JP6208458B2 - Zoom lens with image stabilization - Google Patents

Description

  The present invention relates to a zoom lens having an image blur correction function suitable for a 35 mm single-lens reflex camera, a video camera, and a digital camera, and more specifically, an image blur correction lens having a small diameter and a light weight, and image blur correction. The present invention relates to a zoom lens having an image blur correction function with little aberration deterioration.

  Vibration may be transmitted accidentally or unintentionally to the photographing system. In this case, image blurring occurs in the captured image. Various zoom lenses having a mechanism for correcting image blur due to this accidental or unintentional vibration, ie, an image blur correction function, have been proposed. For example, an optical system that corrects image blur due to vibration by moving a part of a lens group constituting the optical system in a direction substantially perpendicular to the optical axis is known.

  In order to correct image blur by moving a part of the lens group, in general, the lens group (correction lens group) that moves in a direction substantially perpendicular to the optical axis for image blur correction is small and its movement. It is desirable that the amount is small and that the image blur correction efficiency for the movement is high, that is, a large correction can be made with a small movement. Further, in a zoom lens having such an image blur correction function, decentering coma, decentering astigmatism, decentering chromatic aberration, and decentering distortion that occur when the image blur correcting lens group is moved, that is, decentered with respect to the optical axis. It is desirable that decentration aberrations such as aberrations are small.

  As a zoom lens having an image blur correction function of the prior art, it has at least two lens groups of a first refractive power group and a negative second power group in order from the object side, and telephoto from the wide-angle end. A zooming optical system that performs zooming to the end by changing the air gap between the first group and the second group. The second group includes a 21st group having a negative refractive power and a 22nd group having a positive refractive power. And a zoom lens that corrects image blur by moving the 21st group in a direction orthogonal to the optical axis has been proposed (for example, see Patent Document 1).

  With such a configuration, the decentering sensitivity of the image blur correction lens group, that is, the image blur correction amount with respect to the predetermined optical axis orthogonal movement amount of the image blur correction lens group is increased, and various aberrations occurring in the second group are reduced. Corrected well. However, the refractive power of the second group with respect to the focal length at the telephoto end is weak. Therefore, in a super-telephoto optical system with a focal length exceeding 400 mm, in which the present invention can be particularly suitably implemented, if the F-number on the telephoto side is about F5.7 of the present invention, the outer diameter of the image blur correction lens group is As the size of the zoom lens increases, the size of the entire zoom lens becomes difficult. In order to achieve downsizing of the image blur correcting lens group, the refractive power of the second group must be further increased. Furthermore, it is necessary to review the configuration of the second group in order to prevent the deterioration of various aberrations.

  As another zoom lens having an image blur correction function of the prior art, a first lens group G1 having a positive refractive power, a second lens group G2 having a positive refractive power, and a negative refractive power in order from the object side. Third lens group G3, fourth lens group G4 having positive refractive power, fifth lens group G5 having negative refractive power, sixth lens group G6 having positive refractive power, and seventh lens having negative refractive power The lens group G7 has a first lens group, a second lens group, a fourth lens group, a fifth lens group, a sixth lens group, and a seventh lens group when moving from wide angle to telephoto. The seventh lens group is moved in the optical axis direction for focusing. The third lens group is composed of a front part G3A and a rear part G3B in order from the object side, and the third lens group rear part G3B has a component perpendicular to the optical axis. Zoom to correct image blur by moving in the direction Lens has been proposed (e.g., see Patent Document 2).

  In the above configuration, the outer diameter of the image stabilizing lens group G3B is made smaller by setting the position of the third lens group at the telephoto end to the image side than the position of the third lens group at the wide-angle end. However, zooming has a problem that the mechanical structure of the lens barrel is complicated because six lens groups including the anti-vibration lens group G3B are moved.

