Zoom lens and imaging apparatus having the same

Abstract

To provide a small-sized zoom lens having high image forming performance and achieving a high variable power ratio, and an imaging apparatus having the same.SOLUTION: A zoom lens comprises a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear group having one or more lens groups and having a positive refractive power as a whole, which are arranged in order from an object side to an image side. In zooming, the interval between the lens groups changes. Predetermined conditional expressions are satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens and an imaging device having the same, which is suitable for use in electronic cameras such as video cameras and digital still cameras, film cameras, broadcast cameras, and the like. [Background technology]

[0002] 2. Description of the Related Art Imaging devices such as digital cameras and video cameras require zoom lenses that are highly compact, cover a wide range of focal lengths from wide-angle to telephoto, and have high imaging performance throughout the entire zoom range.

[0003] In recent years, imaging devices such as cameras using solid-state imaging elements or silver halide film have become more sophisticated and the overall size of the devices has been reduced. Furthermore, the size of the imaging elements used in imaging devices has been reduced to obtain high-resolution images. Accordingly, the photographic optical systems used in imaging devices are required to have high resolving power up to high spatial frequencies, which is one of the criteria for evaluating resolving power.

[0004] Furthermore, in a small-sized imaging device system, since the imaging device itself is small, even a zoom lens with a large zoom ratio is required to have a small overall optical length.

[0005] Conventionally, zoom lens systems that include a lens group having positive refractive power on the object side are advantageous for achieving high magnification, and various proposals have been made for such systems.

[0006] For example, Patent Document 1 proposes a five-group zoom lens system with a positive-negative-positive-negative-positive configuration. This type of zoom lens system increases the number of lens groups that move during zooming, increasing the degree of freedom in aberration correction, thereby achieving both high imaging performance throughout the entire zoom range and compactness. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-175324 Summary of the Invention [Problem to be solved by the invention]

[0008] Meanwhile, there is a demand for zoom lenses that have not only high imaging performance but also telephoto capabilities, and there is a particularly strong demand for telephoto zoom lenses with a focal length close to 400 mm.

[0009] There is a demand for a zoom lens with a higher zoom ratio than the zoom lens described in Patent Document 1.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a zoom lens that has high imaging performance, achieves a high zoom ratio, and is compact, and an image pickup apparatus having the same. [Means for solving the problem]

[0011] A zoom lens according to one aspect of the present invention is a zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between the lens groups changes during zooming, and when the focal length of the entire system at the wide-angle end is fw, the focal length of the entire system at the telephoto end is ft, the focal length of the second lens group is f2, the refractive index of the positive lens in the second lens group with the smallest Abbe number is nd2p, and the Abbe number of the positive lens in the second lens group with the smallest Abbe number is vd2p, -0.080 <f2 / ft<-0.040 1.750 <nd2p<1.800 22.0 <vd2p<25.0 10.0 <ft / fw<20.0 The present invention is characterized in that the following conditional expression is satisfied:

[0012] Another aspect of the present invention is a zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between the lens groups changes during zooming, the second lens group has a plurality of negative lenses, and when the refractive index of the positive lens in the second lens group having the smallest Abbe number is denoted by nd2p, 1.750 <nd2p<1.800 The present invention is characterized in that the following conditional expression is satisfied:

[0013] Other objects and features of the present invention are illustrated in the following examples. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a zoom lens that has high imaging performance, realizes a high zoom ratio, and is compact, and an imaging apparatus having the same. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view of a zoom lens according to a first embodiment of the present invention when focused on an object at infinity at the wide-angle end (short focal length end). [Figure 2] Longitudinal aberration diagram when the zoom lens of Example 1 is focused on an object at infinity at the wide-angle end. [Figure 3] Longitudinal aberration diagram when the zoom lens of Example 1 is focused on an object at infinity at the telephoto end (long focal length end). [Figure 4] 1 is a cross-sectional view of a zoom lens according to a second embodiment of the present invention when focused on an object at infinity at the wide-angle end. [Figure 5] Longitudinal aberration diagram when the zoom lens of Example 2 is focused on an object at infinity at the wide-angle end. [Figure 6] Longitudinal aberration diagram when the zoom lens of Example 2 is focused on an object at infinity at the telephoto end. [Figure 7]10 is a cross-sectional view of a zoom lens according to a third embodiment of the present invention when focused on an object at infinity at the wide-angle end. [Figure 8] Longitudinal aberration diagram when the zoom lens of Example 3 is focused on an object at infinity at the wide-angle end. [Figure 9] Longitudinal aberration diagram when the zoom lens of Example 3 is focused on an object at infinity at the telephoto end. [Figure 10] 10 is a cross-sectional view of a zoom lens according to a fourth embodiment of the present invention when focused on an object at infinity at the wide-angle end. [Figure 11] Longitudinal aberration diagram when the zoom lens of Example 4 is focused on an object at infinity at the wide-angle end. [Figure 12] Longitudinal aberration diagram when the zoom lens of Example 4 is focused on an object at infinity at the telephoto end. [Figure 13] 10 is a cross-sectional view of a zoom lens according to a fifth embodiment of the present invention when focused on an object at infinity at the wide-angle end. [Figure 14] Longitudinal aberration diagram when the zoom lens of Example 5 is focused on an object at infinity at the wide-angle end. [Figure 15] Longitudinal aberration diagram when the zoom lens of Example 5 is focused on an object at infinity at the telephoto end. [Figure 16] 10 is a cross-sectional view of a zoom lens according to a sixth embodiment of the present invention when focused on an object at infinity at the wide-angle end. [Figure 17] Longitudinal aberration diagram when the zoom lens of Example 6 is focused on an object at infinity at the wide-angle end. [Figure 18] Longitudinal aberration diagram when the zoom lens of Example 6 is focused on an object at infinity at the telephoto end. [Figure 19] Schematic diagram of the main parts of a camera (image capture device) equipped with the optical system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Each embodiment relates to a zoom lens and an image pickup apparatus having the same.

[0017] FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment of the present invention when focused on an object at infinity at the wide-angle end (short focal length end).

[0018] FIG. 2 is a longitudinal aberration diagram when the zoom lens of Example 1 is focused on an object at infinity at the wide-angle end.

[0019] FIG. 3 is a longitudinal aberration diagram when the zoom lens of Example 1 is focused on an object at infinity at the telephoto end (long focal length end).

[0020] FIG. 4 is a cross-sectional view of a zoom lens according to a second embodiment of the present invention when the zoom lens is focused on an object at infinity at the wide-angle end.

[0021] FIG. 5 is a longitudinal aberration diagram when the zoom lens of Example 2 is focused on an object at infinity at the wide-angle end.

[0022] FIG. 6 is a longitudinal aberration diagram when the zoom lens of Example 2 is focused on an object at infinity at the telephoto end.

[0023] FIG. 7 is a cross-sectional view of a zoom lens according to a third embodiment of the present invention when the zoom lens is focused on an object at infinity at the wide-angle end.

[0024] FIG. 8 is a longitudinal aberration diagram when the zoom lens of Example 3 is focused on an object at infinity at the wide-angle end.

[0025] FIG. 9 is a longitudinal aberration diagram when the zoom lens of Example 3 is focused on an object at infinity at the telephoto end.

[0026] FIG. 10 is a cross-sectional view of a zoom lens according to a fourth embodiment of the present invention when the zoom lens is focused on an object at infinity at the wide-angle end.

[0027] FIG. 11 is a longitudinal aberration diagram when the zoom lens of Example 4 is focused on an object at infinity at the wide-angle end.

[0028] FIG. 12 is a longitudinal aberration diagram when the zoom lens of Example 4 is focused on an object at infinity at the telephoto end.

[0029] FIG. 13 is a cross-sectional view of a zoom lens according to a fifth embodiment of the present invention when the zoom lens is focused on an object at infinity at the wide-angle end.

[0030] FIG. 14 is a longitudinal aberration diagram when the zoom lens of Example 5 is focused on an object at infinity at the wide-angle end.

[0031] FIG. 15 is a longitudinal aberration diagram when the zoom lens of Example 5 is focused on an object at infinity at the telephoto end.

[0032] FIG. 16 is a cross-sectional view of a zoom lens according to a sixth embodiment of the present invention when the zoom lens is focused on an object at infinity at the wide-angle end.

[0033] FIG. 17 is a longitudinal aberration diagram when the zoom lens of Example 6 is focused on an object at infinity at the wide-angle end.

[0034] FIG. 18 is a longitudinal aberration diagram when the zoom lens of Example 6 is focused on an object at infinity at the telephoto end.

[0035] FIG. 19 is a schematic diagram of an imaging device.

[0036] The zoom lens of each embodiment is a photographic lens system used in image pickup devices such as video cameras, digital cameras, and silver halide film cameras.

[0037] In the lens cross-sectional view, the left is the object side (front) and the right is the image side (rear). In the lens cross-sectional view, i indicates the order of the lens groups from the object side, and Li is the ith lens group.

[0038] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0039] IP is the image plane, and when used as the shooting optical system of a video camera or digital still camera, it is placed on the imaging surface of a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor, and in the case of a silver halide film camera, it is placed on the photosensitive surface equivalent to the film surface.

[0040] In the aberration diagram, d and g represent the d-line and g-line, respectively. M and S represent the meridional and sagittal image planes, and lateral chromatic aberration is represented by the g-line.

[0041] ω is the half angle of view, and Fno is the F-number.

[0042] In the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when each lens group is located at either end of the range in which it can mechanically move on the optical axis.

[0043] The arrows indicate the movement locus of each lens group during zooming from the wide-angle end to the telephoto end.

[0044] In Examples 1 and 5 shown in FIGS. 1 and 13, focusing is performed by moving the fourth lens group L4 in the optical axis direction. In Example 2 shown in FIG. 4, focusing is performed by moving the fourth lens group L4 and the fifth lens group L5 in the optical axis direction. In Examples 3 and 4 shown in FIGS. 1 and 13, focusing is performed by moving the sixth lens group L6 in the optical axis direction. In Example 6 shown in FIG. 16, focusing is performed by moving the fifth lens group L5 in the optical axis direction.

