JP5344279B2 - Zoom lens, optical apparatus having the same, and zooming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens in which a camera shake is corrected by performing image-shifting by an optical system that is movable so as to have components perpendicular to the optical axis, the refractive power of each lens group is appropriately set so as to achieve high variable magnification and reduce performance deterioration, to provide an optical device having the zoom lens, and to provide a method for varying magnification. <P>SOLUTION: The zoom lens includes in order from the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of negative refractive power, and a fifth lens group G5 of positive refractive power, wherein at least a lens group GA as a part of the fourth lens group G4 is moved so as to have components perpendicular to the optical axis, and distances between the respective lens groups are changed during variable magnification from a wide angle end state to a telephoto end state, an when the focal length of the first lens group G1 is denoted as f1, the focal length of the fourth lens group G4 is denoted as f4, the zoom lens satisfies the condition of the following inequality: 3.45&lt;f1/(-f4)&lt;6.00. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a zoom lens, an optical apparatus having the same, and a zooming method.

Conventionally, zoom lenses having a camera shake correction function suitable for photographic cameras, electronic still cameras, video cameras, and the like have been proposed (see, for example, Patent Document 1).
JP 2006-227526 A

  However, in the conventional zoom lens, a mechanism for correcting camera shake must be incorporated in the lens barrel, and the compactness tends to be lost in the overall length and outer diameter of the lens barrel. In addition, a zoom lens having a camera shake correction function has a problem that optical performance is significantly deteriorated when zooming is performed at a high magnification.

  The present invention has been made in view of such a problem, and performs image shift by an optical system that can move so as to have a component orthogonal to the optical axis, enables camera shake correction, and achieves high zooming. An object of the present invention is to provide a zoom lens in which the refractive power of an appropriate lens group is set so as to reduce the deterioration of performance while aiming, an optical apparatus having the zoom lens, and a zooming method.

In order to achieve such an object, the zoom lens of the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refraction arranged in order from the object side. A third lens group having a power, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. At least a part of the lens groups is moved so as to have a component orthogonal to the optical axis, and the distance between the lens groups changes upon zooming from the wide-angle end state to the telephoto end state. The focal length of the first lens group Is f1, the focal length of the fourth lens group is f4, the focal length of the second lens group is f2, and the focal length f3 of the third lens group is 3.45 <f1 / ( -f4) <6.00, 0.65 ≦ < (- f2) / (- f4 It satisfies the conditions of ≦ 0.78 and 3.50 <f1 / f3 <4.60.
The zoom lens according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power, arranged in order from the object side. And a fourth lens group having negative refracting power and a fifth lens group having positive refracting power, and substantially consisting of five lens groups, and at least a part of the lens groups of the fourth lens group is When the zoom lens is moved so as to have a component orthogonal to the optical axis, the distance between the lens groups changes upon zooming from the wide-angle end state to the telephoto end state, the focal length of the first lens group is f1, and the fourth When the focal length of the lens group is f4, the focal length of the second lens group is f2, and the focal length of the third lens group is f3, the following expression 3.45 <f1 / (− f4) <6.00 0.56 ≦ <(− f2) / (− f4) ≦ 0.78 and 4.14 ≦ To satisfy the conditions of 1 / f3 ≦ 4.31.
The zoom lens according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power, which are arranged in order from the object side. And a fourth lens group having negative refracting power and a fifth lens group having positive refracting power, and substantially consisting of five lens groups, and at least a part of the lens groups of the fourth lens group is The zoom lens is moved so as to have a component orthogonal to the optical axis, and the distance between the lens groups changes upon zooming from the wide-angle end state to the telephoto end state. The third lens group includes at least three positive lenses. The fourth lens group includes a lens group GA having negative refractive power arranged in order from the object side, and a lens group GB having a negative refractive power disposed adjacent to the image side of the lens group GA. the a, a focal length of the first lens group and f1, the fourth When the focal length of the lens group and a f4, the following formula 3.45 <f1 / (- f4) is satisfied <6.00 condition.

When the focal length of the second lens group is f2 and the focal length of the fourth lens group is f4, the following condition 0.45 <(− f2) / (− f4) <1.25 is satisfied. It is preferable to do.

The third lens group preferably includes at least three positive lenses .

The fourth lens group includes a lens group GA having negative refractive power arranged in order from the object side, and a lens group GB having a negative refractive power arranged adjacent to the image side of the lens group GA. It is preferable to have .

Further, when the focal length of the first lens unit is f1 and the focal length of the third lens unit is f3, it is preferable that the following expression 3.50 <f1 / f3 <4.60 is satisfied .

Further, when the focal length of the fourth lens group is f4 and the focal length is ft in the telephoto end state of the entire lens system, the following expression 0.01 <(− f4) / ft <0.20 is satisfied. It is preferable.

Further, 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 increases, and the distance between the second lens group and the third lens group decreases. Preferably, the distance between the third lens group and the fourth lens group is increased, and the distance between the fourth lens group and the fifth lens group is decreased .

The fourth lens group preferably has at least one aspheric surface .

The fourth lens group preferably has a cemented lens .

Further, when the back focus in the telephoto end state is Bft, the back focus in the wide-angle end state is Bfw, and the focal length in the telephoto end state of the entire lens system is f3, the following expression 1.35 <(Bft−Bfw) / It is preferable to satisfy the condition of f3 <1.80 .

Further, when the focal length of the fifth lens unit is f5 and the focal length in the telephoto end state of the entire lens system is ft, the following expression 0.05 <f5 / ft <0.35 is satisfied. preferable.

The second lens group preferably has at least one aspheric surface .

  An optical apparatus according to the present invention includes the zoom lens.

The zoom lens zooming method according to the present invention includes 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, which are arranged in order from the object side. A zoom lens zooming method comprising substantially five lens groups by a lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power, At least a part of the four lens groups is moved so as to have a component orthogonal to the optical axis, and the distance between the lens groups changes upon zooming from the wide-angle end state to the telephoto end state. When the focal length of the group is f1, the focal length of the fourth lens group is f4, the focal length of the second lens group is f2, and the focal length f3 of the third lens group is 3.45, <f1 / (- f4) < 6.00, 0.65 ≦ <(- f2) (-F4) satisfies the conditions of ≦ 0.78 and 3.50 <f1 / f3 <4.60.

