient is 0.84 and the focal length is 18.50 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.44 ° is used. The movement amount of the group VL is 0.17 (mm). Further, in the telephoto end state of the third embodiment, since the image stabilization coefficient is 1.45 and the focal length is 53.40 (mm), the anti-vibration for correcting the rotation blur of 0.26 °. The moving amount of the vibration lens group VL is 0.17 (mm).

  Table 9 below shows values of specifications of the third embodiment. The surface numbers 1 to 21 shown in Table 9 correspond to the numbers 1 to 21 shown in FIG.

(Table 9)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.50 to 35.00 to 53.40
FNO = 3.64 to 4.58 to 5.87
2ω = 78.2 to 44.4 to 29.7
TL = 127.58 to 119.94 to 122.39

[Lens data]
m r d νd nd
1 69.440 2.00 61.22 1.58913
2 15.900 0.17 38.09 1.55389
3 * 13.749 10.00
4 -284.727 1.50 50.84 1.65844
5 39.340 2.70
6 31.807 2.80 23.78 1.84666
7 65.687 d7
8 -823.405 2.00 58.54 1.61272
9 -36.990 1.00
10 18.878 0.90 25.26 1.90200
11 12.630 3.80 58.54 1.61272
12 136.708 d12
13 0.000 1.50 Aperture stop S
14 -64.796 2.60 25.45 1.80518
15 -12.403 0.80 37.18 1.83400
16 52.452 d16
17 -136.622 2.80 70.31 1.48749
18 -17.927 0.10
19 90.259 4.20 63.88 1.51680
20 -15.399 1.30 37.18 1.83400
21 -54.3063 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -25.74
Second lens group 8 26.90
Third lens group 14 -32.18
Fourth lens group 17 40.64

  In the third embodiment, the third surface is formed in an aspheric shape. Table 10 below shows the data of the aspheric surface, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 10)
κ A4 A6 A8 A10
3rd surface -1.0 2.55993E-05 4.63315E-08 -2.47460E-11 6.32636E-13

  In the third embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2 and the axial air distance d12 between the aperture stop S moving together with the second lens group G2 and the third lens group G3. The axial air distance d16 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 11 below shows the values of the variable interval and the back focus Bf at each focal length in 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 Intermediate focal length Telephoto end f 18.50 35.00 53.40
d7 32.88 10.21 2.93
d12 2.87 7.53 12.40
d16 13.06 8.39 3.53
Bf 38.60 53.63 67.80

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

(Table 12)
(1) f1gr / (− f1gf) = 2.35
(2) D3w / (− f3) = 0.41
(3) f2 / (− f3) = 0.84
(4) f2 / f4 = 0.66

  Thus, the variable magnification optical system ZL3 according to the third example satisfies all the conditional expressions (1) to (4).

  FIG. 10A shows an aberration diagram in the infinite focus state in the wide-angle end state of the third embodiment, and FIG. 11 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 12A shows an aberration diagram in the infinitely focused state in the state. FIG. 10B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.17) is performed in the infinite focus state at the wide-angle end state in the third example. FIG. 12B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.17) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the third example, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

[Fourth embodiment]
FIG. 13 is a diagram showing a configuration of the variable magnification optical system ZL4 according to the fourth example. In the zoom optical system ZL4 shown in FIG. 13, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2, in order from the object side, includes a positive meniscus lens L21 having a concave surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a positive meniscus lens L23 having a convex surface facing the object side. This is composed of a cemented lens. The third lens group G3 includes, in order from the object side, a cemented lens of a positive meniscus lens L31 having a concave surface directed toward the object side and a biconcave lens L32. The fourth lens group G4 includes, in order from the object side, a biconvex lens L41, a negative meniscus lens L42 having a convex surface facing the object side, a positive meniscus lens L43 having a convex surface facing the object side, and a biconvex lens L44. .

