Zoom lens and imaging device

Abstract

Provided is a zoom lens that, with a fixed total track, is suitable for moving image capture, is compact, and has high optical performance over the entire object distance.　This zoom lens includes, in order from the object side to the image side: a first lens group that has a negative refractive power and that does not move for zooming; a focusing lens group including at least two lens groups; and a subsequent lens group including at least one lens group. When zooming, the intervals between the lens groups change. The focusing lens group includes at least two lens groups that move along mutually different tracks when focusing is performed. The value of the ratio between the focal length of the first lens group and the focal length of the lens group, in the focusing lens group, which is disposed closest to the object side is set as appropriate.

Description

Zoom lens and imaging device

[0001] The present disclosure relates to a zoom lens and an imaging device.

[0002] In recent years, the image quality of single-lens reflex cameras, digital still cameras, video cameras, etc. that use solid-state image sensors has been improving. In particular, single-lens reflex cameras are required to not only achieve higher image quality during shooting, but also to achieve faster AF speeds in order to meet the growing demand for video.

[0003] To satisfy these demands, in recent years, photographic optical systems have been developed that reduce the weight of focus lens groups and that reduce the amount of movement during focusing by adopting a so-called floating focus system in which multiple focus lenses are driven. By adopting this system, it is possible to increase the focusing speed and the photographic magnification. Patent Documents 1 and 2 disclose zoom lenses that include a first lens group with a fixed negative refractive power during zooming and a subsequent lens group that includes multiple lens groups.

[0004] International Publication No. 2023 / 181903 Japanese Patent Application Laid-Open No. 2019-056916

[0005] The zoom lenses disclosed in Patent Documents 1 and 2 are characterized by a small F-number and high optical performance across the entire zoom range and all object distances, but have issues such as low imaging magnification and significant focusing breathing.

[0006] In order to solve the above-mentioned problems, the present disclosure aims to provide a zoom lens that has a fixed overall length, is suitable for video shooting, is compact, and has high optical performance at all subject distances, and an imaging device having the same.

[0007] The zoom lens of the present disclosure comprises, in order from the object side to the image side, a first lens group having negative refractive power that does not move for varying magnification, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group, wherein the spacing between the lens groups changes during variation of magnification, and the focusing lens group includes at least two lens groups that move on different trajectories during focusing, and wherein the zoom lens satisfies the conditional expression -0.60<f1 / f2<-0.05, where f1 is the focal length of the first lens group and f2 is the focal length of the lens group that is located closest to the object side among the focusing lens groups.

[0008] According to the present disclosure, it is possible to obtain a zoom lens with a fixed overall length that is suitable for video shooting, is compact, and has high optical performance at all subject distances, and an imaging device having the same.

[0009] FIG. 1 is a cross-sectional view of a zoom lens of Example 1. FIG. 2 is a diagram of aberrations at the wide-angle end of the zoom lens of Example 1. FIG. 3 is a diagram of aberrations at the intermediate position of the zoom lens of Example 1. FIG. 4 is a diagram of aberrations at the telephoto end of the zoom lens of Example 1. FIG. 5 is a cross-sectional view of a zoom lens of Example 2. FIG. 6 is a diagram of aberrations at the wide-angle end of the zoom lens of Example 2. FIG. 7 is a diagram of aberrations at the intermediate position of the zoom lens of Example 2. FIG. 8 is a diagram of aberrations at the telephoto end of the zoom lens of Example 2. FIG. 9 is a cross-sectional view of a zoom lens of Example 3. FIG. 10 is a diagram of aberrations at the wide-angle end of the zoom lens of Example 3. FIG. 11 is a diagram of aberrations at the intermediate position of the zoom lens of Example 3. FIG. 12 is a diagram of aberrations at the telephoto end of the zoom lens of Example 3. FIG. 13 is a cross-sectional view of a zoom lens of Example 4. FIG. 14 is a diagram of aberrations at the wide-angle end of the zoom lens of Example 4. FIG. 15 is a diagram of aberrations at the intermediate position of the zoom lens of Example 4. FIG. 16 is a diagram of aberrations at the telephoto end of the zoom lens of Example 4. FIG. 17 is a cross-sectional view of a zoom lens of Example 5. FIG. 18 is a diagram of aberrations at the wide-angle end of the zoom lens of Example 5. 10 is a diagram illustrating aberrations at an intermediate position of the zoom lens of Example 5. FIG. 11 is a diagram illustrating aberrations at a telephoto end of the zoom lens of Example 5. FIG. 12 is a lens cross-sectional view of the zoom lens of Example 6. FIG. 13 is a diagram illustrating aberrations at a wide-angle end of the zoom lens of Example 6. FIG. 14 is a diagram illustrating aberrations at an intermediate position of the zoom lens of Example 6. FIG. 15 is a diagram illustrating aberrations at a telephoto end of the zoom lens of Example 6. FIG. 16 is a diagram illustrating an imaging device (digital camera) having the zoom lenses of Examples 1 to 6.

[0010] In recent years, the image quality of single-lens reflex cameras, digital still cameras, video cameras, etc. that use solid-state image sensors has been improving. In particular, single-lens reflex cameras are required to not only achieve higher image quality during shooting, but also to achieve faster AF speeds in order to meet the growing demand for video.

[0011] To satisfy these demands, photographic optical systems have been developed in recent years that reduce the weight of focus lens groups and that reduce the amount of movement during focusing by adopting a so-called floating focus system that drives multiple focus lenses. By adopting this system, it is possible to increase the focusing speed and increase the photographic magnification.

[0012] In recent years, the number of cameras that do not have a quick-return mirror, so-called mirrorless cameras, has been increasing. Because mirrorless cameras are characterized by their thin bodies, small size, and light weight, there is a demand for the development of small, lightweight interchangeable lenses that are a perfect match for mirrorless cameras. Because mirrorless cameras do not require the space required for a quick-return mirror, there is no need to ensure the same back focus as conventional interchangeable lenses. This allows for greater design freedom in terms of lens configuration, unlike conventional interchangeable lenses, making it possible to design small, lightweight lenses. Wide-angle lenses, in particular, tend to have short back focus, making them more compact for interchangeable lenses for mirrorless cameras.

[0013] Conventionally, there has been known a zoom lens that comprises a first lens group that has negative refractive power and remains fixed during zooming, and a subsequent group that comprises multiple lens groups. This zoom lens achieves high magnification and high performance by moving the multiple lens groups arranged on the image side along different trajectories.

[0014] However, changes in the focus position during video shooting can cause fluctuations in the angle of view, known as focus breathing. Methods for suppressing focus breathing include optimizing the focus group through optical design, and electrically correcting the image data. Electronically correcting various aberrations, particularly chromatic aberration and distortion, and using a configuration suitable for correcting other aberrations, can enable compactness and high image quality.

[0015] The zoom lens disclosed herein is characterized by its fixed overall length, compact size, and high optical performance at all subject distances, making it suitable for video shooting. In particular, a floating focus optical system with multiple focusing groups is advantageous for designing and suppressing lens breathing. This disclosure employs a configuration with a focusing lens group that includes at least two lens groups to achieve both aberration correction and lens breathing suppression.

[0016] The lens also has an arrangement that, from the subject side to the image side, includes a first lens group with negative refractive power, a focusing lens group including at least two lens groups, and a subsequent lens group including at least two lens groups. To create a configuration suitable for video shooting, the first lens group, which is heavy and disadvantageous for power control, is fixed during zooming. Furthermore, to correct aberrations in large-diameter lenses, zooming and aberration correction are achieved simultaneously by moving multiple relatively light lens groups.

[0017] On the other hand, breathing is suppressed by a focusing lens group that includes two or more lens groups arranged on the image side of the first lens group. Specifically, at least two lens groups included in the focusing lens group are moved by different amounts during focusing, thereby canceling out changes in optical performance and angle of view. In addition, by appropriately setting the power distribution of a lens group that is located at a position where off-axial rays are relatively low and moving it during focusing, changes in field curvature that tend to occur in wide-angle lenses are suppressed.

[0018] In this disclosure, by adopting these configurations, changes in optical performance during focusing and suppression of breathing are achieved. Furthermore, a feature of this lens is that a subsequent lens group including two or more lens groups is located on the image side of the focusing lens group. By locating this subsequent lens group on the image side of the focusing lens group, it is possible to appropriately set the share of magnification change in the entire system, and it is possible to effectively correct various aberrations, such as spherical aberration, field curvature, and chromatic aberration, which are particularly susceptible to change during magnification change.

[0019] The above lens configuration achieves a zoom lens that is suitable for video shooting with a fixed overall length, is compact, and has high optical performance at all subject distances.

[0020] The zoom lens of the present disclosure comprises, in order from the object side to the image side, a first lens group having negative refractive power that does not move for varying magnification, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group, wherein the spacing between the lens groups changes during variation of magnification, and the focusing lens group includes at least two lens groups that move on different trajectories during focusing, and wherein, when the focal length of the first lens group is f1 and the focal length of the lens group that is located closest to the object side among the focusing lens groups is f2, the zoom lens satisfies the following conditional expression: -0.60<f1 / f2<-0.05 (1)

[0021] In the zoom lens of the present disclosure, the power arrangement of the lens group at a position where the off-axis rays are relatively low is appropriately set, thereby suppressing fluctuations in various aberrations that occur during focusing and the occurrence of breathing.