  According to the present invention, image shift is performed by an optical system that can move so as to have a component orthogonal to the optical axis, image stabilization is possible, and it is appropriate to reduce performance deterioration while achieving high zooming. It is possible to provide a zoom lens in which the refractive power of various lens groups is set, an optical apparatus having the same, and a zooming method.

  Hereinafter, preferred embodiments will be described with reference to the drawings. As shown in FIG. 1, the zoom lens according to the present embodiment includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive lens arranged in order from the object side. A third lens group G3 having a refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power; and at least a part of the fourth lens group G4. Image plane correction at the time of occurrence of camera shake is performed by moving the lens group so as to have a component orthogonal to the optical axis.

  The fourth lens group G4 is suitable for incorporating a camera shake correction mechanism because the number of constituent lenses is small compared to other lens groups and the lens diameter can be reduced. Accordingly, it is possible to reduce the size of the lens barrel, and it is possible to satisfactorily correct aberration fluctuations accompanying camera shake correction.

  Based on the above configuration, when the focal length of the first lens group G1 is f1, and the focal length of the fourth lens group G4 is f4, it is preferable that the condition of the following formula (1) is satisfied.

  3.45 <f1 / (− f4) <6.00 (1)

  The conditional expression (1) defines the focal length f4 of the fourth lens group G4 with respect to the focal length f1 of the first lens group G1. The zoom lens satisfies the conditional expression (1), so that a predetermined zoom ratio can be ensured while ensuring optical performance during camera shake correction. If the upper limit value of the conditional expression (1) is exceeded, the refractive power of the fourth lens group G4 becomes strong, and it is possible to simultaneously correct the fluctuation of the field curvature and the fluctuation of the eccentric coma at the time of camera shake correction. It becomes difficult. On the other hand, if the lower limit of conditional expression (1) is not reached, the refractive power of the first lens group G1 becomes strong, and it becomes difficult to correct spherical aberration in the telephoto end state. Further, the deterioration of lateral chromatic aberration in the wide-angle end state becomes remarkable, which is not preferable.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (1) to 3.55. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (1) to 5.54.

  In the present embodiment, when the focal length of the fourth lens group G4 is f4 and the focal length is ft in the telephoto end state of the entire lens system, it is preferable that the condition of the following expression (2) is satisfied.

  0.01 <(− f4) / ft <0.20 (2)

  Conditional expression (2) defines the focal length f4 of the fourth lens group G4 with respect to the focal length ft in the telephoto end state. The present zoom lens can achieve a good optical performance by satisfying the conditional expression (2), and can secure a predetermined zoom ratio. If the upper limit value of conditional expression (2) is exceeded, the refractive power of the fourth lens group G4 becomes weak, the shift amount of the fourth lens group G4 increases, and the fluctuation of astigmatism during camera shake correction is corrected. It becomes difficult. On the other hand, if the lower limit of conditional expression (2) is not reached, the refractive power of the fourth lens group G4 becomes strong, and it becomes difficult to correct spherical aberration in the telephoto end state.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (2) to 0.05. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (2) to 0.13.

  In the present embodiment, 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 increases, and the second lens group G2 and the third lens group G3 Preferably, 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. As a result, it is possible to ensure a predetermined zoom ratio while effectively correcting variations in spherical aberration and field curvature.

  In the present embodiment, it is preferable that the fourth lens group G4 includes the lens group GA having negative refractive power and the lens group GB having negative refractive power, which are arranged in order from the object side. As a result, it is possible to simultaneously correct the variation in curvature of field at the time of camera shake correction in the telephoto end state and the variation in eccentric coma.

  In the present embodiment, it is preferable that the fourth lens group G4 has at least one aspheric surface. As a result, it is possible to simultaneously correct the variation in curvature of field at the time of camera shake correction in the telephoto end state and the variation in eccentric coma.

  In the present embodiment, it is preferable that the fourth lens group G4 includes a cemented lens. With this configuration, axial and lateral chromatic aberration can be corrected well.

  In the present embodiment, when the focal length of the second lens group G2 is f2, and the focal length f4 of the fourth lens group G4 is satisfied, it is preferable that the condition of the following expression (3) is satisfied.

  0.45 <(− f2) / (− f4) <1.25 (3)

  Conditional expression (3) defines the focal length f4 of the fourth lens group G4 with respect to the focal length f2 of the second lens group G2. This zoom lens can achieve good optical performance by satisfying conditional expression (3). If the upper limit value of the conditional expression (3) is exceeded, the refractive power of the fourth lens group G4 becomes strong, and it is possible to simultaneously correct the fluctuation of the curvature of field and the fluctuation of the eccentric coma at the time of camera shake correction. It becomes difficult. On the other hand, if the lower limit of conditional expression (3) is not reached, the refractive power of the second lens group G2 becomes strong, and it becomes difficult to correct off-axis aberrations, particularly field curvature and astigmatism in the wide-angle end state.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (3) to 0.53. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (3) to 1.00.

  In this embodiment, when the back focus in the telephoto end state is Bft, the back focus in the wide-angle end state is Bfw, and the focal length in the telephoto end state of the entire lens system is f3, the condition of the following equation (4) Is preferably satisfied.

  1.35 <(Bft−Bfw) / f3 <1.80 (4)

  Conditional expression (4) defines the focal length f3 of the third lens group G3 with respect to the difference between the back focus Bft in the telephoto end state and the back focus Bfw in the wide angle end state. The zoom lens can satisfy the conditional expression (4) to realize good optical performance and to secure a predetermined zoom ratio. If the upper limit of conditional expression (4) is exceeded, the refractive power of the third lens group G3 becomes strong, and it becomes difficult to correct spherical aberration in the telephoto end state. On the other hand, if the lower limit value of conditional expression (4) is not reached, the refractive powers of the first lens group G1 and the second lens group G2 become stronger, and correction of higher-order coma aberration variation that occurs from the wide-angle end state to the telephoto end state is corrected. It becomes difficult.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (4) to 1.40. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (4) to 1.65.

