JP5040358B2 - Zoom lens and optical apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens and an optical device having the same.

Conventionally, zoom lenses used in electronic still cameras have been proposed (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 5-60971 JP-A-11-295594

  The conventional zoom lens has a problem that the telephoto ratio in the telephoto end state is large and the total length is long, and the chromatic aberration in the telephoto imaging region is large.

In order to solve the above problems, the present invention includes, in order from the object side, a plurality of lenses including a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group, and a fourth lens group. The second lens group includes, in order from the object side, a first negative lens of a second lens group having a concave image side surface and a second negative lens of a second lens group having a concave image side surface. And a positive meniscus lens of the second lens group having a convex object side surface, and the first lens group and the first lens group during zooming from the wide-angle end state to the telephoto end state. The gap between the two lens groups is increased, the gap between the second lens group and the third lens group is decreased, and the lens group closest to the image plane among the plurality of lens groups is projected with a locus convex toward the object side. Along the axis, the focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, Serial focal length of the second lens group F2, when said focal length of each F21 of the second negative lens of the first negative lens and the second lens group in the second lens group, F22, satisfies the following conditions Provide a zoom lens characterized by things.
3.000 <F1 / Fw <4.400
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65

In the present invention, in order from the object side, a plurality of lens groups including a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group, and a fourth lens group are provided. The second lens group includes, in order from the object side, a first negative lens of a second lens group having a concave image side surface, a second negative lens of a second lens group having a concave image side surface, and an object side surface. A positive meniscus lens in the second lens group having a convex shape substantially consists of three lenses, the focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, and the second lens group A zoom lens zooming method satisfying the following conditions, where F2 is the focal length and F21 and F22 are the focal lengths of the first negative lens of the second lens group and the second negative lens of the second lens group, respectively. And increasing the gap between the first lens group and the second lens group, By reducing the gap between the second lens group and the third lens group, and moving the lens group closest to the image plane among the plurality of lens groups along the optical axis along a locus convex toward the object side, A zoom lens zooming method characterized in that zooming from the wide-angle end state to the telephoto end state is performed.
3.000 <F1 / Fw <4.4000
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65

In the present invention, in order from the object side, a plurality of lens groups including a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group, and a fourth lens group are provided. The second lens group includes, in order from the object side, a first negative lens of a second lens group having a concave image side surface, a second negative lens of a second lens group having a concave image side surface, and an object side surface. A positive meniscus lens in the second lens group having a convex shape is substantially composed of three lenses, and a gap between the first lens group and the second lens group upon zooming from the wide-angle end state to the telephoto end state. Increases, the gap between the second lens group and the third lens group decreases, and the lens group closest to the image plane among the plurality of lens groups moves along the optical axis along a locus convex toward the object side. The focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, and the second lens group is The focal length F2, the focal length of the second negative lens of the second lens group and the first negative lens of the second lens group and respectively F21, F22, image blur correction of the zoom lens satisfies the following conditions An image blur correction method for a zoom lens, characterized in that image blur correction is performed by moving at least a part of the third lens group in a direction perpendicular to the optical axis.
3.000 <F1 / Fw <4.4000
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65

  In addition, the present invention provides an optical device having the zoom lens.

  According to the present invention, it is possible to provide a small zoom lens having excellent optical performance, in which chromatic aberration in the telephoto imaging region is corrected, and an optical apparatus having the zoom lens.

  A zoom lens according to an embodiment of the present invention will be described.

  The zoom lens according to the embodiment includes, in order from the object side, a plurality of lens groups including a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group, and a fourth lens group. It is the structure which has.

  Further, when zooming from the wide-angle focal length to the telephoto focal length at infinity, the gap between the first lens group and the second lens group increases when zooming from the wide-angle end state to the telephoto end state. The gap between the second lens group and the third lens group decreases, and the lens group closest to the image plane among the plurality of lens groups moves along the optical axis along a locus convex toward the object side.

  To explain the above lens configuration from an optical point of view, the first lens group is a first condenser lens group, the second lens group is a variable power lens group, the third lens group is an imaging lens group, and the lens on the most image plane side. The group is a field lens group.

Further, in order to correct aberrations satisfactorily while keeping the entire length small, when the focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, and the focal length of the second lens group is F2, the following The zoom lens satisfies conditional expressions (1) and (2).
(1) 3.000 <F1 / Fw <4.4000
(2) -0.900 <F2 / Fw <-0.500

  Conditional expressions (1) and (2) are regulations for satisfactorily correcting various aberrations and achieving miniaturization. By satisfying the conditional expressions (1) and (2), it is possible to reduce the size of the zoom lens while favorably correcting curvature of field, spherical aberration, and the like.

  If the lower limit of conditional expression (1) is not reached, the variation in field curvature due to zooming becomes large, which is not preferable. If the upper limit of conditional expression (1) is exceeded, the amount of movement of the second lens group due to zooming increases. As a result, it is necessary to ensure a large air gap between the second lens group and the third lens group, so that the total lens length becomes long. In order to achieve miniaturization under these conditions, it is sufficient to increase the refractive power of the third lens group and shorten the back focus of the entire optical system, but this is not preferable because spherical aberration increases.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (1) to 3.500. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (1) to 4.360.

  If the air gap between the first lens group and the second lens group is secured in a state where the lower limit value of the conditional expression (2) is not reached, the air gap between the second lens group and the third lens group is reduced, and the telephoto end focal length is reduced. Can not be secured. Therefore, since the air space between the second lens group and the third lens group has to be increased, the total lens length becomes longer. In order to achieve miniaturization under these conditions, it is sufficient to increase the refractive power of the third lens group and shorten the back focus of the entire optical system, but this is not preferable because spherical aberration increases. If the upper limit value of conditional expression (2) is exceeded, the variation in field curvature due to zooming becomes large, which is not preferable.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (2) to −0.836. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (2) to −0.600.

  In the zoom lens according to the embodiment, it is preferable that the third lens group has a positive refractive power and the fourth lens group has a positive refractive power. By adopting such a configuration, it becomes possible to correct various aberrations and achieve high imaging performance.

  The first lens group and the second lens group greatly change the incident light height and the incident angle at the time of zooming, and thus greatly contribute to variations in spherical aberration and curvature of field during zooming.

  The third lens group preferably has an aperture stop in or near the third lens group. Since the change of the light incident height and the light incident angle is small during zooming, the contribution of various aberration fluctuations to zooming is small. However, since the image is formed by further condensing the light beam condensed by the first lens group, it has to have a strong refractive power and has a lens configuration with a small radius of curvature.

  In addition, the four lens group has a smaller incident light beam diameter for each image height, and therefore contributes more to fluctuations in field curvature than spherical aberration. In addition, in order to match a solid-state image pickup device represented by shading with a photographing optical system, the exit pupil is further moved away from the image plane on the object side.

  In the zoom lens according to the embodiment, the negative lens of the first lens group having a convex surface facing the object side and the first lens group having a convex surface facing the object side in order from the object side. A positive meniscus lens and a positive lens of the first lens group in which the curvature radius of the object side surface is smaller than 1/6 of the absolute value of the image side curvature radius are desirable.

  Since the refractive power of the first lens group is strengthened for miniaturization, high-order spherical aberration and field curvature aberration are likely to occur. In order to reduce this aberration, each surface of the first lens group has a concentric configuration with respect to the aperture stop in order to reduce the deflection angle of the light beam on each lens surface of the first lens group.

