Zoom lens and imaging device

Abstract

This zoom lens offers a fixed overall length, making it ideal for video recording, while being compact and providing high optical performance across all subject distances. [Solution] The zoom lens has, in order from the object side to the image side, a first lens group having a negative refractive power that does not move for magnification, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group, wherein the distance between each lens group changes when magnification is applied, and the focusing lens group includes at least two lens groups that move on different trajectories when focusing, and the ratio of the focal length of the first lens group to the focal length of the lens group positioned closest to the object among the focusing lens group is appropriately set.

Description

[Technical Field]

[0001] This invention relates to a zoom lens and an imaging device. [Background technology]

[0002] In recent years, image quality has been improving in SLR cameras, digital still cameras, and video cameras that use solid-state image sensors. In particular, SLR cameras are seeing increased demand for faster autofocus (AF) to meet the growing need for video, in addition to higher resolution image quality during shooting.

[0003] To satisfy these requirements, recent developments have focused on imaging optics that reduce the amount of movement during focusing by employing lightweight focusing lens groups and a so-called floating focus system that drives multiple focusing lenses. This system enables faster focusing speeds and increased magnification. Patent documents 1 and 2 disclose a zoom lens comprising a first lens group having a fixed negative refractive power during magnification, and a subsequent group having multiple lens groups. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2023 / 181903 [Patent Document 2] Japanese Patent Publication No. 2019-056916 [Overview of the project] [Problems that the invention aims to solve]

[0005] The zoom lenses disclosed in Patent Documents 1 and 2 are characterized by a small Fno and high optical performance across the entire zoom range and all object distances. However, they have been hampered by low magnification and significant focusing breathing.

[0006] To solve the above problems, the present invention aims to provide a zoom lens that is suitable for video recording with a fixed overall length, is compact, and has high optical performance at all subject distances, as well as an imaging device having the same. [Means for solving the problem]

[0007] The zoom lens of the present invention comprises, in order from the object side to the image side, a first lens group having a negative refractive power that does not move for 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 each lens group changes during magnification, and the focusing lens group includes at least two lens groups that move on different trajectories when focusing, and when the focal length of the first lens group is f1 and the focal length of the lens group positioned closest to the object among the focusing lens group is f2, -0.60 <f1 / f2<-0.05 It is characterized by satisfying the following conditions. [Effects of the Invention]

[0008] According to the present invention, a zoom lens and an imaging device having the same can be obtained that are suitable for video recording with a fixed overall length, are compact, and have high optical performance at all subject distances. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the zoom lens of Example 1. [Figure 2] This is an aberration diagram of the zoom lens of Example 1 at its wide-angle end. [Figure 3] This is an aberration diagram of the zoom lens of Example 1 at the intermediate point. [Figure 4] This is an aberration diagram of the zoom lens of Example 1 at its telephoto end. [Figure 5] This is a cross-sectional view of the zoom lens of Example 2. [Figure 6] This is an aberration diagram of the zoom lens of Example 2 at its wide-angle end. [Figure 7] This is an aberration diagram of the zoom lens in Example 2 at the midpoint. [Figure 8] It is an aberration diagram at the telephoto end of the zoom lens of Example 2. [Figure 9] It is a lens cross-sectional view of the zoom lens of Example 3. [Figure 10] It is an aberration diagram at the wide-angle end of the zoom lens of Example 3. [Figure 11] It is an aberration diagram in the middle of the zoom lens of Example 3. [Figure 12] It is an aberration diagram at the telephoto end of the zoom lens of Example 3. [Figure 13] It is a lens cross-sectional view of the zoom lens of Example 4. [Figure 14] It is an aberration diagram at the wide-angle end of the zoom lens of Example 4. [Figure 15] It is an aberration diagram in the middle of the zoom lens of Example 4. [Figure 16] It is an aberration diagram at the telephoto end of the zoom lens of Example 4. [Figure 17] It is a lens cross-sectional view of the zoom lens of Example 5. [Figure 18] It is an aberration diagram at the wide-angle end of the zoom lens of Example 5. [Figure 19] It is an aberration diagram in the middle of the zoom lens of Example 5. [Figure 20] It is an aberration diagram at the telephoto end of the zoom lens of Example 5. [Figure 21] It is a lens cross-sectional view of the zoom lens of Example 6. [Figure 22] It is an aberration diagram at the wide-angle end of the zoom lens of Example 6. [Figure 23] It is an aberration diagram in the middle of the zoom lens of Example 6. [Figure 24] It is an aberration diagram at the telephoto end of the zoom lens of Example 6. [Figure 25] It is a device diagram of an imaging device (digital camera) having the zoom lenses of Examples 1 to 6.

Modes for Carrying Out the Invention

[0010] In recent years, image quality has been improving in SLR cameras, digital still cameras, and video cameras that use solid-state image sensors. In particular, SLR cameras are seeing increased demand for faster autofocus (AF) to meet the growing need for video, in addition to higher resolution image quality during shooting.

[0011] To satisfy these requirements, recent developments have focused on imaging optics that reduce the amount of movement during focusing by employing lightweight focusing lens groups and a so-called floating focus system that drives multiple focusing lenses. This system enables faster focusing speeds and increased magnification.

[0012] In recent years, so-called mirrorless cameras, which lack a quick-return mirror, have become increasingly common. Because these mirrorless cameras are characterized by their thin, compact, and lightweight bodies, there is a demand for the development of small and lightweight interchangeable lenses that are well-suited to mirrorless cameras. Because mirrorless cameras do not require space for a quick-return mirror, they do not need to secure as much back focus as conventional interchangeable lenses. Therefore, the lens configuration and other aspects differ from conventional interchangeable lenses, increasing design freedom and making it possible to design smaller and lighter lenses. Wide-angle lenses, in particular, tend to have shorter back focus, making them more compact for use as interchangeable lenses for mirrorless cameras.

[0013] Conventionally, zoom lenses are known that consist of a first lens group fixed during magnification and having negative refractive power, and a subsequent group having multiple lens groups. These zoom lenses achieve high magnification and high performance by moving the multiple lens groups located on the image side along different trajectories.

[0014] On the other hand, during video recording, changes in the focus point cause fluctuations in the angle of view, known as focus breathing. Methods to suppress focus breathing include appropriately setting the focus group and suppressing it through optical design, and electrically correcting the image data. In particular, electrically correcting various aberrations such as chromatic aberration and distortion, and creating a configuration suitable for correcting other aberrations, makes it possible to miniaturize and improve image quality.

[0015] The zoom lens of the present invention is characterized by its fixed overall length, suitability for video recording, compact size, and high optical performance across all subject distances. In particular, to suppress breathing through design, a floating focus optical system with multiple focusing groups is advantageous. In this invention, a configuration is adopted that includes a focusing lens group comprising at least two lens groups in order to achieve both aberration correction and breathing suppression.

