JP6281199B2 - Variable magnification optical system, optical apparatus, and variable magnification optical system manufacturing method - Google Patents

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 power optical system having an image stabilization function suitable for a photographic camera, an electronic still camera, a video camera, and the like has been proposed (for example, see Patent Document 1).

JP 2010-237453 A

  However, the conventional variable power optical system has a problem that it is impossible to ensure both mass productivity and good optical performance.

  The present invention has been made in view of such problems, and provides a variable power optical system, an optical device, and a method of manufacturing the variable power optical system having good optical performance while ensuring mass productivity. Objective.

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 a positive refractive power, a second lens group having a negative refractive power, and a positive refraction. The third lens group having power, the fourth lens group having negative refracting power, and the fifth lens group having positive refracting power are substantially composed of five lens groups. During zooming to the state, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the third lens group and the fourth lens group The distance changes, the distance between the fourth lens group and the fifth lens group changes, and the fourth lens group includes at least one lens component having a negative refractive power and at least one lens having a positive refractive power. It includes a component, a, is moved so as to have a component in the direction intersecting the fourth lens group and the optical axis, And satisfies the expression conditions.
1.191 ≦ rNR1 / rP2R2 <1.50
However,
rNR1: the radius of curvature of the most object side surface of the lens component closest to the object side among the lens components having negative refractive power constituting the fourth lens unit
rP2R2: radius of curvature of the most image side surface of the lens component closest to the image side among the lens components having positive refractive power constituting the fourth lens group . The lens component indicates a single lens or a cemented lens.

  The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. And a fourth lens group having a negative refracting power and a fifth lens group having a positive refracting power, and substantially consisting of five lens groups, and 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 changes, the distance between the second lens group and the third lens group changes, the distance between the third lens group and the fourth lens group changes, The distance between the four lens groups and the fifth lens group changes, and the fourth lens group has at least one lens component having a negative refractive power and at least one lens component having a positive refractive power. The fourth lens group consists of a cemented lens composed of a biconcave lens and a positive meniscus lens having a convex surface facing the object side. Has a lens is moved to have a component in the direction intersecting the fourth lens group and the optical axis, and satisfies the conditions of the following equation.
10.0 <νN−νP1 <25.0
  However,
    νN: Abbe number of the medium of the biconcave lens constituting the cemented lens
    νP1: Abbe number of the medium of the positive meniscus lens constituting the cemented lens
  The lens component indicates a single lens or a cemented lens.

  The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. And a fourth lens group having a negative refracting power and a fifth lens group having a positive refracting power, and substantially consisting of five lens groups, and 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 changes, the distance between the second lens group and the third lens group changes, the distance between the third lens group and the fourth lens group changes, The distance between the four lens groups and the fifth lens group changes, and the fourth lens group has at least one lens component having a negative refractive power and at least one lens component having a positive refractive power. The fourth lens group consists of a cemented lens composed of a biconcave lens and a positive meniscus lens having a convex surface facing the object side. Has a lens is moved to have a component in the direction intersecting the fourth lens group and the optical axis, and satisfies the conditions of the following equation.
1.80 <f4 / f2 <2.80
  However,
    f4: focal length of the fourth lens unit
    f2: Focal length of the second lens group
  The lens component indicates a single lens or a cemented lens.

  The zoom optical system according to the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. And a fourth lens group having a negative refracting power and a fifth lens group having a positive refracting power, and substantially consisting of five lens groups, and 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 changes, the distance between the second lens group and the third lens group changes, the distance between the third lens group and the fourth lens group changes, The distance between the four lens groups and the fifth lens group changes, and the fourth lens group has at least one lens component having a negative refractive power and at least one lens component having a positive refractive power. The fourth lens group consists of a cemented lens composed of a biconcave lens and a positive meniscus lens having a convex surface facing the object side. Has a lens is moved to have a component in the direction intersecting the fourth lens group and the optical axis, and satisfies the conditions of the following equation.
0.11 <(− f2) / f1 <0.19
  However,
    f2: Focal length of the second lens group
    f1: Focal length of the first lens group
  The lens component indicates a single lens or a cemented lens.

  An optical apparatus according to the present invention includes any one of the above-described variable magnification optical systems.

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 positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing a variable magnification optical system comprising substantially five lens groups, that is, a third lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. During 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, the distance between the second lens group and the third lens group changes, and the third lens group And the fourth lens group are changed so that the distance between the fourth lens group and the fifth lens group changes, and the fourth lens group includes at least one lens component having negative refractive power; And at least one lens component having a positive refractive power, and the fourth lens group is orthogonal to the optical axis. Arranged to move so as to have a directional component, characterized in that arranged so as to satisfy the condition of following equation.
1.191 ≦ rNR1 / rP2R2 <1.50
However,
rNR1: the radius of curvature of the most object side surface of the lens component closest to the object side among the lens components having negative refractive power constituting the fourth lens unit
rP2R2: radius of curvature of the surface closest to the image side of the lens component closest to the image side among the lens components having positive refractive power constituting the fourth lens unit
The lens component indicates a single lens or a cemented lens.

  According to the present invention, it is possible to provide a variable power optical system, an optical device, and a method for manufacturing the variable power optical system having good optical performance while ensuring mass productivity.

