Zoom lens and imaging device having same

Abstract

[Problem] To provide a compact zoom lens having high imaging performance and achieving a high zoom ratio, and an imaging device having the same. [Solution] The zoom lens includes, in order from an object side to an 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, and is characterized in that an interval between the lens groups changes during zooming and a predetermined conditional expression is satisfied.

Description

Zoom lens and imaging device having the same

[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.

[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 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 smaller overall. Furthermore, the size of the imaging elements used in imaging devices has been miniaturized to obtain high-resolution images. Accordingly, 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 compact 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, thereby increasing the degree of freedom in aberration correction, thereby achieving both high imaging performance throughout the entire zoom range and compactness.

[0007] JP 2009-175324 A

[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.

[0011] According to one aspect of the present invention, there is provided 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 the zoom lens satisfies the following conditional expressions: -0.080<f2 / ft<-0.040, 1.750<nd2p<1.800, 22.0<vd2p<25.0, and 10.0<ft / fw<20.0, where fw is the focal length of the entire system at the wide-angle end, ft is the focal length of the entire system at the telephoto end, f2 is the focal length of the second lens group, nd2p is the refractive index of the positive lens in the second lens group having the smallest Abbe number, and vd2p is the Abbe number of the positive lens in the second lens group having the smallest Abbe number.

[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 where nd2p is the refractive index of the positive lens in the second lens group having the smallest Abbe number, the zoom lens satisfies the condition: 1.750<nd2p<1.800.

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

[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.

[0015] FIG. 1 is a cross-sectional view of a zoom lens according to Example 1 of the present invention when focused on an object at infinity at the wide-angle end (short focal length end). FIG. 2 is a longitudinal aberration diagram of a zoom lens according to Example 1 when focused on an object at infinity at the wide-angle end. FIG. 3 is a longitudinal aberration diagram of a zoom lens according to Example 2 of the present invention when focused on an object at infinity at the wide-angle end. FIG. 4 is a longitudinal aberration diagram of a zoom lens according to Example 2 of the present invention when focused on an object at infinity at the telephoto end. FIG. 5 is a cross-sectional view of a zoom lens according to Example 3 of the present invention when focused on an object at infinity at the wide-angle end. FIG. 6 is a longitudinal aberration diagram of a zoom lens according to Example 3 of the present invention when focused on an object at infinity at the telephoto end. FIG. 1 is a cross-sectional view of a zoom lens according to Example 4 when focused on an object at infinity at the wide-angle end; FIG. 2 is a longitudinal aberration diagram of a zoom lens according to Example 4 when focused on an object at infinity at the wide-angle end; FIG. 3 is a longitudinal aberration diagram of a zoom lens according to Example 4 when focused on an object at infinity at the telephoto end; FIG. 4 is a cross-sectional view of a zoom lens according to Example 5 of the present invention when focused on an object at infinity at the wide-angle end; FIG. 5 is a longitudinal aberration diagram of a zoom lens according to Example 5 of the present invention when focused on an object at infinity at the wide-angle end;

[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 views, the left side is the object side (front) and the right side is the image side (rear). In the lens cross-sectional views, 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 disposed 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 imaging element (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 corresponding to the film surface.

[0040] In the aberration diagrams, d and g represent the d-line and g-line, respectively. M and S represent the meridional image plane and the sagittal image plane, 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 unit L4 in the optical axis direction. In Example 2 shown in FIG. 4, focusing is performed by moving the fourth lens unit L4 and the fifth lens unit 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 unit L6 in the optical axis direction. In Example 6 shown in FIG. 16, focusing is performed by moving the fifth lens unit 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 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] Each embodiment of the present invention is characterized in that it satisfies the following conditional expression: −0.080<f2 / ft<−0.040 (1) where ft is the focal length of the entire system at the telephoto end and f2 is the focal length of the second lens unit L2.