  As another zoom lens having an image blur correction function of the prior art, the first group having a positive refractive power, the second group having a negative refractive power, the third group having a positive refractive power, and a negative refraction in order from the object side. 4th group of power, 5th group of positive refractive power, 6th group of negative refractive power, 2nd group consists of 2a group of positive refractive power and 2b group of negative refractive power, or positive A variable power optical system comprising a refractive power 2a group, a negative refractive power 2b group, and a negative refractive power 2c group, and moving the first, third, fifth, and sixth groups upon zooming A zoom lens that corrects image blur by moving the second group b in the direction perpendicular to the optical axis has been proposed (see, for example, Patent Document 3).

  In the above-described configuration, by making the second group a lens unit having a positive refractive power, the outer diameter of the second group b is reduced and the eccentric sensitivity is increased as compared with the case where the entire second group is vibrated. . However, the positive refractive power of the second group a is weak, and a sufficient correction effect cannot be obtained as compared with the case where the entire second group is vibrated. On the contrary, if the positive refractive power of the 2a group is increased, the incident angle of the axial light beam incident on the 2b group becomes large, which is not preferable for aberration correction.

Japanese Patent No. 3387669 Japanese Patent No. 4226854 Japanese Patent No. 4332384

(Object of invention)
The present invention has been made in view of the problem of the zoom lens having the image blur correction function of the prior art described above. The image blur correction lens group has a small outer diameter, and the image blur correction actuator is small and light. An object of the present invention is to provide a zoom lens having an image blur correction function with low power consumption.
Another object of the present invention is to provide a zoom lens having an image blur correction function in which the number of lens groups that move for zooming is small and the structure of the lens barrel is not complicated.
In the present invention, the image blur correction lens group that is moved in a direction substantially orthogonal to the optical axis for image blur correction has a large decentration sensitivity, and a large blur correction effect can be obtained with a small movement. Another object of the present invention is to provide a zoom lens having an image blur correction function that does not increase the incident angle of the axial light beam incident on the image blur correction lens group and is not disadvantageous for aberration correction.
Furthermore, the present invention can form a high-quality image blur correction image with little deterioration of various aberrations even when the image blur correction lens group is moved in a direction substantially orthogonal to the optical axis for image blur correction. It is an object to provide a zoom lens having an image blur correction function.

The present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a negative lens group. A fifth lens unit having a refractive power of 5 mm, and at the time of zooming from the wide-angle end to the telephoto end, at least the first lens unit, the third lens unit, and the fifth lens unit move to the object side, and the first lens unit The distance between the second lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, the distance between the third lens group and the fourth lens group is increased, and the fourth lens group and the fifth lens group are increased. In zoom lenses where the interval of
The second lens group includes, in order from the object side, at least a second A lens group having a negative refractive power and a second B lens group having a negative refractive power. The second B lens group serves as an image blur correction lens group, and an optical axis. A zoom lens having an image blur correction function, wherein image blur is corrected by moving in a substantially vertical direction, and the following conditional expression is satisfied.
0.1 <| f2 | / ft <0.2 (1)
0.9 <f2B / f2 <1.5 (2)
Here, f2 is the focal length of the second lens group, ft is the focal length of the entire system in the telephoto end state, and f2B is the focal length of the second B lens group.

  The configuration of the zoom lens having an image blur correction function according to the present invention will be described in more detail. In order from the object side, at least a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A third lens group, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power. At the time of zooming from the wide angle end to the telephoto end, at least the first lens group, the third lens group, and the fifth lens group move to the object side. That is, according to the present invention, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, and the distance between the third lens group and the fourth lens group is increased. , The distance between the fourth lens group and the fifth lens group is decreased. With this configuration, the burden of aberration correction for the zooming action of each lens unit does not increase, and a high zoom ratio and a reduction in the overall length can be balanced and balanced.

Focusing from the infinity state to the short-distance object state is performed by moving the fifth lens group to the image side. It is desirable that the second lens group and the fourth lens group are fixed. Thereby, the mechanism of the lens barrel can be simplified. On the other hand, during zooming, the fourth lens group can also be moved. By changing the distance between the third lens group and the fourth lens group, it is possible to satisfactorily correct spherical aberration fluctuations during zooming, and The field curvature at can be corrected well.