[0045] Incidentally, focusing may be performed by moving the entire zoom lens or any one of the lens groups.

[0046] In Examples 1 to 6, the vibration-reduction lens group IS moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur caused when the entire zoom lens vibrates.

[0047] Next, features of each embodiment other than those described above will be described.

[0048] In a positive-lead zoom lens, achieving good optical performance across the entire object distance while achieving a high zoom ratio and compactness of the entire lens system is an important challenge. To achieve this, it is important to properly set the refractive power and lens configuration of each lens group, as well as the movement conditions of each lens group during zooming. Without properly setting these configurations, it becomes extremely difficult to achieve a zoom lens that maintains a high zoom ratio while also exhibiting excellent optical performance across the entire zoom range. Correcting axial chromatic aberration and lateral chromatic aberration becomes increasingly difficult, particularly as the focal length at the telephoto end increases.

[0049] In order to solve the above problem, the present invention sets the following conditions for a zoom lens having, in order from the object side, a first lens unit L1 having positive refractive power, a second lens unit L2 having negative refractive power, and a subsequent lens unit L3 having positive refractive power as a whole.

[0050] In each embodiment of the present invention, when the focal length of the entire system at the telephoto end is ft and the focal length of the second lens unit L2 is f2, -0.080 <f2 / ft<-0.040···(1) The present invention is characterized in that the following conditional expressions are satisfied:

[0051] Conditional formula (1) defines the focal length of the second lens unit L2. Satisfying conditional formula (1) facilitates the creation of a retrofocus-type power arrangement at the wide-angle end, thereby achieving both a wider angle of view at the wide-angle end and high optical performance across the entire zoom range, with minimal fluctuations in aberrations. If the refractive power of the second lens unit L2 becomes too strong, exceeding the upper limit of conditional formula (1), the refractive power of the second lens unit L2 becomes too strong, making it difficult to minimize fluctuations in spherical aberration and lateral chromatic aberration that occur during zooming. Furthermore, the divergence effect of the second lens unit L2 on the axial light beam becomes too great, making it difficult to reduce the size of the subsequent lens groups. If the refractive power of the second lens unit L2 becomes too small, exceeding the lower limit of conditional formula (1), it becomes difficult to create a retrofocus-type power arrangement at the wide-angle end, making it difficult to widen the angle of view at the wide-angle end.

[0052] When the refractive index of the positive lens with the smallest Abbe number in the second lens unit L2 is nd2p, 1.750 <nd2p<1.800···(2) The present invention is characterized in that the following conditional expressions are satisfied:

[0053] Conditional expression (2) defines the refractive index of the positive lens element in the second lens unit L2 that has the smallest Abbe number. If the upper limit of conditional expression (2) is exceeded and the refractive index of the positive lens element becomes too high, the Petzval sum becomes large in the negative direction, making it difficult to correct curvature of field. If the lower limit of conditional expression (2) is exceeded and the refractive index of the positive lens element becomes too low, making it difficult to correct spherical aberration at the telephoto end.

[0054] When the Abbe number of the positive lens with the smallest Abbe number in the second lens unit L2 is vd2p, 22.0 <vd2p<25.0···(3) The present invention is characterized in that the following conditional expressions are satisfied:

[0055] Conditional expression (3) defines the refractive index of the positive lens element in the second lens group that has the smallest Abbe number. By satisfying conditional expression (3), axial chromatic aberration and lateral chromatic aberration at the telephoto end can be effectively corrected.

[0056] When the focal length of the entire system at the wide-angle end is fw and the focal length of the entire system at the telephoto end is ft, 10.0 <ft / fw<20.0···(4) The present invention is characterized in that the following conditional expressions are satisfied:

[0057] By ensuring that the value corresponding to conditional expression (4) is not below the lower limit, an optical system with a higher zoom ratio can be provided. By ensuring that the value corresponding to conditional expression (4) is not above the upper limit, the zoom ratio does not become too high, which is advantageous for miniaturization.

[0058] It is also preferable that the second lens unit L2 has a plurality of negative lenses. By including a plurality of negative lenses in the second lens unit L2, the refractive power of each negative lens can be weakened, off-axis rays can be gently bent in the second lens unit L2, and distortion and curvature of field at the wide-angle end can be effectively corrected.

[0059] In the optical system of each embodiment, it is preferable to satisfy one or more of the following conditional expressions: By doing so, the effects corresponding to each conditional expression can be obtained.

[0060] When the focal length of the positive lens in the second lens unit L2 with the smallest Abbe number is f2p, 0.065 <f2p / ft<0.110···(5) It is preferable to satisfy the following conditional expression.

[0061] Conditional expression (5) defines the focal length of the positive lens element in the second lens unit L2 that has the smallest Abbe number. If the upper limit of conditional expression (5) is exceeded and the refractive power of the positive lens element becomes too weak, it becomes difficult to correct axial chromatic aberration and lateral chromatic aberration at the telephoto end. If the lower limit is exceeded and the refractive power of the positive lens element becomes too strong, it becomes difficult to correct spherical aberration at the telephoto end.

[0062] When the partial dispersion ratio of the positive lens with the smallest Abbe number in the second lens unit L2 is θgF2p, 0.600<θgF2p<0.670 (6) It is preferable to satisfy the following condition: where θgF2p is the partial dispersion ratio of the positive lens, and is defined by the following formula when the refractive index of the positive lens for the g-line is ng2p, the refractive index of the positive lens for the F-line is nF2p, and the refractive index of the positive lens for the C-line is nC2p. θgF2p=(ng2p-nF2p) / (nF2p-nC2p) Conditional expression (6) defines the anomalous dispersion of the positive lens element in the second lens unit L2 that has the smallest Abbe number. By satisfying conditional expression (6), it becomes possible to effectively correct secondary spectrum in addition to primary achromatism in the correction of chromatic aberration. If the upper limit of conditional expression (6) is exceeded and the partial dispersion ratio of the positive lens element becomes too large, chromatic aberration for the g-line at the telephoto end becomes too large on the negative side. If the lower limit of conditional expression (6) is exceeded and the partial dispersion ratio of the positive lens element becomes too small, chromatic aberration for the g-line at the telephoto end becomes too large on the positive side.

[0063] When the average Abbe number of the positive lenses included in the first lens unit L1 is vd1p, 3.00 <vd1p / vd2p<4.00···(7) It is preferable to satisfy the following conditional expression.

[0064] Conditional expression (7) defines the ratio of the Abbe number of the positive lens in the first lens unit L1 to the Abbe number of the positive lens in the second lens unit L2. By satisfying conditional expression (7), first-order chromatic aberration can be effectively corrected (achromatized). If the upper limit of conditional expression (7) is exceeded and the Abbe number of the positive lens in the first lens unit L1 becomes too large, it becomes difficult to correct lateral chromatic aberration at the wide-angle end. If the lower limit of conditional expression (7) is exceeded and the Abbe number of the positive lens in the first lens unit L1 becomes too small, it becomes difficult to correct lateral chromatic aberration at the telephoto end.

[0065] When the average value of the Abbe numbers of the negative lenses included in the second lens unit L2 is vd2n, 1.70 <vd2n / vd2p<2.40···(8) It is preferable to satisfy the following conditional expression.

[0066] Conditional expression (8) defines the ratio of the Abbe number of the negative lens in the second lens unit L2 to the Abbe number of the positive lens in the second lens unit L2. By satisfying conditional expression (8), first-order chromatic aberration can be effectively corrected (achromatization). If the upper limit of conditional expression (8) is exceeded and the Abbe number of the negative lens in the second lens unit L2 becomes too large, it becomes difficult to correct lateral chromatic aberration at the telephoto end. Furthermore, since the refractive index of the negative lens decreases, it becomes difficult to correct field curvature at the wide-angle end. If the Abbe number of the negative lens in the second lens unit L2 becomes too small and the lower limit of conditional expression (8) is exceeded, it becomes difficult to correct lateral chromatic aberration at the wide-angle end.

[0067] When the Abbe number of the negative lens with the smallest Abbe number in the first lens unit L1 is vd1n, 1.00 <vd1n / vd2p<1.80···(9) It is preferable to satisfy the following conditional expression.

[0068] Conditional expression (9) defines the ratio of the Abbe number of the negative lens in the first lens unit L1 to the Abbe number of the positive lens in the second lens unit L2. By satisfying conditional expression (9), it becomes possible to effectively correct not only primary achromatism but also secondary spectrum aberrations. If the upper limit of conditional expression (9) is exceeded and the Abbe number of the negative lens in the first lens unit L1 becomes too large, it becomes difficult to correct chromatic aberrations (primary achromatism). Furthermore, since the refractive index of the negative lens decreases, it becomes difficult to correct spherical aberrations (secondary spectrum aberrations) at the telephoto end. If the Abbe number of the negative lens in the first lens unit L1 becomes too small and the lower limit of conditional expression (9) is exceeded, it becomes difficult to correct chromatic aberrations (secondary spectrum aberrations) at the telephoto end.

[0069] When the refractive index of the negative lens with the smallest Abbe number in the first lens unit L1 is nd1n, 0.95 <nd1n / nd2p<1.30···(10) It is preferable to satisfy the following conditional expression.

[0070] Conditional expression (10) defines the ratio of the refractive index of the negative lens in the first lens unit L1 to the Abbe number of the positive lens in the second lens unit L2. If the upper limit of conditional expression (10) is exceeded and the refractive index of the negative lens in the first lens unit L1 becomes too high, it becomes difficult to correct axial chromatic aberration and the secondary spectrum of lateral chromatic aberration at the telephoto end due to the tendency toward high dispersion. If the lower limit of conditional expression (10) is exceeded and the refractive index of the negative lens in the first lens unit L1 becomes too low, it becomes difficult to correct spherical aberration at the telephoto end.

[0071] When the focal length of the entire system at the wide-angle end is fw and the focal length of the first lens unit L1 is f1, 4.75 <f1 / fw<10.00···(11) It is preferable to satisfy the following conditional expression.