[0016] Furthermore, the lens employs an arrangement that includes a first lens group with negative refractive power, followed by a focusing lens group containing at least two lens groups, and a subsequent lens group containing at least two lens groups, in order from the subject side to the image side. To make the configuration suitable for video shooting, the first lens group, which is heavy and disadvantageous for motorization, is fixed during zooming. In addition, to correct aberrations in large-aperture lenses, zooming and aberration correction are achieved simultaneously by moving multiple relatively lightweight lens groups.

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

[0018] In this invention, by employing these configurations, changes in optical performance and suppression of breathing during focusing are achieved. Furthermore, a key feature is the presence of a subsequent lens group containing two or more lens groups on the image side of the focusing lens group. By positioning the aforementioned trailing lens group on the image side of the focusing lens group, the distribution of magnification across the entire system can be appropriately set, making it possible to effectively correct various aberrations that tend to change during magnification, such as spherical aberration, field curvature, and chromatic aberration.

[0019] By adopting the above lens configuration, a zoom lens is achieved that is suitable for video shooting with a fixed overall length, is compact, and delivers high optical performance across all subject distances.

[0020] The zoom lens of the present invention comprises, in order from the object side to the image side, a first lens group having a negative refractive power that does not move for 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 each lens group changes during magnification, and the focusing lens group includes at least two lens groups that move on different trajectories to each other during focusing, and when the focal length of the first lens group is f1 and the focal length of the lens group positioned closest to the object among the focusing lens group is f2, -0.60 <f1 / f2<-0.05 ···(1) It is characterized by satisfying the following conditions.

[0021] In the zoom lens of the present invention, the power distribution of the lens group where off-axis rays are located at a relatively low position is appropriately set to suppress variations in various aberrations and the occurrence of breathing that occur when focusing.

[0022] Conditional equation (1) is a conditional equation relating to the focal length ratio of the lens group located closest to the object in the first lens group and the focusing lens group, and is a conditional equation relating to the aberration variation during magnification and focusing. If the value falls below the lower limit of condition (1), the power of the lens group located closest to the object in the focusing lens group increases, making it difficult to suppress fluctuations in various aberrations such as field curvature and axial chromatic aberration. It is also undesirable for suppressing breathing during focusing. On the other hand, if the value exceeds the upper limit of condition (1), it is advantageous for widening the angle of view, but the power of the first lens group increases, making it difficult to suppress fluctuations in various aberrations such as distortion and lateral chromatic aberration.

[0023] The object of the present invention is achieved under the above conditions, but more preferably, in the configuration of the zoom lens of the present invention, including an aperture diaphragm, when Lsw is the distance on the optical axis at the wide-angle end from the lens surface located closest to the object in the first lens group to the aperture diaphragm, and TL is the total optical length of the zoom lens, 0.20 <Lsw / TL<0.50 ···(2) The conditions are met.

[0024] Conditional equation (2) is a conditional equation relating to the position of the aperture diaphragm arranged within the zoom lens, and is a conditional equation relating to the front element diameter (the diameter of the lens positioned closest to the object) and the exit pupil. If the value falls below the lower limit of condition (2), the aperture diaphragm is positioned closer to the front element, which is advantageous for reducing the diameter of the front element. However, this is undesirable because it increases the diameter of the rear element (the diameter of the lens closest to the image). On the other hand, if the value exceeds the upper limit of condition (2), the aperture diaphragm is positioned further away from the front element, which is undesirable for reducing the diameter of the front element. Furthermore, because the exit pupil is closer to the image plane, the angle of incidence of light rays to the image sensor increases, making it easier for color unevenness to occur in the peripheral areas of the image, which is undesirable.

[0025] More preferably, the zoom lens of the present invention includes an aperture diaphragm, where Lst is the distance along the optical axis at the telephoto end from the lens surface of the first lens group that is closest to the object to the aperture diaphragm, and TL is the total optical length of the zoom lens. 0.10 <Lst / TL<0.40 ···(3) The following condition is satisfied.

[0026] Conditional equation (3) is a conditional equation relating to the position of the aperture diaphragm located within the zoom lens, and is a conditional equation relating to the rear element diameter and the exit pupil. If the value falls below the lower limit of condition (3), the position of the aperture diaphragm moves closer to the front element, and the diameter of the rear element increases, which is undesirable. On the other hand, if the value exceeds the upper limit of condition (3), the position of the aperture diaphragm moves further away from the front element, and the aperture diameter of the aperture diaphragm increases, making it difficult to correct various aberrations such as spherical aberration and coma aberration.

[0027] In the configuration of the zoom lens of the present invention, at least two lens groups that move for focusing, which are included in the focusing lens group, 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. At this time, when the absolute values ​​of the amount of movement from infinity to a magnification of 0.1x for the first focusing lens group and the second focusing lens group at the wide-angle end are M1w and M2w, respectively, 0.5 <M1w / M2w<3.0 ···(4) The conditions are met.

[0028] Conditional equation (4) is a conditional equation relating to the ratio of movement between the first focusing lens group and the second focusing lens group, and in particular, it is a conditional equation relating to the fluctuations of various aberrations such as breathing and field curvature during focusing. If the value falls below the lower limit of condition (4), the amount of movement of the first focusing lens group located on the object side becomes smaller than the amount of movement of the second focusing lens group located on the image side, which is advantageous in suppressing breathing, but is undesirable because it increases the variation of various aberrations. On the other hand, if the value exceeds the upper limit of condition (4), the amount of movement of the first focusing lens group becomes larger than the amount of movement of the second focusing lens group, making it difficult to suppress breathing.

[0029] More preferably, in the configuration of the zoom lens of the present invention, the focusing lens group includes at least two lens groups that move for focusing, and these are 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 amount of movement from infinity to a magnification of 0.1x for the first focusing lens group and the second focusing lens group are M1t and M2t, respectively, 1.0 <M1t / M2t<6.0 ···(5) The following condition is satisfied.

[0030] Conditional equation (5) is a conditional equation relating to the ratio of movement between the first focusing lens group and the second focusing lens group, and in particular, it is a conditional equation relating to the fluctuations of various aberrations such as breathing and field curvature during focusing. If the value falls below the lower limit of condition (5), the amount of movement of the first focusing lens group located on the object side becomes smaller than the amount of movement of the second focusing lens group located on the image side. This is advantageous in suppressing breathing, but it is undesirable because it increases the fluctuations of various aberrations such as coma aberration and field curvature. On the other hand, if the value exceeds the upper limit of condition (5), the amount of movement of the first focusing lens group becomes larger than the amount of movement of the second focusing lens group. This is undesirable because the entire lens becomes larger in order to secure space for movement. Furthermore, it becomes difficult to suppress breathing.