  The third lens group is desirably composed of two lenses, a negative lens and a positive lens, in order from the object side, and the number of lenses can be suppressed as much as possible.

  It is desirable that the aperture stop is disposed between the fourth lens group and the fifth lens group and moves independently of the other lens groups. With this configuration, the aperture diameter can be reduced and the aperture diameter can be made constant over the entire zoom range.

  In addition, since the fifth lens group, which is the focus group, is adjacent to the aperture stop, the axial light beam and the peripheral light beam passing through the fifth lens group pass through substantially the same height of the lens diameter. For this reason, it is not necessary to make the lens diameter of the fifth lens group larger than necessary, and the size can be reduced. The fifth lens group is composed of a cemented lens of a positive lens and a negative lens in order from the object side, so that the number of lenses can be reduced and the zoom lens having the image blur correction function can be reduced in weight.

  According to the zoom lens having the image blur correction function of the present invention, the image blur correction lens group has an image blur correction function in which the outer diameter of the image blur correction lens group is reduced, the image blur correction actuator is small and light, and power consumption is low. A zoom lens can be configured.

  According to the zoom lens having the image blur correction function of the present invention, the image blur correction function can also be achieved by reducing the outer diameter of the image blur correction lens group, making the image blur correction actuator small and light, and reducing power consumption. The provided zoom lens can be configured.

  According to the zoom lens having the image blur correction function of the present invention, a zoom lens having an image blur correction function that reduces the number of lens groups that move for zooming and does not complicate the structure of the lens barrel. can do.

  According to the zoom lens having the image blur correction function of the present invention, the image blur correction lens group that is moved in a direction substantially orthogonal to the optical axis for image blur correction has a large decentration sensitivity, and is large with a small movement. A zoom lens having an image blur correction function capable of obtaining a blur correction effect and preventing an incident angle of an axial light beam incident on the image blur correction lens group from being increased and disadvantageous in terms of aberration correction. Can do.

  According to the zoom lens having the image blur correction function of the present invention, even when the image blur correction lens group is moved in a direction substantially orthogonal to the optical axis for image blur correction, the deterioration of various aberrations is small. A zoom lens having an image blur correction function capable of forming a high-quality image blur correction image can be configured.

  Preferably, in the zoom lens having the image blur correction function according to the present invention, the second lens group is, in order from the object side, a second A lens group having a negative refractive power and a second B lens having a negative refractive power. It is characterized by comprising three lens groups, that is, a second C lens group having a positive refractive power.

The zoom lens having the image blur correction function according to the present invention preferably satisfies the following conditional expression.
0.6 <f2AB / f2 <0.9 (3)
2.0 <f2C / | f2 | <15 (4)
Here, f2AB represents the combined focal length of the second A lens group and the second B lens group, f2 represents the focal length of the second lens group, and f2C represents the focal length of the second C lens group.

The zoom lens having the image blur correction function according to the present invention preferably satisfies the following conditional expression.
1.0 <f3 / | f2 | <2.0 (5)
Here, f2 represents the focal length of the second lens group, and f3 represents the focal length of the third lens group.

  The zoom lens having the image blur correction function according to the present invention is preferably characterized in that the second lens group and the fourth lens group are fixed during zooming.

  In the zoom lens having the image blur correction function according to the present invention, preferably, the aperture stop is disposed between the fourth lens group and the fifth lens group, and the zoom lens is different from the other lens groups in zooming. It is characterized by moving independently.

(Explanation of conditional expression (1))
0.1 <| f2 | / ft <0.2 (1)
Conditional expression (1) is a conditional expression for appropriately setting the ratio of the focal length of the second lens group to the focal length of the telephoto end.
When the lower limit of conditional expression (1) is exceeded, it becomes easy to reduce the outer diameter of the second lens group. However, the refractive power of the second lens group becomes strong, and aberrations generated in the second lens group, particularly spherical aberration, become large, and it is difficult to correct this in the third lens group and thereafter. In addition, it is difficult to correct astigmatism in the zoom intermediate region.
Exceeding the upper limit value of conditional expression (1) is advantageous for correcting spherical aberration, but causes the problem that the outer diameter of the second lens group increases.

