JP2008209753A - Zoom lens and optical device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact zoom lens excellently correcting color aberration in a telephoto photographing region and having excellent optical performance. <P>SOLUTION: The zoom lens has a plurality of lens groups including a positive refractive power first lens group G1, a negative refractive power second lens group G2, a third lens group G3, and a fourth lens group G4 in order from an object side. The first lens group has a negative lens L11 of the first lens group, a first positive lens L12 of the first lens group, and a second positive lens L13 of the first lens group in order from an object side. The first lens group has an aspheric face to satisfy prescribed conditions. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

Conventionally, zoom lenses used in electronic still cameras and the like have been proposed (see, for example, Patent Documents 1 and 2).
JP 2005-157279 A 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 first lens group includes, in order from the object side, a negative lens of the first lens group, a first positive lens of the first lens group, and a second positive lens of the first lens group. The first lens group has an aspherical surface, the focal length in the wide-angle end state is Fw, the focal length of the second positive lens in the first lens group is F13, and the focal length of the second positive lens in the first lens group is F13. Provided is a zoom lens characterized by satisfying the following conditions when the refractive index is N13.
0.100 <Fw / (F13 × N13) <0.150

In addition, the present invention includes 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 in order from the object side. The first lens group includes, in order from the object side, a negative lens of the first lens group, a first positive lens of the first lens group, and a second positive lens of the first lens group. The lens group has an aspherical surface, the focal length in the wide-angle end state is Fw, the focal length of the second positive lens in the first lens group is F13, and the refractive index of the second positive lens in the first lens group is N13. When the zoom lens zooming method satisfies the following conditions, the gap between the first lens group and the second lens group is increased, and the gap between the second lens group and the third lens group is increased. The lens group closest to the image plane among the plurality of lens groups is reduced along the optical axis along a locus convex toward the object side. Be to dynamic, it provides a method for zooming the zoom lens and performs zooming from the wide-angle end state to the telephoto end state.
0.100 <Fw / (F13 × N13) <0.150

  The present invention also provides an optical device having the zoom lens.

  The present invention also provides an optical apparatus comprising the zoom lens zooming method.

  The present invention also provides an optical device comprising the zoom lens and a zooming method for 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.

  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.

  In addition, 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 field curvature during zooming.

  Further, 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 collected by the first lens group, the lens structure must have a strong refracting power and has a small radius of curvature. As a result, high-order spherical aberration tends to occur greatly.

  Further, the lens unit closest to the image plane has a small incident light beam diameter with respect to 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.

  The first lens group includes, in order from the object side, a negative lens of the first lens group, a first positive lens of the first lens group, and a second positive lens of the first lens group. With such a configuration, it is possible to satisfactorily correct various aberrations while achieving miniaturization, and achieve high imaging performance.

Also, in order to obtain good chromatic aberration with a short overall length, when the wide-angle end focal length is Fw, the focal length of the positive lens in the first lens group is F13, and the refractive index of the positive lens in the first lens group is N13, The configuration satisfies the following conditional expression (1).
(1) 0.100 <Fw / (F13 × N13) <0.150

  If the lower limit of conditional expression (1) is not reached, spherical aberration at the telephoto end focal length is greatly generated, which is not preferable. Exceeding the upper limit value of conditional expression (1) is not preferable because a large variation in field curvature due to zooming occurs.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (1) to 0.105. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (1) to 0.140.

  In order to satisfactorily correct spherical aberration in the vicinity of the upper limit value of conditional expression (1), it is preferable that the object surface side of the positive lens in the first lens group be an aspherical surface.

  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.

  In the zoom lens according to the embodiment, the negative lens of the first lens is a negative meniscus lens having a convex shape on the object side, and the first positive lens of the first lens group is a positive meniscus lens having a convex shape on the object side. In addition, it is desirable that the second positive lens of the first lens group is a positive lens having a convex object side surface.

  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, the negative lens of the first lens group and the first positive lens of the first lens group are cemented, and the Abbe number of the negative lens of the first lens group is ν11, When the average Abbe number of the positive lens and the positive lens in the first lens group is ν1213, it is desirable that the following conditional expression (2) is satisfied.
(2) 0.010 <F1 / {Fw × (ν1213−ν11)} <0.100

  Conditional expression (2) is a rule for correcting aberrations well and obtaining good imaging performance. By satisfying conditional expression (2), it is possible to satisfactorily correct spherical aberration, lateral chromatic aberration, etc., and achieve a zoom lens having high imaging performance.

  If the lower limit of conditional expression (2) is not reached, spherical aberration occurs in the telephoto end state, which is not preferable. Exceeding the upper limit of conditional expression (2) is not preferable because chromatic aberration of magnification at the wide-angle end focal length is greatly generated.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (2) to 0.030. In order to ensure the effect of the embodiment, the upper limit value of conditional expression (2) is 0.085.