  In the present embodiment, it is preferable that the condition of the following expression (5) is satisfied, where f5 is the focal length of the fifth lens group G5 and ft is the focal length in the telephoto end state of the entire lens system.

  0.05 <f5 / ft <0.35 (5)

  Conditional expression (5) defines the focal length ft in the telephoto end state with respect to the focal length f5 of the fifth lens group G5. The present zoom lens can achieve good optical performance by satisfying the conditional expression (5), and can ensure a predetermined zoom ratio. If the upper limit value of the conditional expression (5) is exceeded, the refractive power of the fifth lens group G5 becomes weak, the refractive power of the third lens group G3 becomes strong in order to secure the zoom ratio, and in the telephoto end state. Correction of spherical aberration becomes difficult. On the other hand, if the lower limit of conditional expression (5) is not reached, the refractive power of the fifth lens group G5 becomes strong, and it becomes difficult to correct coma in the wide-angle end state.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (5) to 0.10. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (5) to 0.21.

  In the present embodiment, when the focal length of the first lens group G1 is f1, and the focal length f3 of the third lens group G3 is satisfied, it is preferable that the condition of the following expression (6) is satisfied.

  3.50 <f1 / f3 <4.60 (6)

  The conditional expression (6) defines the focal length f3 of the third lens group G3 with respect to the focal length f1 of the first lens group G1. The present zoom lens can realize good optical performance by satisfying the conditional expression (6), and can also perform color correction more effectively. If the upper limit value of conditional expression (6) is exceeded, the refractive power of the third lens group G3 becomes strong, and it becomes difficult to correct coma aberration in the wide-angle end state and spherical aberration in the telephoto end state. Further, the deterioration of the imaging performance due to a manufacturing error becomes remarkable. On the other hand, if the lower limit of conditional expression (6) is not reached, the refractive power of the first lens group G1 will become strong, and it will be difficult to correct lateral chromatic aberration.

  In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (6) to 4.00. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (6) to 4.40.

  In the present embodiment, it is preferable that the third lens group G3 and the fifth lens group G5 move together when zooming from the wide-angle end state to the telephoto end state. As a result, it is possible to reduce the deterioration in performance due to the eccentricity of the fifth lens group G5 at the time of manufacture while ensuring a predetermined zoom ratio.

  In the present embodiment, it is preferable that the second lens group G2 has an aspherical surface. Thereby, it is possible to satisfactorily correct field curvature and distortion in the wide-angle end state.

  In the present embodiment, it is preferable that the third lens group G3 includes at least three positive lenses. Thereby, the field curvature in the wide-angle end state and the spherical aberration in the telephoto end state can be corrected simultaneously.

  FIG. 13 is a schematic cross-sectional view of a digital single-lens reflex camera CAM (optical apparatus) provided with the zoom lens having the above configuration as a photographing lens 1. In the digital single-lens reflex camera CAM shown in FIG. 13, light from an object (subject) (not shown) is collected by the taking lens 1 and focused on the focusing screen 4 via the quick return mirror 3. The light imaged on the focusing screen 4 is reflected a plurality of times in the pentaprism 5 and guided to the eyepiece lens 6. Thus, the photographer can observe the object (subject) image as an erect image through the eyepiece 6.

  Further, when a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and light of an object (subject) (not shown) condensed by the photographing lens 1 is captured on the image sensor 7. Form an image. Thereby, the light from the object (subject) is captured by the image sensor 7 and recorded as an object (subject) image in a memory (not shown). In this way, the photographer can photograph an object (subject) with the camera CAM. Note that the camera CAM illustrated in FIG. 10 may hold the photographic lens 1 in a detachable manner, or may be formed integrally with the photographic lens 1. The camera CAM may be a so-called single-lens reflex camera or a compact camera that does not have a quick return mirror or the like.

  Hereinafter, each example according to the present embodiment will be described with reference to the drawings. Tables 1 to 3 are shown below, but these are tables of specifications in the first to third examples. In [Overall specifications], f is the focal length of the entire lens system, FNO is the F number, ω is the half field angle, Y is the image height, TL is the total length of the lens system, and Bf is the back focus. In [Lens data], the surface number is the order of the lens surfaces from the object side along the direction in which the light beam travels, r is the radius of curvature of each lens surface, and d is the next optical surface from each optical surface (or The distance between the surfaces, which is the distance on the optical axis to the image plane), nd is the refractive index for the d-line (wavelength 587.6 nm), and νd is the Abbe number for the d-line. When the lens surface is aspherical, an asterisk is attached to the surface number, and the paraxial radius of curvature is indicated in the column of the radius of curvature r. The radius of curvature “0.0000” indicates a plane or an opening. In [variable interval data], f indicates the focal length of the entire lens system, and Di (where i is an integer) indicates the variable surface interval of the i-th surface. In [Lens Group Data], the initial surface and focal length of each group are shown. In [Conditional Expression Corresponding Value], values corresponding to the conditional expressions (1) to (6) are shown.

In [Aspherical data], the shape of the aspherical surface shown in [Lens data] is shown by the following equation (a). That is, y is the height in the direction perpendicular to the optical axis, and S (y) is the distance (sag amount) along the optical axis from the tangent plane at the apex of the aspheric surface to the position on the aspheric surface at height y. When the radius of curvature of the reference spherical surface (paraxial radius of curvature) is r, the conic coefficient is κ , and the n-th aspherical coefficient is An, the following equation (a) is given. In each example, the secondary aspheric coefficient A2 is 0, and the description thereof is omitted. Further, En represents × 10 ^n. For example, 1.234E-05 = 1.234 × 10 ⁻⁵ .

S (y) = (y ² / r) / {1+ (1− κ · y ² / r ² ) ^1/2 } + A 3 × | y ³ |
^{+ A4 × y 4 + A6 ×} y 6 + A8 × y 8 + A10 × y 10 + A12 × y 12 ... (a)

  In the table, “mm” is generally used as the unit of focal length f, radius of curvature r, surface interval d, and other lengths. However, since the optical system can obtain the same optical performance even when proportionally enlarged or proportionally reduced, the unit is not limited to “mm”, and other appropriate units can be used.

  The description of the above table is the same in other examples, and the description thereof is omitted.