  In the zoom lens having the image blur correction function of the present invention, the second lens group further includes at least a second A lens group having a negative refractive power and a second B lens group having a negative refractive power in order from the object side. The second B lens group is an image blur correction lens group, and the image blur is corrected by moving the second B lens group in a direction substantially perpendicular to the optical axis. The second lens group has the greatest zooming effect and tends to have a strong negative refractive power in order to reduce the size of the image blur correcting lens group. Therefore, it is desirable to divide the second lens group into two or three lens groups as in the present invention. Thereby, it is possible to disperse the negative refractive power and correct spherical aberration, astigmatism, and off-axis coma generated in the second lens group. At this time, it is desirable that the second A lens group has a negative refractive power. As a result, the incident angle of the axial beam incident on the image blur correction lens group (second B lens group) becomes gentle, and the occurrence of decentration aberrations during image blur correction can be suppressed.

(Explanation of conditional expression (2))
0.9 <f2B / f2 <1.5 (2)
Conditional expression (2) is a conditional expression for appropriately setting the ratio of the refractive power of the second B lens group to the second lens group.
When the lower limit of conditional expression (2) is exceeded, the lens drive amount for image blur correction becomes small, which is advantageous for the followability of the image blur correction lens group and the size reduction of the image blur correction unit. However, it is difficult to correct spherical aberration and astigmatism during image blur correction.
If the upper limit value of conditional expression (2) is exceeded, the amount of lens drive during image blur correction will increase, leading to an increase in the size of the image blur correction unit.

  The best mode for reducing the size of the second lens group includes, in order from the object side, a second A lens group having a negative refractive power, a second B lens group having a negative refractive power, and a second C lens group having a positive refractive power. That is. By disposing the second C lens group having a positive refractive power on the image side of the second B lens group, the negative refractive power of the second B lens group can be increased. The second B lens group having a strong negative refractive power increases the image blur correction amount with respect to the decentration sensitivity, that is, the image blur correction lens group with respect to the predetermined amount of orthogonal movement of the optical axis, which is advantageous for downsizing the image blur correction actuator. . Dividing the second lens group into three lens groups cancels out negative aberration generated in the second A lens group and the second B lens group from the second C lens group having a positive refractive power from the viewpoint of aberration correction. This makes it possible to further reduce the size of the image blur correction actuator than when the second lens group is divided into two lens groups. The second C lens group is preferably composed of at least a positive lens and a negative lens in order from the object side. With this lens configuration, it is possible to satisfactorily correct mainly astigmatism during image blur correction.

(Explanation of conditional expression (3))
0.6 <f2AB / f2 <0.9 (3)
Conditional expression (3) is a conditional expression for appropriately setting the ratio of the combined focal length of the second A lens group and the second B lens group to the second lens group.
When the lower limit of conditional expression (3) is exceeded, the image blur correction lens group tends to be downsized. On the other hand, the negative refracting power becomes too strong, and it becomes difficult to correct coma and astigmatism particularly during image blur correction.
Exceeding the upper limit of conditional expression (3) is advantageous for correcting various aberrations during image blur correction, but it is difficult to reduce the size of the image blur correction lens group.

(Explanation of conditional expression (4))
2.0 <f2C / | f2 | <15 (4)
Conditional expression (4) is a conditional expression for appropriately setting the ratio of the refractive power of the second C lens group to the second lens group.
Exceeding the lower limit of conditional expression (4) is not preferable because the positive refractive power becomes too strong and the number of lenses increases.
If the upper limit of conditional expression (4) is exceeded, it will be difficult to correct negative aberration generated in the second A lens group and the second B lens group. In particular, it is difficult to satisfactorily correct astigmatism during image blur correction.