[0051] Conditional expression (1) defines the focal length of the second lens unit L2. Satisfying conditional expression (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 image plane with minimal fluctuations in aberrations across the entire zoom range. If the refractive power of the second lens unit L2 becomes too strong, exceeding the upper limit of conditional expression (1), the refractive power of the second lens unit L2 becomes too strong, making it difficult to reduce 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 expression (1), it becomes difficult to create a retrofocus-type power arrangement at the wide-angle end and making it difficult to widen the angle of view at the wide-angle end.

[0052] When the refractive index of the positive lens having the smallest Abbe number in the second lens unit L2 is nd2p, the following condition is satisfied: 1.750<nd2p<1.800 (2).

[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 refractive index of the positive lens element becomes too high, exceeding the upper limit of conditional expression (2), the Petzval sum becomes large in the negative direction, making it difficult to correct curvature of field. If the refractive index of the positive lens element becomes too low, exceeding the lower limit of conditional expression (2), making it difficult to correct spherical aberration at the telephoto end.

[0054] When the Abbe number of the positive lens having the smallest Abbe number in the second lens unit L2 is vd2p, the following condition is satisfied: 22.0<vd2p<25.0 (3).

[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] The lens is characterized in that the following condition is satisfied: 10.0<ft / fw<20.0 (4) where fw is the focal length of the entire system at the wide-angle end and ft is the focal length of the entire system at the telephoto end.

[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 includes a plurality of negative lenses, which weakens the refractive power of each negative lens, gently bending off-axis rays in the second lens unit L2, and effectively correcting distortion, curvature of field, and the like at the wide-angle end.

[0059] In the optical system of each embodiment, it is preferable to satisfy one or more of the following conditional expressions, whereby 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 having the smallest Abbe number is taken as f2p, it is preferable to satisfy the following condition: 0.065<f2p / ft<0.110 (5).

[0061] Conditional expression (5) defines the focal length of the positive lens in the second lens unit L2 that has the smallest Abbe number. If the refractive power of the positive lens becomes too weak when the upper limit of conditional expression (5) is exceeded, it becomes difficult to correct axial chromatic aberration and chromatic aberration of magnification at the telephoto end. If the refractive power of the positive lens becomes too strong when the lower limit is exceeded, 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, it is preferable to satisfy the following conditional expression: 0.600<θgF2p<0.670 (6) where θgF2p is the partial dispersion ratio of the positive lens, and is defined by the following expression when the refractive index of the positive lens with respect to the g-line is ng2p, the refractive index of the positive lens with respect to the F-line is nF2p, and the refractive index of the positive lens with respect to the C-line is nC2p: θgF2p=(ng2p-nF2p) / (nF2p-nC2p) Conditional expression (6) defines the anomalous dispersion of the positive lens with the smallest Abbe number in the second lens unit L2. By satisfying conditional expression (6), it becomes possible to effectively correct secondary spectrum in addition to primary achromatism in correcting chromatic aberration. If the partial dispersion ratio of the positive lens becomes too large, exceeding the upper limit of conditional expression (6), the chromatic aberration for g-line at the telephoto end becomes too large on the negative side, whereas if the partial dispersion ratio of the positive lens becomes too small, exceeding the lower limit of conditional expression (6), the chromatic aberration for g-line at the telephoto end becomes too large on the positive side.

[0063] When the average value of the Abbe numbers of the positive lenses included in the first lens unit L1 is vd1p, it is preferable to satisfy the following condition: 3.00<vd1p / vd2p<4.00 (7).

[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 well corrected (achromatization) in the correction of chromatic aberration. If the Abbe number of the positive lens in the first lens unit L1 becomes too large, exceeding the upper limit of conditional expression (7), it becomes difficult to correct lateral chromatic aberration at the wide-angle end. If the Abbe number of the positive lens in the first lens unit L1 becomes too small, exceeding the lower limit of conditional expression (7), 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, it is preferable to satisfy the following condition: 1.70<vd2n / vd2p<2.40 (8).