[0022] Conditional expression (1) is a conditional expression concerning the focal length ratio between the first lens group and the lens group located closest to the object side of the focusing lens group, and is a conditional expression concerning aberration fluctuations during zooming and focusing. If the lower limit of conditional expression (1) is not satisfied, the power of the lens group located closest to the object side of the focusing lens group becomes stronger, making it difficult to suppress fluctuations in various aberrations such as field curvature and axial chromatic aberration. This is also undesirable in terms of suppressing breathing during focusing. On the other hand, if the upper limit of conditional expression (1) is exceeded, it is advantageous for achieving a wider angle of view, but the power of the first lens group becomes stronger, making it difficult to suppress fluctuations in various aberrations such as distortion and chromatic aberration of magnification.

[0023] The object of the present disclosure is achieved by the above conditional expression, but more preferably, in the configuration of the zoom lens of the present disclosure, the following conditional expression is satisfied: 0.20<Lsw / TL<0.50 (2), where Lsw is the distance on the optical axis at the wide-angle end from the lens surface in the first lens group that is located closest to the object, including the aperture stop, to the aperture stop, and TL is the total optical length of the zoom lens.

[0024] Conditional expression (2) is a conditional expression concerning the position of the aperture stop disposed within the zoom lens, and is a conditional expression concerning the diameter of the front lens (the diameter of the lens disposed closest to the object) and the exit pupil. If the lower limit of conditional expression (2) is not satisfied, the position of the aperture stop will be closer to the front lens, which is advantageous for reducing the diameter of the front lens, but the diameter of the rear lens (the diameter of the lens disposed closest to the image) will be larger, which is undesirable. On the other hand, if the upper limit of conditional expression (2) is exceeded, the position of the aperture stop will be farther from the front lens, which is unfavorable for reducing the diameter of the front lens. Furthermore, the exit pupil will be closer to the image plane, which is undesirable because the angle of incidence of light rays on the image sensor will be larger, which will likely result in color unevenness around the periphery of the image.

[0025] More preferably, the zoom lens of the present disclosure includes an aperture stop, and satisfies the following conditional expression: 0.10<Lst / TL<0.40 (3), where Lst is the distance on the optical axis at the telephoto end from the lens surface in the first lens group that is located closest to the object to the aperture stop, and TL is the total optical length of the zoom lens.

[0026] Conditional expression (3) is a conditional expression concerning the position of the aperture stop disposed within the zoom lens, and is a conditional expression concerning the diameter of the rear lens and the exit pupil. If the lower limit of conditional expression (3) is not satisfied, the position of the aperture stop will be closer to the front lens, and the diameter of the rear lens will increase, which is undesirable. On the other hand, if the upper limit of conditional expression (3) is exceeded, the position of the aperture stop will be farther from the front lens, and the opening diameter of the aperture stop will increase, making it difficult to correct various aberrations such as spherical aberration and coma.

[0027] In the configuration of the zoom lens of the present disclosure, at least two lens groups included in the focusing lens group that move for focusing will be referred to as the first focusing lens group and the second focusing lens group, in that order from the object side to the image side. In this case, at the wide-angle end, when the absolute values ​​of the movement amounts from infinity to a magnification of 0.1 times for the first focusing lens group and the second focusing lens group are M1w and M2w, respectively, the following conditional expression must be satisfied: 0.5<M1w / M2w<3.0 (4)

[0028] Conditional expression (4) is a conditional expression concerning the ratio of the amount of movement between the first focusing lens group and the second focusing lens group, and is a conditional expression concerning fluctuations in various aberrations such as breathing and field curvature during focusing in particular. If the lower limit of conditional expression (4) is exceeded, the amount of movement of the first focusing lens group located on the object side will be smaller than the amount of movement of the second focusing lens group located on the image side, which is advantageous for suppressing breathing, but is undesirable because it increases fluctuations in various aberrations. On the other hand, if the upper limit of conditional expression (4) is exceeded, the amount of movement of the first focusing lens group will be larger than the amount of movement of the second focusing lens group, which makes it difficult to suppress breathing.

[0029] More preferably, in the configuration of the zoom lens of the present disclosure, the focusing lens group includes at least two lens groups that move for focusing, and these will be referred to as the first focusing lens group and the second focusing lens group in order from the object side to the image side. In this case, at the telephoto end, when the absolute values ​​of the movement amounts of the first focusing lens group and the second focusing lens group from infinity to a magnification of 0.1 times are M1t and M2t, respectively, the following conditional expression is satisfied: 1.0<M1t / M2t<6.0 (5)

[0030] Conditional expression (5) is a conditional expression concerning the ratio of the amount of movement between the first focusing lens group and the second focusing lens group, and is a conditional expression concerning fluctuations in various aberrations such as breathing and field curvature during focusing in particular. If the lower limit of conditional expression (5) is exceeded, the amount of movement of the first focusing lens group arranged on the object side will be smaller than the amount of movement of the second focusing lens group arranged on the image side, which is advantageous for suppressing breathing, but this is undesirable because it increases fluctuations in various aberrations such as coma and field curvature. On the other hand, if the upper limit of conditional expression (5) is exceeded, the amount of movement of the first focusing lens group will be larger than the amount of movement of the second focusing lens group, which is undesirable because it increases the overall size of the lens system in order to ensure sufficient space for movement. Furthermore, it will be difficult to suppress breathing.

[0031] More preferably, in the configuration of the zoom lens of the present disclosure, when the distance from the lens surface located closest to the image side at the wide-angle end to the image plane is BFw and the focal length of the entire system at the wide-angle end is fw, the following conditional expression is satisfied: 0.10<BFw / fw<1.30 (6).

[0032] Conditional expression (6) is a conditional expression relating to the back focus at the wide-angle end, and in particular to various aberrations such as the total optical length and curvature of field. If the lower limit of conditional expression (6) is exceeded, the back focus becomes short, which is advantageous in terms of reducing the total optical length, but it is undesirable because it increases the angle of incidence of light rays on the image sensor, making it more likely that color unevenness will occur in the peripheral areas of the image. On the other hand, if the upper limit of conditional expression (6) is exceeded, a retrofocus-type power arrangement is required to ensure the back focus, making it difficult to correct various aberrations such as curvature of field and coma.

[0033] More preferably, in the configuration of the zoom lens of the present disclosure, when the composite lateral magnification of the subsequent lens group at the wide-angle end is βrw and the composite lateral magnification at the telephoto end is βrt, the following conditional expression is satisfied: 0.30<|βrt / βrw|<2.80 (7).

[0034] Conditional expression (7) is a conditional expression relating to the lateral magnification of the subsequent lens group, and in particular to the magnification-varying contribution and overall optical length of the zoom lens. If the lower limit of conditional expression (7) is not reached, the magnification-varying contribution of the subsequent lens group becomes small, so the magnification-varying contribution of the focusing lens group increases, making it difficult to suppress breathing and the overall optical length. On the other hand, if the upper limit of conditional expression (7) is reached, the magnification-varying contribution of the subsequent lens group becomes large, which is advantageous for suppressing breathing, but is undesirable because it increases the change in field curvature during magnification.

[0035] More preferably, in the configuration of the zoom lens of the present disclosure, when the focal length of the lens group arranged closest to the object among the focusing lens groups is f2 and the focal length of the adjacent lens group arranged closest to the image side is f3, the following conditional expression is satisfied: 1.50<f2 / f3<3.00 (8).

[0036] Conditional expression (8) is a conditional expression concerning the focal length ratio between the lens group located closest to the object side of the focusing lens group and the lens group located closest to the image side thereof, and is a conditional expression concerning changes in various aberrations during zooming. Below the lower limit of conditional expression (8), the power of the lens group located closest to the object side of the focusing lens group becomes stronger, making it difficult to suppress lens-breathing. On the other hand, above the upper limit of conditional expression (8), the power of the lens group located closest to the image side of the focusing lens group becomes stronger, which is advantageous for suppressing lens-breathing, but makes it difficult to suppress coma and axial chromatic aberration during zooming.

[0037] More preferably, in the configuration of the zoom lens of the present disclosure, the lens group arranged closest to the image side is composed of a single lens having a convex surface on the image side, and when the focal length of the single lens is fR, the following conditional expression is satisfied: 2.00<fR / fw<6.00 (9).

[0038] Conditional expression (9) is a conditional expression concerning the power arrangement of the lens group arranged closest to the image, and is a conditional expression concerning lateral chromatic aberration and field curvature in particular. If the lower limit of conditional expression (9) is not met, the power of the lens group arranged closest to the image becomes stronger, which is advantageous for correcting lateral chromatic aberration throughout the entire zoom range, but it becomes difficult to ensure back focus. On the other hand, if the upper limit of conditional expression (9) is met, the power of the lens group arranged closest to the image becomes weaker, which makes it difficult to suppress field curvature. Furthermore, it becomes difficult to suppress the angle of incidence to the image sensor, which is undesirable because it is more likely to cause color unevenness in the peripheral areas of the image.

[0039] In each numerical example, it is more preferable in terms of aberration correction to set the numerical ranges of conditional expressions (1) to (9) as follows: -0.50<f1 / f2<-0.05 (1a) 0.25<Lsw / TL<0.50 (2a) 0.15<Lst / TL<0.40 (3a) 0.5<M1w / M2w<2.9 (4a) 1.5<M1t / M2t<5.8 (5a) 0.10<BFw / fw<1.25 (6a) 0.30<|βrt / βrw|<2.60 (7a) 1.60<f2 / f3<2.80 (8a) 2.10<fR / fw<5.60 (9a)

[0040] It is even more preferable to set the numerical ranges of conditional expressions (1) to (9) as follows: -0.40<f1 / f2<-0.10 (1b) 0.30<Lsw / TL<0.48 (2b) 0.20<Lst / TL<0.38 (3b) 0.8<M1w / M2w<2.8 (4b) 1.8<M1t / M2t<5.5 (5b) 0.10<BFw / fw<1.20 (6b) 0.35<|βrt / βrw|<2.50 (7b) 1.70<f2 / f3<2.60 (8b) 2.20<fR / fw<5.20 (9b)

[0041] The first lens group includes at least one negative lens and at least one positive lens, and is composed of four or fewer lenses. Furthermore, during photography, a part of the subsequent lens group or a part of the focusing lens group may be moved in a direction having a component perpendicular to the optical axis to displace the image perpendicular to the optical axis. This may enable a configuration that corrects blurring of the photographed image when the entire optical system vibrates, i.e., enables so-called image stabilization.