It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. The zoom lens system according to the first example shows in-focus at infinity in the wide-angle end state, (a) is an aberration diagram, and (b) is a blur correction for 0.60 ° rotation blur. It is a coma aberration figure when it went. FIG. 6 is a diagram illustrating various aberrations of the variable magnification optical system according to the first example in the intermediate focus processing state. FIG. 2A illustrates various aberrations when the variable magnification optical system according to the first example is in focus at the telephoto end state. FIG. 4A is a diagram illustrating various aberrations, and FIG. It is a coma aberration figure when it went. FIG. 4 is a diagram illustrating various aberrations of the zoom optical system according to the first example when focusing at short distance, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows telephoto. Indicates the end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. The zoom lens system according to the second example is in focus at infinity in the wide-angle end state, (a) is an aberration diagram, and (b) is a blur correction for 0.60 ° rotational blur. It is a coma aberration figure when it went. FIG. 12 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 2 in the intermediate focus processing state. The zoom lens system according to the second example shows the infinite focus in the telephoto end state, (a) is an aberration diagram, and (b) is a blur correction for 0.20 ° rotation blur. It is a coma aberration figure when it went. FIG. 6 is a diagram illustrating various aberrations when the zooming optical system according to Example 2 is in focus at short distance, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows telephoto. Indicates the end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. The zoom lens system according to the third example is shown at the time of focusing at infinity in the wide-angle end state, (a) is an aberration diagram, and (b) is a blur correction for a rotational blur of 0.60 °. It is a coma aberration figure when it went. FIG. 11 is a diagram illustrating various aberrations of the variable magnification optical system according to the third example in the intermediate focus processing state. FIG. 5A shows various aberration diagrams in the telephoto end state of the variable magnification optical system according to the third example, FIG. 5A is a diagram of various aberrations, and FIG. It is a coma aberration figure when it went. FIG. 6 is a diagram illustrating various aberrations of the variable magnification optical system according to Example 3 when focusing at short distance, where (a) shows a wide-angle end state, (b) shows an intermediate focal length state, and (c) shows telephoto. Indicates the end state. 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 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 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, 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 G5 having a positive refractive power are configured. In addition, 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 third lens are changed. The distance between the group G3 is changed, the distance between the third lens group G3 and the fourth lens group G4 is changed, and the distance between the fourth lens group G4 and the fifth lens group G5 is changed. A good aberration correction can be performed.

  In such a variable magnification optical system ZL, 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 is increased, and the second lens group G2 and the third lens are increased. The distance between the group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. A multiplication ratio can be ensured. Further, such a zoom optical system ZL is configured to move the first lens group G1 in the object direction when zooming from the wide-angle end state to the telephoto end state, so that the total lens length in the wide-angle end state is increased. The effective diameter of the first lens group G1 can be reduced and the variable magnification optical system ZL can be reduced in size.

  In such a variable magnification optical system ZL, the fourth lens group G4 includes at least one lens component having negative refractive power and at least one lens component having positive refractive power. The fourth lens group G4 is configured to move so as to have a component in a direction orthogonal to the optical axis (hereinafter, the fourth lens group G4 is also referred to as “anti-vibration lens group”). As described above, at least one lens component having a negative refracting power and at least one lens component having a positive refracting power are used in the image stabilizing lens group to correct the image forming position displacement due to camera shake or the like. By moving the entire group, while maintaining mass productivity, both high magnification zoom lenses exceeding 7 times achieve both good aberration correction at the time of zooming and correction of imaging position displacement due to camera shake, etc. Can do. The “lens component” indicates a single lens or a cemented lens.

  In addition, it is desirable that such a variable magnification optical system ZL satisfies the following conditional expression (1).

0.90 <rNR1 / rP2R2 <1.50 (1)
However,
rNR1: radius of curvature of the most object side surface of the lens component closest to the object side among the lens components having the negative refractive power constituting the fourth lens group G4 rP2R2: positive refraction constituting the fourth lens group G4 The radius of curvature of the surface closest to the image side of the lens component closest to the image among the lens components having power

  Conditional expression (1) is a lens having a negative refracting power that constitutes the fourth lens group G4, which is a vibration-proof lens group, for realizing good aberration correction when correcting the displacement of the imaging position due to camera shake or the like. The radius of curvature of the lens surface on the object side of the lens component closest to the object side among the components, and the radius of curvature of the lens surface on the image side of the lens component closest to the image side among the lens components having positive refractive power The ratio is defined. If the upper limit value of the conditional expression (1) is exceeded, the curvature of the convex surface of the lens component having the positive refractive power constituting the fourth lens group G4 becomes large, the negative spherical aberration becomes excessive, and correction becomes difficult. . For this reason, the decentration aberration when the anti-vibration lens group is decentered to correct the displacement of the imaging position due to camera shake or the like becomes excessive. In addition, the effect of this application can be made more reliable by setting the upper limit of conditional expression (1) to 1.30. On the other hand, if the lower limit value of the conditional expression (1) is not reached, the curvature of the concave surface of the lens component having the negative refractive power constituting the fourth lens group G4 becomes large, the positive spherical aberration becomes excessive, and correction is difficult. It becomes. For this reason, the decentration aberration when the image stabilizing lens group is decentered to correct the imaging position displacement due to camera shake or the like becomes excessive. In addition, the effect of this application can be made more reliable by setting the lower limit of conditional expression (1) to 1.10.

  In such a variable magnification optical system ZL, it is desirable that the fourth lens group G4 includes a cemented lens in which a biconcave lens and a positive meniscus lens having a convex surface facing the object side are cemented. With this configuration, it is possible to realize good aberration correction when correcting the imaging position displacement due to camera shake or the like.

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

0.00 <nP1-nN1 <0.20 (2)
However,
nP1: Refractive index with respect to the d-line of the medium of the positive meniscus lens constituting the cemented lens included in the fourth lens group G4 nN1: Refraction with respect to the d-line of the medium of the biconcave lens constituting the cemented lens included in the fourth lens group G4 rate

  Conditional expression (2) is a biconcave lens of a cemented lens that constitutes the fourth lens group G4 that is an anti-vibration lens group for realizing good aberration correction at the time of correcting the imaging position displacement due to camera shake or the like. It defines the refractive index difference of the positive meniscus lens. If the upper limit of conditional expression (2) is exceeded, field curvature correction by the cemented surface of the cemented lens becomes excessive. For this reason, the decentered image surface tilts when the image stabilizing lens group is decentered to correct the imaging position displacement due to camera shake or the like becomes excessively difficult to correct. In addition, the effect of this application can be made more reliable by setting the upper limit of conditional expression (2) to 0.15. On the other hand, if the lower limit of conditional expression (2) is not reached, field curvature correction by the cemented surface of the cemented lens will be insufficient. For this reason, the decentered image surface tilts when the image stabilizing lens group is decentered to correct the imaging position displacement due to camera shake or the like becomes excessively difficult to correct. In addition, the effect of this application can be made more reliable by setting the lower limit of conditional expression (2) to 0.05.