[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) in the correction of chromatic aberration. 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 lower limit of conditional expression (8) is exceeded and the Abbe number of the negative lens in the second lens unit L2 becomes too small, it becomes difficult to correct lateral chromatic aberration at the wide-angle end.

[0067] When the Abbe number of the negative lens having the smallest Abbe number in the first lens unit L1 is vd1n, it is preferable to satisfy the following condition: 1.00<vd1n / vd2p<1.80 (9).

[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 in the correction of chromatic aberrations. If the Abbe number of the negative lens in the first lens unit L1 becomes too large, exceeding the upper limit of conditional expression (9), 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 at the telephoto end. If the Abbe number of the negative lens in the first lens unit L1 becomes too small, exceeding the lower limit of conditional expression (9), it becomes difficult to correct chromatic aberrations (secondary spectrum aberrations) at the telephoto end.

[0069] When the refractive index of the negative lens having the smallest Abbe number in the first lens unit L1 is nd1n, it is preferable to satisfy the following condition: 0.95<nd1n / nd2p<1.30 (10).

[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 will tend to be highly dispersed, making it difficult to correct axial chromatic aberration and the secondary spectrum of lateral chromatic aberration at the telephoto end. 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 will be 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, it is preferable to satisfy the following condition: 4.75<f1 / fw<10.00 (11).

[0072] Conditional expression (11) defines the focal length of the first lens unit L1. Satisfying conditional expression (11) facilitates the implementation 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. Furthermore, it becomes 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 negative refractive power, and is configured so that the spacing between each lens group changes 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 unit LN is fN, it is preferable to satisfy the following condition: −1.50<fN / ft<−0.10 (12)

[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, and it becomes difficult to shorten the overall optical length at the telephoto end.

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

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

[0079] When the focal length of the lens unit LN-1 is fN-1, it is preferable to satisfy the following condition: -0.30<fN-1 / ft<-0.05 (14).

[0080] Conditional expression (14) is used to appropriately set the focal length of the lens unit LN-1. By satisfying conditional expression (14), it becomes possible to achieve both compactness and good optical performance when the lens unit LF is used as a focus lens unit. If the upper limit of conditional expression (14) is exceeded, the refractive power of the lens unit 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 unit 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 vibration reduction lens group IS is represented by fIS, it is preferable to satisfy the following condition: 0.10<fIS / ft<0.20 (15).

[0082] Conditional expression (15) defines the focal length of the image stabilization lens group IS. If the refractive power of the image stabilization lens group IS becomes too weak by exceeding the upper limit of conditional expression (15), the amount of movement during image stabilization becomes large, making it difficult to reduce the lens outer diameter. If the refractive power of the image stabilization lens group IS becomes too strong by exceeding the lower limit of conditional expression (15), decentering coma and asymmetric curvature of field occur, making it difficult to obtain 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, it is preferable to satisfy the following condition: 0.25<m2 / fw<1.00 (16).

[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 ensure the desired magnification ratio, making it difficult to correct spherical aberration and chromatic aberration at the telephoto end.

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

[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 ensure a sufficient magnification ratio, making it difficult to correct spherical aberration and chromatic aberration at the telephoto end.

[0087] When the focal length of the intermediate lens unit LM at the wide-angle end is represented by fMw, it is preferable to satisfy the following condition: 0.060<fMw / ft<0.130 (18).

[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 zoom 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 of spherical aberration and correct spherical aberration at the wide-angle end.

[0089] When the total optical length at the telephoto end is TLt, it is preferable to satisfy the following condition: 0.55<TLt / ft<0.85 (19).

[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 good optical performance while realizing a compact optical system.

[0091] When the focal length of the first lens unit L1 is f1 and the focal length of the second lens unit L2 is f2, it is preferable to satisfy the following condition: -8.00<f1 / f2<-6.00 (20).