[0031] More preferably, in the configuration of the zoom lens of the present invention, when the distance from the lens surface located closest to the image plane at the wide-angle end to the image plane is BFw, and the total focal length of the system at the wide-angle end is fw, 0.10 <BFw / fw<1.30 ···(6) The condition is that the following equation is satisfied.

[0032] Conditional equation (6) is a conditional equation relating to the back focus at the wide-angle end, and in particular, to various aberrations such as the optical length and field curvature. If the value falls below the lower limit of condition (6), the back focus becomes shorter, which is advantageous in reducing the overall optical length. However, the angle of incidence of light rays to the image sensor becomes larger, making it more likely for color unevenness to occur at the edges of the image, which is undesirable. On the other hand, if the value exceeds the upper limit of condition (6), a retrofocus type power configuration is adopted to ensure sufficient back focus, making it difficult to correct various aberrations such as field curvature and coma aberration.

[0033] More preferably, in the configuration of the zoom lens of the present invention, when the combined horizontal magnification at the wide-angle end of the subsequent lens group is βrw and the combined horizontal magnification at the telephoto end is βrt, 0.30<|βrt / βrw|<2.80 ···(7) The condition is that the following equation is satisfied.

[0034] Conditional equation (7) is a conditional equation relating to the lateral magnification of the subsequent lens group, and in particular, to the division of magnification among zoom lenses and the overall optical length. If the value falls below the lower limit of condition (7), the magnification contribution of the subsequent lens group decreases, increasing the magnification contribution of the focusing lens group, which makes it difficult to suppress breathing and overall optical length. On the other hand, if the value exceeds the upper limit of condition (7), the magnification contribution of the subsequent lens group increases, which is advantageous in suppressing breathing, but it 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 invention, when the focal length of the lens group positioned closest to the object in the focusing lens group is f2, and the focal length of the adjacent lens group positioned closer to the image is f3, 1.50 <f2 / f3<3.00 ···(8) The condition is that the following equation is satisfied.

[0036] Conditional equation (8) is a conditional equation relating to the focal length ratio between the lens group positioned closest to the object and the lens group positioned closest to the image in the focusing lens group, and is particularly a conditional equation relating to the changes in various aberrations during magnification. If the value falls below the lower limit of condition (8), the power of the lens group located on the object side within the focusing lens group increases, making it difficult to suppress breathing. On the other hand, if the value exceeds the upper limit of condition (8), the power of the lens group located on the image side within the focusing lens group increases, which is advantageous in suppressing breathing, but makes it difficult to suppress coma aberration and axial chromatic aberration during magnification.

[0037] More preferably, in the configuration of the zoom lens of the present invention, the lens group positioned closest to the image 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, 2.00 <fR / fw<6.00 ···(9) The condition is that the following equation is satisfied.

[0038] Conditional equation (9) is a conditional equation relating to the power arrangement of the lens group positioned closest to the image, and in particular, it is a conditional equation relating to chromatic aberration and field curvature. If the value falls below the lower limit of condition (9), the power of the lens group located closest to the image sensor increases, which is advantageous in correcting chromatic aberration across the entire zoom range, but makes it difficult to secure back focus. On the other hand, if the value exceeds the upper limit of condition (9), the power of the lens group located closest to the image sensor decreases, making it difficult to suppress field curvature. It also becomes difficult to control the angle of incidence to the image sensor, which is undesirable as it makes color unevenness in the peripheral areas of the image more likely to occur.

[0039] Furthermore, in each numerical example, for aberration correction purposes, it is preferable to set the numerical ranges of conditional equations (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] More preferably, the numerical ranges of conditional expressions (1) to (9) should be set 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 shooting, the image may be displaced perpendicular to the optical axis by moving a portion of the subsequent lens group or a portion of the focusing lens group in a direction having a component perpendicular to the optical axis. This configuration may enable so-called image stabilization, which corrects blurring of the captured image when the entire optical system vibrates.

[0042] In addition, in imaging devices having the zoom lens of each numerical embodiment, distortion aberration among various aberrations may be corrected by electrical image processing of the image data. In particular, the wide-angle side has a smaller imaging range than the effective imaging range of the image sensor, and by correcting the above-mentioned distortion aberration, it contributes to miniaturizing the front element diameter. The zoom lens of the present invention is configured such 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 embodiment, by configuring each lens group as described above, a zoom lens and an imaging device having the same are obtained that are suitable for video shooting with a fixed overall length, are compact, and have high optical performance at all subject distances. [Examples]

[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 at its wide-angle end when focused at infinity. 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 has, in order from the object side to the image side, a first lens group L1 having negative refractive power, a second lens group L2 having positive refractive power, a third lens group L3 having positive refractive power, a fourth lens group L4 having negative refractive power, a fifth lens group L5 having positive refractive power, and a sixth lens group L6 having positive refractive power.

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

[0047] Furthermore, a floating focus system is employed in which the second lens group L2 and the third lens group L3 are moved during focusing. In Figure 1, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 3a and the dashed curve 3b relating to the third lens group L3, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on an object at infinity and a close-up object, respectively.

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

[0049] Furthermore, during shooting, the fourth lens group 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, vertical or approximately vertical) in order to correct blur of the subject image.

[0050] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object.

[0051] In the zoom lens of the present invention, miniaturization is achieved by designing the refractive power of the first lens group L1 to be large within an appropriate range. When the refractive power is increased, various aberrations occur within the first lens group L1, particularly distortion and field curvature at the wide-angle end. Therefore, the negative refractive power of the first lens group 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 group L2 consists of three lenses, arranged from the object side to the image side: a biconvex positive lens, a cemented lens formed by joining a biconcave negative lens and a biconvex positive lens. In the zoom lens of the present invention, the refractive power of the second lens group L2 is set to be large within an appropriate range in order to increase the magnification ratio. When the refractive power of the second lens group L2 is increased, various aberrations occurring in the second lens group L2, especially spherical aberration and axial chromatic aberration, are greatly increased. The positive refractive power of the second lens group L2 is shared by two positive lenses to reduce the occurrence of spherical aberration. Furthermore, axial chromatic aberration is suppressed by arranging a cemented lens. With this lens configuration, the optical length is shortened while increasing the magnification ratio.

[0053] The third lens group L3 is composed of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side facing the object, in order from the object side to the image side. In the zoom lens of the present invention, miniaturization and weight reduction are achieved by constructing the third lens group L3 with a small number of lenses. In particular, by arranging a cemented lens and using a low-dispersion material for the positive lens, fluctuations in axial chromatic aberration are suppressed.

[0054] The fourth lens group L4 is composed of a cemented lens formed by joining a positive meniscus lens with a concave object side and a negative lens with a biconcave side, in order from the object side to the image side. In the zoom lens of the present invention, a thin design is achieved by constructing the fourth lens group with a small number of lenses. In particular, the occurrence of spherical aberration is suppressed by making the object side of the fourth lens group L4 concave.