(Explanation of conditional expression (5))
1.0 <f3 / | f2 | <2.0 (5)
Conditional expression (5) appropriately sets the ratio of the focal lengths of the second lens group and the third lens group in order to reduce the size of the zoom lens having an image blur correction function and to correct various aberrations satisfactorily. It is for setting.
Exceeding the lower limit of conditional expression (5) is advantageous for miniaturization of a zoom lens having an image blur correction function, but it becomes difficult to correct spherical aberration and coma. In order to correct these various aberrations satisfactorily, the number of lenses in the third lens group increases, which is not preferable.
Exceeding the upper limit value of conditional expression (5) is advantageous for correcting spherical aberration and coma aberration, but there is a problem that the outer diameters of the third and fourth lens groups are increased. Further, the movement amount of the third lens group is increased, and the entire length of the zoom lens having the image blur correction function is increased, which is not preferable.

It is an optical sectional view showing an optical section at the time of focusing on infinity of a zoom lens having an image blur correction function of a first embodiment of the present invention and zoom movement of each lens group. FIG. 2 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the wide-angle end state of the first embodiment shown in FIG. 1. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 6 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the intermediate focal length state of the first embodiment shown in FIG. 1. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 6 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the telephoto end state of the first embodiment shown in FIG. 1. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. It is an optical sectional view showing an optical section at the time of focusing on infinity of a zoom lens provided with an image blur correction function of a second embodiment of the present invention and zoom movement of each lens group. FIG. 6 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the wide-angle end state of the second embodiment shown in FIG. 5. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the intermediate focal length state of the second embodiment shown in FIG. 5. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 6 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the telephoto end state of the second embodiment shown in FIG. 5. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. It is an optical sectional view showing an optical section at the time of focusing on infinity of a zoom lens having an image blur correction function of a third embodiment of the present invention and zoom movement of each lens group. FIG. 10 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the wide-angle end state of the third embodiment shown in FIG. 9. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 10 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the intermediate focal length state of the third embodiment shown in FIG. 9. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 10 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the third embodiment illustrated in FIG. 9. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. It is an optical sectional view showing an optical section at the time of infinity focusing of a zoom lens provided with an image blur correction function of a 4th embodiment of the present invention, and zoom movement of each lens group. FIG. 14 is a spherical aberration diagram, astigmatism diagram, and distortion diagram at the time of focusing on infinity in the wide-angle end state of the fourth embodiment shown in FIG. 13. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 14 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the intermediate focal length state of the fourth embodiment shown in FIG. 13. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line. FIG. 14 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the telephoto end state of the fourth embodiment shown in FIG. 13. The solid line graph of the spherical aberration diagram shows a light beam having a wavelength of 587.56 nm, and the dotted line graph shows a light beam having a wavelength of 435.84 nm. In the astigmatism diagram, dm represents the aberration of the meridional image surface of the d line, and ds represents the aberration of the sagittal image surface of the d line.

  In the embodiment described below, the surface number NS in the specification optical data is the surface number of the lens surface counted from the object side, r is the radius of curvature of the lens surface (mm), and d is the distance on the optical axis of the lens surface (mm). ), Nd represents the refractive index for the d-line (wavelength λ = 587.6 nm), and vd represents the Abbe number for the d-line (wavelength λ = 587.6 nm). f is the focal length (mm), FNo. is the numerical aperture, and ω is the half angle of view (°). Those with S on the rear side of the surface number indicate a diaphragm.

(First embodiment)
f = 205.00-487.00
FNo. = 4.59 to 5.75
ω = 5.96 to 2.51

Surface number rd nd vd
Object ∞ (d0)
1 482.5439 2.7000 1.80420 46.50
2 136.9302 10.0000 1.49700 81.61
3 -1311.2444 0.2000
4 154.4406 10.0000 1.49700 81.61
5 -891.1563 (d5)
6 -131.8575 2.0000 1.63854 55.45
7 -465.4831 0.4259
8 172.2754 4.0000 1.69680 55.46
9 517.9251 3.3582
10 3967.0669 1.5000 1.56732 42.84
11 45.8114 4.0000 1.84666 23.78
12 86.1419 8.0164
13 -409.3100 1.8000 1.72916 54.67
14 164.3517 (d14)
15 146.9915 1.8000 1.90366 31.31
16 80.4953 10.5000 1.48749 70.44
17 -78.4715 d (17)
18 110.9146 8.5000 1.49700 81.61
19 -78.3006 1.5000 1.83400 37.34
20 2951.7311 0.2000
21 88.4914 4.4959 1.74330 49.22
22 -3091.0648 d (22)
23S ∞ d (23)
24 188.4400 3.4000 1.67270 32.17
25 -86.6515 1.0000 1.71300 53.94
26 45.7256 d (26)
27 -96.1249 5.0000 1.60342 38.01
28 -47.3945 18.8963
29 -49.4312 1.5000 1.72342 37.99
30 -92.7467 (bf)