[0072] Conditional expression (11) defines the focal length of the first lens unit L1. Satisfying conditional expression (11) facilitates the creation of a telephoto-type power arrangement at the telephoto end, thereby shortening the overall optical length at the telephoto end, minimizing fluctuations in aberrations throughout the entire zoom range, and achieving high optical performance across the entire image field. If the refractive power of the first lens unit L1 becomes too weak by exceeding the upper limit of conditional expression (11), the amount of movement of the first lens unit L1 must be increased for zooming, which undesirably increases the overall lens length at the telephoto end. It also makes it difficult to reduce the diameter of the front lens element. If the refractive power of the first lens unit L1 becomes too strong by exceeding the lower limit of conditional expression (11), this is advantageous for achieving a high zoom ratio, but makes it difficult to correct spherical aberration at the telephoto end.

[0073] The subsequent lens group preferably has, in order from the object side, an intermediate lens group LM having positive refractive power, a lens group LN-1 having negative refractive power, and a lens group LN having other refractive powers, and the spacing between the lens groups should change during zooming.

[0074] The above configuration makes it easier to adopt a telephoto type power arrangement, and makes it easier to shorten the overall length of the optical system.

[0075] When the focal length of the lens group LN is fN, -1.50 <fN / ft<-0.10···(12) It is preferable to satisfy the following conditional expression.

[0076] Conditional expression (12) defines the focal length of the lens unit LN. If the refractive power of the lens unit LN becomes too strong, exceeding the upper limit of conditional expression (12), it becomes difficult to correct curvature of field at the wide-angle end. Furthermore, the exit pupil becomes too short at the wide-angle end, causing the incident light beam to be obliquely incident on the solid-state image sensor, making shading more noticeable. If the refractive power of the lens unit LN becomes too weak, exceeding the lower limit of conditional expression (12), it becomes difficult to achieve a telephoto-type power arrangement, making it difficult to shorten the overall optical length at the telephoto end.

[0077] When the back focus at the wide-angle end is skw, 0.30 <skw / fw<0.70···(13) It is preferable to satisfy the following conditional expression.

[0078] Condition (13) defines the ratio of the focal length of the entire system to the back focus at the wide-angle end. By satisfying condition (13), it is possible to obtain good optical performance while miniaturizing the optical system.

[0079] When the focal length of the lens group LN-1 is fN-1, -0.30 <fN-1 / ft<-0.05···(14) It is preferable to satisfy the following conditional expression.

[0080] Conditional expression (14) is used to appropriately set the focal length of the lens group LN-1. By satisfying conditional expression (14), it becomes possible to achieve both compactness and good optical performance when the lens group LF is used as a focus lens group. If the upper limit of conditional expression (14) is exceeded, the refractive power of the lens group LN-1 becomes too strong, making it difficult to correct lateral chromatic aberration and curvature of field. If the lower limit of conditional expression (14) is exceeded, the refractive power of the lens group LN-1 becomes too weak, increasing the amount of movement during focusing and increasing aberration fluctuations during close focusing.

[0081] When the focal length of the image stabilization lens group IS is fIS, 0.10 <fIS / ft<0.20 ···(15) It is preferable to satisfy the following conditional expression.

[0082] Conditional expression (15) defines the focal length of the image stabilization lens group IS. If the upper limit of conditional expression (15) is exceeded and the refractive power of the image stabilization lens group IS becomes too weak, the amount of movement during image stabilization becomes large, making it difficult to reduce the lens outer diameter. If the lower limit of conditional expression (15) is exceeded and the refractive power of the image stabilization lens group IS becomes too strong, decentering coma and asymmetric curvature of field occur, making it difficult to achieve good image stabilization performance.

[0083] When the amount of movement of the second lens unit L2 from the wide-angle end to the telephoto end is m2, 0.25 <m2 / fw<1.00···(16) It is preferable to satisfy the following conditional expression.

[0084] Conditional expression (16) defines the amount of movement of the second lens unit L2 from the wide-angle end to the telephoto end. If the upper limit of conditional expression (16) is exceeded and the amount of movement of the second lens unit L2 becomes too large, the total optical length at the telephoto end becomes too long, and the optical system becomes large. In addition, the zoom torque during zooming becomes too heavy. If the lower limit of conditional expression (16) is exceeded and the amount of movement of the second lens unit L2 becomes too small, the refractive power of the second lens unit L2 becomes too strong in order to maintain the zoom ratio, making it difficult to correct spherical aberration and chromatic aberration at the telephoto end.

[0085] When the movement amount of the first lens unit L1 from the wide-angle end to the telephoto end is m1, 3.00 <m1 / fw<4.50···(17) It is preferable to satisfy the following conditional expression.

[0086] Conditional expression (17) defines the amount of movement of the first lens unit L1 from the wide-angle end to the telephoto end. If the upper limit of conditional expression (17) is exceeded and the amount of movement of the first lens unit L1 becomes too large, the total optical length at the telephoto end becomes too long, and the optical system becomes large. In addition, the zoom torque during zooming becomes too heavy. If the lower limit of conditional expression (17) is exceeded and the amount of movement of the first lens unit L1 becomes too small, the refractive power of the first lens unit L1 becomes too strong in order to maintain the zoom ratio, making it difficult to correct spherical aberration and chromatic aberration at the telephoto end.

[0087] When the focal length of the intermediate group LM at the wide-angle end is fMw, 0.060 <fMw / ft<0.130···(18) It is preferable to satisfy the following conditional expression.

[0088] Conditional expression (18) defines the focal length of the intermediate unit LM. If the upper limit of conditional expression (18) is exceeded and the refractive power of the intermediate unit LM becomes too weak, it becomes difficult to obtain a magnification ratio exceeding 10. If the lower limit of conditional expression (18) is exceeded and the refractive power of the intermediate unit LM becomes too strong, it becomes difficult to suppress zoom fluctuations in spherical aberration and to correct spherical aberration at the wide-angle end.

[0089] When the total optical length at the telephoto end is TLt, 0.55 <TLt / ft<0.85···(19) It is preferable to satisfy the following conditional expression.

[0090] Conditional expression (19) defines the ratio between the total optical length at the telephoto end and the focal length of the entire system at the telephoto end. By satisfying conditional expression (19), it is possible to achieve a compact optical system while also obtaining good optical performance.

[0091] When the focal length of the first lens group L1 is f1 and the focal length of the second lens group L2 is f2, -8.00 <f1 / f2<-6.00···(20) It is preferable to satisfy the following conditional expression.

[0092] Conditional expression (20) defines the ratio of the focal lengths of the first lens unit L1 and the second lens unit L2. If the upper limit of conditional expression (20) is exceeded and the refractive power of the first lens unit L1 becomes too strong, it becomes difficult to correct spherical aberration at the telephoto end. If the lower limit of conditional expression (20) is exceeded and the refractive power of the second lens unit L2 becomes too strong, it becomes difficult to correct fluctuations in field curvature during zooming.

[0093] When the focal length of the intermediate lens unit LM at the wide-angle end is fMw and the focal length of the second lens unit L2 is f2, -2.50 <fMw / f2<-1.00···(21) It is preferable to satisfy the following conditional expression.

[0094] Conditional expression (21) defines the ratio of the focal lengths of the intermediate lens unit LM and the second lens unit L2. If the upper limit of conditional expression (21) is exceeded and the refractive power of the intermediate lens unit LM becomes too strong, it becomes difficult to correct spherical aberration at the wide-angle end. If the lower limit of conditional expression (21) is exceeded and the refractive power of the second lens unit L2 becomes too strong, it becomes difficult to correct fluctuations in field curvature during zooming.

[0095] When the focal length of the second lens group L2 is f2 and the focal length of the lens group LN is fN, 0.030 <f2 / fN<0.250···(22) It is preferable to satisfy the following conditional expression.

[0096] Conditional expression (22) defines the ratio of the focal lengths of the second lens unit L2 and the lens unit LN. If the upper limit of conditional expression (22) is exceeded and the refractive power of the lens unit LN becomes too strong, it becomes difficult to correct curvature of field at the wide-angle end. If the lower limit of conditional expression (22) is exceeded and the refractive power of the second lens unit L2 becomes too strong, it becomes difficult to correct fluctuations in curvature of field during zooming.

[0097] In each embodiment, it is preferable to set the numerical ranges of the above-mentioned conditional expressions (1) to (22) as follows:

[0098] -0.070 <f2 / ft<-0.045···(1a) 1.752 <nd2p<1.799···(2a) 22.2 <vd2p<24.9···(3a) 12.0 <ft / fw<18.0···(4a) 0.065 <f2p / ft<0.110···(5a) 0.610<θgF2p<0.660 (6a) 3.10 <vd1p / vd2p<3.80···(7a) 1.80 <vd2n / vd2p<2.30···(8a) 1.10 <vd1n / vd2p<1.70···(9a) 1.00 <nd1n / nd2p<1.20···(10a) 4.80 <f1 / fw<8.00···(11a) -1.30 <fN / ft<-0.15···(12a) 0.33 <skw / fw<0.65···(13a) -0.25 <fN-1 / ft<-0.10···(14a) 0.11 <fIS / ft<0.18 ···(15a) 0.25 <m2 / fw<1.00···(16a) 3.20 <m1 / fw<4.20···(17a) 0.070 <fMw / ft<0.125···(18a) 0.60 <TLt / ft<0.80···(19a) -7.50 <f1 / f2<-6.20 ···(20a) -2.40 <fMw / f2<-1.20 ···(21a) 0.040 <f2 / fN<0.230···(22a) It is more preferable to set the numerical ranges of the above-mentioned conditional expressions (1) to (22) as follows:

[0099] -0.060 <f2 / ft<-0.050···(1b) 1.754 <nd2p<1.798···(2b) 22.4 <vd2p<24.8···(3b) 12.0 <ft / fw<18.0···(4b) 0.065 <f2p / ft<0.110···(5b) 0.620<θgF2p<0.650 (6b) 3.20 <vd1p / vd2p<3.60···(7b) 1.90 <vd2n / vd2p<2.20···(8b) 1.20 <vd1n / vd2p<1.60···(9b) 1.05 <nd1n / nd2p<1.15···(10b) 4.80 <f1 / fw<8.00···(11b) -1.30 <fN / ft<-0.15···(12b) 0.33 <skw / fw<0.65···(13b) -0.25 <fN-1 / ft<-0.10···(14b) 0.11 <fIS / ft<0.18 ···(15b) 0.25 <m2 / fw<1.00···(16b) 3.20 <m1 / fw<4.20···(17b) 0.070 <fMw / ft<0.125···(18b) 0.60 <TLt / ft<0.80···(19b) -7.50 <f1 / f2<-6.20 ···(20b) -2.40 <fMw / f2<-1.20 ···(21b) 0.040 <f2 / fN<0.230···(22b) As described above, according to each embodiment, it is possible to provide a zoom lens that has high imaging performance, realizes a high zoom ratio, and is compact, as well as an image pickup apparatus having the same.