[0055] The fifth lens group L5 consists of four lenses, arranged in order from the object side to the image side: a biconvex positive lens, a cemented lens formed by joining a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave side facing the object. In the zoom lens of the present invention, the refractive power of the fifth lens group 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 placement of a cemented lens suppress fluctuations in chromatic aberration. Furthermore, the use of a negative meniscus lens with a concave side facing the object and an aspherical surface suppresses the occurrence of field curvature.

[0056] The sixth lens group L6 consists of a single positive meniscus lens with a convex image side. In the zoom lens of this invention, a thin design is achieved by constructing the sixth lens group with a small number of lenses. In particular, the convex image side suppresses the angle of light rays incident on the image sensor. Furthermore, the sixth lens group L6 employs a highly dispersed material to suppress chromatic aberration across the entire zoom range.

[0057] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves in the optical axis direction together with the third lens group L3 during zooming and focusing. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that Fno decreases at the telephoto end. Furthermore, by positioning the aperture diaphragm SP closest to the object-side lens at the wide-angle end, the entrance pupil position is moved closer to the object, achieving a smaller diameter for the object-side lens.

[0058] An auxiliary aperture is placed on the image side of the fourth lens group L4 to cut out unwanted off-axis light, thereby improving optical performance.

[0059] In Example 1, the second lens group L2 and the third lens group L3 are the focusing lens groups, the fourth lens group L4 and the fifth lens group L5 are the subsequent lens groups, and the sixth lens group L6 is the final lens group. Furthermore, 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 stands for Image Plane, which corresponds to the image plane of a solid-state image sensor such as a CCD or CMOS sensor when used in the shooting optical system of a digital still camera or video camera, and to the film plane when used in a silver halide film camera. GB stands for Glass Block, which corresponds to a low-pass filter or IR cut filter.

[0061] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

[0062] Figures 2-4 show aberration diagrams of spherical aberration, astigmatism, distortion, and chromatic aberration at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens according to Example 1. In each aberration diagram, d and g are the d line and g line, respectively, ΔM and ΔS are the meridional and sagittal image planes, and the chromatic aberration diagram is represented by the g line. Also, fno is the F number and ω is the half-angle of view. In each example, the wide-angle end and telephoto end refer to the zoom position when the variable magnification lens group is located at the end of the range that is mechanically movable in the optical axis direction. The same applies to the following examples. As is clear from each aberration diagram, the aberrations are well corrected.

[0063] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances. [Examples]

[0064] The zoom lens according to Example 2 will be described with reference to Figures 5 to 8. Figure 5 is a cross-sectional view of the zoom lens according to Example 2 at the wide-angle end when it is focused at infinity. The zoom lens of Embodiment 2 has, in order from the object side to the image side, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, and a sixth lens group L6 with positive refractive power. The aperture diaphragm SP is positioned on the object side of the third lens group L3 and moves together with the third lens group L3 during zooming and focusing.

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

[0066] Furthermore, a floating focus system is employed in which the second lens group L2 and the third lens group L3 are moved during focusing. In Figure 5, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 3a and the dashed curve 3b relating to the third lens group L3, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on an object at infinity and a close-up object, respectively.

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

[0068] Furthermore, during shooting, the fourth lens group 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, vertical or approximately vertical) in order to correct blur of the subject image.

[0069] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object. The second lens group L2 consists of three lenses, arranged in order from the object side to the image side: a positive meniscus lens with a concave surface on the object side, and a cemented lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0070] The third lens group L3 consists of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side, in order from the object side to the image side. The fourth lens group L4 consists of a cemented lens formed by joining a positive meniscus lens with a concave surface on the object side and a negative lens with a biconcave surface, arranged in order from the object side to the image side.

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

[0072] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves in the optical axis direction together with the third lens group L3 during zooming and focusing. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that the Fno decreases at the telephoto end.

[0073] An auxiliary aperture is placed on the image side of the fourth lens group L4 to cut out unwanted off-axis light, thereby improving optical performance.

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

[0075] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

[0076] Figures 6-8 show aberration diagrams of spherical aberration, astigmatism, distortion, and 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] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances. [Examples]

[0078] The zoom lens according to Example 3 will be described with reference to Figures 9 to 12. Figure 9 is a cross-sectional view of the zoom lens according to Example 3 at its wide-angle end when it is focused at infinity. The zoom lens according to Embodiment 3 has, in order from the object side to the image side, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power. An aperture diaphragm SP is positioned on the object side of the third lens group L3 and moves together with the third lens group L3 during zooming and focusing.

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

[0080] Furthermore, a floating focus system is employed in which the second lens group L2 and the third lens group L3 are moved during focusing. In Figure 9, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 3a and the dashed curve 3b relating to the third lens group L3, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on objects at infinity and near distances, respectively.

[0081] Furthermore, when focusing from an object at infinity to an object at close range, the second lens group L2 moves towards the image side as indicated by arrow 2c, and the third lens group L3 moves towards the object side as indicated by arrow 3c. Note that the first lens group L1 does not move for focusing, but may be moved as needed for aberration correction. Furthermore, during shooting, in order to correct blur in the subject image, the entirety or a part of the fourth lens group 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, vertical direction, approximately vertical direction).

[0082] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object. The second lens group L2 consists of, in order from the object side to the image side, a positive meniscus lens with a concave surface on the object side, a cemented lens formed by joining a negative meniscus lens with a concave surface on the object side and a positive meniscus lens with a concave surface on the object side.

[0083] The third lens group L3 consists of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side, in order from the object side to the image side. The fourth lens group L4 consists of, in order from the object side to the image side, a cemented lens formed by joining a positive meniscus lens with a concave object side and a negative meniscus lens with a concave object side, and a negative meniscus lens with a concave object side.

[0084] The fifth lens group L5 consists of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by joining a biconvex positive lens and a negative meniscus lens with a concave side facing the object, and a negative meniscus lens with a concave side facing the object.

[0085] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves in the optical axis direction together with the third lens group L3 during zooming and focusing. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that the Fno decreases at the telephoto end.

[0086] An auxiliary aperture is placed inside the fourth lens group L4 to cut out unwanted light from off-axis beams, thereby improving optical performance.

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

[0088] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

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

[0090] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances. [Examples]

[0091] The zoom lens according to Example 4 will be described with reference to Figures 13-16. Figure 13 is a cross-sectional view of the zoom lens according to Example 4 at the wide-angle end when it is focused at infinity. The zoom lens of Embodiment 4 has, in order from the object side to the image side, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, and a sixth lens group L6 with positive refractive power. The aperture diaphragm SP is positioned on the object side of the third lens group L3 and moves together with the third lens group L3 during zooming.