  Moreover, it is desirable that such a variable magnification optical system ZL satisfies the following conditional expression (3).

10.0 <νN−νP1 <25.0 (3)
However,
νN: Abbe number of the medium of the biconcave lens constituting the cemented lens included in the fourth lens group G4 νP1: Abbe number of the medium of the positive meniscus lens constituting the cemented lens included in the fourth lens group G4

  Conditional expression (3) is an Abbe of the biconcave lens and the positive meniscus lens of the cemented lens that constitutes the fourth lens group G4 in order to realize good chromatic aberration correction of the fourth lens group G4 that is the anti-vibration lens group. It defines the difference in numbers. If the upper limit value of conditional expression (3) is exceeded, the chromatic aberration correction of the fourth lens group G4 becomes excessive. For this reason, chromatic aberration fluctuations are excessive when the anti-vibration lens group is decentered in order to correct the imaging position displacement due to camera shake or the like. In addition, the effect of this application can be made more reliable by setting the upper limit of conditional expression (3) to 20.0. On the other hand, if the lower limit of conditional expression (3) is not reached, the chromatic aberration correction of the fourth lens group G4 will be insufficient. For this reason, chromatic aberration fluctuations are excessive when the anti-vibration lens group is decentered in order to correct the imaging position displacement due to camera shake or the like. In addition, the effect of this application can be made more reliable by setting the lower limit of conditional expression (3) to 15.0.

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

1.80 <f4 / f2 <2.80 (4)
However,
f4: focal length of the fourth lens group G4 f2: focal length of the second lens group G2

  Conditional expression (4) indicates that the focal points of the second lens group G2 and the fourth lens group G4 that are suitable for realizing good aberration correction when correcting the displacement of the imaging position due to camera shake or the like and securing a predetermined zoom ratio. It defines the ratio of distances. If the upper limit value of the conditional expression (4) is exceeded, the refractive power of the fourth lens group G4 becomes weak, and the shift amount of the fourth lens group G4 necessary for correcting the imaging position displacement due to camera shake or the like increases. It becomes difficult to simultaneously correct the fluctuation of the decentered image plane tilt at the wide angle end and the decentered coma aberration at the telephoto end when the fourth lens group G4 is decentered. In addition, the effect of this application can be made more reliable by setting the upper limit of conditional expression (4) to 2.50. On the other hand, if the lower limit of conditional expression (4) is not reached, the refractive power of the second lens group G2 becomes weak, and it becomes difficult to ensure a predetermined zoom ratio. In addition, the effect of this application can be made more reliable by setting the lower limit of conditional expression (4) to 2.10.

  Moreover, it is desirable that such a variable magnification optical system ZL satisfies the following conditional expression (5).

0.11 <(− f2) / f1 <0.19 (5)
However,
f2: Focal length of the second lens group G2 f1: Focal length of the first lens group G1

  Conditional expression (5) defines the focal length of the second lens group G2 with respect to the focal length of the first lens group G1 in order to ensure a sufficient zoom ratio and achieve good optical performance. If the upper limit value of the conditional expression (5) is exceeded, the refractive power of the first lens group G1 becomes strong, and the spherical aberration at the telephoto end is significantly deteriorated. Further, the deterioration of lateral chromatic aberration at the wide-angle end becomes remarkable, which is not preferable. In addition, the effect of this application can be made more reliable by making the upper limit of conditional expression (5) 0.16. On the other hand, if the lower limit of conditional expression (5) is not reached, the refractive power of the second lens group G2 becomes strong, and it becomes difficult to correct off-axis aberrations at the wide-angle end, particularly field curvature and astigmatism. In addition, the effect of this application can be made more reliable by setting the lower limit of conditional expression (5) to 0.14.

  In such a variable magnification optical system ZL, it is desirable that the second lens group G2 includes a negative lens, a negative lens, a positive lens, and a negative lens in order from the object side. With this configuration, it is possible to simultaneously correct curvature of field at the wide-angle end and spherical aberration at the telephoto end.

  In such a variable magnification optical system ZL, it is preferable that at least one surface of the second lens group G2 is formed in an aspherical shape. With this configuration, it is possible to satisfactorily correct curvature of field and distortion at the wide angle end.

  Further, such a variable magnification optical system ZL moves an image at the time of focusing by moving at least a part of the second lens group G2 in the optical axis direction when focusing from an infinitely distant object to a close object. The change in the magnitude of the aberration can be suppressed, and aberration fluctuations such as spherical aberration can be satisfactorily suppressed.

  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.

  As described above, the optical apparatus according to the present embodiment includes the variable magnification optical system ZL having the above-described configuration, thereby ensuring image productivity and image formation due to camera shake or the like in a high-power zoom lens exceeding 7 times. An optical device having good optical performance can be realized even at the time of correcting the position displacement.

  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 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 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, the second lens group G2 is preferably a focusing lens group.

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

  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 5 to 15 times.

  Hereinafter, an outline of a method for manufacturing the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. First, the first to fifth lens groups G1 to G5 are prepared by arranging each lens (step S100). Further, upon 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. The distance between the third lens group G3 and the fourth lens group G4 is changed, and the distance between the fourth lens group G4 and the fifth lens group G5 is changed (Step S200). In addition, at least one lens component having a negative refractive power and at least two lens components having a positive refractive power are arranged in the fourth lens group G4 (step S300). Furthermore, the fourth lens group G4 is arranged so as to move so as to have a component in a direction orthogonal to the optical axis (step S400).