[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 middle lens unit LM at the wide-angle end is fMw and the focal length of the second lens unit L2 is f2, it is preferable to satisfy the following condition: -2.50<fMw / f2<-1.00 (21)

[0094] Conditional expression (21) defines the ratio of the focal lengths of the middle 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 middle 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 unit L2 is f2 and the focal length of the lens unit LN is fN, it is preferable to satisfy the following condition: 0.030<f2 / fN<0.250 (22).

[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 compact zoom lens having high imaging performance and realizing a high zoom ratio, as well as an imaging device 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 lenses of each embodiment, the positive and negative lenses constituting the cemented lens are preferably bonded together 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 an 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 configuration 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 the 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, since light reflected by a negative lens with a concave surface facing the image side tends to be focused on the image plane, ghosts tend to be noticeable. Therefore, applying an anti-reflection coating PC to the image-side surface of a negative lens with a concave surface facing the image side can reduce ghosts.

[0105] In particular, it is preferable to provide the anti-reflection coating PC on the negative lens located closest to the object side 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 ]+C ４ ×h ４ +C ６ ×h ６ +C ８ ×h ８ +C １０ ×h １０ +C １２ ×h １２ where x: displacement from the reference plane in the optical axis direction h: height in the direction perpendicular to the optical axis R: radius of the base quadratic surface k: conic constant C ｎ : n-th order aspherical coefficients Note that the "E-Z" indication is "×10 －Ｚ " means.

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

[0110] 1, L1 is a first lens unit with positive refractive power, L2 is a second lens unit with negative refractive power, L3 is a third lens unit (middle unit LM) with positive refractive power, L4 is a fourth lens unit (lens unit LN-1) with negative refractive power, and L5 is a fifth lens unit (lens unit LN) with negative refractive power.

[0111] The first lens unit 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 unit 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 unit 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 in which a biconvex positive lens and a biconcave negative lens are cemented together.

[0115] The fifth lens unit 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 disposed 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 arrows. 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 formed by cementing together 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, thereby displacing the image in a direction approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates.

[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 Pitch Diameter 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 surface ∞ Aspheric data Surface 6 K = 0.00000e+00 A4= 3.83583e-06 A6=-4.89664e-10 A8= 2.81674e-11 A10=-1.08555e-13 A12= 2.38728e-16 Surface 28 K = 0.00000e+00 A4= 1.34099e-05 A 37th surface 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 Total Lens 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 Initial Surface 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 Initial 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 the first lens group with positive refractive power, L2 is the second lens group with negative refractive power, and L3 is the third lens group with positive refractive power. Furthermore, L4 is the fourth lens group with positive refractive power, L5 is the fifth lens group (lens group LN-1) with negative refractive power, and L6 is the sixth lens group (lens group LN) with negative refractive power.

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

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

[0125] The second lens unit 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 unit 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 a 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 unit 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 located 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 formed by cementing together 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, thereby displacing the image in a direction approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates.

[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 Pitch Diameter 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 surface ∞ Aspheric data Surface 6 K = 0.00000e+00 A4= 3.77899e-06 A6=-6.89162e-10 A8= 1.59375e-11 A10=-5.29178e-14 A12= 9.86025e-17 Surface 28 K = 0.00000e+00 A4= 1.05910e-05 A 37th surface 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 Total lens 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 Initial Surface 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 Initial 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, and L4 is a fourth lens group with negative refractive power. Furthermore, L5 is a fifth lens unit with positive refractive power, L6 is a sixth lens unit (lens unit LN-1) with negative refractive power, and L7 is a seventh lens unit (lens unit LN) with negative refractive power.

[0136] The third to fifth lens groups constitute an intermediate lens group LM.

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

[0138] The second lens unit 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 unit 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 unit 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 unit 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 unit L6 is composed of, in order from the object side, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens. The seventh lens unit 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 aspheric surface formed on its object side.