[0042] In an imaging device having a zoom lens according to each numerical embodiment, correction of distortion, among other aberrations, may be performed by electrical image processing of image data. In particular, the wide-angle end has an imaging range that is smaller than the effective imaging range of the image sensor, and correction of the distortion contributes to a reduction in the diameter of the front lens element. The zoom lens according to the present disclosure is configured so that the effective image circle diameter at the wide-angle end is smaller than the effective image circle diameter at the telephoto end.

[0043] In each numerical example, by configuring each lens group as described above, a zoom lens with a fixed overall length, suitable for video shooting, compact, and with high optical performance at all subject distances, and an imaging device having the same are obtained.

[0044] The zoom lens according to Example 1 will be described with reference to Figures 1 to 4. Figure 1 is a cross-sectional view of the zoom lens according to Example 1 when focused at infinity at the wide-angle end. In the cross-sectional view of the zoom lens, the left side is the object side and the right side is the image side.

[0045] The zoom lens of Example 1 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, and a sixth lens unit L6 having positive refractive power.

[0046] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the fifth lens unit L5 move toward the object side, while the first lens unit L1, the fourth lens unit L4, and the sixth lens unit L6 do not move for zooming.

[0047] In addition, a floating focus system is adopted in which the second lens unit L2 and the third lens unit L3 are moved during focusing. In Figure 1, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 3a and the dashed line curve 3b for the third lens unit L3, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance object, respectively.

[0048] Furthermore, when focusing from an object at infinity to an object at a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the third lens unit L3 moves toward the object side as indicated by arrow 3c. Note that the first lens unit L1 does not move for focusing, but may be moved as necessary for aberration correction.

[0049] Furthermore, during photography, the fourth lens group L4, which is part of the subsequent lens group, may be moved in a direction including a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0050] The first lens unit L1 is composed of, in order from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface.

[0051] In the zoom lens disclosed herein, compactness is achieved by designing the refractive power of the first lens unit L1 to be large within an appropriate range. Increasing the refractive power increases various aberrations that occur within the first lens unit L1, particularly distortion and curvature of field at the wide-angle end. Therefore, the negative refractive power of the first lens unit L1 is shared by three negative lenses, and distortion in particular can be effectively corrected by applying electronic distortion correction to the electronic data captured by the imaging device.

[0052] The second lens unit L2 is composed of three lenses, in order from the object side to the image side: a biconvex positive lens, and a cemented lens formed by cementing a biconcave negative lens and a biconvex positive lens. In the zoom lens disclosed herein, the refractive power of the second lens unit L2 is set to be large within an appropriate range in order to increase the zoom ratio. Increasing the refractive power of the second lens unit L2 increases the aberrations that occur in the second lens unit L2, particularly spherical aberration and axial chromatic aberration. The positive refractive power of the second lens unit L2 is shared by two positive lenses, reducing the occurrence of spherical aberration. Furthermore, the use of a cemented lens suppresses axial chromatic aberration. This lens configuration reduces the overall optical length while increasing the zoom ratio.

[0053] The third lens unit L3 is composed of, in order from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex surface facing the object and a biconvex positive lens. In the zoom lens disclosed herein, the third lens unit L3 is composed of a small number of lenses, thereby achieving a compact and lightweight design. In particular, the use of a cemented lens and a low-dispersion material for the positive lens suppresses fluctuations in axial chromatic aberration.

[0054] The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a biconcave negative lens. The zoom lens disclosed herein aims to achieve a slimmer design by configuring the fourth lens unit with a small number of lenses. In particular, the concave object-side surface of the fourth lens unit L4 minimizes spherical aberration.

[0055] The fifth lens unit L5 is composed of four elements, in order from the object side to the image side: a biconvex positive lens, a cemented lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave object-side surface. In the zoom lens disclosed herein, the refractive power of the fifth lens unit L5 is increased within an appropriate range to increase the magnification ratio. In particular, the use of an anomalous dispersion material for the positive lens and the use of a cemented lens suppresses fluctuations in lateral chromatic aberration. Furthermore, the use of a negative meniscus lens with a concave object-side surface and an aspherical surface suppresses the occurrence of field curvature.

[0056] The sixth lens unit L6 is composed of a single positive meniscus lens with a convex image-side surface. The zoom lens disclosed herein achieves a slim design by configuring the sixth lens unit with a small number of lenses. In particular, the convex image-side surface reduces the angle of light rays incident on the image sensor. Furthermore, the sixth lens unit L6 uses a high-dispersion material to reduce lateral chromatic aberration throughout the entire zoom range.

[0057] The aperture diaphragm SP is disposed between the second lens unit L2 and the third lens unit L3 and moves together with the third lens unit L3 in the optical axis direction during zooming and focusing. The aperture diaphragm SP has an aperture diameter that varies in accordance with the magnification, so that the F-number at the telephoto end is small. Furthermore, by disposing the aperture diaphragm SP in a position closest to the lens closest to the object at the wide-angle end, the entrance pupil position is moved closer to the object, thereby achieving a small diameter for the lens closest to the object.

[0058] An auxiliary diaphragm is arranged on the image side of the fourth lens unit L4 to cut off unnecessary off-axis light, thereby improving optical performance.

[0059] In Example 1, the second lens group L2 and the third lens group L3 are focusing lens groups, the fourth lens group L4 and the fifth lens group L5 are subsequent lens groups, and the sixth lens group L6 is the final lens group. Also, the second lens group L2 is the first focusing lens group, and the third lens group L3 is the second focusing lens group.

[0060] IP is the image plane, which corresponds to the imaging surface of a solid-state image sensor such as a CCD sensor or CMOS sensor when used as the photographic optical system of a digital still camera or video camera, or the film surface when used in a silver halide film camera. GB is a glass block, which corresponds to a low-pass filter or IR cut filter.

[0061] The zoom lens of this embodiment has an effective image circle diameter of 26.66 mm at the wide-angle end, which is smaller than the effective image circle diameter of 29.60 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0062] 2 to 4 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration of the zoom lens according to Example 1 at the wide-angle end, intermediate zoom position, and telephoto end. In each aberration diagram, d and g represent the d-line and g-line, respectively, ΔM and ΔS represent the meridional image plane and sagittal image plane, and the lateral chromatic aberration diagram is shown using the g-line. Furthermore, fno represents the F-number, and ω represents the half angle of view. In each example, the wide-angle end and telephoto end refer to zoom positions when the variable magnification lens group is located at the end of the range of mechanical movement in the optical axis direction. This also applies to the following examples. As is clear from each aberration diagram, aberrations are well corrected.

[0063] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0064] A zoom lens according to Example 2 will be described with reference to FIGS. 5 to 8. FIG. 5 is a cross-sectional view of the zoom lens according to Example 2 at the wide-angle end when focused at infinity. The zoom lens according to Example 2 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, and a sixth lens unit L6 having positive refractive power. An aperture stop SP is located on the object side of the third lens unit L3 and moves integrally with the third lens unit L3 during zooming and focusing.

[0065] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the fifth lens unit L5 move toward the object side, while the first lens unit L1, the fourth lens unit L4, and the sixth lens unit L6 do not move for zooming.

[0066] Furthermore, a floating focus system is adopted in which the second lens unit L2 and the third lens unit L3 are moved during focusing. In Figure 5, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 3a and the dashed line curve 3b for the third lens unit L3, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance, respectively.

[0067] Furthermore, when focusing from an object at infinity to an object at a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the third lens unit L3 moves toward the object side as indicated by arrow 3c. Note that the first lens unit L1 does not move for focusing, but may be moved as necessary for aberration correction.

[0068] Furthermore, during photography, the fourth lens group L4, which is part of the subsequent lens group, may be moved in a direction including a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0069] The first lens unit L1 is composed of, from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface. The second lens unit L2 is composed of, from the object side to the image side, three lenses: a positive meniscus lens with a concave object-side surface, and a cemented lens consisting of a biconcave negative lens and a biconvex positive lens.

[0070] The third lens unit L3 is composed of, from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex object-side surface and a biconvex positive lens. The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a biconcave negative lens.

[0071] The fifth lens unit L5 is composed of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave object-side surface. The sixth lens unit L6 is composed of a positive meniscus lens with a convex image-side surface.

[0072] The aperture diaphragm SP is disposed between the second lens unit L2 and the third lens unit L3, and moves together with the third lens unit L3 in the optical axis direction during zooming and focusing. The aperture diameter of the aperture diaphragm SP is variable in response to magnification, so that Fno becomes smaller on the telephoto side.

[0073] An auxiliary diaphragm is arranged on the image side of the fourth lens unit L4 to cut off unnecessary off-axis light, thereby improving optical performance.

[0074] In Example 2, the second lens group L2 and the third lens group L3 are focusing lens groups, the fourth lens group L4 and the fifth lens group L5 are subsequent lens groups, and the sixth lens group L6 is the final lens group. Also, the second lens group L2 is the first focusing lens group, and the third lens group L3 is the second focusing lens group.

[0075] The zoom lens of this embodiment has an effective image circle diameter of 38.96 mm at the wide-angle end, which is smaller than the effective image circle diameter of 43.28 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0076] 6 to 8 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens according to Example 2. As is clear from each aberration diagram, the aberrations are well corrected.