  Specifically, in the present embodiment, for example, as illustrated in FIG. 1, a cemented positive lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12 in order from the object side; A positive meniscus lens L13 having a convex surface facing the object side is arranged as the first lens group G1, and an aspheric surface made of plastic resin is provided on the object side surface of the negative meniscus lens having a convex surface facing the object side. The negative lens L21, the biconcave negative lens L22, and the cemented positive lens of the biconvex positive lens L23 and the biconcave negative lens L24 are arranged as the second lens group G2, and the biconvex positive A lens L31 and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33 are arranged as a third lens group G3, and the convex surface is directed to the object side with the biconcave negative lens L41. Tamen menis A negative lens L42 cemented with the lens L42, a positive meniscus lens L43 having a concave surface facing the object side, and a negative lens L44 having a biconcave shape are arranged as a fourth lens group G4, and a biconvex positive lens L51, and A cemented negative lens composed of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side is arranged as a fifth lens group G5. 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, 6 and 11 are cross-sectional views showing the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL3) according to each example. Further, in the lower part of the sectional views of these zoom optical systems ZL1 to ZL3, along the optical axes of the lens groups G1 to G5 when zooming from the wide-angle end state (W) to the telephoto end state (T) The direction of movement 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 (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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a positive refractive power.

  In the variable magnification optical system ZL1, the first lens group G1 includes, in order from the object side, a cemented positive lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and an object side. It is composed of a positive meniscus lens L13 having a convex surface. The second lens group G2 includes, in order from the object side, a negative lens L21 provided with an aspheric surface made of plastic resin on the object side surface of a negative meniscus lens having a convex surface facing the object side, and a biconcave shape. It is composed of a negative lens L22 and a cemented positive lens of a biconvex positive lens L23 and a biconcave negative lens L24. The third lens group G3 includes, in order from the object side, a biconvex positive lens L31 and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33. The fourth lens group G4 includes, in order from the object side, a cemented negative lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a positive meniscus lens L43 having a concave surface facing the object side. , And a biconcave negative lens L44. The fifth lens group G5 includes, in order from the object side, a biconvex positive lens L51, and a cemented negative lens of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side. Has been.

  In the zoom optical system ZL1 according to the first example, 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 are decreased, the distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is decreased. Each lens group from the first lens group G1 to the fifth lens group G5 moves in the object direction. The aperture stop S is disposed on the object side of the third lens group G3. The aperture stop S moves together with the third lens group G3 during zooming.

  In the variable magnification optical system ZL1 according to the first example, the second lens group G2 is moved in the object direction, thereby focusing from a long distance object to a short distance object.

  Further, the variable magnification optical system ZL1 according to the first example corrects the displacement of the imaging position due to camera shake or the like by moving the fourth lens group G4 so as to have a component in a direction orthogonal to the optical axis. To do.

  Note that the rotational blurring at an angle θ is corrected with a lens having a focal length f of the entire system and an image stabilization coefficient (ratio of image movement amount on the imaging surface with respect to the movement amount of the image stabilization lens group in shake correction). For this purpose, the image stabilizing lens group for blur correction may be moved in the direction orthogonal to the optical axis by (f · tan θ) / K (the same applies to the following embodiments). At the wide-angle end of the variable magnification optical system ZL1 according to the first example, the image stabilization coefficient is 1.24 and the focal length is 18.5 mm, so that the rotational blur of 0.60 ° is corrected. The moving amount of the fourth lens group G4 is 0.16 mm. In the telephoto end state of the variable magnification optical system ZL1, the image stabilization coefficient is 1.92, and the focal length is 136.0 mm. Therefore, the fourth lens group for correcting rotational blur of 0.20 °. The moving amount of G4 is 0.25 mm.

  Table 1 below lists values of specifications of the variable magnification optical system ZL1 according to the first example. In Table 1, f in the overall specifications represents the focal length of the entire system, FNO represents the F number, 2ω represents the angle of view, Ymax represents the maximum image height, 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. 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 nd and the fifth column νd are the refractive index and Abbe number for the d-line (λ = 587.6 nm). Is shown. Further, the radius of curvature ∞ indicates a plane, and the refractive index of air 1.000 is omitted. The surface numbers 1 to 31 shown in Table 1 correspond to the numbers 1 to 31 shown in FIG. The lens group focal length indicates the start surface and the focal length of each of the first to fifth lens groups G1 to G5.

  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]
Scaling ratio = 7.35
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.5 to 70.0 to 136.0
FNO = 3.56 to 5.18 to 5.88
2ω = 78.08-22.20-11.62
Ymax = 14.25 to 14.25 to 14.25
TL = 141.18-175.74-194.15

[Lens data]
m r d nd νd
Object ∞
1 165.9337 2.000 1.80518 25.45
2 74.0941 6.791 1.60311 60.69
3 -1805.4947 0.100
4 67.5262 4.996 1.69680 55.52
5 219.2623 d5
6 * 131.4997 0.150 1.55389 38.23
7 124.1768 1.200 1.80610 40.97
8 14.7597 6.125
9 -48.3234 1.000 1.80610 40.97
10 41.2910 0.450
11 28.4554 5.321 1.84666 23.78
12 -38.5790 1.000 1.77250 49.62
13 103.0192 d13
14 ∞ 0.400 Aperture stop S
15 64.5025 2.927 1.48749 70.31
16 -27.8285 0.100
17 23.4616 3.786 1.59319 67.90
18 -23.4616 1.000 1.75520 27.57
19 169.5634 d19
20 -27.3498 1.180 1.77250 49.62
21 20.1424 3.000 1.85026 32.35
22 350.0000 0.427
23 -59.8514 2.400 1.75520 27.57
24 -22.9656 0.437
25 -57.8291 1.000 1.80610 40.97
26 99.9153 d26
27 210.0736 4.074 1.54814 45.79
28 -25.2251 0.400
29 70.0000 6.482 1.48749 70.31
30 -17.4469 1.300 1.90366 31.27
31 -59.0034 BF
Image plane ∞

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 103.913
Second lens group 6 -15.743
Third lens group 15 25.032
Fourth lens group 20 -35.382
5th lens group 27 42.223

  In the variable magnification optical system ZL1 according to the first example, the sixth surface is formed in an aspherical 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
6th surface 5.0810 4.73610E-06 -3.55497E-08 1.27803E-10 -2.40032E-13

  In the variable magnification optical system ZL1 according to the first example, the axial air gap d5 between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group G3 (aperture stop S), and On-axis air distance d13, on-axis air distance d19 between third lens group G3 and fourth lens group G4, on-axis air distance d26 between fourth lens group G4 and fifth lens group G5, and back focus BF As described above, changes during zooming. Table 3 below shows the values of the variable interval and the back focus 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 and focusing on a short distance. The back focus BF indicates the distance on the optical axis from the most image side lens surface (the 31st surface in FIG. 1) to the image surface I. This description is the same in the following embodiments.