(First embodiment)
A first embodiment will be described with reference to FIGS. FIG. 1 shows a lens configuration diagram and zoom locus of the first embodiment. As shown in FIG. 1, the zoom lens according to the first example includes a first lens group G1 having a positive refractive power and a second lens having a negative refractive power, which are arranged in order from the object side along the optical axis. It has a lens group G2, 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.

  The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having a convex surface facing the object side. Have.

  The second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative meniscus having a concave surface directed toward the object side. And a lens L24. The negative meniscus lens L21 located closest to the object side of the second lens group G2 is an aspheric lens in which an aspheric surface is formed on the glass lens surface on the object side (sixth surface counted from the object side in FIG. 1). It is.

  The third lens group G3 includes, in order from the object side, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32 and a biconcave negative lens L33, and a negative meniscus lens L34 having a convex surface facing the object side. It has a cemented lens with a biconvex positive lens L35.

  The fourth lens group G4 is arranged in order from the object side, the fourth A lens group GA composed of a cemented lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a concave surface facing the object side. And a fourth B lens group GB composed of a negative meniscus lens L43. The negative meniscus lens L43 of the fourth B lens group GB is an aspheric lens in which an aspheric surface is formed on the glass lens surface on the object side (the 27th surface counted from the object side in FIG. 1).

  The fifth lens group G5 is composed of a biconvex positive lens L51, a cemented lens composed of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side, and a concave surface facing the object side. Negative meniscus lens L54. The negative meniscus lens L54 located on the most image side of the fifth lens group G5 has an aspherical surface (the 34th surface counted from the object side in FIG. 1) on the object-side glass lens surface. It is.

  In the zoom lens according to the present embodiment having the above-described configuration, 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 increases, and the second lens group G2 and the second lens group The distance between the third lens 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. The distance between the lens groups changes.

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

  In the zoom lens according to the present embodiment, focusing from a long distance to a short distance is performed by extending the second lens group G2 in the object direction.

  In addition, camera shake correction (anti-vibration) is performed by moving the 4A lens group GA so as to have a component orthogonal to the optical axis.

  In the first embodiment, in a lens in which the focal length of the entire lens system is f, and the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in blur correction, that is, the image stabilization coefficient is K. In order to correct the rotational shake at the angle θ, the moving lens group for shake correction may be moved by (f · tan θ) / K so as to have a component orthogonal to the optical axis. In the first embodiment at the wide-angle end state, the image stabilization coefficient is 0.89 and the focal length is 28.8 (mm). Therefore, the fourth lens group G4 for correcting the rotational blur of 0.58 °. The amount of movement is 0.33 (mm). Further, in the telephoto end state of the first embodiment, since the image stabilization coefficient is 1.50 and the focal length is 292.0 (mm), the fourth lens for correcting the rotation blur of 0.18 °. The movement amount of the group G4 is 0.62 (mm).

  Table 1 below shows values of various specifications of the zoom lens according to the first example. In addition, the surface numbers 1-35 in Table 1 respond | correspond to the surfaces 1-35 shown in FIG.

(Table 1)
[Overall specifications]
f 28.8 95.2 292.0
Fno 3.6 5.5 6.0
2 ω 76.6 24.5 8.2
Y 21.6 21.6 21.6
TL 156.032 198.835 229.227
Bf 38.462 61.654 76.605
[Lens data]
Surface number r d nd νd
1 138.8204 1.000 1.85026 32.35
2 69.6255 9.900 1.49782 82.52
3 -1121.4726 0.100 1.00000
4 66.5234 6.500 1.60300 65.47
5 364.2280 D5 1.00000
* 6 77.5565 0.101 1.55389 38.09
7 69.1985 1.003 1.80400 46.58
8 17.7505 7.303 1.00000
9 -45.2772 1.000 1.81600 46.63
10 64.3914 0.149 1.00000
11 34.6940 4.700 1.84666 23.77
12 -46.1405 1.178 1.00000
13 -27.3129 1.000 1.81600 46.63
14 -2388.7913 D14 1.00000
15 0.0000 0.500 1.00000 (Aperture S)
16 240.3547 2.700 1.61800 63.38
17 -48.3097 0.100 1.00000
18 32.2344 4.000 1.60300 65.47
19 -65.8684 1.000 1.85026 32.35
20 163.3971 0.300 1.00000
21 28.9156 1.500 1.85026 32.35
22 16.0863 5.700 1.51680 64.12
23 -90.6196 D23 1.00000
24 -353.6058 1.000 1.77250 49.61
25 13.7394 2.967 1.80 100 34.96
26 49.7586 5.375 1.00000
* 27 -18.4961 1.000 1.72916 54.66
28 -30.5221 D28 1.00000
29 258.3375 5.299 1.51680 64.12
30 -21.7751 0.100 1.00000
31 71.6589 6.791 1.51823 58.89
32 -19.3953 1.000 1.81600 46.63
33 -37.1560 1.917 1.00000
* 34 -22.1994 1.000 1.79668 45.34
35 -69.8232 Bf 1.00000
[Aspherical data]
6th surface κ = 4.881, A4 = 5.5213E-07, A6 = -3.4799E-09, A8 = -1.0831E-11,
A10 = 8.3083E-14, A12 = 0.0000E + 00
27th surface κ = 0.6133, A4 = 3.3743E-06, A6 = 1.0271E-08, A8 = 0.0000E + 00,
A10 = 0.0000E + 00, A12 = 0.0000E + 00
34th surface κ = 0.8088, A4 = -6.7721E-06, A6 = 1.4720E-08, A8 = -2.0115E-11,
A10 = 0.0000E + 00, A12 = 0.0000E + 00
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state
D5 2.025 37.999 65.479
D14 29.610 13.247 1.208
D23 2.683 7.326 8.459
D28 7.070 2.427 1.293
[Lens group data]
Group number Group first surface Group focal length G1 1 112.11
G2 6 -17.38
G3 16 25.99
G4 24 -30.94
G5 29 51.56
[Conditional expression values]
Conditional expression (1) f1 / (− f4) = 3.62
Conditional expression (2) (-f4) /ft=0.11
Conditional expression (3) (− f2) / (− f4) = 0.56
Conditional expression (4) (Bft−Bfw) /f3=1.47
Conditional expression (5) f5 / ft = 0.18
Conditional expression (6) f1 / f3 = 4.31

  From the table of specifications shown in Table 1, it can be seen that the zoom lens according to Example 1 satisfies all the conditional expressions (1) to (6).