In the zoom lens according to the embodiment, in order to achieve good imaging performance, the refractive index of the negative meniscus lens of the first lens group is N11, and the positive meniscus lens of the first lens group and the first lens group are When the average refractive index of the positive lens is N1213, it is desirable that the following conditional expression (3) is satisfied.
(3) 1.00 <F1 / {Fw × (N11−N1213)} <14.0

  Conditional expression (3) is a rule for correcting aberrations satisfactorily. Satisfying conditional expression (3) makes it possible to satisfactorily correct curvature of field, chromatic aberration, and the like, and achieve high imaging performance.

  If the lower limit of conditional expression (3) is not reached, the field curvature becomes negatively large, which is not preferable. Exceeding the upper limit of conditional expression (3) is not preferable because chromatic aberration increases in the telephoto end state.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (3) to 0.50. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (3) to 12.0.

  In the zoom lens according to the embodiment, the negative meniscus lens of the first lens group and the positive meniscus lens of the first lens group are cemented, and the object side surface of the positive lens of the first lens group may have an aspherical surface. desirable.

  By joining the negative meniscus lens of the first lens group and the positive meniscus lens of the first lens group, it is possible to effectively reduce chromatic aberration in the telephoto end state. In addition, the chromatic aberration in the telephoto end state can be more effectively reduced by making the positive lens of the first lens group a low dispersion glass having an Abbe number of 75 or more. However, since the glass having an Abbe number of 75 or more has a very low refractive index, the curvature radius of the glass surface tends to be small, and a large amount of spherical aberration is generated. In order to reduce this spherical aberration, the object side surface of the positive lens in the first lens group is preferably an aspherical surface.

  In the zoom lens according to the embodiment, the second lens group includes, in order from the object side, a first negative lens of the second lens group having a concave image side surface and a second lens group having a concave image side surface. It is desirable to have a second negative lens and a positive meniscus lens of the second lens group having a convex object side surface, and any of the lens surfaces of the second lens group has an aspherical surface.

  Since the refractive power of the second lens group is increased for miniaturization, higher-order spherical aberration and field curvature aberration are likely to occur. In order to reduce this aberration, each surface of the second lens group has a concentric configuration with respect to the aperture stop in order to reduce the deflection angle of the light beam on each lens surface of the second lens group.

  However, although the lens has a strong refractive power, it has been reduced in size by reducing the number of elements in three groups to three, so the aberration variation due to zooming tends to increase, so the second lens group is configured. Any of the lens surfaces to be aspheric is corrected to increase the aberration fluctuation.

  In the zoom lens according to the embodiment, it is desirable that all the lenses of the second lens group are arranged with air interposed therebetween. By disposing each lens of the second lens group via air, various aberrations can be corrected well and high imaging performance can be achieved.

In the zoom lens according to the embodiment, when the focal lengths of the first negative lens of the second lens group and the second negative lens of the second lens group are F21 and F22, respectively, the following conditional expression (4) is satisfied. It is desirable to be satisfied.
(4) 0.05 <F21 / F22 <0.65

  Conditional expression (4) is a rule for satisfactorily correcting various aberrations and miniaturizing the zoom lens. By satisfying conditional expression (4), it is possible to satisfactorily correct aberrations such as spherical aberration and curvature of field, and achieve a compact zoom lens having high imaging performance.

  If the lower limit value of conditional expression (4) is not reached, the distance between the principal points of the first lens group and the second lens group must be increased, so the air distance between the second lens group and the third lens group decreases. However, the focal length at the telephoto end cannot be secured. Therefore, since the air space between the second lens group and the third lens group has to be increased, the total lens length becomes longer. In order to achieve miniaturization under these conditions, it is sufficient to increase the refractive power of the third lens group and shorten the back focus of the entire optical system, but this is not preferable because spherical aberration increases.

  If the upper limit value of conditional expression (4) is exceeded, the variation in field curvature due to zooming becomes large, which is not preferable.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (4) to 0.10. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (4) to 0.63.

The zoom lens according to the embodiment has an aspheric surface on the image side surface of the first negative lens in the second lens group, and includes a first negative lens in the second lens group and a second negative lens in the second lens group. When the average refractive index is N2, it is desirable that the following conditional expression (5) is satisfied.
(5) 1.810 <N2

  Conditional expression (5) is a rule for correcting aberrations satisfactorily. Satisfying conditional expression (5) makes it possible to satisfactorily correct spherical aberration, curvature of field aberration, and the like, and achieve high imaging performance.

  Deviating from the range of conditional expression (5) is not preferable because the variation in field curvature due to zooming becomes large. In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (3) to 1.825.

  Further, since the refractive power of the first negative lens of the second lens group is increased for miniaturization, higher-order spherical aberration and curvature of field are likely to occur. In order to reduce this aberration, it is preferable that the image side surface of the first negative lens of the second lens group be an aspherical surface.

In the zoom lens according to the embodiment, the lens group closest to the image plane among the plurality of lens groups has one positive lens component having an aspheric surface on the image side surface, and the refractive index of the positive lens component is set to Ne. When the Abbe number is νe, it is desirable that the following conditional expressions (6) and (7) are satisfied.
(6) Ne <1.55
(7) 75 <νe

  Conditional expressions (6) and (7) are rules for satisfactorily correcting chromatic aberration and the like. By satisfying conditional expressions (6) and (7), it is possible to satisfactorily correct aberrations such as lateral chromatic aberration and achieve high imaging performance.

  A deviation from the range of conditional expressions (6) and (7) is not preferable because the variation due to the magnification change of the chromatic aberration of magnification becomes large. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (6) to 1.500. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (7) to 80.00.

  In order to achieve good chromatic aberration with a small lens system, the lens unit closest to the image plane is composed of one positive lens component, and the image side surface of the positive lens component is aspherical for the purpose of correcting spherical aberration. The shape is preferable.

  In the zoom lens according to the embodiment, when blur correction is performed, it is desirable to perform image blur correction by moving at least a part of the third lens group in a direction perpendicular to the optical axis.

  Since the third lens group has little change in light incident height and light incident angle during zooming, aberration correction for performing image stabilization correction can be performed efficiently. Further, if the third lens group that is fixed at the time of zooming and focusing is used as a blur correction lens group, the third lens group can be an anti-vibration driving mechanism that is independent from the focusing driving mechanism. Further, since both drive systems are arranged independently, the outer diameter of the optical system can be reduced.

(Example)
Examples of the zoom lens according to the embodiment will be described below with reference to the drawings.

  The zoom lens according to the first to seventh examples includes, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop, and positive refraction. A third lens group G3 having power, a field stop, a fourth lens group G4 having positive refracting power, an optical low-pass filter OLPF, and a cover glass CG of a solid-state imaging device disposed on the image plane I It is configured.

  The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex shape on the object side and a positive meniscus lens L12 having a convex shape, and the curvature radius of the object side surface is an absolute value of the curvature radius of the image side surface. The positive lens L13 is smaller than 1/6.

  The second lens group G2 includes, in order from the object side, a negative lens L21 having a concave image side surface, a negative lens L22 having a concave image side surface, and a positive meniscus lens L23 having a convex object side surface.

  The third lens group G3 includes, in order from the object side, a positive lens L31 having a convex object side surface, a negative lens L32 having a concave image side surface, and a positive lens L33 having a convex image side surface.

  The fourth lens group G4 includes, in order from the object side, a cemented lens of a negative meniscus lens L41 having a convex shape on the object side and a positive lens L42 having a biconvex shape.