[0141] SP denotes an aperture stop, which is disposed 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 formed by cementing together 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, thereby displacing the image in a direction approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates.

[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 Pitch Diameter 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 surface ∞ Aspheric data Surface 6 K = 0.00000e+00 A4= 4.16182e-06 A6=-1.01293e-09 A8= 3.04594e-11 A10=-1.26477e-13 A12= 2.74307e-16 Surface 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 Surface 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 Medium 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 Total lens 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 Initial Surface 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 Singlet Lens Data Lens Initial 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, and L3 is a third lens group with positive refractive power. Also, 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 constitute an intermediate lens group LM.

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

[0150] The second lens unit 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 unit 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 a concave surface facing the object side.

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

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

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

[0156] SP denotes an aperture stop, which is disposed 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 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 decreasing 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.

[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 formed by cementing together 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, thereby displacing the image in a direction approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates.

[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 Pitch Diameter 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 surface ∞ Aspheric surface data Surface 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 Surface 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 27th surface 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 36th surface 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 Medium 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 Total lens 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 Initial Surface 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 Initial 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 the first lens group with positive refractive power, L2 is the second lens group with negative refractive power, L3 is the third lens group (middle group LM) with positive refractive power, L4 is the fourth lens group (lens group LN-1) with negative refractive power, and L5 is the fifth lens group (lens group LN) with negative refractive power.

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

[0164] The second lens unit 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 unit 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 unit L3 also includes a biconvex positive lens with aspherical surfaces formed 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 in which a biconvex positive lens and a biconcave negative lens are cemented together.

[0167] The fifth lens unit 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 disposed 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 arrows. 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 formed by cementing together 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, thereby displacing the image in a direction approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates.

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

[0173] The surface data of Numerical Example 5 is as follows:

[0174] Unit: mm Surface Data Surface Number rd nd νd Pitch Diameter 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 surface ∞ Aspheric data Surface 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 Surface 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 27th surface 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 36th surface 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 Medium 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 Total lens 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 Initial Surface 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 Initial 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, and L3 is a third lens group with positive refractive power. Furthermore, L4 is a fourth lens unit with positive refractive power, L5 is a fifth lens unit (lens unit LN-1) with negative refractive power, and L6 is a sixth lens unit (lens unit LN) with negative refractive power.

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

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

[0177] The second lens unit 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 unit 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 unit 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 disposed 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, which is made by cementing a negative meniscus lens with its convex surface facing the object side to a biconvex positive lens, and a biconvex positive lens. It moves so as to have 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 when the entire zoom lens vibrates. 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 Pitch Diameter 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 surface ∞ Aspheric data Surface 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 29th side 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 30th side 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 Surface 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 34.50 11.56 3.19 Image height 19.83 21.64 21.64 Lens 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 Initial Surface 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 Initial 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]

[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 showing 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] 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.

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 group having one or more lens groups and having positive refractive power overall, wherein the spacing between each lens group changes during zooming, and wherein the zoom lens satisfies the following conditional expressions: -0.080<f2 / ft<-0.040, 1.750<nd2p<1.800, 22.0<vd2p<25.0, and 10.0<ft / fw<20.0, where fw is the focal length of the entire system at the wide-angle end, ft is the focal length of the entire system at the telephoto end, f2 is the focal length of said second lens group, nd2p is the refractive index of the positive lens in said second lens group with the smallest Abbe number, and vd2p is the Abbe number of the positive lens in said second lens group with the smallest Abbe number.

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

3. The zoom lens according to claim 1 or 2, characterized in that it satisfies the condition: 0.600<θgF2p<0.670, where θgF2p is the partial dispersion ratio of the positive lens in the second lens group with the smallest Abbe number, and θgF2p is the partial dispersion ratio of the positive lens with the smallest Abbe number, and is defined by the following formula: θgF2p=(ng2p-nF2p) / (nF2p-nC2p), where ng2p is the refractive index of the positive lens with the smallest Abbe number with respect to the g-line, nF2p is the refractive index of the positive lens with the smallest Abbe number with respect to the F-line, and nC2p is the refractive index of the positive lens with the smallest Abbe number with respect to the C-line.