[Variable interval when focusing at infinity]
Wide angle Medium telephoto
f 205.0001 300.0000 487.0000
d0 ∞ ∞ ∞
d5 28.8518 80.2974 138.2464
d14 35.8093 20.5025 6.7969
d17 1.5000 16.8068 30.5124
d22 32.5090 21.0137 2.0000
d23 1.5000 6.6922 4.8541
d26 27.2150 33.5181 54.3698
bf 64.2045 64.2045 64.2045

[Variable interval when focusing at close range (shooting distance: 2.2m)]
Wide angle Medium telephoto
f 179.3019 231.4119 288.6839
d0 1902.9363 1851.4907 1793.5415
d5 28.8518 80.2974 138.2464
d14 35.8093 20.5025 6.7969
d17 1.5000 16.8068 30.5124
d22 32.5090 21.0137 2.0000
d23 6.3420 16.4347 25.6545
d26 22.3729 23.7756 33.5695
bf 64.2045 64.2045 64.2045

[Values for conditional expressions]
Conditional expression (1) 0.192
Conditional expression (2) 1.092
Conditional expression (5) 1.496

(Second Embodiment)
f = 205.04-486.97
FNo. = 4.62 to 5.78
ω = 5.90-2.49

Surface number rd nd vd
Object ∞ (d0)
1 436.4287 3.0000 1.80400 46.60
2 122.1130 11.5000 1.49782 82.57
3 -605.0947 0.3000
4 125.4694 11.0000 1.49782 82.57
5 -1875.0633 (d5)
6 -496.2416 4.1000 1.60342 38.01
7 -61.4135 1.5000 1.72916 54.67
8 132.4791 5.1000
9 -188.3876 1.5000 1.51742 52.15
10 46.2336 3.8000 1.80518 25.46
11 99.3055 2.0000
12 -411.8858 1.7000 1.74330 49.22
13 143.7588 3.0000
14 153.9724 9.5000 1.60738 56.82
15 -32.5888 1.7000 1.65844 50.85
16 -200.7252 (d16)
17 121.8569 1.7000 1.90366 31.31
18 73.6444 10.0000 1.48749 70.44
19 -63.3839 (d19)
20 524.0060 7.6000 1.49700 81.61
21 -54.0683 1.7000 1.83400 37.34
22 -164.5813 0.2000
23 69.2565 4.3000 1.74330 49.22
24 203.8076 (d24)
25S ∞ (d25)
26 151.8781 3.1000 1.64769 33.84
27 -106.5949 1.1000 1.72916 54.67
28 44.3402 (d28)
29 -96.2691 5.0000 1.58144 40.89
30 -43.4021 21.0392
31 -40.3878 1.5000 1.83481 42.72
32 -68.1862 (bf)

[Variable interval when focusing at infinity]
Wide angle Medium telephoto
f 205.0431 299.9821 486.9688
d0 ∞ ∞ ∞
d5 52.0770 83.8845 127.4543
d16 23.8204 10.7208 2.0000
d19 1.5000 8.8128 12.3467
d24 32.6377 23.5524 4.9613
d25 8.2078 11.1530 5.8667
d28 19.8179 31.7449 60.8092
bf 54.3185 54.3185 54.3185

[Variable interval when focusing at close range (shooting distance: 2.2m)]
Wide angle Medium telephoto
f 175.7064 225.0670 280.4931
d0 1890.0000 1858.1924 1814.6227
d5 52.0770 83.8845 127.4543
d16 23.8204 10.7208 2.0000
d19 1.5000 8.8128 12.3467
d24 32.6377 23.5524 4.9613
d25 13.6845 21.5022 26.1835
d28 14.3413 21.3957 40.4924
bf 54.3185 54.3185 54.3185

