Zoom lens and image capturing device

Abstract

To provide a wide-angle, compact, and light-weight zoom lens which offers high optical performance.SOLUTION: A zoom lens disclosed herein comprises a positive first lens group configured to be stationary for zooming, three or more movable lens groups configured to move for zooming, a positive succeeding lens group configured to be stationary for zooming, and an aperture stop configured to move for zooming. The zoom lens satisfies conditions expressed as: 1.00≤f1 / fw≤8.00 and 5.80≤(f1+bok1) / f1+1.2×LD1 / f1≤10.00, where f1 represents a focal length of the first lens group, fw represents a focal length of the zoom lens at the wide-angle end, bok1 represents an optical axial distance from a most image-side lens surface of the first lens group to a rear principal point of the first lens group while being focused on an object at infinity, and LD1 represents an optical axial thickness of the first lens group from a most object-side surface to the most image-side surface of the first lens group while being focused on an object at infinity.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a zoom lens. [Background technology]

[0002] Zoom lenses used in imaging devices such as television cameras, movie cameras, digital still cameras, and video cameras are required to have high optical performance, such as being small and lightweight, having a wide angle of view, a high zoom ratio, high resolution from the center to the periphery of the optical axis, and little chromatic aberration.

[0003] Patent Document 1 discloses a zoom lens having, arranged in order from the object side to the image side, a first lens group with positive refractive power that does not move for zooming, three or more movable lens groups that move for zooming, and a subsequent lens group with positive refractive power that does not move for zooming. In this zoom lens, an aperture stop that moves during zooming is included in the movable lens group. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-032924 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to achieve a wider angle of view, a smaller size and lighter weight, and high optical performance in the zoom lens of Patent Document 1, it is important that the aperture diaphragm moves during zooming and that the configuration and focal length of the first lens group are appropriately set. However, in the zoom lens of Patent Document 1, the focal length of the first lens group is large, so in order to further widen the angle of view, the diameter of the first lens group becomes larger.

[0006] The present invention provides a zoom lens that has a wide angle of view, is compact and lightweight, and has high optical performance over the entire zoom range. [Means for solving the problem]

[0007] A zoom lens according to one aspect of the present invention has lens groups arranged in order from the object side to the image side, which are a first lens group with positive refractive power that does not move for zooming, three or more movable lens groups that move for zooming, and a subsequent lens group with positive refractive power that does not move for zooming, and the spacing between adjacent lens groups changes during zooming, and the lens group also has an aperture stop that moves during zooming. When the focal length of the first lens group is f1, the focal length at the wide-angle end of the zoom lens is fw, the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused on an object at infinity is bok1, and the thickness on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface of the first lens group closest to the image side when focused on an object at infinity is LD1, 1.00≦f1 / fw≦8.00 5.80≦(f1+bok1) / f1+1.2×LD1 / f1≦10.00 The present invention is characterized in that the above conditions are satisfied. An image pickup apparatus including the above zoom lens also constitutes another aspect of the present invention. Effect of the Invention

[0008] According to the present invention, it is possible to provide a zoom lens that has a wide angle of view, is small and lightweight, and has high optical performance over the entire zoom range. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment. [Diagram 2] 5A to 5C are aberration diagrams of the zoom lens of the first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a zoom lens according to a second embodiment. [Figure 4] 6A to 6C are aberration diagrams of the zoom lens of Example 2. [Diagram 5] FIG. 11 is a cross-sectional view of a zoom lens according to a third embodiment. [Figure 6] 11A to 11C are aberration diagrams of the zoom lens of Example 3. [Figure 7] FIG. 11 is a cross-sectional view of a zoom lens according to a fourth embodiment. [Figure 8] 11A to 11C are aberration diagrams of the zoom lens of Example 4. [Figure 9] FIG. 13 is a cross-sectional view of a zoom lens according to a fifth embodiment. [Figure 10] 13A to 13C are aberration diagrams of the zoom lens of Example 5. [Figure 11] FIG. 1 is a schematic diagram of an imaging device including a zoom lens according to any one of the first to fifth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, before describing specific embodiments 1 to 5, matters common to each embodiment will be described. FIGS. 1, 3, 5, 7, and 9 respectively show the configuration of the zoom lenses of embodiments 1 to 5 in a state where the zoom lenses are focused on an object at infinity (hereinafter, referred to as an infinity focused state) at the wide-angle end. In each figure, the left side is the object side, and the right side is the image side. Ui (i=1, 2, 3, ...) indicates the i-th lens group, which is the i-th lens group counted from the object side. Below the lens groups that move for zooming, the movement trajectory of each lens group during zooming from the wide-angle end to the telephoto end is shown.

[0011] In a zoom lens, a lens group is a group of one or more lenses that move together during zooming between the wide-angle end and the telephoto end. That is, the spacing between adjacent lens groups changes during zooming. The lens group may include an aperture stop. The wide-angle end and the telephoto end respectively indicate the zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (maximum focal length) when the lens group that moves during zooming is located at both ends of the range that it can move mechanically or controllably on the optical axis.

[0012] The zoom lens of each embodiment has a wide angle of view with an F-number of about 1.9 to 3.0, a zoom ratio of about 2.0 to 15, is small and lightweight, and has high optical performance over the entire zoom range. The zoom lens of each embodiment has, as lens groups arranged in order from the object side to the image side, a first lens group U1 with positive refractive power that does not move for zooming, three or more movable lens groups U2 to U4 that move for zooming, and a subsequent lens group U5 with positive refractive power that does not move for zooming. The zoom lens of each embodiment also has an aperture stop SP that moves during zooming. I is the image plane of the zoom lens. The imaging surface (light receiving surface) of the image sensor and the film surface (photosensitive surface) of the silver halide film are arranged on the image plane I.

[0013] In the zoom lens of each embodiment, the focal length of the first lens group U1 is f1, the focal length of the zoom lens at the wide-angle end is fw, and the length on the optical axis from the lens surface of the first lens group U1 closest to the image side to the rear principal point of the first lens group U1 when focused at infinity is bok1. Also, the thickness on the optical axis from the lens surface of the first lens group U1 closest to the object side to the lens surface closest to the image side when focused at infinity is LD1. In this case, the zoom lens of each embodiment has the following: 1.00≦f1 / fw≦8.00 (1) 5.80≦(f1+bok1) / f1+1.2×LD1 / f1≦10.00 (2) The following conditions are satisfied.

[0014] The condition of formula (1) indicates an appropriate ratio between the focal length of the first lens group U1 and the focal length of the zoom lens at the wide-angle end. By satisfying the condition of formula (1), a wide angle of view, small size and light weight, and high optical performance can be achieved. If f1 / fw exceeds the upper limit of formula (1), the focal length of the first lens group U1 becomes excessively long, the lens diameter of the first lens group becomes large, and it becomes difficult to make the zoom lens small and light, which is not preferable. If f1 / fw falls below the lower limit of formula (1), the focal length of the first lens group U1 becomes excessively short, which makes it difficult to correct aberrations, which is not preferable. In addition, the focal length of the zoom lens at the wide-angle end becomes excessively long, which makes it difficult to achieve a wide angle of view, which is not preferable.