  The object side surface of the positive meniscus lens L13, the image side surface of the negative lens L21 having a concave image side surface, the object side surface of the positive lens L31 having a convex object side surface, and the image side surface of the biconvex positive lens L42 are aspherical surfaces. It is configured in shape.

  When zooming from the wide-angle focal length W to the telephoto focal length T, the first lens group G1 is fixed, the second lens group G2 is moved to the image plane I side, the third lens group G3 is fixed, and the fourth lens group G3 is fixed. The lens group G4 moves along the optical axis along a locus convex toward the object side.

  When the photographic object is focused at a finite distance, the fourth lens group G4 moves along the optical axis. Further, the diagonal length IH from the center of the solid-state imaging device of the embodiment to the diagonal is 3.75 mm.

(First embodiment)
FIG. 1 is a diagram illustrating a lens configuration of a zoom lens according to a first example, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. In addition, the code | symbol which shows the lens used for the following description is described only in the wide-angle end state T, and description is abbreviate | omitted about another state. The same applies to other embodiments.

  In the zoom lens according to the first example, the third lens group G3 is configured to perform blur correction by moving in the direction perpendicular to the optical axis.

  Table 1 below lists the values in the specification table of the zoom lens of the first embodiment. In the table, “f” in (overall specifications) represents the focal length, “Bf” represents the back focus, and “FNO” represents the F number.

  Also, in (lens specifications), the first column is the lens surface number from the object side, the second column r is the radius of curvature of the lens surface, the third column d is the lens surface interval, and the fourth column νd is the d line (wavelength). The Abbe number of the medium with respect to λ = 587.6 nm and the fifth column Nd represent the refractive index of the medium with respect to the d-line (wavelength λ = 587.6 nm). Note that r = 0.0000 represents a plane.

Further, (Aspheric coefficient) indicates an aspheric coefficient when the aspheric surface is expressed by the following expression. The aspherical surface has a height in the direction perpendicular to the optical axis as y, and a distance (sag amount) along the optical axis from the tangent plane of each aspherical surface at the height y to each aspherical surface as X (y), When the radius of curvature (paraxial radius of curvature) of the reference spherical surface is r, the conic constant is K, and the nth-order aspherical coefficient is Cn, the following equation is used. “En” (n is an integer) in the aspherical data column indicates “× 10 ⁻ⁿ ”.
X (y) = y ² / [r · {1+ (1−K · y ² / r ² ) ^1/2 }]
+ C4 · y ⁴ + C6 · y ⁶ + C8 · y ⁸ + C10 · y ¹⁰

  Further, (variable gap at the time of focusing) is variable in the focal length f and magnification β in each of the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing at infinity and focusing on the close range. Indicates the interval value. D0 represents the distance from the object to the lens surface closest to the object, Bf represents the back focus, and TL represents the total length of the zoom lens. Further, (vibration lens group movement amount and image plane movement amount at the time of image stabilization correction) represents the image plane movement amount with respect to the lens movement amount at the time of focusing on infinity and focusing on a close range. Further, (value corresponding to the conditional expression) indicates a value corresponding to each conditional expression.

  In all the following specification values, “mm” is generally used as the focal length f, radius of curvature r, surface interval d and other lengths, etc. unless otherwise specified, but the optical system is proportional. Even if it is enlarged or proportionally reduced, the same optical performance can be obtained. Further, the unit is not limited to “mm”, and other appropriate units may be used. In all the following embodiments, the same reference numerals as those in this embodiment are used, and the description thereof is omitted.

(Table 1)
(Overall specifications)
F = 6.50-30.00-61.00
FNO = 3.8 to 4.1 to 3.7

(Lens specifications)
rd νd Nd
1) 25.9603 1.4000 17.98 1.945950
2) 21.0289 6.1000 82.56 1.497820
3) 327.6951 0.1000
4) 17.2279 4.7000 82.56 1.497820
5) 129.9432 (d5 = variable)

6) -2681.7744 1.0000 40.19 1.850490
7) 4.9916 2.2000
8) -38.8019 1.0000 40.77 1.883000
9) 11.1696 0.9000
10) 11.6255 1.6000 17.98 1.945950
11) 92.2561 (d11 = variable)

12> Aperture stop 0.5000
13) 5.3318 2.1000 64.06 1.516330
14) 41.8200 0.1000
15) 12.6924 1.0000 42.72 1.834810
16) 5.7137 0.8000
17) -114.0651 2.0000 91.20 1.456000
18) -12.1743 0.0000
19) Field stop (d19 = variable)

20) 9.2880 1.0000 25.46 2.000690
21) 6.4169 3.5000 91.20 1.456000
22) -19.3341 (d22 = variable)

23) 0.0000 1.6000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.4808 5.42353E-06 3.74245E-09 0.00000E + 00
7: 0.2537 3.70121E-04 8.82513E-06 6.13778E-10
13: 0.1321 1.00826E-04 1.60307E-05 -9.89080E-07
12: 1.000 -8.66901E-05 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Focusing at infinity Focusing at close range
F, β 6.50000 30.00000 61.00000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 140.9181 683.8795 473.4833
d 5 0.90000 10.93565 13.96348 0.90000 10.93565 13.96348
d 11 15.40831 5.37266 2.34483 15.40831 5.37266 2.34483
d 20 5.02154 1.42306 8.06457 4.74165 0.21801 1.66443
d 22 6.51775 10.11623 3.47472 6.79764 11.32128 9.87486
Bf 4.20934 4.20934 4.20934 4.20934 4.20934 4.20914
TL 64.65693 64.65693 64.65693 64.65693 64.65693 64.65693

(Moving amount of image stabilization lens and amount of image plane movement during image stabilization)
Focusing at infinity Focusing at close range
F, β 6.50000 30.00000 61.00000 -0.04000 -0.04000 -0.10000
Lens ± 0.124 ± 0.248 ± 0.383 ± 0.123 ± 0.239 ± 0.355
Image plane ± 0.118 ± 0.253 ± 0.361 ± 0.118 ± 0.253 ± 0.361

(Values for conditional expressions)
(1) F1 / Fw = 4.096
(2) F2 / Fw = −0.790
(3) F1 / {Fw × (N11−N1213)} = 9.140
(4) F21 / F22 = 0.602
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.20

  2A and 2B are graphs showing various aberrations of the zoom lens according to the first example at infinity and lateral aberrations during image stabilization. FIG. 2A is a wide-angle end state, FIG. 2B is an intermediate focal length state, and FIG. ) Shows respective aberration diagrams in the telephoto end state. FIGS. 3A and 3B are graphs showing various aberrations of the zoom lens according to the first example when the close-up shooting distance is in focus, and lateral aberrations during image stabilization. FIG. 3A shows Rw = 205 mm, and FIG. 3B shows Rm = 749 mm. , (C) shows aberration diagrams of Rt = 538 mm.

  In each aberration diagram, Y is the image height, NA is the numerical aperture, D is the d-line (λ = 587.6 nm), G is the g-line (λ = 435.6 nm), and C is the c-line (λ = 656.3 nm) and F represents the f-line (λ = 486.1 nm). In the aberration diagram showing astigmatism, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. An aberration diagram showing lateral chromatic aberration is shown with reference to the d-line. In the aberration diagrams of all the following examples, the same reference numerals as those in this example are used, and description thereof is omitted.

  From each aberration diagram, the zoom lens according to the first example has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state and during image stabilization correction in each state. I understand that.

(Second embodiment)
FIG. 4 is a diagram illustrating a lens configuration of a zoom lens according to the second example. Table 2 below shows the values in the specification table of the zoom lens of the second embodiment.