[Values for conditional expressions]
Conditional expression (1) 0.140
Conditional expression (2) 1.259
Conditional expression (3) 0.679
Conditional expression (4) 2.606
Conditional expression (5) 1.564

(Third embodiment)
f = 205.00-487.00
FNo. = 4.60 to 5.76
ω = 5.96 to 2.51

Surface number rd nd vd
Object ∞ (d0)
1 558.3655 2.7000 1.80400 46.60
2 139.4024 10.5000 1.49782 82.57
3 -668.2361 0.2000
4 146.6085 9.5000 1.49782 82.57
5 -1118.6091 (d5)
6 -184.3582 3.0958 1.60342 38.01
7 -78.4233 1.7000 1.74400 44.90
8 -759.0474 3.0000
9 -338.8378 1.5000 1.51742 52.15
10 50.9127 4.0000 1.84666 23.78
11 82.0507 3.6574
12 -290.8254 1.5000 1.71300 53.94
13 474.8838 3.3272
14 116.6954 6.6077 1.61800 63.39
15 -73.5919 8.6519
16 -54.6227 1.7000 1.61800 63.39
17 1689.1127 (d17)
18 238.5481 1.8000 1.90366 31.31
19 100.9122 10.5000 1.49700 81.61
20 -62.9714 (d20)
21 172.8037 8.5000 1.48749 70.44
22 -69.2343 1.5000 1.83400 37.34
23 -210.9192 0.2000
24 72.4017 4.3000 1.74330 49.22
25 166.6731 (d25)
26 (Aperture) ∞ (d26)
27 185.1203 3.0000 1.67270 32.17
28 -88.3740 1.0000 1.69680 55.46
29 45.2699 (d29)
30 -87.7232 5.0000 1.51742 52.15
31 -48.0961 24.4805
32 -56.4244 1.5000 1.72916 54.67
33 -109.4653 (bf)

[Variable interval when focusing at infinity]
Wide angle Medium telephoto
f 205.0000 300.0000 486.9998
d0 ∞ ∞ ∞
d5 22.5976 77.8408 132.5976
d17 28.7349 20.1857 11.5943
d20 1.5000 10.0493 18.6406
d25 35.3321 22.2590 3.0000
d26 3.7089 7.5300 4.8106
d29 29.7060 38.9579 60.9364
bf 54.3186 54.3186 54.3186

[Variable interval when focusing at close range (shooting distance: 2.2m)]
Wide angle Medium telephoto
f 177.4144 228.3957 283.2414
d0 1900.0000 1844.7568 1790.0000
d5 22.5976 77.8408 132.5976
d17 28.7349 20.1857 11.5943
d20 1.5000 10.0493 18.6406
d25 35.3321 22.2590 3.0000
d26 8.5748 16.9032 24.2275
d29 24.8400 29.5848 41.5195
bf 54.3186 54.3186 54.3186

[Values for conditional expressions]
Conditional expression (1) 0.179
Conditional expression (2) 1.238
Conditional expression (3) 0.832
Conditional expression (4) 3.327
Conditional expression (5) 1.501