[0100] In the zoom lens of each embodiment, it is preferable to vapor-deposit a fluorine coating on at least one of the object-side surface of the lens positioned closest to the object and the image-side surface of the lens positioned closest to the image. Because the object-side surface of the lens positioned closest to the object and the image-side surface of the lens positioned closest to the image are easily exposed to the outside world, vapor-depositing a fluorine coating can improve water and oil repellency, suppress flare, and achieve high optical performance. In particular, because the object-side surface of the lens positioned closest to the object has a large diameter, it is preferable to vapor-deposit a fluorine coating.

[0101] In the zoom lens of each embodiment, the positive lens and negative lens constituting the cemented lens are preferably bonded with an adhesive having an axial thickness of 0.005 mm or more and 0.05 mm or less. If it is less than 0.005 mm, the adhesive is prone to peeling, and if it is more than 0.03 mm, the axial distance from the surface of the cemented lens closest to the object to the surface closest to the image becomes long, resulting in a long overall lens length. More preferably, it should be 0.008 mm or more and 0.02 mm or less.

[0102] At least one lens element in the zoom lens of each embodiment is provided with an anti-reflection coating for preventing reflection, and the anti-reflection coating is composed of multiple films. Here, when the refractive index of the film closest to the air interface is Nd, the anti-reflection coating PC preferably has Nd of 1.32 or less. By setting Nd to 1.32 or less, the difference in refractive index with air can be reduced, thereby further reducing light reflection and reducing ghosting. Specific examples of the anti-reflection coating PC include, but are not limited to, multilayer films formed using a wet method, as described in JP 2012-230211 A and JP 2014-95877 A. More preferably, setting Nd to 1.30 or less can further reduce ghosting.

[0103] Here, it is preferable to provide an anti-reflection coating PC on the image-side surface of the negative lens element with a concave surface facing the image side among the negative lenses arranged in the zoom lens.Light reflected by a negative lens element with a concave surface facing the image side tends to be reflected at a large angle with respect to the normal direction of the surface of the negative lens element with a concave surface facing the image side, and therefore tends to have a high reflectance.

[0104] Furthermore, light reflected by a negative lens with a concave surface facing the image side tends to converge on the image plane, making ghosting more noticeable. Therefore, ghosting can be reduced by applying an anti-reflection coating PC to the image-side surface of a negative lens with a concave surface facing the image side.

[0105] It is particularly preferable to provide an anti-reflection coating PC on the negative lens located closest to the object in the second lens unit L2.

[0106] Numerical Examples 1 to 6 corresponding to Examples 1 to 6, respectively, are shown below. In each numerical example, i indicates the order of the surface from the object side, ri indicates the radius of curvature of the ith surface (i-th surface), di indicates the distance between the ith surface and the (i+1)th surface, ndi and vdi indicate the refractive index and Abbe number based on the d-line, respectively. f indicates the focal length, and Fno indicates the F-number.

[0107] (Aspherical surface data) shows the aspherical surface coefficients when the aspherical surface is expressed by the following formula.

[0108] x=(h 2 / R) / [1+{1-(1+k)(h / R) 2} 1 / 2 ]+C4×h 4 +C6×h 6 +C8×h 8 +C 10 ×h 10 +C 12 ×h 12 however, x: Displacement from the reference plane in the optical axis direction h: Height perpendicular to the optical axis R: Radius of the base quadratic surface k: conic constant C n :nth-order aspheric coefficient The "EZ" display is "x10 -Z " means.

[0109] Table 1 shows the relationship between the above-mentioned conditional expressions and the various values ​​in the numerical examples.

[0110] [Numerical Example 1] In the lens cross-sectional view of Figure 1, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group (middle group LM) with positive refractive power, L4 is a fourth lens group (lens group LN-1) with negative refractive power, and L5 is a fifth lens group (lens group LN) with negative refractive power.

[0111] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0112] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0113] The third lens group L3 includes, in order from the object side, a biconvex positive lens, a positive meniscus lens with a convex surface facing the object side, and a cemented negative lens formed by cementing a positive meniscus lens with a convex surface facing the object side to a negative meniscus lens with a convex surface facing the object side. Further, located closer to the image side than the cemented negative lens, there is a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side to a biconvex positive lens, and a cemented negative lens formed by cementing a biconcave negative lens to a biconvex positive lens with an aspherical surface formed on the image side. Further, located closer to the image side than the cemented negative lens, there is a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side to a biconvex positive lens.

[0114] The fourth lens unit L4 is composed of, in order from the object side, a cemented negative lens formed by cementing together a biconvex positive lens and a biconcave negative lens.

[0115] The fifth lens group L5 is composed of, in order from the object side, a biconvex positive lens and a negative meniscus lens with its concave surface facing the object side and an aspherical surface formed on its object side.

[0116] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0117] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side as shown by the arrow. The second lens unit L2 moves toward the object side while increasing the distance between it and the first lens unit L1. The third lens unit L3 moves toward the object side while decreasing the distance between it and the second lens unit L2. The fourth lens unit L4 moves toward the object side while increasing the distance between it and the third lens unit L3. The fifth lens unit L5 moves toward the object side while increasing the distance between it and the fourth lens unit L4.

[0118] The aperture stop SP moves together with the third lens unit L3.

[0119] The vibration-reduction lens group IS is a cemented positive lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis and thereby correcting image blur that occurs when the entire zoom lens vibrates.In other words, it performs vibration reduction.

[0120] Focusing is performed by moving the fourth lens unit L4 toward the image side.

[0121] The surface data of the first numerical example is as follows:

[0122] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 168.758 1.85 1.91082 35.2 65.14 2 89.764 8.31 1.49700 81.5 64.01 3 -605.497 0.15 63.85 4 83.297 6.94 1.49700 81.5 62.35 5 870.619 (variable) 61.77 6* 152.791 0.05 1.58946 30.6 34.11 7 106.926 1.00 1.75500 52.3 34.07 8 21.768 7.71 27.77 9 -44.683 0.90 1.77250 49.6 27.07 10 108.211 0.15 26.13 11 47.208 5.10 1.77830 23.9 25.84 0.6248 12 -51.849 2.93 25.17 13 -24.448 0.90 1.77250 49.6 22.90 14 -74.239 (variable) 22.69 15 (Aperture) ∞ 0.40 23.70 16 32.181 4.98 1.48749 70.2 25.02 17 -101.649 0.15 25.03 18 42.818 2.28 1.48749 70.2 24.72 19 118.396 0.15 24.42 20 21.475 5.35 1.51823 58.9 23.50 21 6697.926 1.00 1.83481 42.7 22.35 22 20.359 2.75 20.45 23 35.535 1.00 2.00069 25.5 20.45 24 21.611 4.77 1.63930 44.9 19.88 25 -93.585 2.44 19.62 26 -26.740 1.00 1.81600 46.6 19.17 27 24.727 5.80 1.58313 59.4 19.89 28* -65.360 0.13 20.83 29 33.535 1.10 1.80400 46.5 21.85 30 21.241 8.85 1.58313 59.4 21.62 31 -27.494 (variable) 21.79 32 230.759 2.54 1.84666 23.8 21.77 33 -55.269 0.80 1.70154 41.2 21.71 34 30.810 (variable) 21.39 35 71.151 4.05 1.53172 48.8 29.28 36 -94.689 8.78 29.42 37* -26.644 1.60 1.80400 46.5 29.36 38 -76.837 (variable) 31.07 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 3.83583e-06 A 6=-4.89664e-10 A 8= 2.81674e-11 A10=-1.08555e-13 A12= 2.38728e-16 Page 28 K = 0.00000e+00 A 4= 1.34099e-05 A 6= 1.27757e-08 A 8= 9.54950e-11 A10=-7.67410e-13 A12= 2.63160e-15 Page 37 K = 0.00000e+00 A 4= 9.72747e-06 A 6= 8.48098e-09 A 8=-4.03322e-11 A10= 2.11232e-13 A12=-3.66054e-16 Various data Zoom ratio 13.42 Wide-angle Mid-range Telephoto Focal length 28.90 105.93 388.00 F-number 3.37 5.36 6.49 Half angle of view 33.71 11.54 3.16 Image height 19.28 21.64 21.39 Lens total length 173.50 222.63 282.93 BF 14.73 36.49 45.07 d 5 1.00 43.23 89.39 d14 39.98 13.43 2.54 d31 1.49 11.00 3.27 d34 20.39 22.58 46.74 d38 14.73 36.49 45.07 Zoom lens group data Group starting plane focal length 1 1 143.15 2 6 -20.96 3 15 36.00 4 32 -61.33 5 35 -251.41 Single lens data Lens starting surface focal length 1 1 -212.92 2 2 157.92 3 4 184.79 4 6 -604.52 5 7 -36.38 6 9 -40.83 7 11 32.48 8 13 -47.56 9 16 50.76 10 18 136.25 11 20 41.56 12 21 -24.46 13 23 -57.17 14 24 27.91 15 26 -15.61 16 27 31.51 17 29 -75.06 18 30 22.02 19 32 52.88 20 33 -28.09 21 35 77.06 22 37 -51.46 [Numerical Example 2] In the lens cross-sectional view of Figure 4, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group with positive refractive power, L4 is a fourth lens group with positive refractive power, L5 is a fifth lens group (lens group LN-1) with negative refractive power, and L6 is a sixth lens group (lens group LN) with negative refractive power.

[0123] The intermediate group LM includes a third lens group and a fourth lens group.