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

[0093] Furthermore, a floating focus system is employed in which the second lens group L2 and the fourth lens group L4 are moved during focusing. In Figure 13, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 4a and the dashed curve 4b relating to the fourth lens group L4, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on an object at infinity and a close-range object, respectively.

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

[0095] Furthermore, during shooting, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction that includes a component perpendicular to the optical axis (for example, vertical or approximately vertical) in order to correct blur of the subject image.

[0096] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object. The second lens group L2 consists of a biconvex positive lens, a biconcave negative lens, and a cemented lens formed by joining a biconvex positive lens, in order from the object side to the image side.

[0097] The third lens group L3 consists of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side facing the object, in order from the object side to the image side. The fourth lens group L4 consists of a cemented lens formed by joining a positive meniscus lens with a concave surface on the object side and a negative meniscus lens with a concave surface on the object side, in order from the object side to the image side.

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

[0099] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves in the optical axis direction together with the third lens group L3 during zooming and focusing. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that the Fno decreases at the telephoto end.

[0100] An auxiliary aperture is placed on the image side of the fourth lens group L4 to cut out unwanted 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 the focusing lens groups, the fifth lens group L5 is the successor lens group, and the sixth lens group L6 is the final lens group. Furthermore, the second lens group L2 is the first focusing lens group, and the fourth lens group L4 is the second focusing lens group.

[0102] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

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

[0104] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances. [Examples]

[0105] The zoom lens according to Example 5 will be described with reference to Figures 17-20. Figure 17 is a cross-sectional view of the zoom lens according to Example 5 at the wide-angle end when it is focused at infinity. The zoom lens of Example 5 has, in order from the object side to the image side, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, a sixth lens group L6 with positive refractive power, and a seventh lens group L7 with positive refractive power. An aperture diaphragm SP is positioned on the object side of the third lens group L3 and moves together with the third lens group L3 during zooming.

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

[0107] Furthermore, a floating focus system is employed in which the second lens group L2 and the fourth lens group L4 are moved during focusing. In Figure 17, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 4a and the dashed curve 4b relating to the fourth lens group L4, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on an object at infinity and a close-up object, respectively.

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

[0109] Furthermore, during shooting, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction that includes a component perpendicular to the optical axis (for example, vertical or approximately vertical) in order to correct blur of the subject image.

[0110] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object. The second lens group L2 consists of a biconvex positive lens, a biconcave negative lens, and a cemented lens formed by joining a biconvex positive lens, in order from the object side to the image side.

[0111] The third lens group L3 consists of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side facing the object, in order from the object side to the image side. The fourth lens group L4 consists of a cemented lens formed by joining a positive meniscus lens with a concave surface on the object side and a negative lens with a biconcave surface, arranged in order from the object side to the image side.

[0112] The fifth lens group, L5, consists of a positive meniscus lens with a convex side surface. The sixth lens group L6 consists of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by joining a biconvex positive lens and a biconcave negative lens, and a biconcave negative lens. The seventh lens group, L7, consists of a positive meniscus lens with a concave side.

[0113] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves together with the third lens group L3 during zooming and focusing. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that the Fno decreases at the telephoto end. An auxiliary aperture is placed on the image side of the fourth lens group L4 to cut out unwanted off-axis light, thereby improving optical performance.

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

[0115] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

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

[0117] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances. [Examples]

[0118] The zoom lens according to Example 6 will be described with reference to Figures 21-24. Figure 21 is a cross-sectional view of the zoom lens according to Example 6 at its wide-angle end when it is focused at infinity. The zoom lens of Example 6 has, in order from the object side to the image side, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, and a sixth lens group L6 with positive refractive power. An aperture diaphragm SP is positioned on the object side of the third lens group L3 and moves together with the third lens group L3 during zooming.

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

[0120] Furthermore, a floating focus system is employed in which the second lens group L2 and the fourth lens group L4 are moved during focusing. In Figure 21, the solid curve 2a and the dashed curve 2b relating to the second lens group L2, and the solid curve 4a and the dashed curve 4b relating to the fourth lens group L4, are movement trajectories used to correct image plane fluctuations associated with magnification when focusing on an object at infinity and a nearby object, respectively.

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

[0122] Furthermore, during shooting, the fourth lens group L4, which is part of the focusing lens group, may be moved in a direction that includes a component perpendicular to the optical axis (for example, vertical or approximately vertical) in order to correct blur of the subject image.

[0123] The first lens group L1 consists of, in order from the object side to the image side, a negative meniscus lens with a convex side facing the object, a low-power negative lens, a biconcave negative lens, and a positive meniscus lens with a convex side facing the object. The second lens group L2 consists of a biconvex positive lens, a biconcave negative lens, and a cemented lens formed by joining a biconvex positive lens, in order from the object side to the image side.

[0124] The third lens group L3 consists of a cemented lens formed by joining a negative meniscus lens with a convex side facing the object and a positive lens with a biconvex side facing the object, in order from the object side to the image side. The fourth lens group L4 consists of a cemented lens formed by joining a positive meniscus lens with a concave surface on the object side and a negative lens with a biconcave surface, arranged in order from the object side to the image side.

[0125] The fifth lens group L5 consists of, in order from the object side to the image side, a biconvex positive lens, a cemented lens formed by joining a biconvex positive lens and a biconcave negative lens, and a negative meniscus lens with a concave side facing the object. The sixth lens group, L6, consists of a positive meniscus lens with a concave side.

[0126] The aperture diaphragm SP is positioned between the second lens group L2 and the third lens group L3, and moves together with the third lens group L3 during zooming. The aperture diaphragm SP has a variable aperture diameter according to the magnification, so that the Fno decreases at the telephoto end. An auxiliary aperture is placed on the image side of the fourth lens group L4 to cut out unwanted off-axis 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 the focusing lens groups, and the fifth lens group L5 and the sixth lens group L6 are the successor lens groups. Furthermore, the second lens group L2 is the first focusing lens group, and the fourth lens group L4 is the second focusing lens group.

[0128] In this embodiment, the zoom lens 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 allows for a smaller front element diameter by correcting distortion aberration through electrical image processing of the image data.

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

[0130] This configuration allows the zoom lens of this embodiment to have a fixed overall length, making it suitable for video recording, and enabling it to be compact while achieving high optical performance at all subject distances.

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

[0132] The imaging device having the zoom lens of the present invention as its imaging optical system is suitable for video recording due to its fixed overall length, and can achieve the advantages of being compact and providing high optical performance at all subject distances.