[0015] The condition of formula (2) shows the appropriate relationship between the focal length, rear principal point position, and thickness of the first lens group U1. By satisfying the condition of formula (2), a wide angle of view, a small size, a light weight, and high optical performance can be achieved. (f1+bok1) / f1 in formula (2) is the retro ratio of the first lens group U1. A larger retro ratio is advantageous for a wider angle of view, but is not preferable because it increases the lens diameter on the object side of the first lens group U1 and the number of lenses constituting the first lens group U1. Also, LD1 / f1 in formula (2) is the ratio between the thickness and focal length of the first lens group U1. In order to achieve a wider angle while maintaining the compactness of the zoom lens, it is advantageous to increase the value of LD1 / f1 because the focal length of the first lens group U1 is shorter relative to the thickness of the first lens group U1. On the other hand, if the focal length of the first lens group U1 is too short, it becomes difficult to correct aberrations, which is not preferable.

[0016] It is more preferable that the numerical ranges of the formulas (1) and (2) are as follows:

[0017] 1.50≦f1 / fw≦7.00 (1a) 5.85≦(f1+bok1) / f1+1.2×LD1 / f1≦9.00 (2a) It is more preferable that the numerical ranges of the formulas (1) and (2) are as follows:

[0018] 2.00≦f1 / fw≦5.00 (1b) 5.88≦(f1+bok1) / f1+1.3×LD1 / f1≦8.50 (2b) It is preferable that the zoom lens of each embodiment satisfies at least one of the following expressions (3) to (10) and other conditions.

[0019] The focal length of the second lens group U2, which is adjacent to the first lens group U1 on the image side among the moving lens groups, is denoted as f2. -2.00≦f1 / f2≦-0.10 (3) It is preferable to satisfy the following condition. The condition of formula (3) indicates an appropriate ratio of the focal lengths of the first lens group U1 and the second lens group U2. By satisfying the condition of formula (3), a wide angle of view, a small size, a light weight, and high optical performance can be achieved. If f1 / f2 exceeds the upper limit of formula (3), the focal length of the first lens group U1 becomes excessively short, which is advantageous for achieving a wide angle, but is undesirable because it becomes difficult to correct aberrations occurring in the first lens group U1 at the telephoto end. If f1 / f2 falls below the lower limit of formula (3), the focal length of the first lens group U1 becomes excessively long, which is undesirable because it becomes difficult to obtain a wide angle zoom lens. In addition, the lens diameter of the first lens group U1 becomes large, which is undesirable because it becomes difficult to reduce the size and weight.

[0020] It is more preferable to set the numerical range of the formula (3) as follows:

[0021] -1.80≦f1 / f2≦-0.50 (3a) It is more preferable that the numerical range of the formula (3) is as follows:

[0022] -1.60≦f1 / f2≦-0.60 (3b) When the focal length at the telephoto end of the zoom lens in each embodiment is ft, 0.40≦ft / f1≦2.50 (4) It is preferable to satisfy the following condition. By satisfying the condition of formula (4), a high zoom ratio, a small size, a light weight, and high optical performance can be achieved. When ft / f1 is large, it is advantageous to obtain a zoom lens with a high zoom ratio, but the aberration generated by the first lens group U1 increases at the telephoto end, making it difficult to keep it within the allowable range. When ft / f1 exceeds the upper limit of formula (4), the focal length of the first lens group U1 becomes too short, making it difficult to correct the aberration generated by the first lens group U1 at the telephoto end, which is not preferable. When ft / f1 is below the lower limit of formula (4), the focal length of the first lens group U1 becomes too long, making it difficult to obtain a zoom lens with a high zoom ratio, which is not preferable. In addition, the amount of movement of the moving lens group becomes too large, making it difficult to obtain a small and light zoom lens, which is not preferable.

[0023] It is more preferable to set the numerical range of the formula (4) as follows:

[0024] 0.50≦ft / f1≦2.40 (4a) It is more preferable that the numerical range of the formula (4) is as follows:

[0025] 0.50≦ft / f1≦2.30 (4b) The first lens group U1 has a negative lens G1 closest to the object, and the focal length of the negative lens G1 is fG1. -2.20≦ft / fG1≦-0.20 (5) It is preferable to satisfy the following condition. By satisfying the condition of formula (5), a high zoom ratio, a small size, a light weight, and high optical performance can be achieved. If ft / fG1 exceeds the upper limit of formula (5), the focal length of the negative lens G1 becomes excessively long, the entrance pupil of the zoom lens is disposed excessively toward the object side, and the diameter of the first sub-lens group U1a described later increases, making it difficult to obtain a small first lens group U1, which is not preferable. It is also not preferable because it is difficult to obtain a zoom lens with a high zoom ratio. If ft / fG1 falls below the lower limit of formula (4), the focal length of the negative lens G1 becomes excessively short, and the diameter of the axial light beam at the telephoto end increases. As a result, the diameter of the third sub-lens group U1c described later increases, making it difficult to obtain a small first lens group U1, which is not preferable.

[0026] It is more preferable to set the numerical range of the formula (5) as follows:

[0027] -2.00≦ft / fG1≦-0.30 (5a) It is more preferable that the numerical range of the formula (5) is as follows:

[0028] -1.95≦ft / fG1≦-0.40 (5b) The first lens group U1 preferably has a first sub-lens group U1a with negative refractive power that does not move for focusing, a second sub-lens group U1b with positive refractive power that moves for focusing, and a third sub-lens group U1c with positive refractive power, which are arranged in order from the object side to the image side. The sub-lens group is a group of one or more lenses whose spacing changes during focusing. The third sub-lens group U1c may or may not move for focusing.

[0029] In the first lens group U1 configured in this manner, the focal length of the first sub-lens group U1a is f1a, the focal length of the second sub-lens group U1b is f1b, and the focal length of the third sub-lens group U1c is f1c. -1.50≦f1a / f1≦-0.20 (6) 2.00≦f1b / f1≦10.00 (7) 1.00≦f1c / f1≦5.00 (8) It is preferable to satisfy the following conditions. By satisfying the conditions of formulas (6) to (8), high optical performance can be achieved. If the condition of formula (6) is not satisfied, the focal length f1 of the first lens group U1 or the focal length f1a of the first sub-lens group U1a becomes excessively small, making it difficult to keep the aberration occurring in the first lens group U1 or the first sub-lens group U1a within the allowable range, which is not preferable. If the condition of formula (7) is not satisfied, the focal length f1 of the first lens group U1 or the focal length f1b of the second sub-lens group U1b becomes excessively small, making it difficult to keep the aberration occurring in the first lens group U1 or the second sub-lens group U1b within the allowable range, which is not preferable. If the condition of equation (8) is not satisfied, the focal length f1 of the first lens group U1 or the focal length f1c of the third sub-lens group U1c will become excessively small, making it difficult to keep the aberrations occurring in the first lens group U1 or the third sub-lens group U1c within the acceptable range, which is undesirable.

[0030] It is more preferable to set the numerical ranges of the formulas (6) to (8) as follows:

[0031] -1.20≦f1a / f1≦-0.30 (6a) 2.20≦f1b / f1≦8.00 (7a) 1.20≦f1c / f1≦4.00 (8a) It is more preferable that the numerical ranges of the formulas (6) to (8) are as follows:

[0032] -1.00≦f1a / f1≦-0.40 (6b) 2.40≦f1b / f1≦7.00 (7b) 1.30≦f1c / f1≦3.90 (8b) It is preferable that the first lens group U1 has three negative lenses arranged consecutively from the object side. With this configuration, it is possible to gradually refract off-axis rays accompanying a wide angle of view from the object side to the image side, thereby suppressing the occurrence of aberrations accompanying a wide angle of view.