(Table 2)
(Overall specifications)
F = 6.55-30.00-61.00
FNO = 3.6 to 3.8 to 3.7

(Lens specifications)
rd νd Nd
1) 25.7235 1.4000 20.88 1.922860
2) 20.6571 5.9000 90.22 1.456500
3) 212.5954 0.1000
4) 17.1979 5.3000 90.91 1.454570
5) 321.2332 (d5 = variable)

6) -50.6548 1.0000 40.10 1.851350
7) 4.2633 2.2000
8) -92.4310 1.0000 40.77 1.883000
9) 23.5051 0.6000
10) 11.8678 1.5000 17.98 1.945950
11) 55.8154 (d11 = variable)

12> Aperture stop 0.3000
13) 5.5193 2.1000 63.97 1.514280
14) -37.8518 0.9000
15) 49.7862 1.0000 42.72 1.834810
16) 6.0285 0.5000
17) 12.6257 1.8000 91.20 1.456000
18) -11.7685 0.0000
19) Field stop (d19 = variable)

20) 9.8698 1.0000 25.46 2.000690
21) 6.7108 2.6000 91.30 1.455590
22) -51.2524 (d22 = variable)

23) 0.0000 0.9000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.5000 3.64840E-06 0.00000E + 00 0.00000E + 00
7: -0.8591 1.93500E-03 -2.58040E-05 0.00000E + 00
13: 0.5519 -3.03330E-04 0.00000E + 00 0.00000E + 00
22: -99.0000 -2.56430E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 141.5092 674.0564 452.9397
d 5 1.02022 12.17260 15.26469 1.02022 12.17260 15.26469
d 11 15.97509 4.82271 1.73062 15.97509 4.82271 1.73062
d 19 8.08567 2.30237 9.98218 7.63484 0.80981 1.26412
d 22 3.99302 9.77632 2.09651 4.44385 11.26888 10.81457
Bf 2.37189 2.37189 2.37189 2.37189 2.37189 2.37189
TL 62.54589 62.54589 62.54589 62.54589 62.54589 62.54589

(Values for conditional expressions)
(1) F1 / Fw = 4.358
(2) F2 / Fw = −0.835
(3) F1 / {Fw × (N11−N1213)} = 9.325
(4) F21 / F22 = 0.217
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.30

  FIGS. 5A and 5B are graphs showing various aberrations of the zoom lens according to the second example in an infinite state. FIG. 5A is an aberration diagram in the wide-angle end state, FIG. 5B is an intermediate focal length state, and FIG. Respectively. FIGS. 6A and 6B are graphs showing various aberrations of the zoom lens according to the second embodiment in the close-up shooting distance focus state. FIG. 6A shows Rw = 204 mm, FIG. 6B shows Rm = 737 mm, and FIG. 6C shows Rt = 515 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to the second example has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Third embodiment)
FIG. 7 is a diagram illustrating a lens configuration of a zoom lens according to the third example. Table 3 below lists the values in the specification table of the zoom lens of the third embodiment.

(Table 3)
(Overall specifications)
F = 6.50-30.00-61.00
FNO = 3.7 to 4.0 to 3.8

(Lens specifications)
rd νd Nd
1) 25.9116 1.4000 17.98 1.945950
2) 21.0025 6.1000 82.56 1.497820
3) 347.3024 0.1000
4) 17.1452 4.7000 82.56 1.497820
5) 120.0854 (d5 = variable)

6) 1316.3968 1.0000 40.19 1.850490
7) 4.8440 2.2000
8) -38.8019 1.0000 40.77 1.883000
9) 11.8322 0.9000
10) 11.4204 1.6000 17.98 1.945950
11) 74.3334 (d11 = variable)

12> Aperture stop 0.5000
13) 5.0459 2.1000 64.06 1.516330
14) -15.9483 0.1000
15) 25.7688 1.0000 42.72 1.834810
16) 5.4774 0.7000
17) 61.0443 2.0000 91.20 1.456000
18) -15.0266 0.0000
19) Field stop (d19 = variable)

20) 10.2508 1.0000 25.46 2.000690
21) 6.8801 3.0000 91.20 1.456000
22) -26.6761 (d22 = variable)

23) 0.0000 1.6000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.4287 6.72320E-06 8.65870E-09 0.00000E + 00
7: 0.6444 1.19890E-05 4.36360E-06 -1.60260E-07
13: 0.1247 -2.33820E-04 9.48600E-06 -9.89080E-07
22: 1.0000 -1.49710E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Focusing at infinity Focusing at close range
F, β 6.50000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 140.4928 676.3819 451.3168
d 5 0.90000 11.04804 13.87679 0.90000 11.04804 13.87679
d 11 15.23960 5.09156 2.26281 15.23960 5.09156 2.26281
d 19 5.79062 1.55117 9.48020 5.42736 0.18034 1.32246
d 22 6.49556 10.73501 2.80598 6.85882 12.10584 10.96372
Bf 1.30180 1.30180 1.30180 1.30180 1.30180 1.30180
TL 61.72758 61.72758 61.72758 61.72758 61.72758 61.72758

(Values for conditional expressions)
(1) F1 / Fw = 4.096
(2) F2 / Fw = −0.790
(3) F1 / {Fw × (N11−N1213)} = 9.140
(4) F21 / F22 = 0.562
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.20

  FIGS. 8A and 8B are graphs showing various aberrations of the zoom lens according to the third example in the infinite state. FIG. 8A illustrates aberrations in the wide-angle end state, FIG. 8B illustrates the intermediate focal length state, and FIG. Respectively. FIGS. 9A and 9B are graphs showing various aberrations of the zoom lens according to the third example when the close-up shooting distance is in focus. FIG. 9A shows Rw = 202 mm, FIG. 9B shows Rm = 738 mm, and FIG. 9C shows Rt = 513 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to the third example has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Fourth embodiment)
FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to the fourth example. Table 4 below shows the values in the specification table of the zoom lens of the fourth embodiment.

(Table 4)
(Overall specifications)
F = 6.55-30.00-61.00
FNO = 3.5 to 3.5 to 3.7

(Lens specifications)
rd νd Nd
1) 24.5909 1.4000 20.88 1.922860
2) 19.4777 5.2000 82.56 1.497820
3) 115.1591 0.1000
4) 18.4332 5.0000 82.56 1.497820
5) 195.1358 (d5 = variable)

6) -80.2684 1.0000 40.10 1.851350
7) 4.3262 2.2000
8) 89.2950 1.0000 40.77 1.883000
9) 15.1775 0.6000
10) 10.0334 1.5000 17.98 1.945950
11) 28.1713 (d11 = variable)

12> Aperture stop 0.3000
13) 5.6537 2.1000 63.97 1.514280
14) -23.6916 0.9000
15) -327.0168 1.0000 42.72 1.834810
16) 6.2930 0.4000
17) 10.6945 1.8000 91.20 1.456000
18) -8.9087 0.0000
19) Field stop (d19 = variable)

20) 13.0182 1.0000 25.46 2.000690
21) 8.7558 2.6000 91.30 1.455590
22) -37.1642 (d22 = variable)