In the zoom lens according to the embodiment, in order to obtain good imaging performance, the refractive index of the negative lens of the first lens group is N11, the first positive lens of the first lens group and the first lens of the first lens group. When the average refractive index of the two positive lenses is N1213, it is desirable that the following conditional expression (3) is satisfied.
(3) 0.075 <{Fw × (N11−N1213)} / F1 <0.155

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

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (3) to 0.085. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (3) to 0.140.

  In the zoom lens according to the embodiment, the gap between the first lens group and the second lens group is increased when the object to be photographed is changed from the wide-angle focal length to the telephoto focal length at infinity. It is desirable that the gap of the third lens group is reduced and the lens group closest to the image plane among the plurality of lens groups is moved along the optical axis along a locus convex toward the object side.

  It is preferable to fix the first lens group at the time of zooming because deterioration of the flatness of the imaging surface due to centering is difficult to occur.

  In the zoom lens according to the embodiment, it is desirable that the third lens group is fixed when zooming from the wide-angle end state to the telephoto end state.

  Further, if the third lens group is fixed at the time of zooming, when the third lens group is an anti-vibration lens group, a zooming drive mechanism for the third lens group is not required. The arrangement can be made independent of the drive mechanism. In addition, the outer diameter of the optical system can be reduced.

  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.

  In order to reduce the size, it is desirable to increase the refractive power of the second lens group, but spherical aberration and field curvature aberration are likely to occur. In order to reduce this aberration, each surface of the second lens unit may be configured concentrically 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 unit. preferable.

In the zoom lens according to the embodiment, the focal lengths of the first negative lens in the second lens group and the second negative lens in the second lens group are set to F21, When the refractive index of the second negative lens of F22 and the second lens group is N22, it is desirable that the following conditional expression (4) is satisfied.
(4) 0.050 <F21 / (F22 × N22) <0.328

  If the lower limit value of conditional expression (4) is not reached, the spherical aberration at the telephoto end focal length becomes large, which is not preferable. If the upper limit of conditional expression (4) is exceeded, spherical aberration at the wide-angle end focal length 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 0.070. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (4) to 0.327.

The zoom lens according to the embodiment has an aspheric surface on the image side surface of the first negative lens of the second lens group in order to obtain good imaging performance, and the first negative lens of the second lens group When the average refractive index of the second negative lens of the second lens group and the positive meniscus lens of the second lens group is N2, it is desirable that the following conditional expression (5) is satisfied.
(5) −0.455 <F2 / (Fw × N2) <− 0.300

  If the lower limit of conditional expression (5) is not reached, spherical aberration becomes large in the telephoto end state, which is not preferable. Exceeding the upper limit of conditional expression (5) is not preferable because the field curvature becomes large in the wide-angle end state.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (5) to −0.450. In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (5) to −0.350.

  In addition, the second lens group achieves downsizing by reducing the lens configuration to three in spite of the strong refractive power, so that the spherical aberration fluctuation due to zooming tends to increase. Therefore, spherical aberration is corrected by setting the image side surface of the first negative lens of the second lens group as an aspherical surface.

(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) Fw / (F13 × N13) = 0.110
(2) F1 / {Fw × (ν1213−ν11)} = 0.0634
(3) {Fw × (N11−N1213)} / F1 = 0.109
(4) F21 / (F22 × N22) = 0.320
(5) F2 / (Fw × N2) = − 0.417

  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. Note that. In the aberration diagrams of all the following examples, the same reference numerals as in this example are used, and the 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) Fw / (F13 × N13) = 0.113
(2) F1 / {Fw × (ν1213−ν11)} = 0.0625
(3) {Fw × (N11−N1213)} / F1v = 0.107
(4) F21 / (F22 × N22) = 0.115
(5) F2 / (Fw × N2) = − 0.441

  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) Fw / (F13 × N13) = 0.110
(2) F1 / {Fw × (ν1213−ν11)} = 0.0634
(3) {Fw × (N11−N1213)} / F1 = 0.109
(4) F21 / (F22 × N22) = 0.298
(5) F2 / (Fw × N2) = − 0.417

  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) Fw / (F13 × N13) = 0.108
(2) F1 / {Fw × (ν1213−ν11)} = 0.0707
(3) {Fw × (N11−N1213)} / F1 = 0.098
(4) F21 / (F22 × N22) = 0.122
(5) F2 / (Fw × N2) = − 0.441

  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) Fw / (F13 × N13) = 0.114
(2) F1 / {Fw × (ν1213−ν11)} = 0.0625
(3) {Fw × (N11−N1213)} / F1 = 0.107
(4) F21 / (F22 × N22) = 0.114
(5) F2 / (Fw × N2) = − 0.441