[0033] The radius of curvature of the object-side lens surface of the image-side negative lens Gnr adjacent on the object side to the positive lens closest to the object side among the positive lenses included in the first lens group U1 is Rnr, and the radius of curvature of the image-side lens surface of the object-side negative lens Gnf adjacent on the object side to the image-side negative lens Gnr is Rnf. In this case, |(Rnf+Rnr) / (Rnf-Rnr)|≦1.00 (9) It is preferable to satisfy the following condition. The condition of formula (9) indicates an appropriate range of the shape factor of the air lens formed between Gnf and Gnr. By satisfying the condition of formula (9), it is possible to give the air lens an appropriate convex lens shape, and it is possible to suppress an increase in aberration accompanying a wider angle of view. If |(Rnf+Rnr) / (Rnf-Rnr)| exceeds the upper limit of formula (9), the air lens becomes a meniscus shape, which makes it difficult to suppress an increase in aberration accompanying a wider angle of view, and this is not preferable.

[0034] It is more preferable to set the numerical range of the formula (9) as follows:

[0035] 0.01≦|(Rnf+Rnr) / (Rnf-Rnr)|≦0.50 (9a) More preferably, equation (9a) should be set as follows:

[0036] 0.02≦|(Rnf+Rnr) / (Rnf-Rnr)|≦0.40 (9b) When a zoom lens is used in an imaging device having an imaging surface with a diagonal size of 2Y, the focal length of the zoom lens at the wide-angle end is fw, the half angle of view of the zoom lens at the wide-angle end is ωw, and the half angle of view ωw is expressed as ωw=arctan(Y / fw). 50.0°≦ωw≦65.0° (10) It is preferable to satisfy the following condition. The condition of formula (10) is a condition for obtaining a zoom lens that has a wide angle of view and is small and lightweight. By satisfying the condition of formula (10), it is possible to achieve a wide angle in various format sizes. If ωw exceeds the upper limit of formula (10), it becomes difficult to obtain a small and lightweight zoom lens, which is not preferable. If ωw falls below the lower limit of formula (10), it becomes impossible to obtain a zoom lens with a wide angle of view, which is not preferable.

[0037] It is more preferable to set the numerical range of the formula (10) as follows:

[0038] 51.0°≦ωw≦63.0° (10a) It is more preferable that the numerical range of the formula (10) is as follows:

[0039] 52.0°≦ωw≦62.0° (10b) Specific configurations of the zoom lenses of Examples 1 to 5 will be described below while showing Numerical Examples 1 to 5 corresponding to Examples 1 to 5, respectively. EXAMPLES

[0040] The zoom lens of Example 1 shown in FIG. 1 has a first lens group U1 with positive refractive power that does not move for zooming, closest to the object side. The zoom lens of Example 1 also has a second lens group U2 with negative refractive power, a third lens group U3 with negative refractive power, and a fourth lens group U4 with positive refractive power, each of which moves toward the image side for zooming from the wide-angle end to the telephoto end. The fourth lens group U4 moves in conjunction with the movement of the second lens group U2 and the third lens group U3 to correct image plane fluctuations that accompany zooming. The zoom lens of Example 1 also has a fifth lens group U5 as a subsequent lens group with positive refractive power that does not move for zooming and has an image-forming effect. An aperture stop SP is disposed closest to the object side of the fourth lens group U4.

[0041] Numerical Example 1 is shown after Example 5. In the numerical example, i indicates the order of the surface counted from the object side. r indicates the radius of curvature of the i-th surface from the object side, and di indicates the lens thickness or air distance (mm) on the optical axis between the i-th and (i+1)-th surfaces. nd is the refractive index at the d-line of the optical material between the i-th and (i+1)-th surfaces. νd is the Abbe number based on the d-line of the optical material between the i-th and (i+1)-th surfaces. The Abbe number νd based on the d-line is given by the following 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, respectively: νd=(Nd-1) / (NF-NC) It is expressed as:

[0042] θgF is the partial dispersion ratio, and when the refractive index at the g line (wavelength 435.8 nm) is Ng, θgF=(Ng-NF) / (NF-NC) The effective diameter is the radius (mm) of the area of ​​the i-th lens surface through which light rays that contribute to image formation pass.

[0043] In each numerical example, the half angle of view (°) of the zoom lens is shown, and the maximum image height corresponding to the half angle of view is shown as "image height." The half angle of view ω is expressed as follows: fw is the focal length at the wide-angle end of a zoom lens used in an imaging device having an imaging surface of diagonal size 2Y, ω=arctan(Y / fw) The maximum image height corresponds to Y, which is half the diagonal size 2Y (for example, 29.60 mm).

[0044] In each numerical example, the focal length of each lens group at the d-line is shown as lens group data.

[0045] Furthermore, in each numerical example, BF represents the back focus (mm). The back focus is the distance on the optical axis from the final surface of the zoom lens (the lens surface closest to the image) to the paraxial image plane, expressed as an air-equivalent length. The total lens length (total optical length) is the distance on the optical axis from the foreground surface of the zoom lens (the lens surface closest to the object) to the final surface plus the back focus.

[0046] An "*" next to a surface number means that the surface has an aspheric shape. An aspheric shape is expressed by the following formula, where X is the displacement from the apex of the surface in the optical axis direction, H is the height from the optical axis in a direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, and A2 to A16 are aspheric coefficients. The conic constant and the aspheric coefficients "e±x" are ×10 ±x means...

[0047]

number

[0048] In Numerical Example 1, the first lens group U1 corresponds to surfaces 1 to 18. The second lens group U2 corresponds to surfaces 19 to 25, the third lens group U3 corresponds to surfaces 26 to 28, and the fourth lens group U4 corresponds to surface 29, which is an aperture stop, and surfaces 30 to 34. The fifth lens group U5 corresponds to surfaces 35 to 49.

[0049] The values ​​of expressions (1) to (10) in Numerical Example 1 are summarized in Table 1. The zoom lens of Numerical Example 1 satisfies the conditions of expressions (1) to (10), and has high optical performance over the entire zoom range while having a wide angle of view and being small and lightweight.

[0050] 2(a) and 2(b) show longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) at the wide-angle end and telephoto end of the zoom lens of Numerical Example 1, respectively. In the spherical aberration diagram, Fno indicates the F-number, the solid line indicates the spherical aberration for the d-line (wavelength 587.6 nm), and the two-dot chain line indicates the spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line S indicates the astigmatism at the sagittal image plane, and the dashed line M indicates the astigmatism at the meridional image plane. The distortion aberration diagram shows the distortion aberration at the d-line. The chromatic aberration diagram shows the lateral chromatic aberration at the g-line. ω is the half angle of view (°). The spherical aberration is shown on a scale of 0.2 mm, the astigmatism is shown on a scale of 0.2 mm, the distortion is shown on a scale of 5%, and the lateral chromatic aberration is shown on a scale of 0.05 mm. EXAMPLES

[0051] The zoom lens of Example 2 shown in FIG. 3 has a first lens group U1 with positive refractive power that does not move for zooming, closest to the object side. The zoom lens of Example 2 also has a second lens group U2 with negative refractive power, a third lens group U3 with negative refractive power, and a fourth lens group U4 with positive refractive power, each of which moves toward the image side for zooming from the wide-angle end to the telephoto end. The fourth lens group U4 moves in conjunction with the movement of the second lens group U2 and the third lens group U3 to correct image plane fluctuations that accompany zooming. The zoom lens of Example 2 also has a fifth lens group U5 as a subsequent lens group with positive refractive power that does not move for zooming and has an image-forming effect. The aperture stop SP is disposed closest to the object side of the fourth lens group U4.