[0133] The following shows the numerical data for each of the zoom lenses in Examples 1 to 6. In the numerical data of the numerical example, ri represents the radius of curvature of the i-th surface from the object side, di represents the distance between the i-th surface and the (i+1)-th surface from the object side, ni represents the refractive index at the d-line of the lens between the i-th surface and the (i+1)-th surface, and vi represents the Abbe number (also simply called the Abbe number) at the d-line of the lens between the i-th surface and the (i+1)-th surface.

[0134] The Abbe number ν is defined as follows. When 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 are nd, nF, and nC, ν = (nd - 1) / (nF - nC) ··· (10) It is expressed by this formula.

[0135] Also, let k be the conic constant, and A4, A6, A8, A10, A12, A14, A16 be the aspheric coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th orders. When the displacement in the optical axis direction at the position of the height h from the optical axis is x with respect to the surface vertex, the aspheric shape is 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) It is expressed by this formula. Here, R is the radius of curvature, and "e-X" means "×10 -X ". The aspheric surface is marked with an asterisk (*) on the right side of the surface number in each table.

[0136] {<Numerical Example 1> Unit: mm Surface Data Surface Number r d nd vd Effective 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 ∞ Aspherical data Front page K = 0.00000e+00 A 4=-1.11704e-05 A 6= 1.49309e-07 A 8= 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 A 4=-3.18000e-05 A 6=-1.33671e-07 A 8= 2.22774e-10 A10= 3.50434e-11 A12=-3.16074e-13 A14= 6.76007e-16 3rd page K = 0.00000e+00 A 4=-1.80496e-04 A 6=-2.47551e-07 A 8= 1.43334e-08 A10=-1.02994e-10 A12= 3.50185e-13 A14=-6.19177e-16 A16= 4.53061e-19 Side 4 K = 0.00000e+00 A 4=-1.65000e-04 A 6= 2.59865e-07 A 8= 1.52837e-08 A10=-1.40315e-10 A12= 6.50247e-13 A14=-6.04664e-16 Page 27 K = 0.00000e+00 A 4=-3.21406e-04 A 6= 1.66855e-06 A 8=-2.00842e-08 A10= 3.00718e-10 A12=-1.49836e-12 A14= 5.69216e-16 A16=-2.03667e-17 Page 28 K = 0.00000e+00 A 4=-2.37535e-04 A 6= 2.21381e-06 A 8=-1.44297e-08 A10= 1.60479e-10 A12=-7.69701e-13 Various data Zoom ratio 1.91 Focal length 10.36 14.70 19.80 F number 2.91 2.91 2.91 Field 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 Back principal point position -9.73 -14.07 -19.17 Zoom lens group data Group starting plane Focal length Lens 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 Single lens data Lens starting plane, 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 Face number rd nd vd Effective 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 plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-9.12936e-07 A 6= 1.74132e-08 A 8= 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 A 4=-2.29916e-06 A 6=-7.59909e-09 A 8=-1.02529e-11 A10= 9.55552e-13 A12=-3.92215e-15 A14= 3.89662e-18 3rd page K = 0.00000e+00 A 4=-1.30892e-05 A 6=-1.09456e-07 A 8= 1.03324e-09 A10=-3.05150e-12 A12= 4.23725e-15 A14=-3.15990e-18 A16= 1.21802e-21 Side 4 K = 0.00000e+00 A 4=-4.71583e-06 A 6=-6.71632e-08 A 8= 1.03858e-09 A10=-3.45987e-12 A12= 7.39477e-15 A14=-6.07013e-18 Page 27 K = 0.00000e+00 A 4=-1.14091e-04 A 6= 5.12601e-07 A 8=-2.63741e-09 A10= 1.18036e-11 A12=-3.71566e-14 A14= 9.46222e-17 A16=-1.76678e-19 Page 28 K = 0.00000e+00 A 4=-8.89041e-05 A 6= 5.20287e-07 A 8=-2.07853e-09 A10= 6.13557e-12 A12=-8.71875e-15 Various data Zoom ratio 2.36 Focal length 16.46 24.20 38.80 F-numbers: 2.18, 2.91, 4.12 Field 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 Back principal point position -14.91 -22.64 -37.25 Zoom lens group data Group starting plane Focal length Lens 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 Single lens data Lens starting plane, 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 Face number rd nd vd Effective 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 plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-3.83383e-05 A 6= 2.45312e-07 A 8=-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 A 4=-4.76988e-05 A 6= 1.75246e-08 A 8=-6.10325e-10 A10= 3.53220e-11 A12=-2.49061e-13 A14= 4.49849e-16 3rd page K = 0.00000e+00 A 4=-5.39722e-05 A 6=-8.55438e-07 A 8= 1.56441e-08 A10=-1.00144e-10 A12= 3.15410e-13 A14=-4.48024e-16 A16= 8.73682e-20 Side 4 K = 0.00000e+00 A 4=-3.60102e-05 A 6=-5.73429e-07 A 8= 1.76406e-08 A10=-1.41260e-10 A12= 6.86453e-13 A14=-9.31010e-16 Page 29 K = 0.00000e+00 A 4=-3.40229e-04 A 6= 1.62265e-06 A 8=-2.48541e-08 A10= 4.17717e-10 A12=-2.60276e-12 A14= 4.91728e-15 A16=-1.37053e-17 Page 30 K = 0.00000e+00 A 4=-2.63872e-04 A 6= 1.99718e-06 A 8=-1.48849e-08 A10= 1.68361e-10 A12=-7.40275e-13 Various 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 Overall 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 Starting surface Focal length Lens configuration 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 Single lens data Lens starting plane, 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 Face number rd nd vd Effective 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 [[ID=4⑧]]32 ∞ 0.63 35.00 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-7.18649e-06 A 6= 1.56202e-07 A 8=-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 A 4=-2.94090e-05 A 6=-1.28915e-08 A 8=-1.93748e-10 A10= 3.50797e-11 A12=-2.91188e-13 A14= 5.95785e-16 3rd page K = 0.00000e+00 A 4=-1.72761e-04 A 6=-3.08074e-07 A 8= 1.53103e-08 A10=-1.01314e-10 A12= 2.74412e-13 A14=-2.36300e-16 A16=-1.76418e-19 Side 4 K = 0.00000e+00 A 4=-1.56283e-04 A 6= 1.12970e-07 A 8= 1.81398e-08 A10=-1.70393e-10 A12= 9.06183e-13 A14=-1.34800e-15 Page 27 K = 0.00000e+00 A 4=-3.07454e-04 A 6= 2.20100e-06 A 8=-3.20116e-08 A10= 3.99271e-10 A12=-2.18564e-12 A14= 7.16790e-15 A16=-4.95029e-17 Page 28 K = 0.00000e+00 A 4=-2.23267e-04 A 6= 2.31615e-06 A 8=-2.04763e-08 A10= 1.84333e-10 A12=-7.26456e-13 Various data Zoom ratio 1.96 Focal length 10.36 15.08 20.30 F number 2.91 2.91 2.91 Field 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 Back principal point position -9.73 -14.45 -19.67 Zoom lens group data Group starting plane Focal length Lens 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 Single lens data Lens starting plane, 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 Face number rd nd vd Effective 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 plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-1.68444e-05 A 6= 1.78661e-07 A 8=-5.04887e-12 A10=-2.56408e-12 A12= 9.16018e-15 A14=-1.27537e-17 A16= 6.49167e-21 2nd side K =-5.58259e-01 A 4=-3.41324e-05 A 6=-1.45680e-07 A 8=-1.34539e-10 A10= 3.59212e-11 A12=-2.89450e-13 A14= 5.84212e-16 3rd page K = 0.00000e+00 A 4=-5.65107e-05 A 6=-8.98327e-07 A 8= 1.66100e-08 A10=-1.04746e-10 A12= 2.96600e-13 A14=-2.87071e-16 A16=-1.51836e-19 Side 4 K = 0.00000e+00 A 4=-2.27640e-05 A 6=-6.81060e-07 A 8= 2.18483e-08 A10=-1.78940e-10 A12= 8.67387e-13 A14=-1.32669e-15 Page 29 K = 0.00000e+00 A 4=-2.93423e-04 A 6= 2.11559e-06 A 8=-2.69459e-08 A10= 2.97277e-10 A12=-1.42311e-12 A14= 4.31743e-15 A16=-3.60071e-17 Page 30 K = 0.00000e+00 A 4=-2.14871e-04 A 6= 2.35153e-06 A 8=-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 Field of view: 52.14°, 44.44°, 36.09° Image height 13.33 14.80 14.80 Lens 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 group data Group starting plane Focal length Lens 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 starting plane, 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 Amount of movement of the focusing lens group from infinity to 0.1x magnification. Lens group L2 L4 Wide-angle end 1.074 0.689 Telephoto end 1.039 0.295