(Table 3)
[Variable interval data]
Infinity focusing state Short-distance focusing state Wide-angle end Intermediate Telephoto end Wide-angle end Intermediate Telephoto end f 18.5 70.0 136.0 18.5 70.0 136.0
d5 2.469 36.815 53.332 1.858 36.253 52.398
d13 29.227 8.810 3.108 29.838 9.371 4.041
d19 2.250 9.276 11.640 2.250 9.276 11.640
d26 10.790 3.764 1.400 10.790 3.764 1.400
BF 38.40 59.03 66.62 38.40 59.03 66.62

  Table 4 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL1 according to the first example. In Table 4, rNR1 is the radius of curvature of the most object-side surface of the lens component closest to the object among the lens components having negative refractive power constituting the fourth lens group G4, and rP2R2 is the fourth Among the lens components having positive refractive power constituting the lens group G4, the radius of curvature of the surface closest to the image side of the lens component closest to the image side, and nP1 constitutes a cemented lens included in the fourth lens group G4. The refractive index with respect to the d-line of the medium of the positive meniscus lens, nN1 is the refractive index with respect to the d-line of the medium of the biconcave lens constituting the cemented lens included in the fourth lens group G4, and νN is included in the fourth lens group G4. The Abbe number of the medium of the biconcave lens constituting the cemented lens, νP1 the Abbe number of the medium of the positive meniscus lens constituting the cemented lens included in the fourth lens group G4, and f1 of the first lens group G1. The focal length, f2 represents the focal length of the second lens group G2, and f4 represents the focal length of the fourth lens group G4. The description of the above symbols is the same in the following embodiments. In this first embodiment, rNR1 is the value of the 20th surface, and rP2R2 is the value of the 24th surface.

(Table 4)
[Conditional value]
(1) rNR1 / rP2R2 = 1.191
(2) nP2-nN = 0.078
(3) νN−νP2 = 17.27
(4) f4 / f2 = 2.248
(5) (−f2) /f1=0.152

  Thus, the variable magnification optical system ZL1 according to the first example satisfies all the conditional expressions (1) to (5).

  FIG. 2 (a) shows various aberration diagrams of the variable magnification optical system ZL1 according to the first example when focused at infinity in the wide-angle end state, and performs blur correction for rotational blur of 0.60 °. FIG. 2 (b) shows the coma aberration diagram at this time, FIG. 3 shows the various aberration diagrams in the intermediate focus processing state, and FIG. 4 (a) shows the various aberration diagrams at the infinite focus in the telephoto end state. FIG. 4 (b) shows a coma aberration diagram when blur correction is performed with respect to rotational blur of 0.20 °, and FIG. 5 (b) shows various aberrations when focusing at a short distance, and FIG. FIG. 5 (b) shows the intermediate focal length state, and FIG. 5 (c) shows the telephoto end state. In each aberration diagram, FNO represents an F number, NA represents a numerical aperture, and Y represents an image height. The spherical aberration diagram shows the F-number or numerical aperture 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, the variable magnification optical system ZL1 according to the first example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state. It can be seen that the imaging performance is excellent even when the imaging position displacement is corrected by camera shake or the like during focusing.

[Second Embodiment]
FIG. 6 is a diagram illustrating a configuration of the variable magnification optical system ZL2 according to the second example. The zoom optical system ZL2 shown in FIG. 6 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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a positive refractive power.

  In the variable magnification optical system ZL2, the first lens group G1 includes, in order from the object side, a cemented positive lens of a negative meniscus lens L11 having a convex surface directed toward the object side and a biconvex positive lens L12, and an object side. It is composed of a positive meniscus lens L13 having a convex surface. The second lens group G2 includes, in order from the object side, a negative lens L21 provided with an aspheric surface made of plastic resin on the object side surface of a negative meniscus lens having a convex surface facing the object side, and a biconcave shape. The lens includes a negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. The third lens group G3 includes, in order from the object side, a biconvex positive lens L31 and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33. The fourth lens group G4 includes, in order from the object side, a cemented negative lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a positive meniscus lens L43 having a concave surface facing the object side. , And a biconcave negative lens L44. The fifth lens group G5 includes, in order from the object side, a biconvex positive lens L51, and a cemented negative lens of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side. Has been.

  In the variable magnification optical system ZL2 according to the second example, 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 are decreased, the distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is decreased. Each lens group from the first lens group G1 to the fifth lens group G5 moves in the object direction. The aperture stop S is disposed on the object side of the third lens group G3. The aperture stop S moves together with the third lens group G3 during zooming.

  In the variable magnification optical system ZL2 according to the second example, focusing from a long-distance object to a short-distance object is performed by moving the second lens group G2 in the object direction.

  The variable magnification optical system ZL2 according to the second example corrects the displacement of the imaging position due to camera shake or the like by moving the fourth lens group G4 so as to have a component in a direction orthogonal to the optical axis. To do. At the wide-angle end of the variable magnification optical system ZL2 according to the second example, the image stabilization coefficient is 1.25 and the focal length is 18.5 mm, so that a 0.60 degree rotation blur is corrected. Therefore, the movement amount of the fourth lens group G4 is 0.16 mm. In the telephoto end state of the variable magnification optical system ZL1, the image stabilization coefficient is 1.92, and the focal length is 136.0 mm. Therefore, the fourth lens group for correcting rotational blur of 0.20 °. The moving amount of G4 is 0.25 mm.