[0052] Numerical Example 2 is shown after Example 5. In Numerical Example 2, the first lens group U1 corresponds to surfaces 1 to 19. The second lens group U2 corresponds to surfaces 20 to 26, the third lens group U3 corresponds to surfaces 27 to 29, and the fourth lens group U4 corresponds to surfaces 30 (aperture stop) and surfaces 31 to 35. The fifth lens group U5 corresponds to surfaces 36 to 50.

[0053] The values ​​of expressions (1) to (10) in Numerical Example 2 are summarized in Table 1. The zoom lens of Numerical Example 2 satisfies the conditions of expressions (1) to (10), and has high optical performance over the entire zoom range while having a wide angle of view and being small and lightweight.

[0054] 4(a) and 4(b) show longitudinal aberrations at the wide-angle end and the telephoto end of the zoom lens in Numerical Example 2, respectively. EXAMPLES

[0055] The zoom lens of Example 3 shown in FIG. 5 has a first lens group U1 with positive refractive power that does not move for zooming, closest to the object side. The zoom lens of Example 3 also has a second lens group U2 with negative refractive power, a third lens group U3 with positive refractive power, and a fourth lens group U4 with positive refractive power, each of which moves to the image side for zooming from the wide-angle end to the telephoto end. The fourth lens group U4 moves in conjunction with the movement of the second lens group U2 and the third lens group U3 to correct image plane fluctuations that accompany zooming. The zoom lens of Example 3 also has a fifth lens group U5 as a subsequent lens group with positive refractive power that does not move for zooming and has an image-forming effect. The aperture stop SP is disposed closest to the object side of the fourth lens group U4.

[0056] Numerical Example 3 is shown after Example 5. In Numerical Example 3, the first lens group U1 corresponds to surfaces 1 to 18. The second lens group U2 corresponds to surfaces 19 to 27, the third lens group U3 corresponds to surfaces 28 to 29, and the fourth lens group U4 corresponds to surfaces 30 (aperture stop) and surfaces 31 to 35. The fifth lens group U5 corresponds to surfaces 36 to 49.

[0057] The values ​​of expressions (1) to (10) in Numerical Example 3 are summarized in Table 1. The zoom lens of Numerical Example 3 satisfies the conditions of expressions (1) to (10), and has high optical performance over the entire zoom range while having a wide angle of view and being small and lightweight.

[0058] 6(a) and 6(b) show longitudinal aberrations at the wide-angle end and the telephoto end of the zoom lens in Numerical Example 3, respectively. EXAMPLES

[0059] The zoom lens of Example 4 shown in FIG. 7 has a first lens group U1 with positive refractive power that is closest to the object side and does not move for zooming. The zoom lens of Example 4 also has a second lens group U2 with negative refractive power, a third lens group U3 with positive refractive power, and a fourth lens group U4 with negative refractive power as moving lens groups that move toward the image side for zooming from the wide-angle end to the telephoto end. The fourth lens group U4 moves in conjunction with the movement of the second lens group U2 and the third lens group U3 to correct image plane fluctuations that accompany zooming. The zoom lens of Example 4 also has a fifth lens group U5 as a subsequent lens group with positive refractive power that does not move for zooming and has an image-forming effect. The aperture stop SP is disposed closest to the image side of the fourth lens group U4.

[0060] Numerical Example 4 is shown after Example 5. In Numerical Example 4, the first lens group U1 corresponds to surfaces 1 to 19. The second lens group U2 corresponds to surfaces 20 to 23, the third lens group U3 corresponds to surfaces 24 to 25, the fourth lens group U4 corresponds to surfaces 26 to 28 and the 29th surface which is an aperture stop. The fifth lens group U5 corresponds to surfaces 30 to 49.

[0061] The values ​​of expressions (1) to (10) in Numerical Example 4 are summarized in Table 1. The zoom lens of Numerical Example 4 satisfies the conditions of expressions (1) to (10), and has high optical performance over the entire zoom range while having a wide angle of view and being small and lightweight.

[0062] 8(a) and 8(b) show longitudinal aberrations at the wide-angle end and the telephoto end of the zoom lens of Numerical Example 4, respectively. EXAMPLES

[0063] The zoom lens of Example 5 shown in FIG. 9 has a first lens group U1 with positive refractive power that is located closest to the object side and does not move for zooming. The zoom lens of Example 5 also has a second lens group U2 with negative refractive power, a third lens group U3 with negative refractive power, and a fourth lens group U4 with positive refractive power as moving lens groups that move toward the image side or toward the object side and the image side for zooming from the wide-angle end to the telephoto end. The fourth lens group U4 moves in conjunction with the movement of the second lens group U2 and the third lens group U3 to correct image plane fluctuations that occur during zooming. The zoom lens of Example 5 also has a fifth lens group U5 as a subsequent lens group with positive refractive power that does not move for zooming and has an image-forming effect. The aperture stop SP is located closest to the object side of the fourth lens group U4.

[0064] Numerical Example 5 is shown after this embodiment. In Numerical Example 5, the first lens group U1 corresponds to surfaces 1 to 21. The second lens group U2 corresponds to surfaces 22 to 30, the third lens group U3 corresponds to surfaces 31 to 33, the fourth lens group U4 corresponds to surface 34 which is an aperture stop and surfaces 35 to 39. The fifth lens group U5 corresponds to surfaces 40 to 49.

[0065] The values ​​of formulas (1) to (10) in Numerical Example 5 are summarized in Table 1. The zoom lens of Numerical Example 5 satisfies the conditions of formulas (1) to (10), and has high optical performance over the entire zoom range while having a wide angle of view and being small and lightweight.

[0066] 10(a) and 10(b) show longitudinal aberrations at the wide-angle end and the telephoto end of the zoom lens in Numerical Example 4, respectively.

[0067] It should be noted that the configurations shown in Examples 1 to 5 (and Numerical Examples 1 to 5) are merely examples, and the moving lens group and the subsequent lens group may have configurations different from those in Examples 1 to 5. By satisfying at least the conditions of expressions (1) to (3), it is possible to realize a zoom lens that has a wide angle of view, is small and lightweight, and yet has high optical performance over the entire zoom range.