(Fourth embodiment)
f = 205.00-487.00
FNo. = 4.59 to 5.75
ω = 5.96 to 2.51

Surface number rd nd vd
Object ∞ (d0)
1 3780.7912 2.7000 1.80420 46.50
2 164.6767 11.0525 1.49700 81.61
3 -266.3818 0.2000
4 132.1963 8.0978 1.49700 81.61
5 1175.7104 (d5)
6 314.4323 5.0831 1.62004 36.30
7 -106.1601 6.5862
8 -74.4300 1.8000 1.71736 29.50
9 -1202.3391 7.6422
10 -297.8350 1.5000 1.56883 56.04
11 45.2037 4.0000 1.84666 23.78
12 92.7276 4.0000
13 -194.4620 1.8000 1.72342 37.99
14 246.7662 3.0000
15 134.4913 3.0000 1.63854 55.45
16 184.8712 (d16)
17 113.4290 1.8000 1.90366 31.31
18 69.2087 10.5000 1.48749 70.44
19 -71.3663 (d19)
20 134.9908 8.5000 1.49700 81.61
21 -76.8654 1.5000 1.83400 37.34
22 -283.4054 0.2000
23 91.8322 4.7406 1.74330 49.22
24 223.4482 (d24)
25S ∞ (d25)
26 433.9229 3.8000 1.72342 37.99
27 -37.6454 1.0000 1.69680 55.46
28 47.4180 (bf)

[Variable interval when focusing at infinity]
Wide angle Medium telephoto
f 205.0000 299.9999 486.9996
d0 ∞ ∞ ∞
d5 21.4303 65.9246 120.2513
d16 38.5508 22.5010 8.7809
d19 1.5000 17.5498 31.2699
d24 31.4929 20.4210 2.3032
d25 2.5139 5.7070 1.5000
bf 104.0719 111.9506 134.2754

[Variable interval when focusing at close range (shooting distance: 2.2m)]
Wide angle Medium telephoto
f 179.1165 231.7878 291.6486
d0 1907.2564 1862.7622 1808.4353
d5 21.4303 65.9246 120.2513
d16 38.5508 22.5010 8.7809
d19 1.5000 17.5498 31.2699
d24 31.4929 20.4210 2.3032
d25 7.7118 15.8608 22.2165
bf 98.8740 101.7968 113.5589

[Values for conditional expressions]
Conditional expression (1) 0.195
Conditional expression (2) 0.910
Conditional expression (3) 0.893
Conditional expression (4) 7.951
Conditional expression (5) 1.212

S stop IP imaging surface 1, 2, 3,... Lens surface L1, L2, L3,... Lens group L2A, L2B, L2C lens group

Claims (6)

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a negative refractive power. A fifth lens group, and at the time of zooming from the wide-angle end to the telephoto end, at least the first lens group, the third lens group, and the fifth lens group move to the object side, and the first lens group and the second lens; The distance between the groups increases, the distance between the second lens group and the third lens group decreases, the distance between the third lens group and the fourth lens group increases, and the distance between the fourth lens group and the fifth lens group decreases. Zoom lens
The second lens group fixed upon zooming has at least a second A lens group having a negative refractive power and a second B lens group having a negative refractive power in order from the object side. The second B lens group is an image blur correction lens. A zoom lens having an image blur correction function, wherein the image blur is corrected by moving the lens in a direction substantially perpendicular to the optical axis, and satisfying the following conditional expression:
0.1 <| f2 | / ft <0.2 (1)
0.9 <f2B / f2 <1.5 (2)
Here, f2 is the focal length of the second lens group, ft is the focal length of the entire system in the telephoto end state, and f2B is the focal length of the second B lens group.   The second lens group includes three lens groups in order from the object side: a second A lens group having a negative refractive power, a second B lens group having a negative refractive power, and a second C lens group having a positive refractive power. A zoom lens having an image blur correction function according to claim 1. The zoom lens having an image blur correction function according to claim 2, wherein the following conditional expression is satisfied.
0.6 <f2AB / f2 <0.9 (3)
2.0 <f2C / | f2 | <15 (4)
Here, f2AB represents the combined focal length of the second A lens group and the second B lens group, f2 represents the focal length of the second lens group, and f2C represents the focal length of the second C lens group. The zoom lens having an image blur correction function according to claim 1, wherein the following conditional expression is satisfied.
1.0 <f3 / | f2 | <2.0 (5)
Here, f2 represents the focal length of the second lens group, and f3 represents the focal length of the third lens group.   5. The zoom lens having an image blur correction function according to claim 1, wherein the second lens group and the fourth lens group are fixed at the time of zooming.   The aperture stop is disposed between the fourth lens group and the fifth lens group, and moves independently of the other lens groups during zooming. Zoom lens with image blur correction function.

Images