[0077] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0078] A zoom lens according to Example 3 will be described with reference to FIGS. 9 to 12. FIG. 9 is a cross-sectional view of the zoom lens according to Example 3 at the wide-angle end when focused at infinity. The zoom lens according to Example 3 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, and a fifth lens unit L5 having positive refractive power. An aperture stop SP is located on the object side of the third lens unit L3 and moves integrally with the third lens unit L3 during zooming and focusing.

[0079] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the fifth lens unit L5 move toward the object side, while the first lens unit L1 and the fourth lens unit L4 do not move for zooming.

[0080] Furthermore, a floating focus system is adopted in which the second lens unit L2 and the third lens unit L3 are moved during focusing. In Figure 9, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 3a and the dashed line curve 3b for the third lens unit L3, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance object, respectively.

[0081] Furthermore, when focusing from an object at infinity to a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the third lens unit L3 moves toward the object side as indicated by arrow 3c. The first lens unit L1 does not move for focusing, but may be moved as needed for aberration correction. Furthermore, during photography, all or part of the fourth lens unit L4, which is part of the subsequent lens group, may be moved in a direction that includes a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0082] The first lens unit L1 is composed of, from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface. The second lens unit L2 is composed of, from the object side to the image side, a positive meniscus lens with a concave object-side surface, and a cemented lens formed by cementing together a negative meniscus lens with a concave object-side surface and a positive meniscus lens with a concave object-side surface.

[0083] The third lens unit L3 is composed of, from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex object-side surface and a biconvex positive lens. The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a negative meniscus lens with a concave object-side surface, and a negative meniscus lens with a concave object-side surface.

[0084] The fifth lens unit L5 is composed of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by cementing a biconvex positive lens and a negative meniscus lens with a concave object-side surface, and a negative meniscus lens with a concave object-side surface.

[0085] The aperture diaphragm SP is disposed between the second lens unit L2 and the third lens unit L3, and moves together with the third lens unit L3 in the optical axis direction during zooming and focusing. The aperture diameter of the aperture diaphragm SP is variable in response to magnification, so that Fno becomes smaller on the telephoto side.

[0086] An auxiliary diaphragm is disposed inside the fourth lens unit L4 to cut off unnecessary off-axis light, thereby improving optical performance.

[0087] In Example 3, the second lens group L2 and the third lens group L3 are focusing lens groups, and the fourth lens group L4 and the fifth lens group L5 are subsequent lens groups. The second lens group L2 is the first focusing lens group, and the third lens group L3 is the second focusing lens group.

[0088] The zoom lens of this embodiment has an effective image circle diameter of 26.66 mm at the wide-angle end, which is smaller than the effective image circle diameter of 29.60 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0089] 10 to 12 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to Example 3. As is clear from each aberration diagram, the aberrations are well corrected.

[0090] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0091] A zoom lens according to Example 4 will be described with reference to FIGS. 13 to 16. FIG. 13 is a cross-sectional view of the zoom lens according to Example 4 at the wide-angle end when focused at infinity. The zoom lens according to Example 4 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, and a sixth lens unit L6 having positive refractive power. An aperture stop SP is located on the object side of the third lens unit L3 and moves integrally with the third lens unit L3 during zooming.

[0092] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the fifth lens unit L5 move toward the object side, while the first lens unit L1, the fourth lens unit L4, and the sixth lens unit L6 do not move for zooming.

[0093] Furthermore, a floating focus system is adopted in which the second lens unit L2 and the fourth lens unit L4 are moved during focusing. In Fig. 13, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 4a and the dashed line curve 4b for the fourth lens unit L4, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance object, respectively.

[0094] Furthermore, when focusing from an object at infinity to an object at a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the fourth lens unit L4 moves toward the image side as indicated by arrow 4c. Note that the first lens unit L1 does not move for focusing, but may be moved as necessary for aberration correction.

[0095] Furthermore, during photography, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction including a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0096] The first lens unit L1 is composed of, from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface. The second lens unit L2 is composed of, from the object side to the image side, a biconvex positive lens, and a cemented lens consisting of a biconcave negative lens and a biconvex positive lens cemented together.

[0097] The third lens unit L3 is composed of, from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex object-side surface and a biconvex positive lens. The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a negative meniscus lens with a concave object-side surface.

[0098] The fifth lens unit L5 is composed of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave object-side surface. The sixth lens unit L6 is composed of a positive meniscus lens with a convex image-side surface.

[0099] The aperture diaphragm SP is disposed between the second lens unit L2 and the third lens unit L3, and moves together with the third lens unit L3 in the optical axis direction during zooming and focusing. The aperture diameter of the aperture diaphragm SP is variable in response to magnification, so that Fno becomes smaller on the telephoto side.

[0100] An auxiliary diaphragm is arranged on the image side of the fourth lens unit L4 to cut off unnecessary off-axis light, thereby improving optical performance.

[0101] In Example 4, the second lens group L2, the third lens group L3, and the fourth lens group L4 are focusing lens groups, the fifth lens group L5 is the subsequent lens group, and the sixth lens group L6 is the final lens group. Also, the second lens group L2 is the first focusing lens group, and the fourth lens group L4 is the second focusing lens group.

[0102] The zoom lens of this embodiment has an effective image circle diameter of 26.66 mm at the wide-angle end, which is smaller than the effective image circle diameter of 29.60 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0103] 14 to 16 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to Example 4. As is clear from each aberration diagram, the aberrations are well corrected.

[0104] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0105] A zoom lens according to Example 5 will be described with reference to FIGS. 17 to 20. FIG. 17 is a cross-sectional view of the zoom lens according to Example 5 at the wide-angle end when focused at infinity. The zoom lens according to Example 5 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, a sixth lens unit L6 having positive refractive power, and a seventh lens unit L7 having positive refractive power. An aperture stop SP is located on the object side of the third lens unit L3 and moves integrally with the third lens unit L3 during zooming.

[0106] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the sixth lens unit L6 move toward the object side, while the first lens unit L1, the fourth lens unit L4, the fifth lens unit L5, and the seventh lens unit L7 do not move for zooming.

[0107] Furthermore, a floating focus system is adopted in which the second lens unit L2 and the fourth lens unit L4 are moved during focusing. In Fig. 17, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 4a and the dashed line curve 4b for the fourth lens unit L4, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance, respectively.

[0108] Furthermore, when focusing from an object at infinity to an object at a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the fourth lens unit L4 moves toward the image side as indicated by arrow 4c. Note that the first lens unit L1 does not move for focusing, but may be moved as necessary for aberration correction.

[0109] Furthermore, during photography, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction including a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0110] The first lens unit L1 is composed of, from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface. The second lens unit L2 is composed of, from the object side to the image side, a biconvex positive lens, and a cemented lens consisting of a biconcave negative lens and a biconvex positive lens cemented together.

[0111] The third lens unit L3 is composed of, from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex object-side surface and a biconvex positive lens. The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a biconcave negative lens.

[0112] The fifth lens unit L5 is composed of a positive meniscus lens with a convex object-side surface. The sixth lens unit L6 is composed of, in order from the object side to the image side, a biconvex positive lens, a cemented lens consisting of a biconvex positive lens and a biconcave negative lens, and a biconcave negative lens. The seventh lens unit L7 is composed of a positive meniscus lens with a concave object-side surface.

[0113] The aperture diaphragm SP is located between the second lens unit L2 and the third lens unit L3 and moves integrally with the third lens unit L3 during zooming and focusing. The aperture diaphragm SP has an aperture diameter that varies depending on the magnification, so that the F-number at the telephoto end is small. An auxiliary diaphragm is located on the image side of the fourth lens unit L4, cutting out unnecessary off-axial light to improve optical performance.

[0114] In Example 5, the second lens group L2, the third lens group L3, and the fourth lens group L4 are focusing lens groups, the fifth lens group L5 and the sixth lens group L6 are subsequent lens groups, and the seventh lens group L7 is the final lens group. Also, the second lens group L2 is the first focusing lens group, and the fourth lens group L4 is the second focusing lens group.

[0115] The zoom lens of this embodiment has an effective image circle diameter of 26.66 mm at the wide-angle end, which is smaller than the effective image circle diameter of 29.60 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0116] 18 to 20 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to Example 5. As is clear from each aberration diagram, the aberrations are well corrected.

[0117] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0118] A zoom lens according to Example 6 will be described with reference to FIGS. 21 to 24. FIG. 21 is a cross-sectional view of the zoom lens according to Example 6 at the wide-angle end when focused at infinity. The zoom lens according to Example 6 includes, in order from the object side to the image side, a first lens unit L1 having negative refractive power, a second lens unit L2 having positive refractive power, a third lens unit L3 having positive refractive power, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, and a sixth lens unit L6 having positive refractive power. An aperture stop SP is located on the object side of the third lens unit L3 and moves integrally with the third lens unit L3 during zooming.

[0119] During zooming from the wide-angle end to the telephoto end, the second lens unit L2, the third lens unit L3, and the fifth lens unit L5 move toward the object side, the sixth lens unit L6 moves toward the image side, and the first lens unit L1 and the fourth lens unit L4 do not move for zooming.

[0120] Furthermore, a floating focus system is adopted in which the second lens unit L2 and the fourth lens unit L4 are moved during focusing. In Fig. 21, the solid line curve 2a and the dashed line curve 2b for the second lens unit L2, and the solid line curve 4a and the dashed line curve 4b for the fourth lens unit L4, represent movement loci for correcting image plane fluctuations that occur with magnification changes when focusing on an object at infinity and a close distance object, respectively.