[0068] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -253.468 2.40 1.76385 48.5 0.5589 74.29 2 27.608 14.31 50.21 3 105.984 1.60 2.00100 29.1 0.5997 49.47 4 40.143 18.02 46.06 5 -31.685 1.50 1.76385 48.5 0.5589 46.21 6 -50.980 0.20 50.65 7 3003.474 7.72 1.89286 20.4 0.6393 56.17 8 -72.723 1.50 56.85 9 82.988 9.11 1.61800 63.3 0.5441 56.82 10* -147.576 5.06 56.57 11 133.599 13.21 1.52841 76.5 0.5396 56.36 12 -55.404 1.80 1.95375 32.3 0.5905 55.95 13 -71.004 0.20 56.43 14 238.752 1.65 2.05090 26.9 0.6054 51.72 15 41.558 14.30 1.49700 81.5 0.5375 48.40 16 -84.763 0.20 48.22 17 2180.027 4.69 1.76385 48.5 0.5589 46.68 18 -107.580 (variable) 46.44 19* 99.650 1.20 1.89190 37.1 0.5780 26.29 20 24.509 5.04 23.47 21 -66.164 0.80 1.59522 67.7 0.5442 22.71 22 51.110 3.42 1.85478 24.8 0.6122 21.87 23 -79.694 1.60 21.70 24 -28.497 0.80 1.76385 48.5 0.5589 21.67 25 -50.982 (variable) 22.14 26 -40.299 0.80 1.59522 67.7 0.5442 22.42 27 43.233 2.06 1.85478 24.8 0.6122 23.66 28 77.509 (variable) 23.89 29(Aperture) ∞ 1.00 27.50 30* 31.967 7.75 1.60342 38.0 0.5835 30.37 31 -52.247 0.20 30.40 32 1068.339 6.21 1.76182 26.5 0.6136 29.46 33 -27.253 0.90 2.05090 26.9 0.6054 29.04 34 374.491 (variable) 29.04 35 95.983 3.24 1.56732 42.8 0.5731 29.61 36 -180.749 0.20 29.52 37 110.142 1.00 2.05090 26.9 0.6054 29.18 38 31.469 5.68 1.53775 74.7 0.5392 28.39 39 -128.437 40.06 28.43 40 59.850 10.55 1.48749 70.2 0.5300 37.65 41 -71.930 0.40 37.51 42 58.181 8.55 1.85896 22.7 0.6284 35.71 43 -50.800 1.10 1.88300 40.8 0.5667 34.43 44 33.103 1.60 30.86 45 45.400 10.93 1.43875 94.9 0.5340 30.88 46 -24.480 1.50 2.05090 26.9 0.6054 30.35 47 1603.558 0.20 32.66 48 77.994 8.15 1.53775 74.7 0.5392 34.19 49 -36.510 (variable) 34.73 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 9.63421e-06 A 6=-1.25665e-08 A 8= 1.63812e-11 A10=-1.59429e-14 A12= 1.01106e-17 A14=-3.64168e-21 A16= 5.61323e-25 Side 10 K = 0.00000e+00 A 4= 2.59557e-06 A 6=-4.92566e-10 A 8= 7.10252e-14 Page 19 K = 0.00000e+00 A 4= 5.04595e-06 A 6=-1.12643e-08 A 8= 1.49775e-10 A10=-9.03675e-13 A12= 2.07771e-15 Page 30 K = 0.00000e+00 A 4=-6.97394e-06 A 6= 2.67278e-09 A 8=-2.91492e-12 Various data Zoom ratio 4.87 Wide Angle Mid-Telephoto Focal length 11.30 39.99 55.00 F-number 2.73 2.73 3.65 Half angle of view (°) 52.65 20.31 15.06 Image height 14.80 14.80 14.80 Lens total length 310.95 310.95 310.95 BF 36.98 36.98 36.98 d18 1.00 36.89 41.97 d25 21.21 2.21 6.77 d28 12.85 6.57 0.99 d34 16.51 5.91 1.84 d49 36.98 36.98 36.98 Lens Group Data Group starting plane focal length 1 1 26.85 2 19 -30.40 3 26 -50.15 4 29 51.67 5 35 68.54 [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* 126.921 2.40 1.76385 48.5 0.5589 70.48 2 24.756 18.01 47.75 3 205.334 1.60 2.00100 29.1 0.5997 46.22 4 31.331 16.61 40.59 5 -28.826 1.50 1.88300 40.8 0.5667 40.69 6 -38.396 3.89 43.56 7 362.828 5.91 1.89286 20.4 0.6393 50.00 8 -99.897 4.53 50.39 9 79.733 9.49 1.61800 63.3 0.5441 50.07 10* -98.509 4.47 49.78 11 462.544 8.59 1.49700 81.5 0.5375 46.73 12 -52.417 0.20 45.93 13 -51.044 1.80 1.76385 48.5 0.5589 45.86 14 -59.895 0.20 45.65 15 -92.715 1.65 1.95375 32.3 0.5905 43.69 16 50.357 11.35 1.43875 94.9 0.5340 42.17 17 -52.496 0.20 42.39 18 329.681 6.39 1.76385 48.5 0.5589 42.77 19 -86.347 (variable) 42.81 20* 463.639 1.20 1.90525 35.0 0.5848 27.55 21 40.082 3.64 25.69 22 -250.829 0.80 1.59522 67.7 0.5442 24.98 23 72.439 4.04 1.85478 24.8 0.6122 24.31 24 -64.263 1.25 23.70 25 -33.758 0.80 1.76385 48.5 0.5589 23.43 26 -151.628 (variable) 23.78 27 -62.341 0.80 1.60300 65.4 0.5401 24.05 28 36.556 2.38 1.85478 24.8 0.6122 25.09 29 65.408 (variable) 25.24 30(Aperture) ∞ 3.19 26.88 31* 25.857 8.14 1.58144 40.8 0.5774 31.37 32 -79.991 0.20 31.17 33 72.746 6.52 1.78472 25.7 0.6161 29.85 34 -36.630 0.90 2.00069 25.5 0.6136 29.04 35 39.449 (variable) 27.39 36 793.020 3.49 1.56732 42.8 0.5731 28.43 37 -55.886 0.20 28.63 38 44.558 1.00 2.05090 26.9 0.6054 28.21 39 28.061 3.94 1.53775 74.7 0.5392 27.34 40 84.241 40.06 27.11 41 48.281 8.81 1.55200 70.7 0.5421 37.73 42 -60.818 0.40 37.50 43 51.915 6.05 1.80810 22.8 0.6307 33.90 44 -84.930 1.10 1.88300 40.8 0.5667 32.89 45 32.067 2.44 29.24 46 68.206 10.30 1.43875 94.7 0.5340 29.14 47 -20.155 1.50 2.05090 26.9 0.6054 28.29 48 -886.515 3.11 31.02 49 76.996 9.29 1.48749 70.2 0.5300 35.18 50 -32.448 (variable) 35.79 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 7.30634e-06 A 6=-7.54574e-09 A 8= 8.65243e-12 A10=-4.83724e-15 A12= 2.60356e-19 A14= 1.10034e-21 A16=-3.45510e-25 Side 10 K = 0.00000e+00 A 4= 1.72912e-06 A 6=-5.37259e-10 A 8= 1.75411e-13 Page 20 K = 0.00000e+00 A 4= 3.88741e-06 A 6=-5.31069e-09 A 8= 7.99823e-11 A10=-4.60328e-13 A12= 9.77729e-16 Page 31 K = 0.00000e+00 A 4=-1.08698e-05 A 6=-8.27919e-10 A 8=-1.03830e-11 Various data Zoom ratio 3.85 Wide Angle Mid-Telephoto Focal length 10.40 32.01 40.02 F-number 2.89 2.89 3.61 Half angle of view (°) 54.91 24.81 20.30 Image height 14.80 14.80 14.80 Lens total length 320.72 320.72 320.72 BF 37.00 37.00 37.00 d19 1.00 46.28 52.53 d26 35.34 2.35 2.23 d29 6.01 4.06 0.99 d35 17.03 6.69 3.63 d50 37.00 37.00 37.00 Lens Group Data Group starting plane focal length 1 1 29.16 2 20 -41.45 3 27 -62.78 4 30 63.68 5 36 63.55 [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -595.584 2.40 1.80100 35.0 0.5864 85.84 2 41.392 12.21 67.96 3* 36.602 1.80 1.90366 31.3 0.5946 60.65 4 30.008 13.70 49.88 5 503.014 1.65 1.90366 31.3 0.5946 49.32 6 61.953 9.56 47.37 7 -66.840 1.66 1.48749 70.2 0.5300 47.42 8 85.800 7.46 1.80518 25.5 0.6156 50.43 9 -528.865 0.15 50.84 10 146.997 7.60 1.73800 32.3 0.5900 52.18 11 -162.643 1.84 53.10 12 339.886 6.15 1.43875 94.9 0.5340 54.50 13* -149.957 5.27 54.92 14 127.624 1.74 1.84666 23.8 0.6205 55.92 15 54.593 15.05 1.43875 94.9 0.5340 54.98 16 -68.304 0.20 55.23 17 2062.245 8.76 1.52841 76.5 0.5396 54.02 18 -68.144 (variable) 53.60 19 103.208 1.00 1.59282 68.6 0.5458 29.24 20 27.999 4.58 27.88 21 -2395.887 1.00 1.72916 54.7 0.5444 27.94 22 48.542 0.32 28.09 23 37.569 4.96 1.72825 28.5 0.6077 28.72 24 -168.546 1.00 1.71300 53.9 0.5459 28.64 25 419.140 2.32 28.54 26 -52.603 1.00 1.91082 35.2 0.5824 28.54 27 343.689 (variable) 29.34 28 249.140 2.59 1.49700 81.5 0.5375 30.20 29 -104.331 (variable) 30.53 30(Aperture) ∞ 6.59 31.46 31* 56.337 7.15 1.72047 34.7 0.5834 34.61 32 -59.631 0.20 34.48 33 -92.343 4.41 1.51633 64.1 0.5353 33.76 34 -31.588 1.20 1.80400 46.5 0.5577 33.47 35 288.921 (variable) 33.47 36 -193.895 2.49 1.59282 68.6 0.5458 36.40 37 -72.634 0.20 36.80 38 46.007 1.27 1.59270 35.3 0.5933 39.22 39 37.060 8.68 1.49700 81.5 0.5375 38.88 40 -102.859 10.70 38.78 41 67.367 6.53 1.53775 74.7 0.5392 34.18 42 -45.534 1.17 1.95375 32.3 0.5898 33.76 43 34.911 1.15 32.78 44 37.609 10.88 1.49700 81.5 0.5375 33.90 45 -30.450 1.00 1.71700 47.9 0.5605 34.22 46 -81.406 0.20 35.69 47 70.008 1.10 1.91082 35.2 0.5824 36.92 48 