  FIGS. 2A and 2B are diagrams illustrating various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the first example and blur correction for 0.58 ° rotational blur. It is a meridional transverse aberration diagram at the time. FIG. 3 is a diagram illustrating various aberrations when the zoom lens according to Example 1 is focused at infinity in the intermediate focal length state. FIGS. 4A and 4B are diagrams illustrating various aberrations at the time of focusing on infinity in the telephoto end state of the zoom lens according to the first example and blur correction with respect to a rotational shake of 0.18 °. It is a meridional transverse aberration diagram at the time.

  In each aberration diagram, FNO represents an F number, and Y represents an image height (unit: mm). The spherical aberration diagram shows the F-number value corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum image height, and the coma diagram shows the value of each image height. Further, d indicates various aberrations with respect to the d-line (wavelength 587.6 nm), g indicates various aberrations with respect to the g-line (wavelength 435.8 nm), and those not described indicate various aberrations with respect to the d-line. In the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. The explanation of the above aberration diagrams is the same in the other examples, and the explanation is omitted.

  As is apparent from the respective aberration diagrams, in the first example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Second embodiment)
A second embodiment will be described with reference to FIGS. FIG. 5 shows a lens configuration diagram and zoom locus of the second embodiment. As shown in FIG. 5, the zoom lens according to the second example includes a first lens group G1 having a positive refractive power and a second lens having a negative refractive power, which are arranged in order from the object side along the optical axis. It has a lens group G2, 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.

  The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having a convex surface facing the object side. Have.

  The second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative meniscus having a concave surface directed toward the object side. And a lens L24. The negative meniscus lens L21 located closest to the object side in the second lens group G2 is an aspherical lens in which an aspheric surface is formed on the glass lens surface on the object side (sixth surface counted from the object side in FIG. 5). .

  The third lens group G3 includes, in order from the object side, a biconvex positive lens L31, a cemented lens of a biconvex positive lens L32 and a biconcave negative lens L33, and a negative meniscus lens L34 having a convex surface facing the object side. It has a cemented lens with a biconvex positive lens L35.

  The fourth lens group G4 is arranged in order from the object side, the fourth A lens group GA composed of a cemented lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a concave surface facing the object side. And a fourth B lens group GB composed of a negative meniscus lens L43. The negative meniscus lens L43 of the fourth B lens group GB is an aspheric lens in which an aspheric surface is formed on the glass lens surface on the object side (the 26th surface counted from the object side in FIG. 5).

  The fifth lens group G5 is composed of a biconvex positive lens L51, a cemented lens composed of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side, and a concave surface facing the object side. Negative meniscus lens L54. The negative meniscus lens L54 located closest to the image side of the fifth lens group G5 is an aspherical lens having an aspherical surface formed on the glass lens surface on the object side (the 33rd surface counted from the object side in FIG. 5). .

  In the zoom lens according to the present embodiment having the above-described configuration, 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 increases, and the second lens group G2 and the second lens group The distance between the third lens 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. The distance between the lens groups changes.

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

  In the zoom lens according to the present embodiment, focusing from a long distance to a short distance is performed by extending the second lens group G2 in the object direction.

  In addition, camera shake correction (anti-vibration) is performed by moving the 4A lens group GA so as to have a component orthogonal to the optical axis.

  In the second embodiment, in the lens in which the focal length of the entire lens system is f, and the ratio of the image movement amount on the imaging surface to the movement amount of the moving lens group in blur correction, that is, the image stabilization coefficient is K. In order to correct the rotational shake at the angle θ, the moving lens group for shake correction may be moved by (f · tan θ) / K so as to have a component orthogonal to the optical axis. In the wide-angle end state of the second embodiment, since the image stabilization coefficient is 0.98 and the focal length is 28.8 (mm), the fourth lens group G4 for correcting the rotational blur of 0.58 °. The amount of movement is 0.30 (mm). Further, in the telephoto end state of the second embodiment, since the image stabilization coefficient is 1.70 and the focal length is 292.0 (mm), the fourth lens for correcting the rotation blur of 0.18 °. The movement amount of the group G4 is 0.54 (mm).

  Table 2 below shows values of various specifications of the zoom lens according to the second example. The surface numbers 1 to 34 in Table 2 correspond to the surfaces 1 to 34 shown in FIG.

(Table 2)
[Overall specifications]
f 28.8 100.0 291.9
Fno 3.6 5.4 5.9
2 ω 76.3 23.4 8.2
Y 21.6 21.6 21.6
TL 157.869 204.116 230.852
Bf 38.668 65.898 78.377
[Lens data]
Surface number r d nd νd
1 124.2669 1.000 1.85026 32.35
2 65.6300 10.060 1.49782 82.56
3 -11797.766 0.100 1.00000
4 69.1189 6.568 1.59319 67.87
5 585.6642 D5 1.00000
* 6 112.8410 1.000 1.76684 46.82
7 17.9479 7.242 1.00000
8 -46.5542 1.000 1.81600 46.63
9 66.1042 0.100 1.00000
10 34.8030 4.801 1.84666 23.77
11 -39.9905 1.014 1.00000
12 -27.6099 1.000 1.83481 42.72
13 1177.0768 D13 1.00000
14 0.0000 0.500 1.00000 (Aperture S)
15 45.9090 3.500 1.75500 52.29
16 -58.7912 0.100 1.00000
17 35.0034 4.500 1.49782 82.56
18 -35.3849 1.000 1.79504 28.69
19 65.2580 0.100 1.00000
20 28.8329 1.871 1.81600 46.63
21 15.4357 6.462 1.51742 52.32
22 -87.3182 D22 1.00000
23 -117.6399 1.000 1.77250 49.61
24 16.7518 3.000 1.85026 32.35
25 51.4655 4.628 1.00000
* 26 -24.4461 1.200 1.71300 53.89
27 -58.2076 D27 1.00000
28 73.1770 5.500 1.60311 60.68
29 -24.7896 0.166 1.00000
30 91.8843 6.791 1.51823 58.89
31 -18.6935 1.000 1.81600 46.63
32 -48.9134 1.917 1.00000
* 33 -24.2966 1.000 1.82080 42.71
34 -56.3780 Bf 1.00000
[Aspherical data]
6th surface κ = -1.000, A4 = 1.2946E-06, A6 = 6.9345E-09, A8 = -7.3236E-11,
A10 = 2.8299E-13, A12 = -2.9971E-16
26th surface κ = 0.1763, A4 = -1.5504E-06, A6 = 1.8584E-08, A8 = 0.0000E + 00,
A10 = 0.0000E + 00, A12 = 0.0000E + 00
33rd surface κ = 1.000, A4 = -4.8013E-06, A6 = -2.8757E-09, A8 = 8.0066E-11,
A10 = -2.4817E-13, A12 = 0.0000E + 00
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state
D5 2.226 38.148 64.584
D13 31.000 14.096 1.917
D22 1.523 5.269 6.049
D27 6.332 2.586 1.806
[Lens group data]
Group number Group first surface Group focal length G1 1 110.62
G2 6 -17.76
G3 15 26.64
G4 23 -27.33
G5 28 41.87
[Conditional expression values]
Conditional expression (1) f1 / (− f4) = 4.03
Conditional expression (2) (-f4) /ft=0.09
Conditional expression (3) (− f2) / (− f4) = 0.65
Conditional expression (4) (Bft−Bfw) /f3=1.49
Conditional expression (5) f5 / ft = 0.14
Conditional expression (6) f1 / f3 = 4.14