4. A zoom lens according to any one of claims 1 to 3, characterized in that the following condition is satisfied: 3.00<vd1p / vd2p<4.00, where vd1p is the average value of the Abbe numbers of the positive lenses included in the first lens group.

5. A zoom lens according to any one of claims 1 to 4, characterized in that the following condition is satisfied: 1.70<vd2n / vd2p<2.40, where vd2n is the average value of the Abbe numbers of the negative lenses included in the second lens group.

6. A zoom lens according to any one of claims 1 to 5, characterized in that the following condition is satisfied: 1.00<vd1n / vd2p<1.80, where vd1n is the Abbe number of the negative lens in the first lens group that has the smallest Abbe number.

7. A zoom lens according to any one of claims 1 to 6, characterized in that the following condition is satisfied: 0.95<nd1n / nd2p<1.30, where nd1n is the refractive index of the negative lens in the first lens group that has the smallest Abbe number.

8. A zoom lens according to any one of claims 1 to 7, characterized in that the following condition is satisfied: 4.75<f1 / fw<10.00, where f1 is the focal length of the first lens group.

9. A zoom lens according to any one of claims 1 to 8, characterized in that the subsequent group comprises, 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. The zoom lens according to claim 9, wherein the following condition is satisfied: -1.50<fN / ft<-0.10, where fN is the focal length of the lens unit LN.

11. A zoom lens according to any one of claims 1 to 10, characterized in that the following condition is satisfied: 0.30<skw / fw<0.70, where skw is the back focus at the wide-angle end.

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

13. A zoom lens according to any one of claims 1 to 12, characterized in that the subsequent group has an image stabilizing lens group, and where fIS is the focal length of the image stabilizing lens group, the following condition is satisfied: 0.10<fIS / ft<0.

20.

14. A zoom lens according to any one of claims 1 to 13, characterized in that the following condition is satisfied: 0.25<m2 / fw<1.00, where m2 is the amount of movement of the second lens group from the wide-angle end to the telephoto end.

15. A zoom lens according to any one of claims 1 to 14, characterized in that the following condition is satisfied: 3.00<m1 / fw<4.50, where m1 is the amount of movement of the first lens group from the wide-angle end to the telephoto end.

16. A zoom lens according to any one of claims 9, 10 and 12, characterized in that the following condition is satisfied: 0.060<fMw / ft<0.130, where fMw is the focal length of the intermediate group at the wide-angle end.

17. A zoom lens according to any one of claims 1 to 16, characterized in that the following condition is satisfied: 0.55<TLt / ft<0.85, where TLt is the total optical length at the telephoto end.

18. A zoom lens according to any one of claims 1 to 17, characterized in that the following condition is satisfied: -8.00<f1 / f2<-6.00, where f1 is the focal length of the first lens group and f2 is the focal length of the second lens group.

19. A zoom lens according to any one of claims 9, 10, 12, and 16, characterized in that the following condition is satisfied: -2.50<fMw / f2<-1.00, where fMw is the focal length of the intermediate lens group at the wide-angle end and f2 is the focal length of the second lens group at the wide-angle end.

20. A zoom lens according to any one of claims 9, 10, 12, 16, and 19, characterized in that the following condition is satisfied: 0.030<f2 / fN<0.250, where f2 is the focal length of the second lens group and fN is the focal length of the lens group LN.

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 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 has a plurality of negative lenses, and wherein, when the refractive index of the positive lens in the second lens group having the smallest Abbe number is nd2p, the zoom lens satisfies the condition: 1.750<nd2p<1.

800.

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

Images