  Table 5 below lists values of specifications of the variable magnification optical system ZL2 according to the second example. The surface numbers 1 to 32 shown in Table 5 correspond to the numbers 1 to 32 shown in FIG.

(Table 5) Second Example [Overall Specifications]
Scaling ratio = 7.35
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.5 to 70.0 to 136.0
FNO = 3.54 to 5.18 to 5.88
2ω = 78.08-22.12-11.58
Ymax = 14.25 to 14.25 to 14.25
TL = 141.12-176.28-194.32

[Lens data]
m r d nd νd
Object ∞
1 160.3894 2.000 1.80518 25.45
2 71.1064 7.020 1.60311 60.69
3 -1504.5988 0.100
4 68.0566 4.980 1.69680 55.52
5 242.6179 d5
6 * 299.0828 0.150 1.55389 38.23
7 191.1066 1.200 1.80610 40.97
8 15.2384 5.720
9 -58.1090 1.000 1.80610 40.97
10 40.4666 0.410
11 27.0680 5.880 1.84666 23.78
12 -27.0680 0.200
13 -24.8824 1.000 1.80610 40.97
14 88.6415 d14
15 ∞ 0.400 Aperture stop S
16 75.4172 2.900 1.48749 70.31
17 -25.8556 0.100
18 22.8159 3.850 1.59319 67.90
19 -22.8159 1.000 1.75520 27.57
20 180.3601 d20
21 -25.6336 1.180 1.77250 49.62
22 21.0308 3.000 1.85026 32.35
23 330.0000 0.570
24 -50.0551 2.400 1.75520 27.57
25 -21.4578 0.260
26 -57.0337 1.000 1.80610 40.97
27 131.3468 d27
28 130.0000 4.550 1.54814 45.79
29 -25.9651 0.400
30 70.0000 6.620 1.48749 70.31
31 -17.8064 1.300 1.90366 31.27
32 -64.1559 BF
Image plane ∞

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 100.517
Second lens group 6 -14.920
Third lens group 16 24.356
Fourth lens group 21 -35.145
5th lens group 28 41.678

  In the variable magnification optical system ZL2 according to the second example, the sixth surface is 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
6th surface 5.0810 7.21463E-06 -2.08543E-08 4.94093E-11 -2.04372E-14

  In the variable magnification optical system ZL2 according to the second example, the axial air gap d5 between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group G3 (aperture stop S), and On-axis air distance d14, on-axis air distance d20 between third lens group G3 and fourth lens group G4, on-axis air distance d27 between fourth lens group G4 and fifth lens group G5, and back focus BF As described above, changes during zooming. Table 7 below shows the values of the variable interval and the back focus 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 and focusing on a short distance.

(Table 7)
[Variable interval data]
Infinity focusing state Short-distance focusing state Wide-angle end Intermediate Telephoto end Wide-angle end Intermediate Telephoto end f 18.5 70.0 136.0 18.5 70.0 136.0
d5 2.572 35.975 51.850 2.019 35.460 50.990
d14 27.155 8.471 3.191 27.708 8.986 4.051
d20 2.300 9.818 12.283 2.300 9.818 12.283
d27 11.474 3.956 1.491 11.474 3.956 1.491
BF 38.43 58.88 66.31 38.43 58.88 66.31

  Table 8 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL2 according to the second example. In this second embodiment, rNR1 is the value of the 21st surface, and rP2R2 is the value of the 25th surface.

(Table 8)
[Conditional value]
(1) rNR1 / rP2R2 = 1.195
(2) nP2-nN = 0.078
(3) νN−νP2 = 17.27
(4) f4 / f2 = 2.356
(5) (−f2) /f1=0.148

  Thus, the zoom optical system ZL2 according to the second example satisfies all the conditional expressions (1) to (5).

  FIG. 7A shows various aberration diagrams of the variable magnification optical system ZL2 according to the second example when focused at infinity in the wide-angle end state. FIG. 7 (b) shows the coma aberration diagram at this time, FIG. 8 shows the various aberration diagrams in the intermediate focus processing state, and FIG. 9 (a) shows the various aberration diagrams at the infinite focus in the telephoto end state. FIG. 9 (b) shows a coma aberration diagram when blur correction is performed with respect to 0.20 ° rotational blur. FIG. 9 (b) shows various aberration diagrams when focusing on a short distance, and FIG. FIG. 10 (b) shows the intermediate focal length state, and FIG. 10 (c) shows the telephoto end state. From these respective aberration diagrams, the variable magnification optical system ZL2 according to the second example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state. It can be seen that the imaging performance is excellent even when the imaging position displacement is corrected by camera shake or the like during focusing.

[Third embodiment]
FIG. 11 is a diagram illustrating a configuration of the variable magnification optical system ZL3 according to the third example. The zoom optical system ZL3 shown in FIG. 11 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 first lens group having a positive refractive power. The third lens group G3 includes a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a positive refractive power.

  In the variable magnification optical system ZL3, the first lens group G1 includes, in order from the object side, a cemented positive lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and an object side. It is composed of a positive meniscus lens L13 having a convex surface. The second lens group G2 includes, in order from the object side, a negative lens L21 provided with an aspheric surface made of plastic resin on the object side surface of a negative meniscus lens having a convex surface facing the object side, and a biconcave shape. The lens includes a negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. The third lens group G3 includes, in order from the object side, a biconvex positive lens L31 and a cemented positive lens of a biconvex positive lens L32 and a biconcave negative lens L33. The fourth lens group G4 includes, in order from the object side, a cemented negative lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a positive meniscus lens L43 having a concave surface facing the object side. , And a biconcave negative lens L44. The fifth lens group G5 includes, in order from the object side, a biconvex positive lens L51, and a cemented negative lens of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side. Has been.