  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) Fw / (F13 × N13) = 0.110
(2) F1 / {Fw × (ν1213−ν11)} = 0.0634
(3) {Fw × (N11−N1213)} / F1 = 0.109
(4) F21 / (F22 × N22) = 0.325
(5) F2 / (Fw × N2) = − 0.417

  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) Fw / (F13 × N13) = 0.122
(2) F1 / {Fw × (ν1213−ν11)} = 0.0644
(3) {Fw × (N11−N1213)} / F1 = 0.128
(4) F21 / (F22 × N22) = 0.089
(5) F2 / (Fw × N2) = − 0.447

  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) Fw / (F13 × N13) = 0.114
(2) F1 / {Fw × (ν1213−ν11)} = 0.0625
(3) {Fw × (N11−N1213)} / F1 = 0.107
(4) F21 / (F22 × N22) = 0.097
(5) F2 / (Fw × N2) = − 0.441

  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 over a wide wavelength range, flare and ghost can be reduced and high contrast and high optical performance 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. 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 (15)

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,
The first lens group includes, in order from the object side, a negative lens of the first lens group, a first positive lens of the first lens group, and a second positive lens of the first lens group,
The first lens group has an aspherical surface;
When the focal length in the wide-angle end state is Fw, the focal length of the second positive lens in the first lens group is F13, and the refractive index of the second positive lens in the first lens group is N13, the following conditions are satisfied. A zoom lens characterized by things.
0.100 <Fw / (F13 × N13) <0.150 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 negative lens of the first lens is a negative meniscus lens having a convex shape on the object side, the first positive lens of the first lens group is a positive meniscus lens having a convex shape on the object side, and the first lens group has a first meniscus lens having a convex shape on the object side. The zoom lens according to claim 1, wherein the two positive lenses are positive lenses having a convex object side surface.   4. The zoom lens according to claim 1, wherein the aspheric surface is formed on an object side surface of a second positive lens of the first lens group. 5. The negative lens of the first lens group and the first positive lens of the first lens group are cemented,
The focal length of the first lens group is F1, the Abbe number of the negative lens of the first lens group is ν11, and the average Abbe of the first positive lens of the first lens group and the second positive lens of the first lens group The zoom lens according to any one of claims 1 to 4, wherein the following condition is satisfied when the number is ν1213.
0.010 <F1 / {Fw × (ν1213−ν11)} <0.100 When the refractive index of the negative lens of the first lens group is N11 and the average refractive index of the first positive lens of the first lens group and the second positive lens of the first lens group is N1213, the following conditions are satisfied. The zoom lens according to claim 1, wherein the zoom lens is satisfied.
0.075 <{Fw × (N11−N1213)} / F1 <0.155   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 zoom lens according to any one of claims 1 to 6, wherein a lens group closest to the image plane among the lens groups moves along an optical axis along a locus convex toward the object side.   The zoom lens according to any one of claims 1 to 7, wherein the third lens group is fixed when zooming from the wide-angle end state to the telephoto end state.   The second lens group includes, in order from the object side, a first negative lens of the second lens group having a concave shape on the image side, a second negative lens of the second lens group having a concave shape on the image side surface, and a convex shape on the object side surface. The zoom lens according to claim 1, further comprising a positive meniscus lens of the second lens group. When the focal lengths of the first negative lens of the second lens and the second negative lens of the second lens are F21 and F22, respectively, and the refractive index of the second negative lens of the second lens is N22, the following conditions are satisfied. The zoom lens according to claim 9, wherein the zoom lens according to claim 9 is satisfied.
0.050 <F21 / (F22 × N22) <0.328 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 first negative lens of the second lens group, the second negative lens of the second lens group, and the positive meniscus lens of the second lens group is N2, the following condition is satisfied. The zoom lens according to claim 9 or 10.
−0.455 <F2 / (Fw × N2) <− 0.300 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,
The first lens group includes, in order from the object side, a negative lens of the first lens group, a first positive lens of the first lens group, and a second positive lens of the first lens group,
The first lens group has an aspherical surface;
When the focal length in the wide-angle end state is Fw, the focal length of the second positive lens in the first lens group is F13, and the refractive index of the second positive lens in the first lens group is N13, the following conditions are satisfied. A zoom lens zooming method,
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 G3 is decreased, and the lens group closest to the image plane is selected from the plurality of lens groups. A zoom lens zooming method, wherein zooming is performed from a wide-angle end state to a telephoto end state by moving along an optical axis along a locus convex toward the object side.
0.100 <Fw / (F13 × N13) <0.150   An optical apparatus comprising the zoom lens according to any one of claims 1 to 11.   An optical apparatus comprising the zoom lens zooming method according to claim 12.   An optical apparatus comprising: the zoom lens according to any one of claims 1 to 11; and the zoom lens zooming method according to claim 12.

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