[0121] Furthermore, when focusing from an object at infinity to an object at a close distance, the second lens unit L2 moves toward the image side as indicated by arrow 2c, and the fourth lens unit L4 moves toward the image side as indicated by arrow 4c. Note that the first lens unit L1 does not move for focusing, but may be moved as necessary for aberration correction.

[0122] Furthermore, during photography, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction including a component perpendicular to the optical axis (for example, a vertical direction or a substantially vertical direction) to correct blurring of the subject image.

[0123] The first lens unit L1 is composed of, from the object side to the image side, a negative meniscus lens with a convex object-side surface, a negative lens with weak power, a biconcave negative lens, and a positive meniscus lens with a convex object-side surface. The second lens unit L2 is composed of, from the object side to the image side, a biconvex positive lens, and a cemented lens consisting of a biconcave negative lens and a biconvex positive lens cemented together.

[0124] The third lens unit L3 is composed of, from the object side to the image side, a cemented lens formed by cementing together a negative meniscus lens with a convex object-side surface and a biconvex positive lens. The fourth lens unit L4 is composed of, from the object side to the image side, a cemented lens formed by cementing together a positive meniscus lens with a concave object-side surface and a biconcave negative lens.

[0125] The fifth lens unit L5 is composed of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave object-side surface. The sixth lens unit L6 is composed of a positive meniscus lens with a concave object-side surface.

[0126] The aperture stop SP is located between the second lens unit L2 and the third lens unit L3 and moves integrally with the third lens unit L3 during zooming. The aperture stop SP's aperture diameter varies in accordance with the magnification, so that the F-number at the telephoto end is small. An auxiliary stop is located on the image side of the fourth lens unit L4 to cut off unnecessary off-axial light, thereby improving optical performance.

[0127] In Example 6, the second lens group L2, the third lens group L3, and the fourth lens group L4 are focusing lens groups, and the fifth lens group L5 and the sixth lens group L6 are subsequent lens groups. The second lens group L2 is the first focusing lens group, and the fourth lens group L4 is the second focusing lens group.

[0128] The zoom lens of this embodiment has an effective image circle diameter of 26.66 mm at the wide-angle end, which is smaller than the effective image circle diameter of 29.60 mm at the telephoto end. This configuration makes it possible to reduce the diameter of the front lens by correcting distortion through electrical image processing of image data.

[0129] 22 to 24 show aberration diagrams of spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to Example 6. As is clear from each aberration diagram, the aberrations are well corrected.

[0130] With this configuration, the zoom lens of this embodiment is suitable for video shooting with a fixed overall length, is compact, and can provide high optical performance at all subject distances.

[0131] 25 is a conceptual diagram of an imaging device (digital camera) 30 having a zoom lens 31 according to the present disclosure described in any one of Examples 1 to 6 as a photographing optical system and an imaging element that receives an image formed by the zoom lens. The imaging element is configured with a CCD (Charge Coupled Device) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor, or the like.

[0132] An imaging device having a zoom lens according to the present disclosure as a photographing optical system has a fixed overall length and is suitable for video shooting, and can achieve the effects of being compact and providing high optical performance at all subject distances.

[0133] Below, numerical data for each of Numerical Examples 1 to 6 corresponding to the zoom lenses of Examples 1 to 6 is shown. In the numerical data for the Numerical Examples, ri denotes the radius of curvature of the ith surface from the object side, di denotes the distance between the ith surface and the (i+1)th surface from the object side, ni denotes the refractive index at the d-line of the lens between the ith surface and the (i+1)th surface, and vi denotes the Abbe number at the d-line of the lens between the ith surface and the (i+1)th surface (also simply referred to as the Abbe number).

[0134] The Abbe number ν is expressed as follows: ν=(nd−1) / (nF−nC) (10) where nd, nF, and nC are the refractive indices at the d-line (wavelength 587.6 nm), F-line (wavelength 486.1 nm), and C-line (wavelength 656.3 nm) of the Fraunhofer lines.

[0135] Furthermore, when k is a conic constant, A4, A6, A8, A10, A12, A14, and A16 are aspherical coefficients of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders, and the displacement in the optical axis direction at a position of height h from the optical axis is x with the vertex of the surface as the reference, the aspherical shape is expressed as follows: x = (h ２ / R) / [1+{1-(1+k)(h / R) ２} １／２ ] +A4h ４ +A6h ６ +A8h ８ +A10h １０ +A12h １２ +A14h １４ +A16h １６ ... (11) where R is the radius of curvature, and "e-X" is "×10 －Ｘ ". Aspherical surfaces are indicated by an asterisk (*) to the right of the surface number in each table.

[0136] <Numerical Example 1> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 65.207 1.95 1.58313 59.4 38.47 2* 11.968 6.76 27.96 3* 24.090 1.75 1.85400 40.4 26.22 4* 18.735 4.89 21.55 5 -55.593 0.83 1.48749 70.2 20.61 6 14.285 0.10 18.53 7 14.432 3.47 1.92119 24.0 18.55 8 29.834 (Variable) 17.61 9 90.303 1.86 1.85478 24.8 13.52 10 -84.026 0.38 13.11 11 -26.987 0.80 1.92286 20.9 13.25 12 27.132 4.61 1.75520 27.5 13.01 13 -23.700 (Variable) 14.17 14 (Aperture) ∞ 0.60 15.64 15 20.764 0.86 1.77047 29.7 16.27 16 12.954 4.84 1.53775 74.7 15.85 17 -42.387 (Variable) 15.82 18 -28.911 2.43 1.92286 20.9 13.00 19 -13.809 0.75 1.76634 35.8 13.62 20 1203.720 2.33 14.63 21 ∞ (Variable) 16.33 22 17.956 7.68 1.49700 81.6 22.21 23 -52.351 0.15 21.87 24 23.645 6.35 1.49700 81.6 20.36 25 -33.868 0.90 2.05090 26.9 18.84 26 51.701 2.97 18.15 27* 436.934 1.75 1.85400 40.4 18.09 28* 53.961 (variable) 19.55 29 -73.004 3.43 2.00100 29.1 26.19 30 -27.532 8.27 26.90 31 ∞ 1.34 1.51633 64.1 34.20 32 ∞ 0.63 34.20 Image plane ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-1.11704e-05 A6= 1.49309e-07 A8= 1.55218e-11 A10=-2.59405e-12 A12= 9.88132e-15 A14=-1.51052e-17 A16= 8.73342e-21 2nd side K =-6.30137e-01 A4=-3.18000e-05 A6=-1.33671e-07 A8= 2.22774e-10 A10= 3.50434e-11 A12=-3.16074e-13 A14= 6.76007e-16 3rd side K = 0.00000e+00 A4=-1.80496e-04 A6=-2.47551e-07 A8= 1.43334e-08 A10=-1.02994e-10 A12= 3.50185e-13 A14=-6.19177e-16 A16= 4.53061e-19 4th side K = 0.00000e+00 A4=-1.65000e-04 A6= 2.59865e-07 A8= 1.52837e-08 A10=-1.40315e-10 A12= 6.50247e-13 A14=-6.04664e-16 Surface 27 K = 0.00000e+00 A4=-3.21406e-04 A6= 1.66855e-06 A8=-2.00842e-08 A10= 3.00718e-10 A12=-1.49836e-12 A14= 5.69216e-16 A16=-2.03667e-17 Surface 28 K = 0.00000e+00 A4=-2.37535e-04 A6= 2.21381e-06 A8=-1.44297e-08 A10= 1.60479e-10 A12=-7.69701e-13 Data Zoom ratio 1.91 Focal length 10.36 14.70 19.80 F-number 2.91 2.91 2.91 Angle of view 52.13 45.19 36.78 Image height 13.33 14.80 14.80 Lens length 101.53 101.53 101.53 BF 9.78 9.78 9.78 d 8 13.01 4.55 1.99 d13 3.90 7.87 4.23 d17 1.84 6.32 12.53 d21 8.78 3.77 0.51 d28 1.79 6.80 10.06 Entrance pupil position 15.36 14.85 13.81 Exit pupil position -103.44 -145.30 -258.33 Front principal point position 24.69 28.07 32.10 Rear principal point position -9.73 -14.07 -19.17 Zoom lens group data group Start plane Focal length Lens construction length Front principal point position Rear principal point position 1 1 -14.85 19.75 5.45 -8.67 2 9 76.85 7.65 7.47 3.23 3 15 32.11 5.70 1.21 -2.54 4 18 -48.09 5.51 -0.64 -4.68 5 22 40.66 19.80 -14.95 -21.05 6 29 42.55 3.43 2.65 1.00 Singlet Data Lens Initial Surface Focal Length 1 1 -25.48 2 3 -116.20 3 5 -23.22 4 7 27.38 5 9 51.17 6 11 -14.56 7 12 17.43 8 15 -46.95 9 16 19.03 10 18 26.59 11 19 -17.81 12 22 27.91 13 24 29.08 14 25 -19.37 15 27 -72.24 16 29 42.55 Amount of movement of the focusing lens group from infinity to 0.1x magnification Lens group L2 L3 Wide-angle end 1.779 -0.809 Telephoto end 1.466 -0.374.