28.184 6.99 1.68893 31.1 0.6004 36.26 49 255.435 1.15 36.34 50 ∞ 2.62 1.51680 64.2 0.5342 36.46 51 ∞ (variable) 36.86 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 1.20517e-05 A 6=-1.96995e-08 A 8= 3.33247e-11 A10=-4.42843e-14 A12= 4.33316e-17 A14=-2.95117e-20 A16= 1.31723e-23 A18=-3.44994e-27 A20= 4.01994e-31 3rd page K = 0.00000e+00 A 4=-1.08233e-05 A 6= 4.23897e-09 A 8=-2.33049e-13 A10=-2.49654e-14 A12= 8.32792e-17 A14=-1.59337e-19 A16= 1.84049e-22 A18=-1.17562e-25 A20= 3.13870e-29 Page 13 K = 0.00000e+00 A 4= 9.57051e-07 A 6=-1.15557e-09 A 8= 8.56025e-12 A10=-3.72449e-14 A12= 1.03427e-16 A14=-1.82947e-19 A16= 1.96550e-22 A18=-1.16119e-25 A20= 2.88108e-29 Page 31 K = 0.00000e+00 A 4=-9.21947e-07 A 6=-2.15869e-09 A 8= 2.79408e-11 A10=-1.35808e-13 A12=-2.46813e-16 A14= 6.64739e-18 A16=-3.37682e-20 A18= 7.59097e-23 A20=-6.56854e-26 Various data Zoom ratio 2.67 Wide Angle Mid-Telephoto Focal length 16.50 43.98 43.98 F-number 2.58 2.76 2.76 Half angle of view (°) 52.67 26.19 26.19 Image height 21.64 21.64 21.64 Lens total length 288.19 288.20 288.20 BF 40.50 40.52 40.52 d18 0.20 49.19 49.19 d27 1.77 1.37 1.37 d29 25.32 1.60 1.60 d35 28.73 3.86 3.86 d51 40.50 40.52 40.52 Lens Group Data Group starting plane focal length 1 1 40.63 2 19 -28.05 3 28 148.32 4 30 118.52 5 36 70.83 [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* 266.971 5.02 1.76385 48.5 0.5589 101.01 2 29.597 25.61 59.12 3* 80.438 3.00 1.76385 48.5 0.5589 57.76 4 36.114 15.96 49.33 5 -66.787 1.92 1.80400 46.5 0.5577 48.86 6 -178.814 3.02 1.84666 23.8 0.6205 49.77 7 -176.920 1.76 50.34 8 -125.277 3.27 1.77250 49.6 0.5520 50.45 9 -75.948 2.90 50.80 10 233.899 7.87 1.49700 81.5 0.5375 51.98 11 -72.479 1.73 1.85478 24.8 0.6122 52.39 12 -235.795 0.50 54.24 13 350.921 1.42 1.76385 48.5 0.5589 55.79 14 71.990 12.71 1.43875 94.9 0.5340 57.01 15 -83.498 0.50 57.78 16 207.820 14.73 1.55200 70.7 0.5421 60.55 17 -56.568 0.50 60.97 18 65.495 2.81 1.76385 48.5 0.5589 51.98 19 85.166 (variable) 51.02 20* 55.569 1.41 1.45860 90.2 0.5354 32.23 21 25.944 7.10 28.77 22 -60.005 1.20 1.69680 55.5 0.5434 27.58 23 48.143 (variable) 26.07 24 114.558 2.43 1.85150 40.8 0.5695 25.91 25 -121.204 (variable) 25.71 26 -33.858 1.30 1.64850 53.0 0.5547 23.80 27 186.778 2.81 1.85150 40.8 0.5695 25.20 28 -70.536 -0.19 25.57 29 (Aperture) ∞ (Variable) 25.82 30 87.576 2.42 1.45860 90.2 0.5354 26.83 31 -492.051 0.20 26.92 32 67.677 4.47 1.84666 23.8 0.6205 27.05 33 -864.111 5.71 26.62 34 104.809 3.88 1.59522 67.7 0.5442 24.67 35 -36.470 1.23 1.76385 48.5 0.5589 24.38 36 121.224 17.13 23.69 37 47.556 5.25 1.53996 59.5 0.5441 27.56 38 -48.171 0.20 27.51 39 42.443 6.09 1.61800 63.3 0.5426 25.81 40 -28.587 1.20 1.89190 37.1 0.5780 25.25 41 22.211 1.23 23.38 42 27.326 10.00 1.43875 94.9 0.5340 23.87 43 -16.710 1.20 2.00100 29.1 0.5997 24.19 44 -91.511 0.50 27.59 45 -679.686 7.44 1.55200 70.7 0.5421 29.01 46 -21.410 0.20 29.95 47 ∞ 3.70 1.51680 64.2 0.5342 29.89 48 ∞ (variable) 29.86 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 3.99901e-06 A 6=-1.97599e-09 A 8= 1.06539e-12 A10=-3.28566e-16 A12= 5.13268e-20 3rd page K = 0.00000e+00 A 4=-2.91569e-06 A 6=-1.63767e-09 A 8= 5.19740e-12 A10=-5.71883e-15 A12= 2.47769e-18 Page 20 K = 0.00000e+00 A 4= 3.86483e-06 A 6= 8.14154e-10 A 8= 1.40520e-11 A10=-4.40377e-14 A12= 8.44483e-17 Various data Zoom ratio 2.41 Wide Angle Mid-Telephoto Focal length 8.30 20.00 20.00 F-number 2.64 2.64 2.64 Half angle of view (°) 60.71 36.50 36.50 Image height 14.80 14.80 14.80 Lens total length 290.40 290.40 290.40 BF 29.48 29.48 29.48 d19 0.50 48.62 48.62 d23 2.05 10.70 10.70 d25 37.46 5.25 5.25 d29 27.57 3.01 3.01 d48 29.48 29.48 29.48 Lens Group Data Group starting plane focal length 1 1 39.46 2 20 -26.95 3 24 69.49 4 26 -182.99 5 30 51.51 [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -651.846 2.50 1.83481 42.7 0.5648 80.83 2 29.886 17.96 54.93 3* 205.029 2.00 1.83481 42.7 0.5648 54.39 4 133.762 8.37 53.04 5 -93.844 1.80 1.83481 42.7 0.5648 52.38 6 -529.040 0.15 52.82 7 94.300 3.70 1.92286 18.9 0.6495 53.20 8 254.951 1.67 52.90 9 137.316 7.43 1.60300 65.4 0.5401 52.15 10* -129.387 4.41 51.25 11 -3986.720 6.22 1.43387 95.1 0.5373 51.04 12 -72.185 0.30 51.43 13 -68.763 1.70 1.80000 29.8 0.6017 51.43 14 -129.110 0.18 52.89 15 177.001 1.70 1.91650 31.6 0.5911 54.56 16 53.973 15.73 1.43875 94.7 0.5340 54.69 17 -72.950 0.40 55.94 18 145.677 9.06 1.43387 95.1 0.5373 58.68 19 -98.739 0.40 58.81 20 198.764 6.83 1.76385 48.5 0.5589 57.74 21 -143.417 (variable) 57.35 22 109.025 0.70 2.00100 29.1 0.5997 20.35 23 17.638 3.22 18.16 24 -147.134 0.70 1.43875 94.7 0.5340 17.98 25 52.607 2.33 17.53 26 -222.929 5.23 1.85478 24.8 0.6122 17.21 27 -13.213 0.70 1.88300 40.8 0.5667 17.04 28 124.147 0.21 17.90 29 32.929 2.64 1.64769 33.8 0.5938 18.56 30 640.048 (variable) 18.66 31 -29.435 0.80 1.72916 54.7 0.5444 18.90 32 42.341 2.57 1.84666 23.8 0.6205 20.20 33 558.323 (variable) 20.64 34(Aperture) ∞ 1.20 27.23 35* 66.693 6.40 1.59522 67.7 0.5442 28.92 36 -55.306 0.20 29.53 37 129.439 6.58 1.53172 48.8 0.5631 29.55 38 -31.398 1.00 1.88300 40.8 0.5667 29.40 39 -87.887 (variable) 29.86 40 65.836 5.42 1.63980 34.5 0.5922 27.58 41 -55.379 3.39 27.13 42 -71.478 0.90 1.88300 40.8 0.5667 24.95 43 30.858 5.07 1.48749 70.2 0.5300 24.66 44 -107.443 0.20 24.93 45 51.336 7.84 1.43875 94.7 0.5340 25.21 46 -21.995 0.90 2.00100 29.1 0.5997 25.04 47 -59.375 0.13 26.13 48 92.546 5.49 1.48749 70.2 0.5300 26.63 49 -34.223 3.27 26.70 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52 ∞ (variable) 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 6.48442e-06 A 6= 2.19226e-09 A 8= 6.50797e-12 A10= 8.92330e-14 A12= 1.11240e-16 A14= 1.77070e-20 A16= 3.15292e-25 A 3= 8.54799e-06 A 5=-1.41802e-07 A 7=-4.53639e-11 A 9=-1.10620e-12 A11=-4.05612e-15 A13=-1.83948e-18 A15=-9.72378e-23 3rd page K = 0.00000e+00 A 4=-3.35608e-06 A 6=-7.00472e-08 A 8=-7.37142e-10 A10=-3.24129e-13 A12= 1.58966e-15 A14=-6.55545e-19 A16=-2.03600e-22 A 3=-8.90697e-07 A 5= 3.79740e-07 A 7= 9.30814e-09 A 9= 3.11630e-11 A11=-3.28771e-14 A13=-1.76087e-17 A15= 2.23720e-20 Side 10 K = 0.00000e+00 A 4= 1.29716e-06 A 6= 1.84566e-08 A 8= 2.81340e-10 A10= 2.05135e-13 A12=-7.68327e-16 A14= 1.04059e-18 A16= 2.18082e-22 A 3= 3.31773e-07 A 5=-5.38599e-08 A 7=-2.96537e-09 A 9=-1.45178e-11 A11= 1.68411e-14 A13=-4.57121e-18 A15=-2.62172e-20 Page 35 K = 6.60773e+00 A 4=-4.74213e-06 A 6=-9.99912e-11 A 8=-7.56379e-12 Various data Zoom ratio 15.32 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.32 F-number 1.87 1.86 3.05 Angle of view(°) 52.22 19.53 4.81 Image height 5.50 5.50 5.50 Lens total length 313.33 313.33 313.33 BF 6.60 6.60 6.60 d21 0.47 36.42 53.16 d30 39.91 5.86 3.67 d33 14.99 17.75 2.07 d39 45.53 40.87 42.01 d52 6.60 6.60 6.60 Lens Group Data Group starting plane focal length 1 1 29.67 2 22 -19.60 3 31 -42.47 4 34 45.06 5 40 52.58