[0124] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0125] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0126] The third lens group L3 includes, in order from the object side, a biconvex positive lens, a positive meniscus lens with a convex surface facing the object side, and a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens. Further, on the image side of the cemented negative lens, there is a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a cemented negative lens formed by cementing a biconcave negative lens and a biconvex positive lens with an aspherical surface formed on the image side.

[0127] The fourth lens unit L4 is composed of, in order from the object side, a cemented positive lens in which a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens are cemented together.

[0128] The fifth lens unit L5 is composed of, in order from the object side, a cemented negative lens formed by cementing together a biconvex positive lens and a biconcave negative lens.

[0129] The sixth lens group L6 is composed of, in order from the object side, a biconvex positive lens, and a negative meniscus lens with its concave surface facing the object side and an aspherical surface formed on its object side.

[0130] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3. During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side as shown by the arrow. The second lens unit L2 moves toward the object side while increasing the distance between it and the first lens unit L1. The third lens unit L3 moves toward the object side while decreasing the distance between it and the second lens unit L2. The fourth lens unit L4 moves toward the object side while increasing the distance between it and the third lens unit L3. The fifth lens unit L5 moves toward the object side while increasing the distance between it and the fourth lens unit L4. The sixth lens unit L6 moves toward the object side while increasing the distance between it and the fifth lens unit L5.

[0131] The aperture stop SP moves together with the third lens unit L3.

[0132] The vibration-reduction lens group IS is a cemented positive lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis and thereby correcting image blur that occurs when the entire zoom lens vibrates.In other words, it performs vibration reduction.

[0133] Focusing is performed by moving the fourth lens unit L4 toward the object side and the fifth lens unit L5 toward the image side.

[0134] The surface data of the second numerical example is as follows:

[0135] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 186.979 1.85 1.95375 32.3 65.11 2 99.214 7.68 1.53775 74.7 64.12 3 -600.997 0.15 63.96 4 93.708 6.11 1.53775 74.7 62.51 5 772.080 (variable) 61.98 6* 271.468 0.05 1.58946 30.6 35.89 7 152.510 1.00 1.76385 48.5 35.83 8 23.533 7.65 29.38 9 -54.298 0.90 1.76385 48.5 28.80 10 100.603 0.15 27.83 11 47.732 5.12 1.79631 22.6 27.54 0.6411 12 -65.368 3.83 26.87 13 -25.807 0.90 1.76385 48.5 23.91 14 -76.285 (variable) 23.70 15 (Aperture) ∞ 0.40 24.11 16 34.492 4.77 1.51633 64.1 25.35 17 -109.203 0.15 25.36 18 39.244 2.57 1.51633 64.1 25.01 19 121.652 0.15 24.66 20 22.769 5.14 1.51742 52.4 23.66 21 -2159.302 1.00 1.83481 42.7 22.53 22 21.642 2.54 20.66 23 34.614 1.00 2.00069 25.5 20.57 24 20.482 5.01 1.63930 44.9 19.88 25 -90.992 2.17 19.54 26 -30.523 1.00 1.81554 44.4 19.02 27 19.998 6.37 1.58313 59.4 19.35 28* -76.397 (variable) 20.16 29 31.495 1.10 1.76385 48.5 21.25 30 20.758 8.47 1.53996 59.5 21.42 31 -29.023 (variable) 22.31 32 143.085 3.09 1.85478 24.8 22.23 33 -46.847 0.80 1.72342 38.0 22.12 34 26.199 (variable) 21.56 35 78.782 4.31 1.60342 38.0 30.48 36 -84.392 8.31 30.66 37* -28.291 1.60 1.80400 46.5 30.59 38 -96.921 (variable) 32.36 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 3.77899e-06 A 6=-6.89162e-10 A 8= 1.59375e-11 A10=-5.29178e-14 A12= 9.86025e-17 Page 28 K = 0.00000e+00 A 4= 1.05910e-05 A 6= 2.98231e-09 A 8= 4.98908e-11 A10=-5.77344e-13 A12= 1.82184e-15 Page 37 K = 0.00000e+00 A 4= 8.98490e-06 A 6= 6.31025e-09 A 8=-4.00895e-11 A10= 2.20453e-13 A12=-4.05114e-16 Various data Zoom ratio 13.44 Wide-angle Mid-range Telephoto Focal length 28.87 105.89 388.00 F-number 3.34 5.16 6.49 Half angle of view 34.20 11.55 3.18 Image height 19.62 21.64 21.59 Lens total length 173.50 222.29 280.50 BF 12.64 35.69 47.17 d 5 1.00 46.37 91.38 d14 41.94 14.86 2.55 d28 1.22 1.35 1.40 d31 1.50 10.35 4.53 d34 19.88 18.35 38.12 d38 12.64 35.69 47.17 Zoom lens group data Group starting plane focal length 1 1 146.45 2 6 -21.80 3 15 55.76 4 29 32.72 5 32 -54.12 6 35 -396.05 Single lens data Lens starting surface focal length 1 1 -223.93 2 2 158.97 3 4 197.71 4 6 -590.52 5 7 -36.55 6 9 -46.05 7 11 35.35 8 13 -51.46 9 16 51.35 10 18 111.02 11 20 43.58 12 21 -25.66 13 23 -51.97 14 24 26.62 15 26 -14.68 16 27 27.86 17 29 -83.42 18 30 23.84 19 32 41.60 20 33 -23.12 21 35 68.20 22 37 -50.21 [Numerical Example 3] In the lens cross-sectional view of Figure 7, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group with positive refractive power, L4 is a fourth lens group with negative refractive power, L5 is a fifth lens group with positive refractive power, L6 is a sixth lens group (lens group LN-1) with negative refractive power, and L7 is a seventh lens group (lens group LN) with negative refractive power.

[0136] The third to fifth lens groups are the intermediate group LM.

[0137] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0138] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0139] The third lens group L3 is composed of, from the object side, a biconvex positive lens, a positive meniscus lens with a convex surface facing the object side, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. The fourth lens group L4 is composed of, from the object side, a cemented negative lens formed by cementing a biconcave negative lens and a biconvex positive lens. The fifth lens group L5 is composed of, from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens.

[0140] The sixth lens group L6 is composed of, in order from the object side, a cemented negative lens formed by cementing together a biconvex positive lens and a biconcave negative lens. The seventh lens group L7 is composed of, in order from the object side, a biconvex positive lens, a negative meniscus lens with its concave surface facing the object side, and a negative lens with a negative meniscus shape with its concave surface facing the object side and an aspherical surface formed on its object side.

[0141] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0142] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side as shown by the arrow. The second lens unit L2 moves toward the object side while increasing the distance between it and the first lens unit L1. The third lens unit L3 moves toward the object side while decreasing the distance between it and the second lens unit L2. The fourth lens unit L4 moves toward the object side while increasing the distance between it and the third lens unit L3. The fifth lens unit L5 moves toward the object side while decreasing the distance between it and the fourth lens unit L4. The sixth lens unit L6 moves toward the object side while increasing the distance between it and the fifth lens unit L5. The seventh lens unit L7 moves toward the object side while increasing the distance between it and the sixth lens unit L6.

[0143] The aperture stop SP moves together with the third lens unit L3.

[0144] The vibration-reduction lens group IS is a cemented positive lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis and thereby correcting image blur that occurs when the entire zoom lens vibrates.In other words, it performs vibration reduction.

[0145] Focusing is performed by moving the sixth lens unit L6 toward the image side.

[0146] The surface data of the third numerical example is as follows:

[0147] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 159.863 1.85 1.91082 35.2 65.11 2 86.107 8.43 1.49700 81.5 63.93 3 -725.282 0.15 63.76 4 83.091 7.04 1.49700 81.5 62.32 5 1015.161 (variable) 61.74 6* 96.905 0.05 1.58946 30.6 35.11 7 73.732 1.00 1.75500 52.3 35.05 8 20.213 9.19 28.04 9 -38.607 0.90 1.77250 49.6 26.52 10 106.233 0.15 25.58 11 46.649 5.03 1.77830 23.9 25.32 0.6248 12 -50.254 2.67 24.68 13 -24.024 0.90 1.77250 49.6 22.94 14 -58.905 (variable) 22.80 15 (Aperture) ∞ 0.40 24.16 16 32.428 4.97 1.48749 70.2 25.48 17 -115.098 0.15 25.47 18 33.549 3.06 1.48749 70.2 25.09 19 121.535 0.15 24.66 20 27.969 4.96 1.51742 52.4 23.79 21 -118.758 1.00 1.83481 42.7 22.77 22 23.716 2.52 21.03 23 39.097 1.00 2.00069 25.5 21.04 24 21.303 4.95 1.70000 48.1 20.44 25 -107.828 (variable) 20.19 26 -33.576 1.00 1.77250 49.6 19.38 27 21.327 6.19 1.58313 59.4 19.75 28* -79.673 (variable) 20.45 29 34.656 1.10 1.80400 46.5 23.83 30 23.384 7.94 1.58313 59.4 23.95 31 -36.925 (variable) 24.54 32 273.941 2.52 1.84666 23.8 24.40 33 -68.322 0.80 1.71700 47.9 24.33 34 33.877 (variable) 23.94 35 87.748 5.80 1.51633 64.1 28.63 36 -37.582 2.54 28.88 37 -78.988 1.00 1.75500 52.3 27.99 38 -375.941 9.19 28.06 39* -19.835 1.60 1.80400 46.5 28.08 40 -38.559 (variable) 30.58 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 4.16182e-06 A 6=-1.01293e-09 A 8= 3.04594e-11 A10=-1.26477e-13 A12= 2.74307e-16 Page 28 K = 0.00000e+00 A 4= 9.02768e-06 A 6= 6.78154e-09 A 8=-9.06375e-11 A10= 1.09121e-12 A12=-3.94638e-15 Page 39 K = 0.00000e+00 A 4= 9.10460e-06 A 6= 2.48299e-08 A 8=-7.07897e-11 A10= 5.35600e-13 A12=-7.60518e-16 Various data Zoom ratio 13.43 Wide-angle Mid-range Telephoto Focal length 28.90 105.98 388.00 F-number 3.26 5.31 6.49 Half angle of view 34.94 11.54 3.19 Image height 20.19 21.64 21.64 Lens total length 173.50 216.82 282.06 BF 15.53 33.81 49.89 d 5 1.00 41.32 88.39 d14 38.52 10.49 2.53 d25 2.17 2.75 3.13 d28 1.95 1.37 0.99 d31 1.49 15.15 1.50 d34 12.62 11.71 35.41 d40 15.53 33.81 49.89 Zoom lens group data Group starting plane focal length 1 1 141.94 2 6 -21.11 3 15 33.10 4 26 -42.24 5 29 35.27 6 32 -62.32 7 35 -306.59 Single lens data Lens starting surface focal length 1 1 -207.38 2 2 155.40 3 4 181.63 4 6 -523.50 5 7 -37.18 6 9 -36.56 7 11 31.81 8 13 -53.12 9 16 52.48 10 18 93.99 11 20 44.26 12 21 -23.60 13 23 -48.13 14 24 25.82 15 26 -16.75 16 27 29.52 17 29 -93.49 18 30 25.80 19 32 64.81 20 33 -31.48 21 35 51.78 22 37 -132.64 23 39 -52.82 [Numerical Example 4] In the lens cross-sectional view of Figure 10, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group with positive refractive power, L4 is a fourth lens group with negative refractive power, L5 is a fifth lens group with positive refractive power, L6 is a sixth lens group (lens group LN-1) with negative refractive power, and L7 is a seventh lens group (lens group LN) with negative refractive power.