[0137] <Numerical Example 2> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 83.155 2.85 1.58313 59.4 54.89 2* 20.058 9.31 42.38 3* 94.086 2.25 1.85400 40.4 40.17 4* 57.161 6.38 33.39 5 -59.871 1.21 1.45860 90.2 33.17 6 23.741 0.15 29.75 7 23.748 3.84 2.00272 19.3 29.77 8 37.507 (variable) 28.77 9 -1779.352 2.30 1.85025 30.1 23.36 10 -58.257 1.05 23.17 11 -29.919 1.04 1.92119 24.0 23.27 12 87.046 4.87 1.83400 37.2 23.63 13 -30.999 (Variable) 23.80 14 (Aperture) ∞ 0.72 24.41 15 27.802 1.25 1.80610 33.3 25.59 16 18.376 7.70 1.55032 75.5 24.73 17 -86.180 (Variable) 24.61 18 -58.249 2.29 1.92286 20.9 20.50 19 -26.335 0.77 1.82080 42.7 20.64 20 308.573 3.40 21.69 21 ∞ (Variable) 23.98 22 29.002 10.52 1.49700 81.6 34.57 23 -57.999 0.22 34.34 24 34.953 9.37 1.43700 95.1 31.10 25 -38.436 1.25 2.00069 25.5 29.29 26 236.343 4.33 28.45 27* -231.686 2.10 1.85400 40.4 28.21 28* 76.799 (variable) 30.49 29 -97.742 5.18 1.92286 18.9 38.12 30 -41.691 11.63 39.40 31 ∞ 1.34 1.51633 64.1 50.00 32 ∞ 1.55 50.00 Image surface ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-9.12936e-07 A6= 1.74132e-08 A8= 4.14399e-13 A10=-6.67938e-14 A12= 1.16895e-16 A14=-8.43472e-20 A16= 2.59202e-23 2nd side K =-7.27966e-01 A4=-2.29916e-06 A6=-7.59909e-09 A8=-1.02529e-11 A10= 9.55552e-13 A12=-3.92215e-15 A14= 3.89662e-18 3rd side K = 0.00000e+00 A4=-1.30892e-05 A6=-1.09456e-07 A8= 1.03324e-09 A10=-3.05150e-12 A12= 4.23725e-15 A14=-3.15990e-18 A16= 1.21802e-21 4th side K = 0.00000e+00 A4=-4.71583e-06 A6=-6.71632e-08 A8= 1.03858e-09 A10=-3.45987e-12 A12= 7.39477e-15 A14=-6.07013e-18 Surface 27 K = 0.00000e+00 A4=-1.14091e-04 A6= 5.12601e-07 A8=-2.63741e-09 A10= 1.18036e-11 A12=-3.71566e-14 A14= 9.46222e-17 A16=-1.76678e-19 Surface 28 K = 0.00000e+00 A4=-8.89041e-05 A6= 5.20287e-07 A8=-2.07853e-09 A10= 6.13557e-12 A12=-8.71875e-15 Data Zoom Ratio 2.36 Focal Length 16.46 24.20 38.80 F-Number 2.18 2.91 4.12 Angle of View 49.80 41.80 29.14 Image Height 19.48 21.64 21.64 Lens Length 149.73 149.73 149.73 BF 14.06 14.06 14.06 d 8 20.60 7.59 2.87 d13 11.84 16.48 5.63 d17 2.00 10.38 25.95 d21 14.96 7.75 0.60 d28 1.92 9.13 16.28 Entrance pupil position 24.25 23.46 20.49 Exit pupil position -105.78 -141.77 -235.74 Front principal point position 38.19 43.57 52.94 Rear principal point position -14.91 -22.64 -37.25 Zoom lens group data group Start plane Focal length Lens construction length Front principal point position Rear principal point position 1 1 -22.17 25.98 9.05 -9.80 2 9 92.88 9.26 9.02 3.74 3 15 47.34 8.95 1.27 -4.56 4 18 -68.41 6.46 -0.02 -5.04 5 22 62.29 27.79 -23.48 -31.19 6 29 75.43 5.18 4.50 1.92 Singlet Data Lens Initial Surface Focal Length 1 1 -46.10 2 3 -175.47 3 5 -36.90 4 7 56.65 5 9 70.79 6 11 -24.07 7 12 27.93 8 15 -71.47 9 16 28.26 10 18 50.35 11 19 -29.53 12 22 40.53 13 24 43.58 14 25 -32.96 15 27 -67.33 16 29 75.43 Amount of movement of the focusing lens group from infinity to 0.1x magnification Lens group L2 L3 Wide-angle end 2.324 -0.893 Telephoto end 1.764 -0.348.

[0138] <Numerical Example 3> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 35.935 1.95 1.58313 59.4 39.23 2* 12.831 7.66 30.81 3* 38.840 1.75 1.85400 40.4 26.86 4* 28.319 4.37 21.79 5 -49.772 0.83 1.59282 68.6 20.56 6 13.914 0.10 17.57 7 13.792 3.27 1.80809 22.8 17.56 8 27.478 (Variable) 16.57 9 -142.069 2.71 1.90043 37.4 13.95 10 -25.965 0.68 13.79 11 -15.643 0.80 1.92286 20.9 13.78 12 -175.705 4.31 1.67270 32.1 14.10 13 -16.079 (Variable) 14.65 14 (Aperture) ∞ 0.60 16.60 15 17.551 0.86 1.95375 32.3 17.44 16 12.638 5.18 1.55032 75.5 16.75 17 -59.639 (Variable) 16.63 18 -42.720 1.48 1.98612 16.5 13.36 19 -20.449 0.75 1.88300 40.8 13.37 20 -93.916 1.50 13.34 21 ∞ 1.00 14.20 22 -42.420 0.90 1.89190 37.1 14.39 23 420.417 (Variable) 15.07 24 19.024 7.99 1.49700 81.6 22.96 25 -44.860 0.15 22.87 26 23.900 7.50 1.48071 85.3 21.51 27 -26.061 0.90 2.00069 25.5 19.92 28 -175.997 3.74 19.53 29* -68.396 1.75 1.85400 40.4 18.93 30* 12072.379 (variable) 20.54 31 ∞ 1.34 1.51633 64.1 34.20 32 ∞ 0.63 34.20 Image surface ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-3.83383e-05 A6= 2.45312e-07 A8=-4.16267e-11 A10=-3.01634e-12 A12= 1.08353e-14 A14=-1.57762e-17 A16= 1.01179e-20 2nd side K =-5.17647e-01 A4=-4.76988e-05 A6= 1.75246e-08 A8=-6.10325e-10 A10= 3.53220e-11 A12=-2.49061e-13 A14= 4.49849e-16 3rd side K = 0.00000e+00 A4=-5.39722e-05 A6=-8.55438e-07 A8= 1.56441e-08 A10=-1.00144e-10 A12= 3.15410e-13 A14=-4.48024e-16 A16= 8.73682e-20 4th side K = 0.00000e+00 A4=-3.60102e-05 A6=-5.73429e-07 A8= 1.76406e-08 A10=-1.41260e-10 A12= 6.86453e-13 A14=-9.31010e-16 Surface 29 K = 0.00000e+00 A4=-3.40229e-04 A6= 1.62265e-06 A8=-2.48541e-08 A10= 4.17717e-10 A12=-2.60276e-12 A14= 4.91728e-15 A16=-1.37053e-17 Surface 30 K = 0.00000e+00 A4=-2.63872e-04 A6= 1.99718e-06 A8=-1.48849e-08 A10= 1.68361e-10 A12=-7.40275e-13 Data Zoom Ratio 2.02 Focal Length 10.36 18.20 20.20 F-Number 2.91 2.91 2.91 Angle of View 52.13 39.12 36.23 Image Height 13.33 14.80 14.80 Lens Length 100.84 100.84 100.84 BF 11.50 17.98 19.03 d 8 13.44 2.72 1.99 d13 3.14 6.63 5.42 d17 1.51 8.74 10.68 d23 8.53 2.05 1.00 d30 9.98 16.46 17.51 ​​Entrance pupil position 17.09 16.14 15.80 Exit pupil position -54.89 -51.71 -52.10 Front principal point position 25.51 28.01 28.27 Rear principal point position -9.73 -17.56 -19.57 Zoom lens group data group Start plane Focal length Lens construction length Front principal point position Rear principal point position 1 1 -13.43 19.92 8.07 -6.21 2 9 59.98 8.50 9.09 4.50 3 14 31.77 6.64 1.28 -3.22 4 18 -30.73 5.63 2.15 -1.83 5 24 25.44 22.03 -3.54 -16.13 Singlet Data Lens Initial Surface Focal Length 1 1 -35.32 2 3 -132.57 3 5 -18.26 4 7 30.96 5 9 34.90 6 11 -18.65 7 12 26.03 8 15 -51.76 9 16 19.44 10 18 38.51 11 19 -29.75 12 22 -43.16 13 24 28.04 14 26 27.26 15 27 -30.66 16 29 -79.63 Amount of movement of the focusing lens group from infinity to 0.1x magnification Lens group L2 L3 Wide-angle end 1.779 -0.809 Telephoto end 1.466 -0.374