23) 0.0000 0.9000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.5000 2.43110E-06 0.00000E + 00 0.00000E + 00
7: -0.8038 1.87930E-03 -1.33170E-05 0.00000E + 00
13: 0.5707 -4.07580E-04 0.00000E + 00 0.00000E + 00
22: -99.0000 -3.32860E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 140.5720 667.7010 426.1274
d 5 1.02020 12.36308 15.22189 1.02020 12.36308 15.22189
d 11 15.63505 4.29217 1.43336 15.63505 4.29217 1.43336
d 19 10.13097 3.05373 12.83541 9.46632 1.30190 1.39860
d 22 3.47935 10.55659 0.77491 4.14400 12.30842 12.21172
Bf 0.15320 0.15320 0.15320 0.15320 0.15320 0.15320
TL 60.41878 60.41878 60.41878 60.41878 60.41878 60.41878

(Values for conditional expressions)
(1) F1 / Fw = 4.358
(2) F2 / Fw = −0.835
(3) F1 / {Fw × (N11−N1213)} = 10.258
(4) F21 / F22 = 0.230
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.30

  FIGS. 11A and 11B are graphs showing various aberrations of the zoom lens according to the fourth example in the infinite state. FIG. 11A illustrates aberrations in the wide-angle end state, FIG. 11B illustrates the intermediate focal length state, and FIG. Respectively. FIGS. 12A and 12B are graphs showing various aberrations of the zoom lens according to the fourth example in the close-up shooting distance focus state. FIG. 12A shows Rw = 201 mm, FIG. 12B shows Rm = 728 mm, and FIG. 12C shows Rt = 487 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to the fourth example has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(5th Example)
FIG. 13 is a diagram illustrating a lens configuration of a zoom lens according to a fifth example. Table 5 below shows the values in the specification table of the zoom lens of the fifth embodiment.

(Table 5)
(Overall specifications)
F = 6.55-30.00-60.10
FNO = 3.5 to 3.6 to 3.6

(Lens specifications)
rd νd Nd
1) 26.2824 1.4000 20.88 1.922860
2) 21.0438 5.9000 90.22 1.456500
3) 228.8413 0.1000
4) 17.1969 5.3000 90.91 1.454570
5) 384.2679 (d5 = variable)

6) -48.0949 1.0000 40.10 1.851350
7) 4.3298 2.2000
8) 67.2370 1.0000 40.77 1.883000
9) 14.7215 0.6000
10) 10.4892 1.5000 17.98 1.945950
11) 35.3651 (d11 = variable)

12> Aperture stop 0.3000
13) 5.3545 2.1000 63.97 1.514280
14) 20.6091 0.9000
15) 22.0033 1.0000 42.72 1.834810
16) 6.1272 0.4000
17) 10.2439 1.8000 91.20 1.456000
18) -9.5325 0.0000
19) Field stop (d19 = variable)

20) 9.9547 1.0000 25.46 2.000690
21) 6.7749 2.6000 91.30 1.455590
22) -50.2288 (d22 = variable)

23) 0.0000 0.9000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.5000 3.76710E-06 0.00000E + 00 0.00000E + 00
7: -0.7125 1.62070E-03 -2.29890E-05 0.00000E + 00
13: 0.6618 -3.30480E-04 0.00000E + 00 0.00000E + 00
22: -99.0000 -2.73180E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 141.5092 674.0564 452.9397
d 5 1.02020 12.17258 15.26467 1.02020 12.17258 15.26467
d 11 15.30818 4.15580 1.06371 15.30818 4.15580 1.06371
d 19 8.76585 2.98255 10.66236 8.31502 1.48999 1.94430
d 22 4.01583 9.79913 2.11932 4.46666 11.29169 10.83738
Bf 2.37189 2.37189 2.37189 2.37189 2.37189 2.37189
TL 62.48195 62.48195 62.48195 62.48195 62.48195 62.48195

(Values for conditional expressions)
(1) F1 / Fw = 4.358
(2) F2 / Fw = −0.835
(3) F1 / {Fw × (N11−N1213)} = 9.325
(4) F21 / F22 = 0.215
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.30

  FIGS. 14A and 14B are graphs showing various aberrations of the zoom lens according to the fifth example in the infinite state. FIG. 14A is an aberration diagram in the wide-angle end state, FIG. 14B is the intermediate focal length state, and FIG. Respectively. FIGS. 15A and 15B are graphs showing various aberrations of the zoom lens of the fifth example when the close-up shooting distance is in focus. FIG. 15A shows Rw = 204 mm, FIG. 15B shows Rm = 737 mm, and FIG. 15C shows Rt = 515 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to Example 5 has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Sixth embodiment)
FIG. 16 is a diagram illustrating a lens configuration of a zoom lens according to the sixth example. Table 6 below shows the values in the specification table of the zoom lens of the sixth embodiment.

(Table 6)
(Overall)
F = 6.50-30.00-61.00
FNO = 3.5 to 3.8 to 3.4

(Lens specifications)
rd νd Nd
1) 25.9678 1.4000 17.98 1.945950
2) 21.0210 6.1000 82.56 1.497820
3) 339.3220 0.1000
4) 17.2833 4.7000 82.56 1.497820
5) 132.3282 (d5 = variable)

6) -1236.7392 1.0000 40.19 1.850490
7) 5.0328 2.2000
8) -38.8019 1.0000 40.77 1.883000
9) 11.0291 0.9000
10) 11.6547 1.6000 17.98 1.945950
11) 96.0997 (d11 = variable)

12> Aperture stop 0.5000
13) 4.8302 1.8000 70.45 1.487490
14) 11.7906 0.1000
15) 9.0250 1.0000 42.72 1.834810
16) 5.3685 0.8000
17) -83.9696 1.7000 82.56 1.497820
18) -10.6798 0.0000
19) Field stop (d19 = variable)

20) 9.8440 1.0000 25.46 2.000690
21) 6.4780 3.5000 82.56 1.497820
22) -21.7650 (d22 = variable)

23) 0.0000 1.6000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.4504 6.12900E-06 4.75680E-09 0.00000E + 00
7: 0.2496 3.63880E-04 7.00120E-06 -1.36530E-08
13: 0.1671 1.54140E-04 2.28490E-05 -9.89080E-07
22: 1.0000 -1.16660E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 140.9181 683.8795 473.4833
d 5 0.90000 10.93565 13.96348 0.90000 10.93565 13.96348
d 11 15.13311 5.09746 2.06963 15.13311 5.09746 2.06963
d 19 5.66087 2.06239 8.70390 5.38098 0.85734 2.30376
d 22 6.59264 10.19112 3.54961 6.87253 11.39617 9.94975
Bf 4.20934 4.20934 4.20934 4.20934 4.20934 4.20934
TL 64.49596 64.49596 64.49596 64.49596 64.49596 64.49596

(Values for conditional expressions)
(1) F1 / Fw = 4.096
(2) F2 / Fw = −0.790
(3) F1 / {Fw × (N11−N1213)} = 9.140
(4) F21 / F22 = 0.611
(5) N2 = 1.867
(6) Ne = 1.50
(7) νe = 82.56

  FIGS. 17A and 17B are graphs showing various aberrations of the zoom lens according to the sixth example in the infinity state. FIG. 17A illustrates aberrations in the wide-angle end state, FIG. 17B illustrates the intermediate focal length state, and FIG. Respectively. 18A and 18B are graphs showing various aberrations of the zoom lens according to the sixth example in the close-up shooting distance state. FIG. 18A shows Rw = 205 mm, FIG. 18B shows Rm = 748 mm, and FIG. 18C shows Rt = 538 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to Example 6 has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Seventh embodiment)
FIG. 19 is a diagram illustrating a lens configuration of a zoom lens according to the seventh example. Table 7 below shows the values in the specification table of the zoom lens of the seventh embodiment.