  The aperture stop S is disposed between the second lens group G2 and the third lens group G3 (near the object side of the third lens group G3), and is used for zooming from the wide-angle end state to the telephoto end state. It moves together with the three lens group G3. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

  In image blur correction (anti-shake), the positive meniscus lens L21 of the second lens group G2 is set as the anti-shake lens group VL, and the anti-shake lens group VL is moved to include a component in a direction orthogonal to the optical axis. By doing. In the fourth embodiment, in the wide-angle end state, the image stabilization coefficient is 0.81 and the focal length is 18.74 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.45 ° is used. The movement amount of the group VL is 0.18 (mm). In the telephoto end state of the fourth embodiment, the image stabilization coefficient is 1.38 and the focal length is 53.15 (mm). The moving amount of the vibration lens group VL is 0.18 (mm).

  Table 13 below lists values of specifications of the fourth embodiment. The surface numbers 1 to 24 shown in Table 13 correspond to the numbers 1 to 24 shown in FIG.

(Table 13)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.74 to 44.99 to 53.15
FNO = 3.47 to 5.15 to 6.12
2ω = 78.0 to 34.9 to 29.7
TL = 127.97 to 122.70 to 123.10

[Lens data]
m r d νd nd
1 60.955 2.00 61.22 1.58913
2 14.479 0.17 38.09 1.55389
3 * 14.004 10.00
4 -189.528 1.50 50.84 1.65844
5 41.116 2.70
6 32.479 2.80 23.78 1.84666
7 65.687 d7
8 -471.246 2.00 58.54 1.61272
9 -36.768 1.00
10 18.710 0.90 25.26 1.90200
11 12.572 3.80 58.54 1.61272
12 136.708 d12
13 0.000 1.50 Aperture stop S
14 -68.773 2.60 25.45 1.80518
15 -12.883 0.80 37.18 1.83400
16 52.452 d16
17 130.964 2.00 70.31 1.48749
18 -28.695 0.10
19 97.235 1.30 37.18 1.83400
20 18.752 0.30
21 19.4416 3.00 63.88 1.51680
22 737.7872 0.30
23 50.7898 1.80 63.88 1.51680
24 -142.991 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -26.03
Second lens group 8 26.97
Third lens group 14 -33.06
Fourth lens group 17 41.33

  In the fourth embodiment, the third surface is formed in an aspheric shape. Table 14 below shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

(Table 14)
κ A4 A6 A8 A10
3rd surface -1.0 2.55993E-05 4.63315E-08 -2.47460E-11 6.32636E-13

  In the fourth example, the axial air distance d7 between the first lens group G1 and the second lens group G2, and the axial air distance d12 between the aperture stop S moving together with the second lens group G2 and the third lens group G3. The axial air distance d16 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 15 below shows the values of the variable interval and the back focus Bf at each focal length in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

(Table 15)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 18.74 44.99 53.15
d7 32.88 5.45 2.93
d12 2.87 10.64 12.40
d16 13.06 5.29 3.53
Bf 38.59 60.76 67.54

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

(Table 16)
(1) f1gr / (− f1gf) = 2.32
(2) D3w / (− f3) = 0.40
(3) f2 / (− f3) = 0.82
(4) f2 / f4 = 0.65

  Thus, the zoom optical system ZL4 according to the fourth example satisfies all the conditional expressions (1) to (4).

  FIG. 14A shows an aberration diagram in the infinite focus state in the wide-angle end state of the fourth embodiment, and FIG. 15 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 16A shows an aberration diagram in the infinitely focused state in the state. FIG. 14B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.18) is performed in the infinitely focused state at the wide-angle end state in the fourth example. FIG. 16B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.18) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the fourth example, various aberrations are satisfactorily corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuation at the time of camera shake correction is also excellent. It can be seen that the imaging performance is excellent.