[0139] <Numerical Example 4> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 61.152 1.95 1.58313 59.4 38.50 2* 12.492 6.90 29.26 3* 25.267 1.75 1.85400 40.4 26.77 4* 18.064 5.56 21.38 5 -47.598 0.83 1.49700 81.5 21.05 6 16.614 0.10 19.06 7 16.092 3.82 2.00272 19.3 19.06 8 28.053 (Variable) 17.51 ​​9 192.389 3.13 1.85478 24.8 13.38 10 -37.820 0.38 13.17 11 -22.740 0.80 1.92286 20.9 13.17 12 34.903 4.17 1.73800 32.3 14.11 13 -21.749 (Variable) 15.09 14 (Aperture) ∞ 0.60 16.47 15 19.198 0.86 1.73800 32.3 17.20 16 12.125 5.59 1.53775 74.7 16.64 17 -54.504 (Variable) 16.52 18 -37.773 1.92 1.98612 16.5 13.13 19 -16.502 0.75 1.85883 30.0 13.53 20 230.097 2.33 14.34 21 ∞ (Variable) 15.98 22 18.855 7.10 1.49700 81.6 22.39 23 -37.238 0.15 22.23 24 27.480 6.70 1.49700 81.6 20.43 25 -22.879 0.90 2.05090 26.9 18.96 26 125.065 2.97 18.58 27* -60.561 1.75 1.85400 40.4 18.54 28* 188.544 (variable) 20.57 29 -107.699 3.17 1.92286 20.9 26.22 30 -32.442 8.27 26.80 31 ∞ 1.34 1.51633 64.1 35.00 32 ∞ 0.63 35.00 Image surface ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-7.18649e-06 A6= 1.56202e-07 A8=-3.72182e-11 A10=-2.18728e-12 A12= 8.11692e-15 A14=-1.10998e-17 A16= 5.07737e-21 2nd side K =-7.21250e-01 A4=-2.94090e-05 A6=-1.28915e-08 A8=-1.93748e-10 A10= 3.50797e-11 A12=-2.91188e-13 A14= 5.95785e-16 3rd side K = 0.00000e+00 A4=-1.72761e-04 A6=-3.08074e-07 A8= 1.53103e-08 A10=-1.01314e-10 A12= 2.74412e-13 A14=-2.36300e-16 A16=-1.76418e-19 4th side K = 0.00000e+00 A4=-1.56283e-04 A6= 1.12970e-07 A8= 1.81398e-08 A10=-1.70393e-10 A12= 9.06183e-13 A14=-1.34800e-15 Surface 27 K = 0.00000e+00 A4=-3.07454e-04 A6= 2.20100e-06 A8=-3.20116e-08 A10= 3.99271e-10 A12=-2.18564e-12 A14= 7.16790e-15 A16=-4.95029e-17 Surface 28 K = 0.00000e+00 A4=-2.23267e-04 A6= 2.31615e-06 A8=-2.04763e-08 A10= 1.84333e-10 A12=-7.26456e-13 Data Zoom ratio 1.96 Focal length 10.36 15.08 20.30 F-number 2.91 2.91 2.91 Angle of view 52.14 44.46 36.09 Image height 13.33 14.80 14.80 Lens length 103.53 103.53 103.53 BF 9.78 9.78 9.78 d 8 11.86 4.43 1.99 d13 5.32 7.28 3.58 d17 1.44 6.91 13.04 d21 9.89 5.05 1.77 d28 1.06 5.90 9.18 Entrance pupil position 15.64 15.10 14.14 Exit pupil position -77.07 -102.39 -139.92 Front principal point position 24.61 27.97 31.51 Rear principal point position -9.73 -14.45 -19.67 Zoom lens group data group Start plane Focal length Lens construction length Front principal point position Rear principal point position 1 1 -13.30 20.91 6.39 -8.17 2 9 59.61 8.47 6.69 1.88 3 14 32.13 7.05 1.66 -3.21 4 18 -45.35 5.00 -0.11 -3.81 5 22 41.72 19.57 -15.61 -21.37 6 29 49.31 3.17 2.32 0.70 Singlet Data Lens Initial Surface Focal Length 1 1 -27.33 2 3 -83.55 3 5 -24.67 4 7 32.45 5 9 37.21 6 11 -14.82 7 12 18.74 8 15 -47.02 9 16 19.00 10 18 28.44 11 19 -17.90 12 22 26.29 13 24 26.28 14 25 -18.35 15 27 -53.50 16 29 49.31 Amount of movement of the focusing lens group from infinity to 0.1x magnification Lens group L2 L4 Wide-angle end 0.997 0.860 Telephoto end 0.985 0.457.

[0140] <Numerical Example 5> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 58.141 1.95 1.58313 59.4 38.15 2* 12.713 6.90 28.87 3* 50.049 1.75 1.85400 40.4 26.60 4* 24.466 5.43 21.24 5 -48.228 0.83 1.45860 90.2 21.04 6 15.731 0.10 19.15 7 15.720 4.04 1.86966 20.0 19.16 8 32.071 (variable) 17.77 9 310.796 2.15 1.85478 24.8 13.80 10 -33.992 0.38 13.52 11 -22.697 0.80 1.92286 20.9 13.49 12 42.995 4.51 1.72047 34.7 14.29 13 -22.466 (Variable) 15.48 14 (Aperture) ∞ 0.60 17.19 15 20.126 0.86 1.80000 29.8 17.95 16 13.105 5.59 1.53775 74.7 17.37 17 -44.239 (Variable) 17.30 18 -43.867 1.90 1.98612 16.5 13.18 19 -18.896 0.75 1.89190 37.1 13.48 20 66.009 2.33 14.24 21 ∞ (Variable) 15.94 22 41.278 1.80 1.48071 85.3 19.10 23 186.020 (Variable) 19.45 24 19.828 7.55 1.49700 81.6 23.86 25 -45.571 0.15 23.61 26 24.521 6.74 1.49700 81.6 21.59 27 -30.252 0.90 2.05090 26.9 19.96 28 57.952 3.60 19.16 29* -114.347 1.75 1.85400 40.4 19.04 30* 70.310 (Variable) 20.94 31 -207.839 3.84 1.90110 27.1 27.35 32 -32.941 8.27 27.94 33 ∞ 1.34 1.51633 64.1 35.00 34 ∞ 0.63 35.00 Image surface ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-1.68444e-05 A6= 1.78661e-07 A8=-5.04887e-12 A10=-2.56408e-12 A12= 9.16018e-15 A14=-1.27537e-17 A16= 6.49167e-21 2nd surface K =-5.58259e-01 A4=-3.41324e-05 A6=-1.45680e-07 A8=-1.34539e-10 A10= 3.59212e-11 A12=-2.89450e-13 A14= 5.84212e-16 3rd side K = 0.00000e+00 A4=-5.65107e-05 A6=-8.98327e-07 A8= 1.66100e-08 A10=-1.04746e-10 A12= 2.96600e-13 A14=-2.87071e-16 A16=-1.51836e-19 4th side K = 0.00000e+00 A4=-2.27640e-05 A6=-6.81060e-07 A8= 2.18483e-08 A10=-1.78940e-10 A12= 8.67387e-13 A14=-1.32669e-15 29th surface K = 0.00000e+00 A4=-2.93423e-04 A6= 2.11559e-06 A8=-2.69459e-08 A10= 2.97277e-10 A12=-1.42311e-12 A14= 4.31743e-15 A16=-3.60071e-17 30th surface K = 0.00000e+00 A4=-2.14871e-04 A6= 2.35153e-06 A8=-2.06770e-08 A10= 1.74335e-10 A12=-6.62366e-13 Various data Zoom ratio 1.96 Focal length 10.36 15.09 20.30 F-number 2.91 2.91 2.91 Angle of view 52.14 44.44 36.09 Image height 13.33 14.80 14.80 Lens total length 110.01 110.01 110.01 BF 9.78 9.78 9.78 d 8 12.53 4.66 1.99 d13 6.13 8.42 4.67 d17 1.44 7.01 13.43 d21 2.50 2.50 2.50 d23 9.37 4.19 1.00 d30 1.06 6.25 9.43 Entrance pupil position 15.46 14.97 14.06 Exit pupil position -103.38 -166.83 -318.12 Front principal point position 24.79 28.71 33.07 Back principal point position -9.73 -14.46 -19.67 Zoom lens data group Initial surface Focal length Lens construction length Front principal point position Rear principal point position 1 1 -13.25 21.01 6.06 -8.96 2 9 61.48 7.84 6.66 2.21 3 14 32.10 7.05 1.91 -2.96 4 18 -31.97 4.98 0.43 -3.24 5 22 109.91 1.80 -0.35 -1.56 6 24 50.69 20.69 -23.15 -26.08 7 31 43.00 3.84 2.37 0.38 Single lens data lens Initial surface Focal length 1 1 -28.35 2 3 -57.87 3 5 -25.76 4 7 31.80 5 9 35.95 6 11 -16.00 7 12 21.09 8 15 -49.66 9 16 19.46 10 18 32.44 11 19 -16.40 12 22 109.91 13 24 28.91 14 26 28.41 15 27 -18.82 16 29 -50.76 17 31 43.00 Lens group L2 L4 Focusing distance from infinity to 0.1x magnification: Wide-angle end 1.074 0.689 Telephoto end 1.039 0.295.