[0148] The third to fifth lens groups are the intermediate group LM.

[0149] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0150] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0151] The third lens group L3 is composed of, in order from the object side, a biconvex positive lens, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a cemented positive lens formed by cementing a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens.

[0152] The fourth lens unit L4 is composed of a negative meniscus lens with its concave surface facing the object side.

[0153] The fifth lens group L5 is composed of, in order from the object side, a biconvex positive lens with aspherical surfaces formed on both sides, and a cemented positive lens formed by cementing together a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens.

[0154] The sixth lens group L6 is composed of, in order from the object side, a cemented negative lens formed by cementing together a biconvex positive lens and a biconcave negative lens.

[0155] The seventh lens group L7 is composed of, in order from the object side, a biconvex positive lens, an object, and a negative meniscus lens with its concave surface facing the object side and an aspherical surface formed on its object side.

[0156] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0157] During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves toward the object side as shown by the arrow. The second lens group L2 moves toward the object side while increasing the distance between it and the first lens group L1. The third lens group L3 moves toward the object side while decreasing the distance between it and the second lens group L2. The fourth lens group L4 moves toward the object side while increasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while decreasing the distance between it and the fourth lens group L4. The sixth lens group L6 moves toward the object side while decreasing the distance between it and the fifth lens group L5. The seventh lens group L7 moves toward the object side while increasing the distance between it and the sixth lens group L6.

[0158] The aperture stop SP moves together with the third lens unit L3.

[0159] The vibration-reduction lens group IS is a cemented positive lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis and thereby correcting image blur that occurs when the entire zoom lens vibrates.In other words, it performs vibration reduction.

[0160] Focusing is performed by moving the sixth lens unit L6 toward the image side.

[0161] The surface data of the fourth numerical example is as follows:

[0162] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 166.687 1.85 1.91082 35.2 63.80 2 88.826 7.91 1.49700 81.5 61.52 3 -549.982 0.15 60.88 4 80.882 6.23 1.49700 81.5 58.71 5 605.897 (variable) 58.15 6* 167.160 0.05 1.58946 30.6 32.88 7 104.545 1.00 1.77250 49.6 32.82 8 21.610 8.00 26.93 9 -41.826 0.90 1.77250 49.6 25.41 10 122.590 0.15 24.56 11 50.249 4.67 1.77830 23.9 24.27 0.6248 12 -47.783 2.24 23.64 13 -23.207 0.90 1.72916 54.7 22.55 14 -61.582 (variable) 22.36 15 (Aperture) ∞ 0.40 21.07 16 26.236 5.23 1.61772 49.8 22.15 17 -65.669 0.15 21.91 18 29.387 5.15 1.67270 32.1 20.62 19 -33.203 1.00 2.00100 29.1 19.61 20 24.162 2.17 18.14 21 37.849 1.00 2.00069 25.5 18.31 22 22.195 4.12 1.63930 44.9 17.96 23 -79.831 (variable) 17.88 24 -23.992 1.00 1.75500 52.3 17.30 25 -1671.541 (variable) 17.84 26* 33.180 4.72 1.53775 74.7 18.65 27* -45.660 0.15 19.22 28 6947.270 1.10 1.77250 49.6 19.58 29 47.494 5.82 1.48749 70.2 20.01 30 -21.736 (variable) 20.71 31 103.253 2.79 1.85478 24.8 20.60 32 -53.745 0.80 1.76200 40.1 20.47 33 27.562 (variable) 19.99 34 73.440 2.61 1.67270 32.1 29.14 35 -6331.920 7.14 29.20 36* -23.993 1.60 1.80400 46.5 29.45 37 -60.068 (variable) 31.52 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 5.20706e-06 A 6=-9.02718e-10 A 8= 3.96956e-11 A10=-1.72026e-13 A12= 4.24840e-16 Page 26 K = 0.00000e+00 A 4=-1.12675e-05 A 6= 5.61282e-08 A 8=-1.09114e-09 A10= 8.74791e-12 A12=-5.31082e-14 Page 27 K = 0.00000e+00 A 4= 2.44648e-05 A 6= 5.54986e-08 A 8=-8.11706e-10 A10= 5.89464e-12 A12=-4.05971e-14 Page 36 K = 0.00000e+00 A 4= 1.21610e-05 A 6= 2.24346e-08 A 8=-1.37031e-10 A10= 6.55396e-13 A12=-1.05185e-15 Various data Zoom ratio 13.45 Wide-angle Mid-range Telephoto Focal length 28.85 105.72 388.00 F-number 3.70 5.76 7.31 Half angle of view 34.03 11.57 3.14 Image height 19.48 21.64 21.29 Lens total length 163.50 210.40 263.50 BF 11.90 30.91 41.58 d 5 1.00 48.07 89.67 d14 38.84 13.83 2.55 d23 2.72 3.04 3.72 d25 2.00 1.68 1.00 d30 1.50 8.41 1.50 d33 24.56 23.47 42.48 d37 11.90 30.91 41.58 Zoom lens group data Group starting plane focal length 1 1 142.38 2 6 -21.52 3 15 35.92 4 24 -32.25 5 26 24.48 6 31 -58.16 7 34 -111.29 Single lens data Lens starting surface focal length 1 1 -211.17 2 2 154.51 3 4 187.07 4 6 -473.61 5 7 -35.45 6 9 -40.27 7 11 32.14 8 13 -51.58 9 16 31.02 10 18 23.97 11 19 -13.85 12 21 -55.40 13 22 27.60 14 24 -32.25 15 26 36.50 16 28 -61.91 17 29 31.46 18 31 41.69 19 32 -23.81 20 34 107.94 21 36 -50.69 [Numerical Example 5] In the lens cross-sectional view of Figure 13, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group (middle group LM) with positive refractive power, L4 is a fourth lens group (lens group LN-1) with negative refractive power, and L5 is a fifth lens group (lens group LN) with negative refractive power.

[0163] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0164] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0165] The third lens group L3 includes, in order from the object side, a biconvex positive lens, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens, a cemented positive lens formed by cementing a negative meniscus lens with its convex surface facing the object side to a biconvex positive lens, and a biconcave negative lens. Further, closer to the image side than the cemented negative lens, the third lens group L3 also includes a biconvex positive lens with aspherical surfaces on both sides, and a cemented positive lens formed by cementing a biconcave negative lens and a biconvex positive lens.

[0166] The fourth lens unit L4 is composed of, in order from the object side, a cemented negative lens formed by cementing together a biconvex positive lens and a biconcave negative lens.

[0167] The fifth lens group L5 is composed of, in order from the object side, a biconvex positive lens, and a negative meniscus lens with its concave surface facing the object side and an aspherical surface formed on its object side.

[0168] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0169] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side as shown by the arrow. The second lens unit L2 moves toward the object side while increasing the distance between it and the first lens unit L1. The third lens unit L3 moves toward the object side while decreasing the distance between it and the second lens unit L2. The fourth lens unit L4 moves toward the object side while increasing the distance between it and the third lens unit L3. The fifth lens unit L5 moves toward the object side while increasing the distance between it and the fourth lens unit L4.

[0170] The aperture stop SP moves together with the third lens unit L3.

[0171] The vibration-reduction lens group IS is a cemented positive lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and moves so as to have a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis and thereby correcting image blur that occurs when the entire zoom lens vibrates.In other words, it performs vibration reduction.

[0172] Focusing is performed by moving the fourth lens unit L4 toward the image side.