[0069] [Table 1]

[0070] [Imaging device] 11 shows the configuration of an imaging device 125 that uses the zoom lens according to the above-mentioned Examples 1 to 5 as an imaging optical system. Reference numeral 101 denotes the zoom lens according to any one of Examples 1 to 5. Reference numeral 124 denotes a camera body. The zoom lens 101 is detachable from the camera body 124. However, the zoom lens may be provided integrally with the camera body.

[0071] The zoom lens 101 has a first lens group F, three or more movable lens groups LZ that move for zooming, and a subsequent lens group R for imaging. The first lens group F includes a second sub-lens group that moves for focusing, and a first sub-lens group and a third sub-lens group that do not move for focusing. The zoom lens 101 also has an aperture stop SP in the movable lens group LZ.

[0072] Reference numerals 114 and 115 denote driving mechanisms for driving the second sub-lens group and the three or more moving lens groups LZ, respectively. The driving mechanisms include a helicoid, a cam, and the like.

[0073] Reference numerals 116 to 118 denote motors that drive drive mechanisms 114 and 115 and aperture diaphragm SP, respectively. Reference numerals 119 to 121 denote detection units for detecting the positions on the optical axis of the second sub-lens group and the moving lens group LZ and the aperture diameter of the aperture diaphragm SP, respectively. The detection units are constituted by an encoder, a potentiometer, a photosensor, etc.

[0074] In the camera body 124, reference numeral 109 denotes a glass block including an optical filter and the like, and reference numeral 110 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that captures an image of a subject through the zoom lens 101. Reference numerals 111 and 122 denote a CPU as a processing unit in the camera body 124 and a CPU as a processing unit in the zoom lens 101, respectively.

[0075] According to an imaging device using the zoom lens of each embodiment, it is small and lightweight, and is capable of imaging at a wide angle of view, and it is possible to obtain images with good image quality over the entire zoom range.

[0076] The above embodiment includes the following configurations.