[0141] <Numerical Example 6> Unit: mm Surface data Face number rd nd vd Effective 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 ∞ Aspherical data Front page K = 0.00000e+00 A 4=-1.26269e-05 A 6= 1.57648e-07 A 8=-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 A 4=-3.41104e-05 A 6=-3.22124e-08 A 8=-1.83260e-10 A10= 3.36916e-11 A12=-2.80046e-13 A14= 5.72098e-16 3rd page K = 0.00000e+00 A 4=-1.94547e-04 A 6=-2.46171e-07 A 8= 1.50124e-08 A10=-9.95973e-11 A12= 2.72256e-13 A14=-2.64438e-16 A16=-9.17560e-20 Side 4 K = 0.00000e+00 A 4=-1.87924e-04 A 6= 2.06228e-07 A 8= 1.75592e-08 A10=-1.64843e-10 A12= 8.65760e-13 A14=-1.25299e-15 Page 27 K = 0.00000e+00 A 4=-2.68051e-04 A 6= 1.99062e-06 A 8=-3.22492e-08 A10= 4.16733e-10 A12=-2.35998e-12 A14= 7.85765e-15 A16=-4.86430e-17 Page 28 K = 0.00000e+00 A 4=-1.84377e-04 A 6= 1.94610e-06 A 8=-1.84829e-08 A10= 1.79527e-10 A12=-7.27107e-13 Various data Zoom ratio 1.96 Focal length 10.36 14.77 20.30 F number 2.91 2.91 2.91 Field 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 Back principal point position -9.71 -14.13 -19.65 Zoom lens group data Group starting plane Focal length Lens 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 Single lens data Lens starting plane, 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 the numerical values ​​in the numerical examples corresponding to conditional expressions (1) to (9). [Table 1]

[0143] This embodiment includes the following configuration. (Composition 1) The lens comprises, in order from the object side to the image side, a first lens group having a negative refractive power that does not move for magnification, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group. When magnification is changed, the spacing between each lens group changes. The focusing lens group includes at least two lens groups that move along different trajectories when focusing, When the focal length of the first lens group is f1, and the focal length of the lens group positioned closest to the object among the focusing lens group is f2, -0.60 <f1 / f2<-0.05 A zoom lens characterized by satisfying the following conditions. (Configuration 2) When the zoom lens has an aperture diaphragm, and the distance along the optical axis at the wide-angle end from the lens surface located closest to the object in the first lens group to the aperture diaphragm is Lsw, and the total optical length of the zoom lens is TL, 0.20 <Lsw / TL<0.50 A zoom lens according to configuration 1, characterized by satisfying the following conditions. (Composition 3) When the zoom lens has an aperture diaphragm, and the distance along the optical axis at the telephoto end from the lens surface closest to the object in the first lens group to the aperture diaphragm is Lst, and the total optical length of the zoom lens is TL, 0.10 <Lst / TL<0.40 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditions. (Composition 4) The at least two lens groups that move for focusing include a first focusing lens group and a second focusing lens group, arranged in order from the object side to the image side. When the absolute values ​​of the movement 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, 0.5 <M1w / M2w<3.0 A zoom lens according to any one of the configurations 1 to 3, characterized by satisfying the following conditions. (Composition 5) The at least two lens groups that move for focusing include a first focusing lens group and a second focusing lens group, arranged in order from the object side to the image side. When the absolute values ​​of the movement 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, 1.0 <M1t / M2t<6.0 A zoom lens according to any one of the configurations 1 to 4, characterized by satisfying the following conditions. (Composition 6) When BFw is the distance from the lens surface located closest to the image plane at the wide-angle end of the zoom lens to the image plane, and fw is the total focal length of the system at the wide-angle end, 0.10 <BFw / fw<1.30 A zoom lens according to any one of the configurations 1 to 5, characterized by satisfying the following conditions. (Composition 7) The zoom lens according to any one of configurations 1 to 6, characterized in that the first lens group includes at least one negative lens and at least one positive lens, and is composed of four or fewer lenses. (Composition 8) A zoom lens according to any one of the configurations 1 to 7, characterized in that the lens group that moves during magnification is three or less. (Composition 9) The zoom lens according to any one of configurations 1 to 8, characterized in that the subsequent lens group includes a lens group that does not move for magnification. (Composition 10) The zoom lens according to any one of configurations 1 to 9, characterized in that the subsequent lens group includes a lens group that moves in a direction containing a component perpendicular to the optical axis to perform image stabilization. (Composition 11) The zoom lens according to any one of configurations 1 to 9, characterized in that the focusing lens group includes a lens group that moves in a direction containing a component perpendicular to the optical axis to perform image stabilization. (Composition 12) When the combined horizontal magnification at the wide-angle end of the aforementioned successor lens group is βrw, and the combined horizontal magnification at the telephoto end of the aforementioned successor lens group is βrt, 0.30 < |βrt / βrw| < 2.80 A zoom lens according to any one of the configurations 1 to 11, characterized by satisfying the following conditions. (Composition 13) The zoom lens according to any one of configurations 1 to 12, characterized in that the focusing lens group is composed of a lens group having positive refractive power and a lens group having positive refractive power, in order from the object side to the image side. (Composition 14) The zoom lens according to any one of configurations 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. (Composition 15) When the focal length of the lens group positioned closest to the object among the aforementioned focusing lens group is f2, and the focal length of the lens group positioned adjacent to that lens group on the image side is f3, 1.50 <f2 / f3<3.00 A zoom lens according to any one of the configurations 1 to 14, characterized by satisfying the following conditions. (Composition 16) The zoom lens according to any one of configurations 1 to 15, characterized in that the focusing lens group includes lens groups that move to focus on the object side and the image side. (Composition 17) The zoom lens according to any one of configurations 1 to 16, characterized in that the focusing lens group is composed of two or three lens groups. (Composition 18) The zoom lens according to any one of configurations 1 to 17, characterized in that the subsequent lens group is composed of a lens group having negative refractive power and a lens group having positive refractive power, in order from the object side to the image side. (Composition 19) The zoom lens according to any one of configurations 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. (Composition 20) The zoom lens according to any one of configurations 1 to 19, characterized in that the lens group positioned closest to the image in the aforementioned successor lens group is a lens group that moves for magnification. (Composition 21) A zoom lens according to any one of configurations 1 to 20, characterized in that it has a final lens group positioned on the image side of the aforementioned successor lens group, having positive refractive power, and not moving for magnification. (Composition 22) The lens group positioned closest to the image sensor consists of a single lens with a convex surface on the image sensor side. When the focal length of this single lens is fR and the focal length of the entire system at the wide-angle end is fw, 2.00 <fR / fw<6.00 A zoom lens according to any one of the configurations 1 to 21, characterized by satisfying the following conditions. (Composition 23) A zoom lens according to any one of configurations 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. (Composition 24) The lens has, 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. When magnification is changed, the spacing between each lens group changes. The focusing lens group includes at least two lens groups that move along different trajectories when focusing, The first lens group is characterized by including a positive lens. (Composition 25) An imaging device characterized by having a zoom lens described in any one of items 1 to 24 and an image sensor that receives an image formed by the zoom lens. [Explanation of symbols]