  From the table of specifications shown in Table 2, it can be seen that the zoom lens according to Example 2 satisfies all the conditional expressions (1) to (6).

  6A and 6B are diagrams illustrating various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to Example 2 and blur correction with respect to a rotational shake of 0.58 °. It is a meridional transverse aberration diagram at the time. FIG. 7 is a diagram illustrating various aberrations when the zoom lens according to Example 2 is focused at infinity in the intermediate focal length state. FIGS. 8A and 8B are diagrams illustrating various aberrations at the time of focusing on infinity in the telephoto end state of the zoom lens according to the second example and blur correction for 0.18 ° rotational shake. It is a meridional transverse aberration diagram at the time.

  As is apparent from the respective aberration diagrams, in the second example, it is understood that various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

(Third embodiment)
A third embodiment will be described with reference to FIGS. 9 to 12 and Table 3. FIG. FIG. 9 shows a lens configuration diagram and zoom locus of the third embodiment. As shown in FIG. 9, the zoom lens according to the third example includes a first lens group G1 having a positive refractive power arranged in order from the object side along the optical axis, and a second lens having a negative refractive power. It has a lens group G2, 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.

  The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having a convex surface facing the object side. Have.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative meniscus having a concave surface directed toward the object side. And a lens L24. The negative meniscus lens L21 located closest to the object side of the second lens group G2 is an aspheric lens having an aspheric surface formed on the glass lens surface on the object side (sixth surface counted from the object side in FIG. 9). It is.

  The third lens group G3 includes a biconvex positive lens L31, a biconvex positive lens L32, a negative meniscus lens L33 having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side, which are arranged in order from the object side. And a cemented lens with L34.

The fourth lens group G4 is arranged in order from the object side, the fourth A lens group GA composed of a cemented lens of a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side, and a concave surface facing the object side. And a fourth B lens group GB composed of a negative meniscus lens L43 . The negative meniscus lens L43 constituting the fourth B lens group GB is an aspherical lens in which an aspherical surface is formed on the image side glass lens surface (27th surface counted from the object side in FIG. 9). .

The fifth lens group G5 is composed of a biconvex positive lens L51, a cemented lens composed of a biconvex positive lens L52 and a negative meniscus lens L53 having a concave surface facing the object side, and a concave surface facing the object side. Negative meniscus lens L54. The negative meniscus lens L54 located closest to the image side of the fifth lens group G5 is an aspherical lens in which an aspherical surface is formed on the image side glass lens surface (the 34th surface counted from the object side in FIG. 9).

  In the zoom lens according to the present embodiment having the above-described configuration, 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 increases, and the second lens group G2 and the second lens group The distance between the third lens 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. The distance between the lens groups changes.

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

  In the zoom lens according to the present embodiment, focusing from a long distance to a short distance is performed by extending the second lens group G2 in the object direction.

  In addition, camera shake correction (anti-vibration) is performed by moving the 4A lens group GA so as to have a component orthogonal to the optical axis.

  In the third embodiment, in a lens in which the focal length of the entire lens system is f, and the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in blur correction, that is, the image stabilization coefficient is K. In order to correct the rotational shake at the angle θ, the moving lens group for shake correction may be moved by (f · tan θ) / K so as to have a component orthogonal to the optical axis. In the third embodiment, in the wide-angle end state, the image stabilization coefficient is 1.06, and the focal length is 28.8 (mm). Therefore, the fourth lens group G4 for correcting the rotation blur of 0.58 °. The amount of movement is 0.27 (mm). Further, in the telephoto end state of the third embodiment, since the image stabilization coefficient is 1.70 and the focal length is 291.8 (mm), the fourth lens for correcting the rotation blur of 0.18 °. The movement amount of the group G4 is 0.48 (mm).

Table 3 below shows values of various specifications of the zoom lens according to the third example. The surface numbers 1 to 34 in Table 3 correspond to the surfaces 1 to 34 shown in FIG.