(Table 7)
(Overall)
F = 6.55-30.00-60.10
FNO = 3.5 to 3.8 to 3.5

(Lens specifications)
rd νd Nd
1) 23.8479 1.4000 25.46 2.000690
2) 18.7624 5.9000 95.25 1.433852
3) 167.9070 0.1000
4) 16.8888 5.3000 90.91 1.454570
5) -5137.1460 (d5 = variable)

6) -46.5253 1.0000 40.10 1.851350
7) 4.2808 2.2000
8) 21.5453 1.0000 46.58 1.804000
9) 10.8456 0.6000
10) 9.0254 1.5000 17.98 1.945950
11) 20.1834 (d11 = variable)

12> Aperture stop 0.3000
13) 5.4471 2.1000 63.97 1.514280
14) 20.0657 0.9000
15) 21.6048 1.0000 42.72 1.834810
16) 6.2337 0.4000
17) 10.2439 1.8000 91.20 1.456000
18) -9.5325 0.0000
19) Field stop (d19 = variable)

20) 9.4629 1.0000 25.46 2.000690
21) 6.5553 2.6000 95.25 1.433852
22) -46.2338 (d22 = variable)

23) 0.0000 0.9000 70.51 1.544370
24) 0.0000 0.5000
25) 0.0000 0.5000 64.12 1.516800
26) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.5000 3.36290E-06 0.00000E + 00 0.00000E + 00
7: -0.4928 1.29050E-03 -1.76320E-05 0.00000E + 00
13: 0.6368 -2.96970E-04 0.00000E + 00 0.00000E + 00
22: -99.0000 -3.01210E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 141.5092 674.0564 452.9397
d 5 1.02020 12.17258 15.26467 1.02020 12.17258 15.26467
d 11 15.43955 4.28717 1.19508 15.43955 4.28717 1.19508
d 19 8.90776 3.12446 10.80427 8.45693 1.63190 2.08621
d 22 3.92934 9.71264 2.03283 4.38017 11.20520 10.75089
Bf 2.37189 2.37189 2.37189 2.37189 2.37189 2.37189
TL 62.66873 62.66873 62.66873 62.66873 62.66873 62.66873

(Values for conditional expressions)
(1) F1 / Fw = 4.358
(2) F2 / Fw = −0.835
(3) F1 / {Fw × (N11−N1213)} = 7.831
(4) F21 / F22 = 0.161
(5) N2 = 1.828
(6) Ne = 1.43
(7) νe = 95.25

  20A and 20B are graphs showing various aberrations of the zoom lens according to the seventh example in the infinity state. FIG. 20A is an aberration diagram in the wide-angle end state, FIG. 20B is the intermediate focal length state, and FIG. Respectively. FIGS. 21A and 21B are graphs showing various aberrations of the zoom lens according to the seventh example when the close-up shooting distance is in focus. FIG. 21A shows Rw = 204 mm, FIG. 21B shows Rm = 737 mm, and FIG. 21C shows Rt = 516 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to the seventh example has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Eighth embodiment)
FIG. 22 is a diagram illustrating a lens configuration of a zoom lens according to the eighth example.

  The zoom lens according to the eighth example 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, an aperture stop, and a third lens having a positive refractive power. A lens group G3, a field stop, a fourth lens group G4 having positive refracting power, a fifth lens group G5 having positive refracting power, an optical low-pass filter OLPF, and a solid-state image pickup arranged on the image plane I It is comprised from the cover glass CG of an element.

  The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 having a convex shape on the object side and a positive meniscus lens L12 having a convex shape, and the curvature radius of the object side surface is an absolute value of the curvature radius of the image side surface. The positive lens L13 is smaller than 1/6.

  The second lens group G2 includes, in order from the object side, a negative lens L21 having a concave image side surface, a negative lens L22 having a concave image side surface, and a positive meniscus lens L23 having a convex object side surface.

  The third lens group G3 includes, in order from the object side, a positive lens L31 having a convex object side surface, a negative lens L32 having a concave image side surface, and a positive lens L33 having a convex image side surface.

  The fourth lens group G4 includes a positive lens L41 having a convex object side surface.

  The fifth lens group G5 includes, in order from the object side, a cemented lens of a negative meniscus lens L51 having a convex shape on the object side and a positive lens L52 having a biconvex shape.

  The object side surface of the positive meniscus lens L13, the image side surface of the negative lens L21 having a concave image side surface, the object side surface of the positive lens L31 having a convex object side surface, and the object side surface of the positive lens L41 having a convex object side surface The image side surface of the biconvex positive lens L52 is formed in an aspherical shape.

  When zooming from the wide-angle focal length W to the telephoto focal length T, the first lens group G1 is fixed, the second lens group G2 is moved to the image plane I side, the third lens group G3 is fixed, and the fourth lens group G3 is fixed. The lens group G4 moves to the object side, and the fifth lens group G5 moves along the optical axis along a locus convex to the object side.

  When the photographic object is focused at a finite distance, the fifth lens group G5 moves along the optical axis. In addition, the diagonal length IH from the center of the solid-state imaging device of the eighth embodiment to the diagonal is 3.75 mm.

Table 8 below shows the values in the specification table of the zoom lens of the eighth embodiment.
(Table 8)
(Overall specifications)
F = 6.55-30.00-61.00
FNO = 3.9 to 4.0 to 4.0

(Lens specifications)
rd νd Nd
1) 25.9550 1.4000 20.88 1.922860
2) 20.8100 5.9000 90.22 1.456500
3) 222.0859 0.1000
4) 17.1799 5.3000 90.91 1.454570
5) 331.1581 (d5 = variable)

6) -55.2024 1.0000 40.10 1.851350
7) 4.0941 2.5000
8) -52.5834 1.0000 40.77 1.883000
9) 36.3122 0.1000
10) 10.8248 1.5000 17.98 1.945950
11) 42.0827 (d11 = variable)

12> Aperture stop 0.3000
13) 5.3590 2.1000 63.97 1.514280
14) -18.4083 0.9000
15) -105.1597 1.0000 42.72 1.834810
16) 6.1759 0.5000
17) 14.0411 1.8000 91.20 1.456000
18) -12.8987 0.0000
19) Field stop (d19 = variable)

20) 7.6567 1.0000 82.56 1.497820
21) 7.8294 (d21 = variable)

22) 9.4449 1.0000 25.46 2.000690
23) 6.5133 2.6000 91.30 1.455590
24) -46.4002 (d24 = variable)

25) 0.0000 0.9000 70.51 1.544370
26) 0.0000 0.5000
27) 0.0000 0.5000 64.12 1.516800
28) 0.0000 Bf

(Aspheric coefficient)
Surface: KC 4 C 6 C 8
4: 0.5000 3.64110E-06 0.00000E + 00 0.00000E + 00
7: -0.8224 2.14650E-03 -2.55770E-05 0.00000E + 00
13: 0.3073 -1.33760E-04 0.00000E + 00 0.00000E + 00
20: 0.4401 0.00000E + 00 0.00000E + 00 0.00000E + 00
24: -99.0000 -3.15800E-04 0.00000E + 00 0.00000E + 00