[0144] L1: First lens group L2: Second lens group L3: Third lens group L4: Fourth lens group L5: Fifth lens group L6: Lens group #6 L7: Lens group 7 LF: Focusing lens group LR: Successor lens group

Claims

1. The lens comprises, in order from the object side to the image side, a first lens group having a negative refractive power that does not move for magnification, a focusing lens group including at least two lens groups, and a subsequent lens group including at least one lens group. When magnification is changed, the spacing between each lens group changes. The focusing lens group includes at least two lens groups that move along different trajectories when focusing, When the focal length of the first lens group is f1, and the focal length of the lens group positioned closest to the object among the focusing lens group is f2, -0.60<f1 / f2<-0.05 A zoom lens characterized by satisfying the following conditions.

2. When the zoom lens has an aperture diaphragm, and the distance along the optical axis at the wide-angle end from the lens surface located closest to the object in the first lens group to the aperture diaphragm is Lsw, and the total optical length of the zoom lens is TL, 0.20<Lsw / TL<0.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

3. When the zoom lens has an aperture diaphragm, and the distance along the optical axis at the telephoto end from the lens surface located closest to the object in the first lens group to the aperture diaphragm is Lst, and the total optical length of the zoom lens is TL, 0.10<Lst / TL<0.40 The zoom lens according to claim 1, characterized by satisfying the following conditions.

4. The at least two lens groups that move for focusing include a first focusing lens group and a second focusing lens group, arranged in order from the object side to the image side. When the absolute values ​​of the movement 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, 0.5<M1w / M2w<3.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

5. The at least two lens groups that move for focusing include a first focusing lens group and a second focusing lens group, arranged in order from the object side to the image side. When the absolute values ​​of the movement 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, 1.0<M1t / M2t<6.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

6. When BFw is the distance from the lens surface closest to the image plane at the wide-angle end of the zoom lens to the image plane, and fw is the total focal length of the system at the wide-angle end, 0.10<BFw / fw<1.30 The zoom lens according to claim 1, characterized by satisfying the following conditions.

7. The zoom lens according to claim 1, characterized in that the first lens group includes at least one negative lens and at least one positive lens, and is composed of four or fewer lenses.

8. The zoom lens according to claim 1, characterized in that the lens group that moves during magnification is three or less.

9. The zoom lens according to claim 1, characterized in that the subsequent lens group includes a lens group that does not move for magnification.

10. The zoom lens according to claim 1, characterized in that the subsequent lens group includes a lens group that moves in a direction containing a component perpendicular to the optical axis to perform image stabilization.

11. The zoom lens according to claim 1, characterized in that the focusing lens group includes a lens group that moves in a direction containing a component perpendicular to the optical axis to perform image stabilization.

12. When the combined horizontal magnification at the wide-angle end of the aforementioned successor lens group is βrw, and the combined horizontal magnification at the telephoto end of the aforementioned successor lens group is βrt, 0.30<|βrt / βrw|<2.80 The zoom lens according to claim 1, characterized by satisfying the following conditions.

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

14. The zoom lens according to claim 1, 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. When the focal length of the lens group positioned closest to the object among the aforementioned focusing lens group is f2, and the focal length of the lens group positioned adjacent to that lens group on the image side is f3, 1.50<f2 / f3<3.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

16. The zoom lens according to claim 1, characterized in that the focusing lens group includes lens groups that move to focus on the object side and the image side.

17. The zoom lens according to claim 1, characterized in that the focusing lens group is composed of two or three lens groups.

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

19. The zoom lens according to claim 1, 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. The zoom lens according to claim 1, characterized in that the lens group positioned closest to the image in the aforementioned successor lens group is a lens group that moves for magnification.

21. The zoom lens according to claim 1, characterized in that it has a final lens group positioned on the image side of the aforementioned successor lens group, having a positive refractive power, and not moving for magnification.

22. The lens group positioned closest to the image sensor consists of a single lens with a convex surface on the image sensor side. When the focal length of this single lens is fR and the focal length of the entire system at the wide-angle end is fw, 2.00<fR / fw<6.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

23. The zoom lens according to claim 1, 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. The lens has, 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. When magnification is changed, the spacing between each lens group changes. The focusing lens group includes at least two lens groups that move along different trajectories when focusing, The first lens group is characterized by including a positive lens.

25. An imaging device characterized by having a zoom lens according to any one of claims 1 to 24 and an image sensor that receives an image formed by the zoom lens.

Images