[0141] <Numerical Example 6> Unit: mm Surface data Surface number rd nd vd Pitch diameter 1* 49.852 1.95 1.58313 59.4 38.43 2* 12.034 6.98 29.25 3* 22.140 1.75 1.85400 40.4 26.74 4* 16.284 5.52 21.37 5 -49.573 0.83 1.49700 81.5 20.21 6 16.899 0.20 18.30 7 16.301 3.52 2.00272 19.3 18.30 8 28.057 (Variable) 16.98 9 383.277 3.11 1.85478 24.8 13.25 10 -34.628 0.45 13.12 11 -21.924 0.80 1.92286 20.9 13.14 12 37.079 4.40 1.73800 32.3 14.09 13 -21.553 (Variable) 15.20 14 (Aperture) ∞ 0.60 16.69 15 19.316 0.86 1.73800 32.3 17.43 16 12.129 5.55 1.53775 74.7 16.84 17 -53.403 (Variable) 16.73 18 -38.250 2.30 1.98612 16.5 13.10 19 -16.502 0.75 1.85883 30.0 13.44 20 269.093 2.33 14.22 21 ∞ (Variable) 15.81 22 19.395 6.80 1.48071 85.3 21.97 23 -36.012 0.15 21.92 24 25.341 6.76 1.43700 95.1 20.42 25 -25.221 0.90 2.05090 26.9 18.97 26 121.702 2.97 18.68 27* -52.925 1.75 1.85400 40.4 18.67 28* -2320.313 (variable) 20.61 29 -93.836 3.16 1.92119 24.0 26.40 30 -31.663 (variable) 26.99 31 ∞ 1.34 1.51633 64.1 35.00 32 ∞ 0.65 35.00 Image plane ∞ Aspheric surface data 1st surface K = 0.00000e+00 A4=-1.26269e-05 A6= 1.57648e-07 A8=-4.33516e-12 A10=-2.25416e-12 A12= 8.13506e-15 A14=-1.11503e-17 A16= 5.24603e-21 2nd side K =-6.89840e-01 A4=-3.41104e-05 A6=-3.22124e-08 A8=-1.83260e-10 A10= 3.36916e-11 A12=-2.80046e-13 A14= 5.72098e-16 3rd side K = 0.00000e+00 A4=-1.94547e-04 A6=-2.46171e-07 A8= 1.50124e-08 A10=-9.95973e-11 A12= 2.72256e-13 A14=-2.64438e-16 A16=-9.17560e-20 4th side K = 0.00000e+00 A4=-1.87924e-04 A6= 2.06228e-07 A8= 1.75592e-08 A10=-1.64843e-10 A12= 8.65760e-13 A14=-1.25299e-15 Surface 27 K = 0.00000e+00 A4=-2.68051e-04 A6= 1.99062e-06 A8=-3.22492e-08 A10= 4.16733e-10 A12=-2.35998e-12 A14= 7.85765e-15 A16=-4.86430e-17 Surface 28 K = 0.00000e+00 A4=-1.84377e-04 A6= 1.94610e-06 A8=-1.84829e-08 A10= 1.79527e-10 A12=-7.27107e-13 Data Zoom Ratio 1.96 Focal Length 10.36 14.77 20.30 F-Number 2.91 2.91 2.91 Angle of View 52.14 45.05 36.09 Image Height 13.33 14.80 14.80 Lens Length 104.21 104.21 104.21 BF 9.80 9.45 9.53 d 8 12.79 5.24 1.99 d13 4.42 7.03 3.98 d17 1.44 6.38 12.68 d21 10.31 5.63 1.78 d28 1.06 6.09 9.86 d30 8.27 7.92 8.00 Entrance pupil position 15.83 15.34 14.40 Exit pupil position -82.85 -109.71 -151.57 Front principal point position 24.90 28.13 31.99 Rear principal point position -9.71 -14.13 -19.65 Zoom lens group data group Start plane Focal length Lens construction length Front principal point position Rear principal point position 1 1 -13.52 20.75 6.47 -8.20 2 9 62.26 8.77 7.41 2.48 3 14 32.17 7.01 1.68 -3.16 4 18 -47.29 5.38 -0.19 -4.08 5 22 44.27 19.33 -15.46 -21.78 6 29 50.64 3.16 2.42 0.82 Singlet Data Lens Initial Surface Focal Length 1 1 -27.73 2 3 -83.60 3 5 -25.25 4 7 33.74 5 9 37.28 6 11 -14.83 7 12 19.08 8 15 -46.54 9 16 18.94 10 18 27.96 11 19 -18.08 12 22 27.31 13 24 30.15 14 25 -19.82 15 27 -63.44 16 29 50.64 Amount of movement of the focusing lens group from infinity to 0.1x magnification Lens group L2 L4 Wide-angle end 0.937 0.911 Telephoto end 1.006 0.489

[0142] Table 1 shows various numerical values ​​in the numerical examples corresponding to the conditional expressions (1) to (9).

[0143] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present disclosure. Therefore, the following claims are appended to apprise the public of the scope of the present disclosure.

[0144] This application claims priority based on Japanese Patent Application No. 2024-151329, filed September 3, 2024, the entire contents of which are incorporated herein by reference.

[0145] L1: First lens group L2: Second lens group L3: Third lens group L4: Fourth lens group L5: Fifth lens group L6: Sixth lens group L7: Seventh lens group LF: Focusing lens group LR: Subsequent lens group

Claims

1. A zoom lens having, in order from the object side to the image side, a first lens group having negative refractive power that does not move for zooming, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group, wherein the spacing between each lens group changes during zooming, and the focusing lens group includes at least two lens groups that move on different trajectories during focusing, where f1 is the focal length of the first lens group and f2 is the focal length of the lens group of the focusing lens group that is located closest to the object, and wherein the zoom lens satisfies the condition: -0.60<f1 / f2<-0.

05.

2. The zoom lens according to claim 1, characterized in that it has an aperture stop, and satisfies the condition: 0.20<Lsw / TL<0.50, where Lsw is the distance on the optical axis at the wide-angle end from the lens surface in the first lens group located closest to the object to said aperture stop, and TL is the total optical length of said zoom lens.

3. A zoom lens according to claim 1 or 2, characterized in that it has an aperture stop, and satisfies the condition: 0.10<Lst / TL<0.40, where Lst is the distance on the optical axis at the telephoto end from the lens surface in the first lens group located closest to the object to said aperture stop, and TL is the total optical length of said zoom lens.

4. A zoom lens according to any one of claims 1 to 3, characterized in that the at least two lens groups that move for focusing include, in order from the object side to the image side, a first focusing lens group and a second focusing lens group, and when the absolute values ​​of the movement amounts of the first focusing lens group and the second focusing lens group from infinity to a magnification of 0.1x at the wide-angle end are M1w and M2w, respectively, the following condition is satisfied: 0.5<M1w / M2w<3.

0.

5. A zoom lens according to any one of claims 1 to 4, characterized in that the at least two lens groups that move for focusing include, in order from the object side to the image side, a first focusing lens group and a second focusing lens group, and when the absolute values ​​of the movement amounts of the first focusing lens group and the second focusing lens group from infinity to a magnification of 0.1x at the telephoto end are M1t and M2t, respectively, the following condition is satisfied: 1.0<M1t / M2t<6.

0.

6. A zoom lens according to any one of claims 1 to 5, characterized in that the following condition is satisfied: 0.10<BFw / fw<1.30, where BFw is the distance from the lens surface located closest to the image at the wide-angle end of the zoom lens to the image plane, and fw is the focal length of the entire system at the wide-angle end.

7. A zoom lens according to any one of claims 1 to 6, characterized in that the first lens group is made up of four or less lenses, including at least one negative lens and at least one positive lens.

8. A zoom lens according to any one of claims 1 to 7, characterized in that the number of lens groups that move during zooming is three or less.

9. A zoom lens according to any one of claims 1 to 8, wherein the subsequent lens group includes a lens group that does not move for varying magnification.

10. A zoom lens according to any one of claims 1 to 9, characterized in that the subsequent lens group includes a lens group that performs image stabilization by moving in a direction that includes a component perpendicular to the optical axis.

11. A zoom lens according to any one of claims 1 to 9, characterized in that the focusing lens group includes a lens group that performs image stabilization by moving in a direction including a component perpendicular to the optical axis.

12. A zoom lens according to any one of claims 1 to 11, characterized in that the following condition is satisfied: 0.30<|βrt / βrw|<2.80, where βrw is the composite lateral magnification of the subsequent lens group at the wide-angle end and βrt is the composite lateral magnification of the subsequent lens group at the telephoto end.

13. A zoom lens according to any one of claims 1 to 12, characterized in that the focusing lens group is composed of, in order from the object side to the image side, a lens group having positive refractive power and a lens group having positive refractive power.

14. A zoom lens according to any one of claims 1 to 12, characterized in that the focusing lens group is composed of, in order from the object side to the image side, a lens group having positive refractive power, a lens group having positive refractive power, and a lens group having negative refractive power.

15. A zoom lens according to any one of claims 1 to 14, characterized in that, when the focal length of the lens group located closest to the object among the focusing lens groups is f2 and the focal length of the lens group located adjacent to said lens group on the image side is f3, the following condition is satisfied: 1.50<f2 / f3<3.

00.

16. A zoom lens according to any one of claims 1 to 15, characterized in that the focusing lens group includes a lens group that moves to the most object side and the most image side for focusing.

17. A zoom lens according to any one of claims 1 to 16, characterized in that the focusing lens group is composed of two or three lens groups.

18. A zoom lens according to any one of claims 1 to 17, characterized in that the subsequent lens group is composed of, in order from the object side to the image side, a lens group having negative refractive power and a lens group having positive refractive power.

19. A zoom lens according to any one of claims 1 to 17, characterized in that the subsequent lens group is composed of, in order from the object side to the image side, a lens group having positive refractive power and a lens group having positive refractive power.

20. A zoom lens according to any one of claims 1 to 19, characterized in that the lens group arranged closest to the image side among the subsequent lens groups is a lens group that moves for varying magnification.

21. A zoom lens according to any one of claims 1 to 10, characterized in that it further comprises a final lens group which is disposed on the image side of the subsequent lens group, has positive refractive power, and does not move for varying magnification.

22. A zoom lens according to any one of claims 1 to 21, characterized in that the lens group arranged closest to the image side is composed of a single lens having a convex surface on the image side, and where fR is the focal length of the single lens and fw is the focal length of the entire system at the wide-angle end, the following condition is satisfied: 2.00<fR / fw<6.

00.

23. A zoom lens according to any one of claims 1 to 22, characterized in that the effective image circle diameter at the wide-angle end is smaller than the effective image circle diameter at the telephoto end.

24. A zoom lens comprising, in order from the object side to the image side, a first lens group having negative refractive power, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group, wherein the spacing between the lens groups changes during magnification variation, the focusing lens group includes at least two lens groups that move on different trajectories during focusing, and the first lens group includes a positive lens.

25. An imaging device comprising the zoom lens according to any one of claims 1 to 24 and an imaging element for receiving an image formed by the zoom lens.

Images