[0173] The surface data of the fifth numerical example is as follows:

[0174] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 158.894 1.85 1.91082 35.2 63.80 2 85.971 8.01 1.49700 81.5 61.45 3 -614.819 0.15 60.67 4 79.731 5.83 1.49700 81.5 55.83 5 623.231 (variable) 55.06 6* 144.821 0.05 1.58946 30.6 32.28 7 95.969 1.00 1.77250 49.6 32.21 8 20.722 7.78 26.34 9 -44.587 0.90 1.72916 54.7 24.88 10 91.207 0.15 23.88 11 43.841 4.50 1.75575 24.7 23.57 0.6291 12 -54.530 2.18 22.87 13 -23.027 0.90 1.72916 54.7 22.14 14 -57.713 (variable) 21.95 15 (Aperture) ∞ 0.40 19.21 16 23.103 4.99 1.51823 58.9 19.89 17 -57.291 0.15 19.62 18 23.158 4.99 1.72825 28.5 18.59 19 -32.934 1.00 2.00100 29.1 17.54 20 19.492 2.34 16.00 21 36.457 1.00 1.92286 20.9 16.15 22 21.447 3.52 1.61340 44.3 15.88 23 -84.290 2.55 15.80 24 -22.581 1.00 1.75500 52.3 15.49 25 207.087 1.00 16.00 26* 29.929 5.10 1.53775 74.7 17.16 27* -34.246 0.15 18.23 28 -1089.056 1.10 1.72916 54.7 18.64 29 41.178 5.64 1.48749 70.2 19.12 30 -21.757 (variable) 19.82 31 73.525 2.51 1.85478 24.8 19.84 32 -80.488 0.80 1.76200 40.1 19.68 33 25.382 (variable) 19.21 34 227.047 2.87 1.85478 24.8 29.47 35 -90.756 3.28 29.64 36* -24.616 1.60 1.88202 37.2 29.64 37 -75.705 (variable) 31.71 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 5.45719e-06 A 6=-7.50113e-10 A 8= 3.28006e-11 A10=-1.38107e-13 A12= 3.97489e-16 Page 26 K = 0.00000e+00 A 4=-1.90883e-05 A 6= 1.11710e-07 A 8=-2.04761e-09 A10= 2.31153e-11 A12=-1.17407e-13 Page 27 K = 0.00000e+00 A 4= 2.21989e-05 A 6= 8.71479e-08 A 8=-1.34283e-09 A10= 1.45609e-11 A12=-7.44549e-14 Page 36 K = 0.00000e+00 A 4= 1.21548e-05 A 6= 1.66728e-08 A 8=-8.88282e-11 A10= 4.16987e-13 A12=-6.51728e-16 Various data Zoom ratio 13.45 Wide-angle Mid-range Telephoto Focal length 28.85 105.83 388.00 F-number 4.12 6.32 8.24 Half angle of view 34.34 11.55 3.15 Image height 19.71 21.64 21.38 Lens total length 161.50 207.66 259.50 BF 12.32 33.25 47.08 d 5 1.00 47.20 87.67 d14 39.70 14.67 2.56 d30 1.50 9.00 2.62 d33 27.69 24.25 40.28 d37 12.32 33.25 47.08 Zoom lens group data Group starting plane focal length 1 1 139.93 2 6 -21.22 3 15 32.73 4 31 -60.19 5 34 -103.50 Single lens data Lens starting surface focal length 1 1 -208.18 2 2 152.34 3 4 183.31 4 6 -482.83 5 7 -34.41 6 9 -40.96 7 11 32.80 8 13 -53.13 9 16 32.46 10 18 19.40 11 19 -12.12 12 21 -58.31 13 22 28.23 14 24 -26.92 15 26 30.55 16 28 -54.39 17 29 30.09 18 31 45.29 19 32 -25.24 20 34 76.17 21 36 -41.97 [Numerical Example 6] In the lens cross-sectional view of Figure 16, L1 is a first lens group with positive refractive power, L2 is a second lens group with negative refractive power, L3 is a third lens group with positive refractive power, L4 is a fourth lens group with positive refractive power, L5 is a fifth lens group (lens group LN-1) with negative refractive power, and L6 is a sixth lens group (lens group LN) with negative refractive power.

[0175] The third and fourth lens groups are the intermediate group LM.

[0176] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens with a convex surface facing the object side.

[0177] The second lens group L2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object side, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0178] The third lens group L3 includes, in order from the object side, a biconvex positive lens, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens, and, located closer to the image side than the cemented negative lens, a cemented positive lens formed by cementing a negative meniscus lens with its convex surface facing the object side to a biconvex positive lens, a biconvex positive lens, and a cemented negative lens formed by cementing a biconcave negative lens and a biconvex positive lens.

[0179] The fourth lens group L4 is composed of, from the object side, a biconvex positive lens with aspherical surfaces on both sides, a cemented positive lens formed by cementing a biconcave negative lens and a biconvex positive lens, and a biconvex positive lens. The fifth lens group L5 is composed of, from the object side, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens.

[0180] The sixth lens group L6 is composed of, in order from the object side, a positive meniscus lens with a concave surface facing the object side, and a negative meniscus lens with a concave surface facing the object side and an aspherical surface formed on the object side.

[0181] SP denotes an aperture stop, which is arranged on the object side of the third lens unit L3.

[0182] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side as shown by the arrow. The second lens unit L2 moves toward the object side while increasing the distance between it and the first lens unit L1. The third lens unit L3 moves toward the object side while decreasing the distance between it and the second lens unit L2. The fourth lens unit L4 moves toward the object side while decreasing the distance between it and the third lens unit L3. The fifth lens unit L5 moves toward the object side while decreasing the distance between it and the fourth lens unit L4. The sixth lens unit L6 moves toward the object side while increasing the distance between it and the fifth lens unit L5.

[0183] The vibration-reduction lens group IS is composed of a cemented positive lens, consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and a biconvex positive lens. It moves with a component in the direction approximately perpendicular to the optical axis, displacing the image in the direction approximately perpendicular to the optical axis, thereby correcting image blur caused by vibration of the entire zoom lens. In other words, it performs vibration reduction.

[0184] Focusing is performed by moving the fifth lens unit L5 toward the image side.

[0185] The surface data of Numerical Example 6 is as follows:

[0186] Unit: mm Surface Data Surface number rd nd νd Clear aperture θgf 1 154.352 1.85 1.95375 32.3 64.42 2 94.121 7.65 1.49700 81.5 63.06 3 -717.085 0.15 62.85 4 87.077 6.20 1.49700 81.5 61.34 5 604.310 (variable) 60.78 6* 156.274 0.05 1.58946 30.6 31.64 7 116.244 1.00 1.77250 49.6 31.59 8 22.189 7.05 26.29 9 -46.946 0.90 1.77250 49.6 25.17 10 133.903 0.15 24.32 11 46.917 4.84 1.75575 24.7 23.93 0.6291 12 -44.952 1.44 23.20 13 -25.820 0.90 1.77250 49.6 22.69 14 -144.002 (variable) 22.24 15 (Aperture) ∞ 0.40 21.75 16 42.353 3.90 1.80100 35.0 22.53 17 -72.791 0.15 22.48 18 37.317 4.41 1.51633 64.1 21.66 19 -52.372 1.00 2.00100 29.1 20.95 20 38.991 1.96 20.26 21 58.535 1.00 1.92286 20.9 20.46 22 32.714 3.85 1.51633 64.1 20.28 23 -76.287 0.15 20.35 24 779.423 1.45 1.85478 24.8 20.29 25 -120.770 2.68 20.24 26 -32.624 1.00 1.76385 48.5 19.86 27 67.829 2.31 2.00069 25.5 20.34 28 -139.445 (variable) 20.44 29* 161.058 5.62 1.53775 74.7 26.07 30* -31.726 0.15 27.10 31 -52.146 1.10 2.00100 29.1 27.31 32 1435.075 2.54 1.49700 81.5 28.40 33 -78.122 0.15 28.96 34 94.303 7.26 1.48749 70.2 30.50 35 -31.867 (variable) 31.00 36 821.199 3.35 1.85478 24.8 28.04 37 -51.276 0.80 1.76385 48.5 27.91 38* 37.541 (variable) 27.19 39 -178.968 1.70 1.85478 24.8 28.64 40 -79.599 3.64 28.88 41* -24.200 1.60 1.88202 37.2 28.93 42 -40.969 (variable) 31.18 Image plane ∞ Aspheric data Side 6 K = 0.00000e+00 A 4= 3.20237e-06 A 6= 8.46229e-10 A 8= 3.27575e-11 A10=-1.79922e-13 A12= 4.76949e-16 Page 29 K = 0.00000e+00 A 4=-8.38926e-06 A 6= 1.96612e-08 A 8=-3.03253e-10 A10= 1.59460e-12 A12=-3.56219e-15 Page 30 K = 0.00000e+00 A 4= 7.19901e-06 A 6= 2.47272e-08 A 8=-3.06372e-10 A10= 1.57687e-12 A12=-3.26561e-15 Page 38 K = 0.00000e+00 A 4=-1.31223e-06 A 6=-6.92521e-09 A 8= 8.13712e-11 A10=-3.90562e-13 A12= 5.94240e-16 Page 41 K = 0.00000e+00 A 4= 2.14371e-06 A 6= 7.49319e-09 A 8=-4.93415e-11 A10= 3.14079e-13 A12=-6.84197e-16 Various data Zoom ratio 13.45 Wide-angle Mid-range Telephoto Focal length 28.85 105.81 388.00 F-number 2.99 5.33 6.49 Half angle of view 34.50 11.56 3.19 Image height 19.83 21.64 21.64 Lens total length 163.50 224.51 268.50 BF 10.92 39.03 48.18 d 5 1.00 51.33 93.14 d14 27.73 16.68 2.56 d28 17.83 3.27 1.24 d35 14.29 5.75 1.50 d38 7.38 24.09 37.54 d42 10.92 39.03 48.18 Zoom lens group data Group starting plane focal length 1 1 145.22 2 6 -21.27 3 15 51.64 4 29 38.07 5 36 -57.23 6 39 -123.43 Single lens data Lens starting surface focal length 1 1 -256.75 2 2 167.93 3 4 203.89 4 6 -770.23 5 7 -35.66 6 9 -44.90 7 11 31.08 8 13 -40.86 9 16 33.94 10 18 42.92 11 19 -22.21 12 21 -81.89 13 22 44.88 14 24 122.42 15 26 -28.72 16 27 45.86 17 29 49.80 18 31 -50.25 19 32 149.16 20 34 49.80 21 36 56.56 22 37 -28.26 23 39 166.40 24 41 -70.17

[0187] [Table 1]

[0188] Next, an embodiment in which the zoom lens of the present invention is used as a photographing optical system will be described with reference to FIG.

[0189] In Figure 19, 10 is a diagram of an example of an imaging device, 11 is a photographic optical system constituted by the zoom lens of the present invention, and 12 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor that receives the subject image formed by the photographic optical system 11. Also, 13 is a recording means that records the subject image received by the image sensor 12, and 14 is a finder for observing the subject image displayed on a display element (not shown). The display element is constituted by a liquid crystal panel or the like, and displays the subject image formed on the image sensor 12.

[0190] In this way, by applying the zoom lens of the present invention to an optical device such as a digital camera, an optical device with high optical performance can be realized.