(Table 3)
[Overall specifications]
f 28.8 97.8 291.8
Fno 3.6 5.4 5.9
2 ω 76.3 24.0 8.2
Y 21.6 21.6 21.6
TL 155.259 200.892 230.440
Bf 38.296 61.715 79.010
[Lens data]
Surface number r d nd νd
1 131.9600 1.000 1.85026 32.35
2 64.7763 10.026 1.49782 82.52
3 -1939.8917 0.100 1.00000
4 64.6003 6.329 1.61800 63.38
5 410.2657 D5 1.00000
* 6 89.4836 0.100 1.55389 38.09
7 89.4836 1.000 1.81600 46.63
8 17.9244 7.340 1.00000
9 -42.0840 1.000 1.81600 46.63
10 73.2932 0.100 1.00000
11 36.7795 4.691 1.84666 23.78
12 -39.1344 1.214 1.00000
13 -26.1074 1.000 1.81600 46.63
14 -3773.9951 D14 1.00000
15 0.0000 0.500 1.00000 (Aperture S)
16 224.1127 2.598 1.69680 55.52
17 -66.2510 0.100 1.00000
18 30.7404 3.300 1.49782 82.56
19 -2017.6973 0.100 1.00000
20 27.5622 1.000 1.84666 23.78
21 16.0865 5.531 1.51680 64.12
22 1640.3102 D22 1.00000
23 -254.1339 1.000 1.81600 46.63
24 15.9374 3.355 1.85026 32.35
25 45.3566 5.500 1.00000
26 -20.8777 1.000 1.81600 46.63
* 27 -53.9758 D27 1.00000
28 67.5729 6.000 1.51860 69.89
29 -20.5166 4.000 1.00000
30 47.4864 7.500 1.51742 52.32
31 -20.4408 1.500 1.81600 46.63
32 -56.8501 1.619 1.00000
33 -33.4116 1.000 1.81600 46.63
* 34 -130.4172 Bf 1.00000
[Aspherical data]
6th surface κ = 8.332, A4 = 1.1402E-06, A6 = 5.3964E-10, A8 = -2.3261E-11,
A10 = 1.0349E-13, A12 = 0.0000E + 00
27th surface κ = -3.0393, A4 = 4.0455E-06, A6 = -5.4765E-09, A8 = 2.7129E-11,
A10 = 0.0000E + 00, A12 = 0.0000E + 00
34th surface κ = 0.181, A4 = -1.3072E-06, A6 = 5.5840E-09, A8 = -8.7610E-11,
A10 = 2.5603E-13, A12 = 0.0000E + 00
[Variable interval data]
Wide-angle end state Intermediate focal length state Telephoto end state
D5 2.325 38.632 62.363
D14 26.770 12.676 1.198
D22 2.836 6.232 7.367
D27 5.530 2.134 1.000
[Lens group data]
Group number Group first surface Group focal length G1 1 107.36
G2 6 -16.98
G3 16 25.15
G4 23 -21.73
G5 28 32.44
[Conditional expression values]
Conditional expression (1) f1 / (− f4) = 4.94
Conditional expression (2) (-f4) /ft=0.07
Conditional expression (3) (-f2) / (-f4) = 0.78
Conditional expression (4) (Bft−Bfw) /f3=1.62
Conditional expression (5) f5 / ft = 0.11
Conditional expression (6) f1 / f3 = 4.27

  From the table of specifications shown in Table 3, it can be seen that the zoom lens according to Example 3 satisfies all the conditional expressions (1) to (6).

  FIGS. 10A and 10B are diagrams illustrating various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to Example 3 and blur correction with respect to a rotational shake of 0.58 °. It is a meridional transverse aberration diagram at the time. FIG. 11 is a diagram illustrating various aberrations when the zoom lens according to Example 3 is focused at infinity in the intermediate focal length state. FIGS. 12A and 12B are graphs showing various aberrations at the time of focusing on infinity in the telephoto end state of the zoom lens according to Example 3 and blur correction for 0.18 ° rotational shake. It is a meridional transverse aberration diagram at the time.

  As is apparent from the respective aberration diagrams, in the third example, it is understood that various aberrations are well corrected in each focal length state from the wide-angle end state to the telephoto end state, and excellent imaging performance is obtained.

  In the above-described embodiment, the following description can be appropriately adopted as long as the optical performance is not impaired.

  In the above embodiment, the five-group configuration is shown, but the present invention 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 is a portion having at least one lens separated by an air interval that changes during zooming.

  In addition, 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. 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, it is preferable that at least a part of the second lens group G2 is a focusing lens group.

  In addition, the lens group or the partial lens group is moved so as to have a component in a direction perpendicular to the optical axis, or is rotated (swayed) in the in-plane direction including the optical axis to reduce image blur caused by camera shake. An image stabilizing lens group to be corrected may be used. The movement may be rotational movement (swing) with a certain point on the optical axis as the rotation center. In particular, it is preferable that at least a part of the third lens group G3 or the fourth lens group G4 is an anti-vibration lens group.

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

  The aperture stop S is preferably arranged in the vicinity of the third lens group G3 or the fourth lens group G4. However, the role of the aperture stop may be substituted by a lens frame without providing a member as an aperture stop. . In particular, the aperture stop S is more preferably on the object side of the third lens group G3.

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

  The zoom lens (variable magnification optical system) of the present embodiment has a magnification ratio of 5 to 18 times, more preferably 8 to 12 times.

  In the zoom lens (variable magnification optical system) of the present embodiment, it is preferable that the first lens group G1 has two positive lenses and one negative lens. In the first lens group G1, it is preferable to dispose the lenses in order of negative / positive from the object side.

  In the zoom lens (variable magnification optical system) of the present embodiment, it is preferable that the second lens group G2 has one positive lens and three negative lenses. In the second lens group G2, it is preferable that lens components are arranged in order of negative, negative, positive and negative in order from the object side with an air gap interposed therebetween.

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

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

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

  In addition, in order to make this invention intelligible, although demonstrated with the component requirement of embodiment, it cannot be overemphasized that this invention is not limited to this.