ZL (ZL1 to ZL4) Variable magnification optical system G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group S Aperture stop 1 Camera (optical device)

Claims (13)

From the object side,
A first lens group having negative refractive power;
A second lens group having a positive refractive power;
A third lens group having negative refractive power;
Substantially consisting of four lens groups with a fourth lens group having positive refractive power,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The distance between the third lens group and the fourth lens group changes,
At least one single lens of the second lens group is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
The first lens group includes a first negative lens closest to the object side and a positive lens closest to the image side, and satisfies the following expression:
2.32 ≦ f1gr / (− f1gf) < 2.44
0.65 ≦ f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f4: focal length of the fourth lens group From the object side,
A first lens group having negative refractive power;
A second lens group having a positive refractive power;
A third lens group having negative refractive power;
Substantially consisting of four lens groups with a fourth lens group having positive refractive power,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The distance between the third lens group and the fourth lens group changes,
At least one single lens of the second lens group is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
The first lens group includes a first negative lens closest to the object side and a positive lens closest to the image side, and satisfies the following expression:
2.10 <f1gr / (− f1gf) <3.00
0.82 ≦ f2 / (− f3) ≦ 0.84
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f3: focal length of the third lens group From the object side,
A first lens group having negative refractive power;
A second lens group having a positive refractive power;
A third lens group having negative refractive power;
Substantially consisting of four lens groups with a fourth lens group having positive refractive power,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The distance between the third lens group and the fourth lens group changes,
At least one single lens of the second lens group is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
The first lens group includes a first negative lens closest to the object side and a positive lens closest to the image side, and satisfies the following expression:
2.10 <f1gr / (− f1gf) <2.44
0.81 <f2 / (− f3) ≦ 0.84
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f3: focal length of the third lens group From the object side,
A first lens group having negative refractive power;
A second lens group having a positive refractive power;
A third lens group having negative refractive power;
Substantially consisting of four lens groups with a fourth lens group having positive refractive power,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The distance between the third lens group and the fourth lens group changes,
At least one single lens of the second lens group is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
The first lens group includes a first negative lens closest to the object side and a positive lens closest to the image side, and satisfies the following expression:
2.10 <f1gr / (− f1gf) <3.00
0.81 <f2 / (− f3) <1.00
0.60 <f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f3: focal length of the third lens group f4: focal length of the fourth lens group 5. The variable magnification optical system according to claim 1, wherein the first lens group includes at least one negative lens between the first negative lens and the positive lens. . 6. The variable magnification optical system according to claim 5 , wherein the first lens group includes the first negative lens, the second negative lens, and the positive lens in order from the object side. The variable power optical system according to claim 1, further comprising an aperture stop between the second lens group and the third lens group. The variable-power optical system according to claim 1, wherein a lens closest to the object side of the first lens group has an aspherical surface. The variable magnification optical system according to any one of claims 1 to 8, wherein the third lens group is a cemented lens in which a positive lens and a negative lens are bonded together. When zooming from the wide-angle end state to the telephoto end state, the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases. The variable power optical system according to any one of claims 1 to 9, wherein: The zooming according to any one of claims 1 to 10, wherein in the second lens group, the third lens group, and the fourth lens group, all lenses are constituted by spherical lenses. Optical system. An optical apparatus comprising the variable magnification optical system according to claim 1, wherein an object image is formed on a predetermined image plane. In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A variable magnification optical system comprising substantially four lens groups with a group,
When the first lens group, the second lens group, the third lens group, and the fourth lens group are zoomed from the wide-angle end state to the telephoto end state, the first lens group and the second lens group And the distance between the second lens group and the third lens group is changed, and the distance between the third lens group and the fourth lens group is changed,
Arranging at least one single lens of the second lens group as an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
A first negative lens is disposed closest to the object side of the first lens group, and a positive lens is disposed closest to the image side;
A method of manufacturing a variable magnification optical system, wherein the zoom lens is disposed so as to satisfy the condition of the following formula.
2.32 ≦ f1gr / (− f1gf) < 2.44
0.65 ≦ f2 / f4 <0.70
However,
f1gf: focal length of the first negative lens f1gr: focal length of the positive lens f2: focal length of the second lens group f4: focal length of the fourth lens group

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