[0191] The present invention can also be applied to a camera without a quick return mirror.

[0192] The zoom lens of the present invention can also be applied to a video camera.

[0193] The disclosure of each embodiment includes the following configuration. (Configuration 1) A zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent lens group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between each lens group changes during zooming; When the focal length of the entire system at the wide-angle end is fw, the focal length of the entire system at the telephoto end is ft, the focal length of the second lens group is f2, the refractive index of the positive lens in the second lens group with the smallest Abbe number is nd2p, and the Abbe number of the positive lens in the second lens group with the smallest Abbe number is vd2p, -0.080 <f2 / ft<-0.040 1.750 <nd2p<1.800 22.0 <vd2p<25.0 10.0 <ft / fw<20.0 A zoom lens characterized by satisfying the following conditional expressions: (Configuration 2) When the focal length of the positive lens in the second lens group having the smallest Abbe number is f2p, 0.065 <f2p / ft<0.110 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) When the partial dispersion ratio of the positive lens in the second lens group having the smallest Abbe number is θgF2p, 0.600<θgF2p<0.670 1. The zoom lens according to claim 1, wherein the following condition is satisfied:

[0194] where θgF2p is the partial dispersion ratio of the positive lens in the second lens group with the smallest Abbe number, and is defined by the following equation, where ng2p is the refractive index of the positive lens with the smallest Abbe number for the g-line, nF2p is the refractive index of the positive lens in the second lens group with the smallest Abbe number for the F-line, and nC2p is the refractive index of the positive lens in the second lens group with the smallest Abbe number for the C-line. θgF2p=(ng2p-nF2p) / (nF2p-nC2p) (Configuration 4) When the average value of the Abbe numbers of the positive lenses included in the first lens group is vd1p, 3.00 <vd1p / vd2p<4.00 4. The zoom lens according to any one of the first to third aspects, wherein the following condition is satisfied: (Configuration 5) When the average value of the Abbe numbers of the negative lenses included in the second lens group is vd2n, 1.70 <vd2n / vd2p<2.40 5. The zoom lens according to any one of the first to fourth aspects, wherein the following condition is satisfied: (Configuration 6) When the Abbe number of the negative lens having the smallest Abbe number in the first lens group is vd1n, 1.00 <vd1n / vd2p<1.80 6. The zoom lens according to any one of configurations 1 to 5, wherein the following condition is satisfied: (Configuration 7) When the refractive index of the negative lens having the smallest Abbe number in the first lens group is nd1n, 0.95 <nd1n / nd2p<1.30 7. The zoom lens according to any one of configurations 1 to 6, wherein the following condition is satisfied: (Configuration 8) When the focal length of the first lens group L1 is f1, 4.75 <f1 / fw<10.00 8. The zoom lens according to any one of configurations 1 to 7, wherein the following condition is satisfied: (Configuration 9) The zoom lens according to any one of configurations 1 to 8, wherein the subsequent group includes, in order from the object side, an intermediate group LM having positive refractive power, a lens group LN-1 having negative refractive power, and a lens group LN having negative refractive power, and the spacing between each lens group changes during zooming. (Configuration 10) When the focal length of the lens group LN is fN, -1.50 <fN / ft<-0.10 10. The zoom lens according to configuration 9, wherein the following condition is satisfied: (Configuration 11) When the back focus at the wide-angle end is skw, 0.30 <skw / fw<0.70 11. The zoom lens according to any one of configurations 1 to 10, wherein the following condition is satisfied: (Configuration 12) When the focal length of the lens group LN-1 is fN-1, -0.30 <fN-1 / ft<-0.05 11. The optical system according to configuration 9 or 10, wherein the following condition is satisfied: (Configuration 13) the subsequent lens group includes a vibration reduction lens group, When the focal length of the image stabilization lens group is fIS, 0.10 <fIS / ft<0.20 13. The zoom lens according to any one of configurations 1 to 12, wherein the following condition is satisfied: (Configuration 14) When the amount of movement of the second lens group from the wide-angle end to the telephoto end is m2, 0.25 <m2 / fw<1.00 14. The zoom lens according to any one of configurations 1 to 13, wherein the following condition is satisfied: (Configuration 15) When the amount of movement of the first lens group from the wide-angle end to the telephoto end is m1, 3.00 <m1 / fw<4.50 15. The zoom lens according to any one of configurations 1 to 14, wherein the following condition is satisfied: (Configuration 16) When the focal length of the intermediate group at the wide-angle end is fMw, 0.060 <fMw / ft<0.130 13. The zoom lens according to any one of configurations 9, 10, and 12, wherein the following condition is satisfied: (Configuration 17) When the total optical length at the telephoto end is TLt, 0.55 <TLt / ft<0.85 17. The zoom lens according to any one of configurations 1 to 16, wherein the following condition is satisfied: (Configuration 18) When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, -8.00 <f1 / f2<-6.00 18. The optical system according to any one of configurations 1 to 17, wherein the following condition is satisfied: (Configuration 19) When the focal length of the intermediate lens group at the wide-angle end is fMw and the focal length of the second lens group at the wide-angle end is f2, -2.50 <fMw / f2<-1.00 17. The optical system according to any one of configurations 9, 10, 12, and 16, wherein the following condition is satisfied: (Configuration 20) When the focal length of the second lens group is f2 and the focal length of the lens group LN is fN, 0.030 <f2 / fN<0.250 20. The optical system according to any one of configurations 9, 10, 12, 16, and 19, wherein the following condition is satisfied: (Configuration 21) A zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent lens group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between each lens group changes during zooming; the second lens group includes a plurality of negative lenses; When the refractive index of the positive lens element in the second lens group having the smallest Abbe number is nd2p, 1.750 <nd2p<1.800 A zoom lens characterized by satisfying the following conditional expressions: (Configuration 22) An imaging device comprising the optical system according to any one of configurations 1 to 21.

[0195] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0196] L1: First lens group L2: Second lens group SP: Aperture stop IP: image plane

Claims

1. A zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent lens group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between the lens groups changes during zooming; When the focal length of the entire system at the wide-angle end is fw, the focal length of the entire system at the telephoto end is ft, the focal length of the second lens group is f2, the refractive index of the positive lens in the second lens group with the smallest Abbe number is nd2p, and the Abbe number of the positive lens in the second lens group with the smallest Abbe number is vd2p, -0.080<f2 / ft<-0.040 1.750<nd2p<1.800 22.0<vd2p<25.0 10.0<ft / fw<20.0 A zoom lens characterized by satisfying the following conditional expressions:

2. When the focal length of the positive lens in the second lens group having the smallest Abbe number is f2p, 0.065<f2p / ft<0.110 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. When the partial dispersion ratio of the positive lens in the second lens group having the smallest Abbe number is θgF2p, 0.600<θgF2p<0.670 2. The zoom lens according to claim 1, wherein the following condition is satisfied: where θgF2p is the partial dispersion ratio of the positive lens with the smallest Abbe number in the second lens group, and is defined by the following equation when the refractive index of the positive lens with the smallest Abbe number for the g-line is ng2p, the refractive index of the positive lens with the smallest Abbe number for the F-line is nF2p, and the refractive index of the positive lens with the smallest Abbe number for the C-line is nC2p. θgF2p=(ng2p-nF2p) / (nF2p-nC2p)

4. When the average value of the Abbe numbers of the positive lenses included in the first lens group is vd1p, 3.00<vd1p / vd2p<4.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. When the average value of the Abbe numbers of the negative lenses included in the second lens group is vd2n, 1.70<vd2n / vd2p<2.40 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. When the Abbe number of the negative lens having the smallest Abbe number in the first lens group is vd1n, 1.00<vd1n / vd2p<1.80 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

7. When the refractive index of the negative lens having the smallest Abbe number in the first lens group is nd1n, 0.95<nd1n / nd2p<1.30 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. When the focal length of the first lens group is f1, 4.75<f1 / fw<10.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

9. 2. The zoom lens according to claim 1, wherein the subsequent group includes, in order from the object side, an intermediate group having positive refractive power, a lens group LN-1 having negative refractive power, and a lens group LN having negative refractive power, and the spacing between each lens group changes during zooming.

10. When the focal length of the lens group LN is fN, -1.50<fN / ft<-0.10 10. The zoom lens according to claim 9, wherein the following condition is satisfied:

11. When the back focus at the wide-angle end is skw, 0.30<skw / fw<0.70 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

12. When the focal length of the lens group LN-1 is fN-1, -0.30<fN-1 / ft<-0.05 10. The zoom lens according to claim 9, wherein the following condition is satisfied:

13. the subsequent lens group includes a vibration reduction lens group, When the focal length of the vibration-proof lens group is fIS, 0.10<fIS / ft<0.20 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

14. When the amount of movement of the second lens group from the wide-angle end to the telephoto end is m2, 0.25<m2 / fw<1.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

15. When the amount of movement of the first lens group from the wide-angle end to the telephoto end is m1, 3.00<m1 / fw<4.50 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

16. When the focal length of the intermediate group at the wide-angle end is fMw, 0.060<fMw / ft<0.130 10. The zoom lens according to claim 9, wherein the following condition is satisfied:

17. When the total optical length at the telephoto end is TLt, 0.55<TLt / ft<0.85 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

18. When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, -8.00<f1 / f2<-6.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

19. When the focal length of the intermediate lens group at the wide-angle end is fMw and the focal length of the second lens group at the wide-angle end is f2, -2.50<fMw / f2<-1.00 10. The zoom lens according to claim 9, wherein the following condition is satisfied:

20. When the focal length of the second lens group is f2 and the focal length of the lens group LN is fN, 0.030<f2 / fN<0.250 10. The zoom lens according to claim 9, wherein the following condition is satisfied:

21. A zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, and a subsequent lens group having one or more lens groups and having positive refractive power as a whole, wherein the spacing between the lens groups changes during zooming; the second lens group includes a plurality of negative lenses; When the refractive index of the positive lens having the smallest Abbe number in the second lens group is nd2p, 1.750<nd2p<1.800 A zoom lens characterized by satisfying the following conditional expressions:

22. An imaging device comprising the optical system according to any one of claims 1 to 21.

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