It is a figure which shows the structure of a lens system and zoom locus | trajectory based on 1st Example. (A) and (b) are diagrams showing various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the first example and when blur correction is performed for 0.58 ° rotational blur. It is a meridional lateral aberration diagram. FIG. 5 is a diagram illustrating various aberrations when the zoom lens according to Example 1 is in focus at infinity in the intermediate focal length state. (A) and (b) are graphs showing various aberrations during focusing on infinity in the telephoto end state of the zoom lens according to the first example, and meridional when blurring is corrected for 0.18 ° rotational blur. It is a lateral aberration diagram. It is a figure which shows the structure of a lens system and zoom locus | trajectory based on 2nd Example. (A) and (b) are diagrams showing various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the second example and when shake correction is performed with respect to a rotational shake of 0.58 °. It is a meridional lateral aberration diagram. FIG. 12 is a diagram illustrating various aberrations when the zoom lens according to Example 2 is focused at infinity in the intermediate focal length state. FIGS. 9A and 9B are graphs showing various aberrations when focusing at infinity in the telephoto end state of the zoom lens according to the second example. It is a meridional lateral aberration diagram. It is a figure which shows the structure of a lens system and zoom locus | trajectory based on 3rd Example. FIGS. 9A and 9B are graphs showing various aberrations at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the third example and when shake correction is performed with respect to a rotational shake of 0.58 °. It is a meridional lateral aberration diagram. FIG. 11 is a diagram illustrating various aberrations when the zoom lens according to Example 3 is in focus at infinity in the intermediate focal length state. FIGS. 9A and 9B are diagrams showing various aberrations at the time of focusing on infinity in the telephoto end state of the zoom lens according to the third example, and are obtained when shake correction is performed for a rotational shake of 0.18 °. It is a meridional lateral aberration diagram. It is a schematic sectional view of a digital single-lens reflex camera CAM (optical device) provided with the zoom lens having the above configuration as a photographing lens.

Explanation of symbols

G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group
GA 4A lens group GB 4B lens group G5 5th lens group S Aperture stop I Image surface CAM Digital SLR camera

Claims (16)

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 first lens group having a negative refractive power, arranged in order from the object side. The lens group is substantially composed of five lens groups by four lens groups and a fifth lens group having a positive refractive power,
Moving at least a part of the fourth lens group so as to have a component orthogonal to the optical axis;
When zooming from the wide-angle end state to the telephoto end state, the distance between the lens groups changes,
When the focal length of the first lens group is f1, the focal length of the fourth lens group is f4, the focal length of the second lens group is f2, and the focal length f3 of the third lens group is Formula 3.45 <f1 / (− f4) <6.00
0.65 ≦ <(− f2) / (− f4) ≦ 0.78
3.50 <f1 / f3 <4.60
A zoom lens that satisfies the following conditions. 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 first lens group having a negative refractive power, arranged in order from the object side. The lens group is substantially composed of five lens groups by four lens groups and a fifth lens group having a positive refractive power,
Moving at least a part of the fourth lens group so as to have a component orthogonal to the optical axis;
When zooming from the wide-angle end state to the telephoto end state, the distance between the lens groups changes,
When the focal length of the first lens group is f1, the focal length of the fourth lens group is f4, the focal length of the second lens group is f2, and the focal length f3 of the third lens group is Formula 3.45 <f1 / (− f4) <6.00
0.56 ≦ <(− f2) / (− f4) ≦ 0.78
4.14 ≦ f1 / f3 ≦ 4.31
A zoom lens that satisfies the following conditions. 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 first lens group having a negative refractive power, arranged in order from the object side. The lens group is substantially composed of five lens groups by four lens groups and a fifth lens group having a positive refractive power,
Moving at least a part of the fourth lens group so as to have a component orthogonal to the optical axis;
When zooming from the wide-angle end state to the telephoto end state, the distance between the lens groups changes,
The third lens group includes at least three positive lenses,
The fourth lens group includes a lens group GA having negative refractive power, which is arranged in order from the object side, and a lens group GB which is disposed adjacent to the image side of the lens group GA and has negative refractive power. Have
When the focal length of the first lens group is f1, and the focal length of the fourth lens group is f4, the following expression 3.45 <f1 / (− f4) <6.00
A zoom lens that satisfies the following conditions. When the focal length of the second lens group is f2 and the focal length of the fourth lens group is f4, the following formula 0.45 <(− f2) / (− f4) <1.25
The zoom lens according to claim 3 , wherein the following condition is satisfied. The third lens group, a zoom lens according to claim 1 or 2, characterized in that it comprises at least three positive lenses. The fourth lens group includes a lens group GA having negative refractive power, which is arranged in order from the object side, and a lens group GB which is disposed adjacent to the image side of the lens group GA and has negative refractive power. the zoom lens according to claim 1 or 2, characterized in that it has. When the focal length of the first lens unit is f1 and the focal length of the third lens unit is f3, the following formula 3.50 <f1 / f3 <4.60
The zoom lens according to claim 3 , wherein the following condition is satisfied. When the focal length of the fourth lens group is f4 and the focal length ft in the telephoto end state of the entire lens system is 0.01 <(− f4) / ft <0.20
The zoom lens according to any one of claims 1 to 7, characterized by satisfying the condition. 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 distance between the third lens and the fourth lens group and group increases, in any one of claims 1-8, wherein the distance between the fourth lens group and the fifth lens group is characterized by a decrease The described zoom lens. The fourth lens group, the zoom lens according to any one of claims 1 to 9, characterized in that it has at least one aspherical surface. The fourth lens group, the zoom lens according to any one of claims 1 to 10, characterized in that it has a cemented lens. When the back focus in the telephoto end state is Bft, the back focus in the wide-angle end state is Bfw, and the focal length in the telephoto end state of the entire lens system is f3, the following expression 1.35 <(Bft−Bfw) / f3 < 1.80
The zoom lens according to any one of claims 1 to 11, characterized by satisfying the condition. When the focal length of the fifth lens group is f5 and the focal length in the telephoto end state of the entire lens system is ft, the following expression 0.05 <f5 / ft <0.35
The zoom lens according to any one of claims 1 to 12, characterized by satisfying the condition.   The zoom lens according to claim 1, wherein the second lens group has at least one aspheric surface.   An optical apparatus comprising the zoom lens according to claim 1. 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 first lens group having a negative refractive power, arranged in order from the object side. A zoom lens zooming method comprising substantially five lens groups by four lens groups and a fifth lens group having a positive refractive power,
Moving at least a part of the fourth lens group so as to have a component orthogonal to the optical axis;
When zooming from the wide-angle end state to the telephoto end state, the distance between the lens groups changes,
When the focal length of the first lens group is f1, the focal length of the fourth lens group is f4, the focal length of the second lens group is f2, and the focal length f3 of the third lens group is Formula 3.45 <f1 / (− f4) <6.00
0.65 ≦ <(− f2) / (− f4) ≦ 0.78
3.50 <f1 / f3 <4.60
A zoom lens zooming method characterized by satisfying the following conditions:

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