(Variable interval during focusing)
Infinite focus state Close focus state
F, β 6.55000 30.00000 60.10000 -0.04000 -0.04000 -0.10000
D0 ∞ ∞ ∞ 140.7636 667.4376 435.3158
d 5 0.74690 12.21974 15.17127 0.65678 12.21974 15.17127
d 11 17.63827 6.16543 3.21390 17.72839 6.16543 3.21390
d 19 1.99764 0.85035 0.55520 2.00665 0.85035 0.55520
d 21 7.68233 2.90191 10.59213 7.26838 1.41864 1.84668
d 24 2.87011 8.79782 1.40275 3.27505 10.28109 10.14820
Bf 2.04158 2.04158 2.04158 2.04158 2.04158 2.04158
TL 64.87683 64.87683 64.87683 64.87683 64.87683 64.87683

(Values for conditional expressions)
(1) F1 / Fw = 4.358
(2) F2 / Fw = −0.835
(3) F1 / {Fw × (N11−N1213)} = 9.326
(4) F21 / F22 = 0.184
(5) N2 = 1.867
(6) Ne = 1.46
(7) νe = 91.30

  FIGS. 23A and 23B are graphs showing various aberrations of the zoom lens according to the eighth example in the infinity state. FIG. 23A is an aberration diagram in the wide-angle end state, FIG. 23B is the intermediate focal length state, and FIG. Respectively. FIGS. 24A and 24B are graphs showing various aberrations of the zoom lens according to the eighth example when the close-up shooting distance is in focus. FIG. 24A shows Rw = 206 mm, FIG. 24B shows Rm = 732 mm, and FIG. 24C shows Rt = 500 mm. Each aberration diagram is shown.

  From each aberration diagram, it can be seen that the zoom lens according to Example 8 has excellent imaging characteristics with various aberrations corrected well from the wide-angle end state to the telephoto end state.

  A camera having a zoom lens according to an embodiment will be described below.

  FIG. 25 shows an electronic still camera equipped with the zoom lens according to the embodiment, where (a) shows a front view and (b) shows a rear view. FIG. 26 is a cross-sectional view taken along the line A-A ′ of FIG.

  In FIGS. 25 and 26, when the electronic still camera 1 (hereinafter simply referred to as a camera) presses a power button (not shown), a shutter (not shown) of the photographing lens 2 is opened, and the photographing lens 2 removes an object from a subject (not shown). The light is condensed and imaged on an image sensor C (for example, CCD or CMOS) disposed on the image plane I. The subject image formed on the image sensor C is displayed on the liquid crystal monitor 3 disposed behind the camera 1. The photographer determines the composition of the subject image while looking at the liquid crystal monitor 3, and then presses the release button 4 to photograph the subject image with the image sensor C, and records and saves it in a memory (not shown). At this time, blurring of the camera 1 caused by camera shake or the like is detected by an angular velocity sensor (not shown) built in the camera 1, and the image stabilization lens G3 disposed on the photographing lens 2 is taken by the image stabilization lens (not shown). 2 is shifted in the direction perpendicular to the optical axis 2 to correct image blur on the image plane I caused by camera shake.

  The taking lens 2 is composed of a zoom lens according to an embodiment described later. The camera 1 also includes an auxiliary light emitting unit 5 that emits auxiliary light when the subject is dark, and a zoom lens that is the photographing lens 2 when zooming from the wide-angle end state (W) to the telephoto end state (T). A wide (W) -tele (T) button 6 and a function button 7 used for setting various conditions of the camera 1 are arranged.

  Thus, the camera 1 including the zoom lens according to the embodiment is configured.

  As described above, according to the present embodiment, the telephoto end half angle of view is 3.0 degrees or less, the zoom ratio is approximately 10 times or more, and the telephoto end Fno is 5 or less. A small zoom lens having excellent imaging performance can be achieved.

  In the above embodiment, the first lens unit and the third lens unit are fixed at the time of zooming. However, the intention of the present application is not limited to this zooming method. For example, the gap between the first lens group and the second lens group increases, the gap between the second lens group and the third lens group decreases, and the lens group closest to the image plane among the plurality of lens groups is convex toward the object side. It is also possible to move along the optical axis along the trajectory.

  Also, if the image stabilization correction mechanism and the zooming mechanism of the third lens group can coexist, the first lens group is fixed, the second lens group is moved to the image side, and the third lens group is moved to the object side. The lens group closest to the image plane may be moved convexly toward the object side.

  Further, if the zooming mechanism of the first lens unit has a configuration with little decentering and the third lens unit can coexist with the image stabilization mechanism and the zooming mechanism, the first lens unit is moved to the object side. The second lens group may be moved toward the image side, the third lens group may be moved toward the object side, and the lens group closest to the image plane may be moved convexly toward the object side.

  In the first embodiment, the entire third lens group G3 is decentered in the direction perpendicular to the optical axis to correct image shake caused by so-called camera shake, but may be performed in other embodiments. Further, the correction may be performed by driving not only the entire third lens group G3 but also any lens or lens group of the above-described design example in a direction perpendicular to the optical axis. Further, the fourth lens group may have a single convex lens configuration for cost reduction.

  Further, the short distance focusing in each embodiment is performed by the fourth lens group or the fifth lens group which is the lens group closest to the image plane side, but the zooming mechanism and the short distance focusing mechanism of the first lens group are different. As long as the coexistence is possible, the entire first lens unit or a part thereof may be used.

  Further, in the embodiment, the 4-group or 5-group configuration is shown, but the present invention can also be applied to other group configurations such as a 3-group or 6-group configuration.

  The lens surface may be an aspherical surface. The aspherical surface may be any of an aspherical surface by grinding, a glass mold aspherical surface in which a glass is formed into an aspherical shape, or a composite aspherical surface in which a resin is formed in an aspherical shape on the glass surface.

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

  Further, if each lens surface is provided with an antireflection film having a high transmittance at a wide wavelength range, flare and ghost can be reduced and high optical performance with high contrast can be achieved.