  In the zoom optical system ZL3 according to the third example, the distance between the first lens group G1 and the second lens group G2 increases during zooming from the wide-angle end state to the telephoto end state, and the second lens group G2 And the third lens group G3 are decreased, the distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is decreased. Each lens group from the first lens group G1 to the fifth lens group G5 moves in the object direction. The aperture stop S is disposed on the object side of the third lens group G3. The aperture stop S moves together with the third lens group G3 during zooming.

  In the variable magnification optical system ZL3 according to the third example, focusing from a long-distance object to a short-distance object is performed by moving the second lens group G2 in the object direction.

  The variable magnification optical system ZL3 according to the third example corrects the displacement of the imaging position due to camera shake or the like by moving the fourth lens group G4 so as to have a component in a direction orthogonal to the optical axis. To do. At the wide-angle end of the variable magnification optical system ZL3 according to the third example, the image stabilization coefficient is 1.26 and the focal length is 18.5 mm, so that a 0.60 degree rotation blur is corrected. Therefore, the moving amount of the fourth lens group G4 is 0.15 mm. In the telephoto end state of the variable magnification optical system ZL1, the image stabilization coefficient is 1.92, and the focal length is 136.0 mm. Therefore, the fourth lens group for correcting rotational blur of 0.20 °. The moving amount of G4 is 0.25 mm.

  Table 9 below provides values of specifications of the variable magnification optical system ZL3 according to the third example. The surface numbers 1 to 32 shown in Table 9 correspond to the numbers 1 to 32 shown in FIG.

(Table 9) Third Example [Overall Specifications]
Scaling ratio = 7.35
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.5 to 70.0 to 136.0
FNO = 3.57 to 5.18 to 5.88
2ω = 78.06-22.16-11.58
Ymax = 14.25 to 14.25 to 14.25
TL = 141.15-176.17-194.26

[Lens data]
m r d nd νd
Object ∞
1 155.4660 2.000 1.80518 25.45
2 70.2015 6.920 1.60311 60.69
3 -3550.8733 0.100
4 68.2181 5.000 1.69680 55.52
5 247.2368 d5
6 * 170.6214 0.150 1.55389 38.23
7 135.4820 1.200 1.80610 40.97
8 15.0687 5.900
9 -52.2858 1.000 1.80610 40.97
10 41.1795 0.450
11 27.8892 5.790 1.84666 23.78
12 -27.8892 0.200
13 -25.5581 1.000 1.80610 40.97
14 104.6205 d14
15 ∞ 0.400 Aperture stop S
16 79.4438 2.910 1.48749 70.31
17 -26.4039 0.100
18 23.0807 3.850 1.59319 67.90
19 -23.0807 1.000 1.75520 27.57
20 249.8639 d20
21 -26.0884 1.180 1.77250 49.62
22 20.8038 3.000 1.85026 32.35
23 240.7989 0.560
24 -49.4113 2.400 1.75520 27.57
25 -21.3466 0.260
26 -55.7885 1.000 1.80610 40.97
27 153.4116 d27
28 201.6612 4.140 1.54814 45.51
29 -25.5537 0.400
30 56.9736 6.620 1.48749 70.31
31 -18.2556 1.300 1.90366 31.27
32 -74.4491 BF
Image plane ∞

[Lens focal length]
Lens group Start surface Focal length First lens group 1 101.356
Second lens group 6 -15.090
Third lens group 16 24.336
Fourth lens group 21 -35.418
5th lens group 28 42.783

  In the variable magnification optical system ZL3 according to the third example, the sixth surface is formed in an aspherical shape. Table 10 below shows the aspheric data, that is, the values of the conic constant K and the aspheric constants A4 to A10.

(Table 10)
[Aspherical data]
K A4 A6 A8 A10
6th surface 5.0810 6.10878E-06 -1.89829E-08 3.66056E-11 -4.16035E-15

  In the variable magnification optical system ZL3 according to the third example, the axial air distance d5 between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group G3 (aperture stop S), and On-axis air distance d14, on-axis air distance d20 between third lens group G3 and fourth lens group G4, on-axis air distance d27 between fourth lens group G4 and fifth lens group G5, and back focus BF As described above, changes during zooming. Table 11 below shows the values of the variable interval and the back focus 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 and focusing on a short distance.

(Table 11)
[Variable interval data]
Infinity focusing state Short-distance focusing state Wide-angle end Intermediate Telephoto end Wide-angle end Intermediate Telephoto end f 18.5 70.0 136.0 18.5 70.0 136.0
d5 2.375 36.135 52.084 1.811 35.609 51.211
d14 27.791 8.542 3.106 28.355 9.068 3.978
d20 2.280 9.437 11.860 2.280 9.437 11.860
d27 11.517 4.360 1.937 11.517 4.360 1.937
BF 38.35 58.86 66.45 38.35 58.86 66.45

  Table 12 below shows values corresponding to the conditional expressions in the variable magnification optical system ZL3 according to the third example. In this third embodiment, rNR1 is the value of the 21st surface, and rP2R2 is the value of the 25th surface.

(Table 12)
[Conditional value]
(1) rNR1 / rP2R2 = 1.222
(2) nP2-nN = 0.078
(3) νN−νP2 = 17.27
(4) f4 / f2 = 2.347
(5) (−f2) /f1=0.149

  Thus, the variable magnification optical system ZL3 according to the third example satisfies all the conditional expressions (1) to (5).

  FIG. 12A shows various aberration diagrams of the variable magnification optical system ZL3 according to the third example at the time of focusing on infinity in the wide-angle end state. FIG. 12 (b) shows the coma aberration diagram at this time, FIG. 13 shows the various aberration diagrams in the intermediate focus processing state, and FIG. 14 (a) shows the various aberration diagrams at the infinite focus in the telephoto end state. FIG. 14 (b) shows a coma aberration diagram when blur correction is performed with respect to 0.20 ° rotational blur, and FIG. 15 (b) shows various aberrations when focusing at a short distance, and FIG. FIG. 15B shows the intermediate focal length state, and FIG. 15C shows the telephoto end state. From these respective aberration diagrams, the variable magnification optical system ZL3 according to the third example has excellent imaging performance by satisfactorily correcting various aberrations from the wide-angle end state to the telephoto end state. It can be seen that the imaging performance is excellent even when the imaging position displacement is corrected by camera shake or the like during focusing.