[0077] (Configuration 1) A zoom lens having lens groups arranged in order from an object side to an image side, the lens groups being a first lens group having positive refractive power that does not move for zooming, three or more movable lens groups that move for zooming, and a subsequent lens group having positive refractive power that does not move for zooming, the spacing between adjacent lens groups changing during zooming, and the zoom lens having an aperture stop that moves during zooming, Let f1 be the focal length of the first lens group, fw be the focal length of the zoom lens at the wide-angle end, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image to the rear principal point of the first lens group when focused on an object at infinity, and LD1 be the thickness on the optical axis from the lens surface of the first lens group closest to the object to the lens surface closest to the image when focused on an object at infinity, 1.00≦f1 / fw≦8.00 5.80≦(f1+bok1) / f1+1.2×LD1 / f1≦10.00 A zoom lens characterized by satisfying the following conditions. (Configuration 2) Let f2 be the focal length of the second lens group adjacent to the first lens group on the image side of the movable lens group. -2.00≦f1 / f2≦-0.10 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) If the focal length of the zoom lens at the telephoto end is ft, 0.40≦ft / f1≦2.50 3. The zoom lens according to configuration 1 or 2, which satisfies the following conditions: (Configuration 4) The first lens group has a negative lens closest to the object side, and when the focal length of the negative lens is fG1, -2.20≦ft / fG1≦-0.20 4. The zoom lens according to any one of configurations 1 to 3, which satisfies the following condition: (Configuration 5) The zoom lens according to any one of configurations 1 to 4, wherein the first lens group has, arranged in order from the object side to the image side, a first sub-lens group with negative refractive power that does not move for focusing, a second sub-lens group with positive refractive power that moves for focusing, and a third sub-lens group with positive refractive power. (Configuration 6) When the focal length of the first sub-lens group is f1a, -1.50≦f1a / f1≦-0.20 6. The zoom lens according to any one of configurations 1 to 5, which satisfies the following condition: (Configuration 7) When the focal length of the second sub-lens group is f1b, 2.00≦f1b / f1≦10.00 7. The zoom lens according to any one of configurations 1 to 6, which satisfies the following condition: (Configuration 8) When the focal length of the third sub-lens group is f1c, 1.00≦f1c / f1≦5.00 8. The zoom lens according to any one of configurations 1 to 7, which satisfies the following condition: (Configuration 9) 9. The zoom lens according to any one of configurations 1 to 8, wherein the first lens group has three negative lenses arranged consecutively from the most object side. (Configuration 10) Let Rnr be the radius of curvature of the object-side lens surface of the image-side negative lens adjacent on the object side to the positive lens closest to the object side among the positive lenses included in the first lens group, and Rnf be the radius of curvature of the image-side lens surface of the object-side negative lens adjacent on the object side to the image-side negative lens, |(Rnf+Rnr) / (Rnf-Rnr)|≦1.00 10. The zoom lens according to any one of configurations 1 to 9, which satisfies the following condition: (Configuration 11) When the zoom lens is used in an imaging device having an imaging surface with a diagonal size of 2Y, the focal length of the zoom lens at the wide-angle end is fw, and the half angle of view of the zoom lens at the wide-angle end is ωw. 50.0°≦ωw≦65.0° ωw=arctan(Y / fw) 11. The zoom lens according to any one of configurations 1 to 10, characterized in that the following condition is satisfied: (Configuration 12) The zoom lens according to any one of configurations 1 to 11, characterized in that the moving lens groups include, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power. (Configuration 13) The zoom lens according to any one of configurations 1 to 12, characterized in that the moving lens groups include, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. (Configuration 14) The zoom lens according to any one of configurations 1 to 13, characterized in that the moving lens groups include, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having negative refractive power. (Configuration 15) the movable lens group includes, in order from the object side to the image side, a second lens group, a third lens group, and a fourth lens group; 15. The zoom lens according to any one of configurations 1 to 14, wherein the aperture stop is provided in the fourth lens group. (Configuration 16) The zoom lens according to any one of configurations 1 to 15, and an image sensor for capturing an image of a subject through the zoom lens.

[0078] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0079] U1 First lens group U2 2nd lens group U3 Third lens group U4 4th lens group U5 Fifth lens group SP Aperture I image plane

Claims

1. A zoom lens having lens groups arranged in order from an object side to an image side, the lens groups being a first lens group having positive refractive power that does not move for zooming, three or more movable lens groups that move for zooming, and a subsequent lens group having positive refractive power that does not move for zooming, the spacing between adjacent lens groups changing during zooming, and the zoom lens having an aperture stop that moves during zooming, Let f1 be the focal length of the first lens group, fw be the focal length of the zoom lens at the wide-angle end, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused on an object at infinity, and LD1 be the thickness on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface closest to the image side when focused on an object at infinity, 1.00≦f1 / fw≦8.00 5.80≦(f1+bok1) / f1+1.2×LD1 / f1≦10.00 A zoom lens characterized by satisfying the following conditions.

2. When the focal length of the second lens group adjacent to the first lens group on the image side among the moving lens groups is f2, -2.00≦f1 / f2≦-0.10 2. The zoom lens according to claim 1, which satisfies the following condition:

3. When the focal length of the zoom lens at the telephoto end is ft, 0.40≦ft / f1≦2.50 2. The zoom lens according to claim 1, which satisfies the following condition:

4. The first lens group has a negative lens closest to the object side, and when the focal length of the negative lens is fG1, -2.20≦ft / fG1≦-0.20 2. The zoom lens according to claim 1, which satisfies the following condition:

5. 2. The zoom lens according to claim 1, wherein the first lens group comprises, arranged in order from the object side to the image side, a first sub-lens group with negative refractive power that does not move for focusing, a second sub-lens group with positive refractive power that moves for focusing, and a third sub-lens group with positive refractive power.

6. When the focal length of the first sub-lens group is f1a, −1.50≦f1a / f1≦−0.20 2. The zoom lens according to claim 1, which satisfies the following condition:

7. When the focal length of the second sub-lens group is f1b, 2.00≦f1b / f1≦10.00 2. The zoom lens according to claim 1, which satisfies the following condition:

8. When the focal length of the third sub-lens group is f1c, 1.00≦f1c / f1≦5.00 2. The zoom lens according to claim 1, which satisfies the following condition:

9. 2. The zoom lens according to claim 1, wherein the first lens group has three negative lenses arranged consecutively from the most object side.

10. Let Rnr be the radius of curvature of the object-side lens surface of the image-side negative lens adjacent on the object side to the positive lens closest to the object side among the positive lenses included in the first lens group, and Rnf be the radius of curvature of the image-side lens surface of the object-side negative lens adjacent on the object side to the image-side negative lens, |(Rnf+Rnr) / (Rnf-Rnr)|≦1.00 2. The zoom lens according to claim 1, which satisfies the following condition:

11. When the zoom lens is used in an imaging device having an imaging surface with a diagonal size of 2Y, the focal length of the zoom lens at the wide-angle end is fw, and the half angle of view of the zoom lens at the wide-angle end is ωw. 50.0°≦ω≦65.0° ωw=arctan(Y / fw) 2. The zoom lens according to claim 1, which satisfies the following condition:

12. 2. The zoom lens according to claim 1, wherein the moving lens groups include, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power.

13. 2. The zoom lens according to claim 1, wherein the moving lens groups include, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power.

14. 2. The zoom lens according to claim 1, wherein the moving lens groups comprise, in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having negative refractive power.

15. the moving lens group includes, in order from the object side to the image side, a second lens group, a third lens group, and a fourth lens group; 2. The zoom lens according to claim 1, wherein the aperture stop is provided in the fourth lens group.

16. A zoom lens according to any one of claims 1 to 15; and an image sensor for capturing an image of a subject through the zoom lens.

Images