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

1 is a diagram illustrating a lens configuration of a zoom lens according to a first example, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 4 is a diagram illustrating various aberrations in the infinity state of the zoom lens according to the first embodiment and a lateral aberration diagram during image stabilization, where (a) is a wide-angle end state, (b) is an intermediate focal length state, and (c) is a telephoto end. Each aberration diagram in the state is shown. FIG. 5A is a diagram illustrating various aberrations of the zoom lens according to the first example when the close-up shooting distance is in focus, and a lateral aberration diagram during image stabilization. FIG. 7A illustrates Rw = 205 mm, FIG. 7B illustrates Rm = 749 mm, and FIG. Shows aberration diagrams of Rt = 538 mm. FIG. 4 is a diagram illustrating a lens configuration of a zoom lens according to a second example, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 4A is a diagram illustrating various aberrations of the zoom lens according to the second example in an infinite state. FIG. 4A illustrates each aberration diagram in a wide-angle end state, FIG. 5B illustrates an intermediate focal length state, and FIG. FIG. 7A is a diagram illustrating various aberrations of the zoom lens according to the second example when the close-up shooting distance is in focus. FIG. 7A illustrates each aberration diagram of Rw = 204 mm, FIG. 7B illustrates Rm = 737 mm, and FIG. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to Example 3, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the third example in an infinite state. FIG. 10A illustrates aberration diagrams in a wide-angle end state, FIG. 10B illustrates an intermediate focal length state, and FIG. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the third example when the close-up shooting distance is in focus, where FIG. 10A illustrates each aberration diagram of Rw = 202 mm, FIG. 7B illustrates Rm = 738 mm, and FIG. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to a fourth example, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the fourth example in an infinite state. FIG. 10A illustrates aberration diagrams in a wide-angle end state, FIG. 10B illustrates an intermediate focal length state, and FIG. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the fourth example when the close-up shooting distance is in focus. FIG. 9A illustrates each aberration diagram of Rw = 201 mm, FIG. 7B illustrates Rm = 728 mm, and FIG. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to Example 5, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the fifth example in an infinite state. FIG. 10A illustrates aberration diagrams in a wide-angle end state, FIG. 10B illustrates an intermediate focal length state, and FIG. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the fifth example when the close-up shooting distance is in focus, in which FIG. 9A illustrates each aberration diagram of Rw = 204 mm, FIG. 7B illustrates Rm = 737 mm, and FIG. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to Example 6, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the sixth example in an infinite state, where FIG. 10A illustrates each aberration diagram in a wide-angle end state, FIG. 10B illustrates an intermediate focal length state, and FIG. FIG. 10A is a diagram illustrating various aberrations of the zoom lens according to the sixth example when the close-up shooting distance is in focus, where FIG. 10A illustrates each aberration diagram of Rw = 205 mm, FIG. 7B illustrates Rm = 748 mm, and FIG. 7C illustrates Rt = 538 mm. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to Example 7, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the seventh example in an infinite state, where FIG. 9A illustrates aberration diagrams in a wide-angle end state, FIG. 9B illustrates an intermediate focal length state, and FIG. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the seventh example when the close-up shooting distance is in focus. FIG. 9A illustrates aberration diagrams of Rw = 204 mm, FIG. 7B illustrates Rm = 737 mm, and FIG. Each is shown. FIG. 10 is a diagram illustrating a lens configuration of a zoom lens according to Example 8, where W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. FIG. 9A is a diagram illustrating various aberrations of the zoom lens according to the eighth example in the infinite state, where FIG. 10A illustrates each aberration diagram in the wide-angle end state, FIG. 10B illustrates the intermediate focal length state, and FIG. FIG. 10A is a diagram illustrating various aberrations of the zoom lens according to the eighth example when the close-up shooting distance is in focus. FIG. 10A illustrates each aberration diagram of Rw = 206 mm, FIG. 9B illustrates Rm = 732 mm, and FIG. Each is shown. 1 shows an electronic still camera equipped with a zoom lens according to an embodiment, where (a) shows a front view and (b) shows a rear view. FIG. 26 is a cross-sectional view taken along the line A-A ′ of FIG.

Explanation of symbols

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group I Image surface 1 Electronic still camera 2 Imaging lens (zoom lens)
L11 Negative meniscus lens of the first lens group L12 Positive meniscus lens of the first lens group L13 Positive lens of the first lens group L21 First negative lens of the second lens group L22 Second negative lens of the second lens group L23 Second lens Group of positive meniscus lenses

Claims (13)

In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, a third lens group, and a plurality of lens groups including a fourth lens group,
In order from the object side, the second lens group includes a first negative lens of a second lens group having a concave image side surface, a second negative lens of a second lens group having a concave image side surface, and a convex object side surface. The lens is substantially composed of three lenses by the positive meniscus lens of the second lens group having a shape,
During zooming from the wide-angle end state to the telephoto end state, the gap between the first lens group and the second lens group increases, the gap between the second lens group and the third lens group decreases, The lens group closest to the image plane in the lens group moves along the optical axis along a locus convex toward the object side,
The focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, the focal length of the second lens group is F2 , and the second negative of the second lens group and the second of the second lens group. A zoom lens that satisfies the following conditions when the focal length of the negative lens is F21 and F22, respectively .
3.000 <F1 / Fw <4.4000
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65 The third lens group has positive refractive power;
The zoom lens according to claim 1, wherein the fourth lens group has a positive refractive power. The first lens group includes, in order from the object side, a negative meniscus lens of the first lens group having a convex surface facing the object side, a positive meniscus lens of the first lens group having a convex surface facing the object side, and a curvature of the object side surface. 3. The zoom lens according to claim 1, wherein the zoom lens includes substantially three lenses including a positive lens of the first lens unit whose radius is smaller than 1/6 of an absolute value of an image side curvature radius. . When the refractive index of the negative meniscus lens of the first lens group is N11 and the average refractive index of the positive meniscus lens of the first lens group and the positive lens of the first lens group is N1213, the following conditions are satisfied. The zoom lens according to claim 1, wherein:
1.00 <F1 / {Fw × (N11−N1213)} <14.0 The negative meniscus lens of the first lens group and the positive meniscus lens of the first lens group are cemented,
5. The zoom lens according to claim 1, wherein the object side surface of the positive lens of the first lens group has an aspherical surface. Before SL zoom lens according to any one of claims 1 to 5, one of the lens surfaces of the second lens group and having an aspherical surface. Wherein the lenses of the second lens group, the zoom lens according to any one of claims 1 6, characterized in that all are disposed by interposing the air. An aspherical surface on the image side surface of the first negative lens of the second lens group;
When the average refractive index of the second negative lens of the first negative lens and the second lens group of the second lens group and N2, any one of claims 1 to 7, characterized in that the following condition is satisfied The zoom lens according to one item.
1.810 <N2 The lens group closest to the image plane among the plurality of lens groups has one positive lens component having an aspheric surface on the image side surface,
The positive lens refractive index Ne of components, when the Abbe number and ve, characterized in that it satisfies the following conditions, the zoom lens according to any one of claims 1 to 8.
Ne <1.55
75 <νe Wherein characterized in that performing the image blur correction by moving vertically at least a portion of the third lens group with respect to the optical axis, the zoom lens according to any one of claims 1 to 9. In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, a third lens group, and a plurality of lens groups including a fourth lens group,
In order from the object side, the second lens group includes a first negative lens of a second lens group having a concave image side surface, a second negative lens of a second lens group having a concave image side surface, and a convex object side surface. The lens is substantially composed of three lenses by the positive meniscus lens of the second lens group having a shape,
The focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, the focal length of the second lens group is F2 , and the second negative of the second lens group and the second of the second lens group. When the focal length of the negative lens is F21 and F22, respectively, a zoom lens zooming method that satisfies the following conditions,
The gap between the first lens group and the second lens group is increased, the gap between the second lens group and the third lens group is decreased, and the lens group closest to the image plane among the plurality of lens groups is defined as an object. A zoom lens zooming method characterized in that zooming from the wide-angle end state to the telephoto end state is performed by moving the lens along the optical axis along a locus convex toward the side.
3.000 <F1 / Fw <4.4000
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65 In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, a third lens group, and a plurality of lens groups including a fourth lens group,
In order from the object side, the second lens group includes a first negative lens of a second lens group having a concave image side surface, a second negative lens of a second lens group having a concave image side surface, and a convex object side surface. The lens is substantially composed of three lenses by the positive meniscus lens of the second lens group having a shape,
During zooming from the wide-angle end state to the telephoto end state, the gap between the first lens group and the second lens group increases, the gap between the second lens group and the third lens group decreases, The lens group closest to the image plane in the lens group moves along the optical axis along a locus convex toward the object side,
The focal length in the wide-angle end state is Fw, the focal length of the first lens group is F1, the focal length of the second lens group is F2 , and the second negative of the second lens group and the second of the second lens group. When the focal length of the negative lens is F21 and F22, respectively, a zoom lens image blur correction method that satisfies the following conditions,
An image blur correction method for a zoom lens, wherein image blur correction is performed by moving at least a part of the third lens group in a direction perpendicular to the optical axis.
3.000 <F1 / Fw <4.4000
-0.900 <F2 / Fw <-0.500
0.05 <F21 / F22 <0.65 An optical apparatus comprising the zoom lens according to any one of claims 1 to 10 .

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