DESCRIPTION OF SYMBOLS 1 Camera (optical apparatus) ZL (ZL1-ZL3) Variable magnification optical system G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group

Claims (14)

From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
Substantially consisting of five lens groups with a fifth lens group having positive refractive power,
During 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, the distance between the fourth lens group and the fifth lens group changes,
The fourth lens group includes at least one lens component having a negative refractive power and at least one lens component having a positive refractive power;
Moving the fourth lens group to have a component in a direction perpendicular to the optical axis ;
A variable magnification optical system characterized by satisfying the following condition:
1.191 ≦ rNR1 / rP2R2 <1.50
However,
rNR1: radius of curvature of the most object-side surface of the lens component closest to the object among the lens components having the negative refractive power constituting the fourth lens group
rP2R2: radius of curvature of the most image-side surface of the lens component having the positive refractive power that constitutes the fourth lens group , and the lens component is a single lens or a cemented lens Show. From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
Substantially consisting of five lens groups with a fifth lens group having positive refractive power,
During 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, the distance between the fourth lens group and the fifth lens group changes,
The fourth lens group includes at least one lens component having a negative refractive power and at least one lens component having a positive refractive power;
The fourth lens group includes a cemented lens in which a biconcave lens and a positive meniscus lens having a convex surface facing the object side are cemented,
Moving the fourth lens group to have a component in a direction perpendicular to the optical axis ;
A variable magnification optical system characterized by satisfying the following condition:
10.0 <νN−νP1 <25.0
However,
νN: Abbe number of the medium of the biconcave lens constituting the cemented lens
νP1: Abbe number of the medium of the positive meniscus lens constituting the cemented lens The lens component represents a single lens or a cemented lens. From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
Substantially consisting of five lens groups with a fifth lens group having positive refractive power,
During 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, the distance between the fourth lens group and the fifth lens group changes,
The fourth lens group includes at least one lens component having a negative refractive power and at least one lens component having a positive refractive power;
The fourth lens group includes a cemented lens in which a biconcave lens and a positive meniscus lens having a convex surface facing the object side are cemented,
Moving the fourth lens group to have a component in a direction perpendicular to the optical axis ;
A variable magnification optical system characterized by satisfying the following condition:
1.80 <f4 / f2 <2.80
However,
f4: focal length of the fourth lens group
f2: Focal length of the second lens group The lens component indicates a single lens or a cemented lens. From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having negative refractive power;
Substantially consisting of five lens groups with a fifth lens group having positive refractive power,
During 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, the distance between the fourth lens group and the fifth lens group changes,
The fourth lens group includes at least one lens component having a negative refractive power and at least one lens component having a positive refractive power;
The fourth lens group includes a cemented lens in which a biconcave lens and a positive meniscus lens having a convex surface facing the object side are cemented,
Moving the fourth lens group to have a component in a direction perpendicular to the optical axis ;
A variable magnification optical system characterized by satisfying the following condition:
0.11 <(− f2) / f1 <0.19
However,
f2: Focal length of the second lens group
f1: Focal length of the first lens group The lens component indicates a single lens or a cemented lens. 2. The variable magnification optical system according to claim 1 , wherein the fourth lens group includes a cemented lens in which a biconcave lens and a positive meniscus lens having a convex surface directed toward the object side are cemented. 5. The variable magnification optical system according to claim 2, wherein a condition of the following formula is satisfied.
0.90 <rNR1 / rP2R2 <1.50
However,
rNR1: radius of curvature of the most object side surface of the lens component closest to the object side among the lens components having the negative refractive power constituting the fourth lens group rP2R2: the positive constituting the fourth lens group Radius of curvature of the most image-side surface of the lens component closest to the image among lens components having a refractive power of The zoom lens system according to any one of claims 2 to 6, wherein a condition of the following formula is satisfied.
0.00 <nP1-nN1 <0.20
However,
nP1: Refractive index with respect to d-line of the medium of the positive meniscus lens constituting the cemented lens nN1: Refractive index with respect to d-line of the medium of the biconcave lens constituting the cemented lens The zoom optical system according to any one of claims 1 to 7 , wherein the first lens unit moves in the object direction during zooming from the wide-angle end state to the telephoto end state. 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 increases, the distance between the second lens group and the third lens group decreases, the third lens distance between the second lens group increases the group, in any one of claims 1-8, wherein the distance between the fourth lens group and said fifth lens group and said reducing The variable power optical system described.   The variable power optical system according to claim 1, wherein the second lens group includes a negative lens, a negative lens, a positive lens, and a negative lens in order from the object side.   The variable power optical system according to any one of claims 1 to 10, wherein at least one surface of the second lens group is formed in an aspherical shape.   The zooming according to any one of claims 1 to 11, wherein at least a part of the second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance. Optical system.   An optical apparatus comprising the variable magnification optical system according to claim 1. In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a negative refractive power A method of manufacturing a variable magnification optical system comprising substantially five lens groups of a group and a fifth lens group having a positive refractive power,
During 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 is changed, and the distance between the fourth lens group and the fifth lens group is changed.
A lens component having at least one negative refractive power and at least one lens component having a positive refractive power are disposed in the fourth lens group;
The fourth lens group is arranged to move so as to have a component in a direction orthogonal to the optical axis ,
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 .
1.191 ≦ rNR1 / rP2R2 <1.50
However,
rNR1: radius of curvature of the most object-side surface of the lens component closest to the object among the lens components having the negative refractive power constituting the fourth lens group
rP2R2: the radius of curvature of the surface closest to the image side of the lens component closest to the image side among the lens components having the positive refractive power constituting the fourth lens group
The lens component indicates a single lens or a cemented lens.

Images